Dynamic adsorption and desorption of crude mulberry anthocyanin on a fixed-bed column: breakthrough curves, flow rate, and ethanol enrichment

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Abstract In the water and wastewater treatment field several simplistic models of packed bed dynamics such as the Bohart-Adams, Thomas, and Yoon-Nelson models are frequently used by investigators to fit adsorption breakthrough data. The century-old Bohart-Adams model is arguably the best known one which also serves as the foundation of the bed depth-service time equation. In recent years a substantial body of literature on the subject of fixed bed modeling has however claimed that it is inferior to other models. The present paper shows that such claims are incorrect and misleading because of biased comparisons in which the fitting ability of an oversimplified version of the Bohart-Adams model was compared with those of the Thomas and Yoon-Nelson models. The oversimplified Bohart-Adams equation is in effect an exponential function which predicts an exponentially increasing breakthrough value with time. As such, it is unable to fit typical breakthrough curves which are S-shaped or sigmoidal. It can be shown that a proper version of the Bohart-Adams model gives fit quality similar to those of the Thomas and Yoon-Nelson models. This is not unexpected since the three simplistic fixed bed models can be expressed in terms of the logistic equation of population growth; that is, mathematically they are equivalent.

Continuous removal of toxic element boron from aqueous solution was investigated with new phenolic hydroxyl modified resin (T-resin) using a fixed bed column reactor operated under various flow rates, bed height and influent concentrations. The breakthrough time, exhaustion time and uptake capacity of the column bed increased with increasing column bed height, whereas decreased with increasing influent flow rate. The breakthrough time and exhaustion time decreased, but uptake capacity increased with increasing influent concentration, and actual uptake capacity was obtained as 6.52 mg/g at a concentration of 7.64 mg/L. The three conventional models of bed depth service time (BDST), Thomas and Yoon-Nelson were used to appropriately predict the whole breakthrough behavior of the column and to estimate the characteristic model parameters for boron removal. However, artificial neural network (ANN) model was more accurate than the conventional models with the least relative error and the highest correlation coefficients. By the relative importance of the operational parameters obtained from ANN model, the sequence is as follows: total effluent time > initial concentration > flow rate > column height. The adsorption capacity of boron was changed between 5.24 and 1.74 mg/g during the five time regeneration. From the life factor calculation, it is suggested that the column bed could avoid the breakthrough time of t = 0 for 6.8 cycles, whereas, the uptake capacity would be zero after 7.8 cycles.

Abstract The Bohart–Adams model was preferred for the modeling of water pollutants adsorption in a fixed-bed column. However, its fitting quality was increasingly questioned. Chu proposed that a poor fit was caused by the severe simplification of the Bohart–Adams model [1]. In fact, our previous work has proved that the Bohart–Adams model changed from a logistic function to an exponential function in mathematical nature after oversimplification [2]. To better understand the Bohart–Adams model, this comment mainly addressed the following aspects: (1) Correct forms of the Amundson and original Bohart–Adams models; (2) Effects of the void fraction on the breakthrough curve; (3) Curve characteristics of the original Bohart–Adams model; (4) Rationality of simplification for the original and fractal-like Bohart–Adams models. This work is expected to help readers to better understand the original Bohart–Adams model.

ZSM-5, as a hydrophobic zeolite, has a good adsorption capacity for methyl tert-butyl ether (MTBE) in batch adsorption studies. This study explores the applicability of ZSM-5 as a reactive material in permeable reactive barriers (PRBs) to decontaminate the MTBE-containing groundwater. A series of laboratory scale fixed-bed column tests were carried out to determine the breakthrough curves and evaluate the adsorption performance of ZSM-5 towards MTBE under different operational conditions, including bed length, flow rate, initial MTBE concentration and ZSM-5 dosage, and regeneration tests were carried out at 80, 150 and 300 °C for 24 h. Dose-Response model was found to best describe the breakthrough curves. MTBE was effectively removed by the fixed-bed column packed with a ZSM-5/sand mixture with an adsorption capacity of 31.85 mg g-1 at 6 cm bed length, 1 mL min-1 flow rate, 300 mg L-1 initial MTBE concentration and 5% ZSM-5 dosage. The maximum adsorption capacity increased with the increase of bed length and the decrease of flow rate and MTBE concentration. The estimated kinetic parameters can be used to predict the dynamic behaviour of column systems. In addition, regeneration study shows that the adsorption capacity of ZSM-5 remains satisfactory (>85%) after up to four regeneration cycles.

Abstract This work investigates the performance and optimization of a hybrid process consisting of a fixed-bed adsorption (FBA) column and a dead-end filtration (DEF) cell for the removal of methylene blue (MB) from water. Granular activated carbon and cellulose acetate depth filter sheets were used as adsorbent and filter medium, respectively. Effects of four operation parameters (initial concentration, feed flowrate, bed length, and filter type) on the MB removal rate (RR) were investigated using breakthrough data analysis and response surface methodology. This RR (mass of MB removed per second) captures the removal capacity and separation rate, simultaneously. The maximum RR was found theoretically equal to 3.875 s−1 at the optimized conditions of initial concentration =39.86 mg/L, flowrate = 1.15 L/min, bed length =29.95 cm, and filter type = OS100, and validated with the experimental data with 99% agreement. The performance of the hybrid process operating at the optimal operation conditions was found to be superior to those of the individual FBA column and DEF cell. After 100 s from the process commencement, the RR obtained with the hybrid process was about 64% higher than that obtained with the FBA column and 30% higher than that obtained with the DEF cell.

This study presents a novel polyurethane-activated carbon composite (PACC) as an effective and sustainable adsorbent for treating lead-ion-contaminated waters. The PACC was characterized using Scanning Electron Microscopy with Energy Dispersive X-ray (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer, Emmett, and Teller (BET) surface area analyzer, X-ray Diffraction (XRD), and Thermogravimetric Analyzer (TGA) to evaluate its physicochemical and thermal properties. Furthermore, the PACC was employed in an experimental column adsorption setup to investigate its adsorption performance and to develop a dynamic method suitable for industrial implementation. Parameters such as bed height (50, 100, 150 mm), flow rate (4, 6, 8 mL min−1), pH (2, 4, 6), and initial metal-ion concentrations (10, 50, 100 mg L−1) were examined. The experimental data exhibited strong agreement with the Thomas and Yoon–Nelson models (R2 ≥ 0.96), indicating efficient adsorption mechanisms. Remarkably, the used adsorbent has the potential for facile regeneration without substantial loss in capacity. The PACC demonstrated excellent adsorption performance for lead ions in aqueous solutions in a fixed-bed column system. Thus, the novel PACC material holds the potential for scalable application in industrial settings to address water pollution challenges, especially in regions with uncontrolled effluent discharge.

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Abstract Simple fixed bed models such as the Bohart–Adams and Thomas equations are often used to describe the breakthrough characteristics of water and air contaminant adsorption in fixed bed adsorbers. However, these popular models are confined to correlating highly symmetric breakthrough curves. The present study explores the feasibility of using two probability distributions (normal and log-normal) to track asymmetric breakthrough curves for water and air contaminant adsorption in fixed bed columns (ciprofloxacin, ammonium, hydrogen chloride, and hydrogen sulfide). The normal and log-normal probability distributions provided accurate fits to the slightly asymmetric ciprofloxacin breakthrough curve. They also provided a good representation of the overall shape of the ammonium breakthrough curve, but failed to describe the leakage of ammonium during the initial period of column operation. The log-normal distribution was able to match the asymmetric HCI and H2S breakthrough curves. The normal distribution, by comparison, failed to describe these two asymmetric breakthrough curves. Because the log-normal distribution has a floating inflection point, it was very effective in describing the asymmetric HCI and H2S breakthrough curves that were sharp initially and then broadened significantly as the column approached saturation. The ability of the normal distribution to track such asymmetric breakthrough data was impeded by its invariant inflection point.

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This study focused on evaluating the fixed-bed adsorption performance of a newly developed, chemically activated biochar derived from king coconut nuts (KBC800-HCl) for the removal of BPA. The breakthrough curves for KBC800-HCl adsorption were analyzed under varying flow rates, bed heights, and initial BPA concentrations to determine the optimal parameters for subsequent experiments. The fixed-bed column study revealed that alterations in flow rate, initial concentration, and bed height had a notable impact on the column's efficiency and operation. As the flow rate elevated from 1.0 mL/min to 2.0 mL/min, both the breakthrough and exhaustion times shortened. Similarly, an increase in bed height was found to elongate both the breakthrough and exhaustion times. Moreover, the findings revealed that increasing the initial concentrations from 100.0 to 200.0 mg/L resulted in shorter breakthrough and exhaustion times. Optimal performance for KBC800-HCl was observed at a flow rate of 1.0 mL/min, an initial concentration of 100.0 mg/L and a bed height of 3.0 cm. The breakthrough curves were evaluated using the Thomas, Yoon–Nelson, and Adams–Bohart models. The Thomas and Yoon-Nelson models (Adj. R2 = 0.9992) accurately represented the experimental breakthrough curve, exhibiting better performance than the Adams-Bohart model. The study assesses the fixed-bed adsorption efficiency of a novel, chemically activated king coconut biochar (KBC800-HCl) for removing bisphenol A. Breakthrough curves demonstrated that flow rate, bed height, and initial BPA concentration significantly impacted the fixed-bed column performance. The Thomas and Yoon-Nelson models accurately predicted the breakthrough behavior, outperforming the Adams-Bohart model. The study assesses the fixed-bed adsorption efficiency of a novel, chemically activated king coconut biochar (KBC800-HCl) for removing bisphenol A. Breakthrough curves demonstrated that flow rate, bed height, and initial BPA concentration significantly impacted the fixed-bed column performance. The Thomas and Yoon-Nelson models accurately predicted the breakthrough behavior, outperforming the Adams-Bohart model.

Oily wastewater is a major environmental issue resulting from different industrial and manufacturing activities. Contaminated water with oil represents a significant environmental hazard that can harm numerous life forms. Several methodologies have been tested for the removal of oily wastewater from aqueous solutions, and adsorption in a flow-through reactor is an effective mechanism to reduce these effluents. This study focuses on evaluating the ability of Fe3O4/Bent material to adsorb gasoline emulsion from a solution using a fixed-bed column, and it involves analyzing the resulting breakthrough curves. The FT-IR, SEM, EDX, and XRD techniques were used to characterize Fe3O4/Bent. Various ranges of variables were examined, including bed height (2–4 cm), flow rate (3–3.8 mL/min), and initial concentration (200–1000 mg/L), to determine their impacts on the mass transfer zone (MTZ) length and the adsorption capacity (qe). It was shown that a higher bed height and a lower flow rate contributed to a longer time of breakthrough and exhaustion. At the same time, it was noted that under high initial gasoline concentrations, the fixed-bed system rapidly reached breakthrough and exhaustion. Models like the Yoon–Nelson and Thomas kinetic column models were employed to predict the breakthrough curves. Thomas and Yoon–Nelson’s breakthrough models provided a good fit for the breakthrough curves with a correlation coefficient of R2 > 0.95. Furthermore, with a fixed-bed system, the Thomas and Yoon–Nelson models best describe the breakthrough curves for gasoline removal.

A novel activated carbon has been produced from pine cone, a sustainable resource, by phosphoric activation at 900 °C. The BET surface area of the activated carbon was 869 m2/g and the methylene blue isotherm area was 734 m2/g. The adsorption of two single-component acid azo dyes, Acid Blue 113 (AB113) and Acid Black 1 (AB1), onto this activated carbon was studied using fixed-bed adsorption. Breakthrough curves and equilibrium isotherms were obtained for the adsorption of these two dyes onto the prepared active carbon. The highest adsorption capacities achieved for AB113 and AB1 were 485 and 286 mg dye/g carbon, respectively. Two-column breakthrough curve models were applied to correlate the experimental adsorption breakthrough curves for each dye: the Thomas model, based on solid-phase internal diffusion, has been applied with considerable success; and the saturation isotherm model approach of Michaels was used with a reasonable degree of success.

Abstract In the search for cost-effective and highly selective adsorbents for the removal of Mo(VI) from aqueous systems, the Mo(VI)-imprinted polymer (Mo(VI)-IIP) has been identified as a potential candidate. In this study, we investigated the performance of Mo(VI)-IIP in the packed fixed-bed column, to assess its potential for industrial extension. In a laboratory-scale fixed-bed column, the effluent Mo(VI) concentration versus time span (i.e., breakthrough curves) were determined for various operational parameters, such as flow rate (5, 7 and 9 mL min−1), influent Mo(VI) concentrations (50, 70 and 90 mg L−1), bed depths (0.5, 1 and 1.5 cm) at pH 3. The breakthrough curve of various bed height demonstrated that the life span of the continuous fixed-bed column will be extended with a longer bed column. The maximum capacity and total metal removal reached 94.3 mg g−1 and 80.2% respectively, using 1.5 cm bed depth, 7 mL min−1 flow rate and 50 mg L−1 influent Mo(VI) concentration. The growth of influent Mo(VI) concentration and flow rate caused the earlier exhaustion time in the column. The experimental data were fitted with well-established mathematical models such as Yoon-Nelson, Thomas, and Adams-Bohart. The results were best-fitted with Thomas and Yoon-Nelson models (with correlation coefficient R2 ≥ 0.99) rather than the Adams-Bohart model for all conditions.

Pesticide contamination in wastewater poses a significant environmental challenge, driven by extensive agricultural use. This study evaluates the removal of chlorpyrifos (CPS) using sugarcane bagasse-based biochar alginate beads in a continuous fixed-bed adsorption column, achieving a remarkable 95-98% removal efficiency. Compared to conventional adsorbents like activated carbon, which typically show CPS adsorption capacities ranging from 50-70 mg g⁻1 under similar conditions, the biochar alginate beads demonstrate better performance with a sorption capacity of 91.93 mg g⁻1. Fixed-bed column (FBC) experiments demonstrated optimal CPS removal at 10 ppm concentration, 5 cm bed height and a flow rate of 25 mL min⁻1. The Yoon-Nelson Model exhibited the best fit, with high correlation coefficients (R2 = 0.80 to 0.98), low Akaike's Information Criterion (AIC) and Sum of Square Error (SSE) values, confirming its predictive accuracy. The model predicted a CPS removal efficiency of 95-98% and a sorption capacity of 91.93 mg g⁻1. The immobilization process using sodium alginate not only provided structural integrity to the biochar alginate beads but also improved their surface area and functional groups, significantly enhancing the adsorption dynamics. An inverse relationship between breakthrough time (τcal) and flow rate was observed, indicating improved adsorption dynamics at higher flow rates. SEM analysis revealed a porous biochar structure with significant surface area (131.09 m2/g) and pore volume (0.165 cm³/g), contributing to its high adsorption efficiency. XRD analysis indicated the partial crystalline nature of the biochar alginate beads, influenced by the presence of alginate. Additionally, breakthrough curves suggested a rapid initial uptake followed by a plateau, highlighting the material's fast adsorption kinetics. Biochar alginate beads for pesticide adsorption demonstrated good results in the scale-up investigation. This research demonstrates the potential of biochar-based adsorbents for efficient and scalable pesticide remediation in contaminated water systems, underscoring the unique contributions of alginate-immobilized biochar in enhancing performance.

Granular acid-activated neutralized red mud (AaN-RM) has been successfully prepared with good chemical stability and physical strength. However, its potential for industrial application remains unknown. Therefore, the performance of granular AaN-RM for phosphate recovery in a fixed-bed column was investigated. The results demonstrated that the phosphate adsorption performance of granular AaN-RM in a fixed-bed column was affected by various operational parameters, such as the bed depth, flow rate, initial solution pH and initial phosphate concentration. With the optimal empty-bed contact time (EBCT) of 24.27 min, the number of processed bed volumes and the phosphate adsorption capacity reached 496.95 and 84.80 mg/g, respectively. Then, the saturated fixed-bed column could be effectively regenerated with a 0.5 mol/L HCl solution. The desorption efficiency remained as high as 83.45% with a low weight loss of 3.57% in the fifth regeneration cycle. In addition, breakthrough curve modelling showed that a 5-9-1 feed-forward artificial neural network (ANN) could be effectively applied for the optimization of the fixed-bed adsorption system; the coefficient of determination (R2) and the root mean square error (RMSE) evaluated on the validation-testing data were 0.9987 and 0.0183, respectively. Therefore, granular AaN-RM fixed-bed adsorption exhibits promising potential for phosphate removal and recovery from polluted water.

The widespread use of 2,4-Dichlorophenoxyacetic acid (2,4-D) as a weedkiller has resulted in its persistence in the environment, leading to surface and groundwater pollution. In this study, the fixed bed column experiments were performed to remove 2,4-D from aqueous solutions using magnetic activated carbon derived from Peltophorum pterocarpum tree pods. The evaluation was done on effects of operating parameters such as bed depth (2-4 cm), influent flow rate (4.6-11.4 mL/min), and 2,4-D concentration (25-100 mg/L) on the breakthrough curves. The data fit well with the Yoon-Nelson and Thomas models, exhibiting high R2 values. Results indicated that lower flow rates, lower 2,4-D concentrations, and greater bed depths enhanced adsorption capacity, achieving up to 196.31 mg/g. Reusability studies demonstrated the material's potential for repeated use, while toxicity studies with Vigna radiata seeds confirmed the effectiveness of Fe3O4-CPAC in removing 2,4-D. This investigation highlights the promising application of Fe3O4-CPAC in fixed bed adsorption systems for efficient 2,4-D removal.

In this study, the Fe–Mn oxide/mulberry stem biochar composite adsorbent (FM-MBC) was prepared and fully characterized by SEM-EDS, XRD, BET, and XPS. The solution pH (3.0, 4.5, and 6.0), initial concentration of phosphorus (10, 20, and 30 mg L−1), adsorbent bed height (2, 3, and 4 cm), and solution flow rate (1, 2, and 3 mL min−1) were investigated to analyze the breakthrough curves. The results showed that the breakthrough time was shortened as the initial phosphorus concentration, the flow rate increased and the bed height decreased. Higher initial phosphorus concentrations, flow rates, and lower bed heights, led to a faster breakthrough of phosphate ions in the FM-MBC adsorbent. Additionally, it was observed that increasing the pH value was not conducive to the adsorption of phosphorus by the FM-MBC adsorbent. Dynamic adsorption data were fitted to four models (Yoon-Nelson, Thomas, Adams-Bohart, and Bed Depth Service Time), and the R2 values of the Thomas and Yoon-Nelson models exhibited minimal variation, suggesting that the dynamic adsorption process of FM-MBC was rather intricate. The saturated fixed-bed column (including FM-MBC) was regenerated with NaOH or HCl, and it was found that a 0.1 mol L−1 NaOH solution had the best regeneration effect. XRD analysis showed that the reaction product between the FM-MBC composite and phosphate anions was Fe3(PO4)2·H2O. Moreover, the experimental results that FM-MBC can successfully be used to remove phosphorus from actual wastewater.

The intensive use of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide has resulted in the presence of its residues in the environment, which leads to contamination of surface and groundwater. In this study, a fixed-bed column experiment was conducted for the removal of 2,4-D from an aqueous solution using termite mound soil (TMS). Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), atomic absorption spectrometry (AAS), and Brunauer–Emmett–Teller (BET) techniques were used to characterize the adsorbent. The effect of significant variables, such as the initial 2,4-D concentration (50 mg/L and 75 mg/L), flow rate (2.5 ml/min and 5 ml/min), solution pH (2, 4, and 6), and bed height (3, 6, and 9 cm), on the breakthrough characteristics of the adsorption system was assessed. In addition, the Thomas and Yoon–Nelson models were applied to predict the breakthrough curves and to determine the characteristic parameters of the column that are useful for process design. The findings showed that at a lower pH (2), a lower flow rate (2.5 ml/min), a lower 2,4-D concentration (50 mg/L), a higher bed depth (9 cm), and 840 min breakthrough time, a higher removal percentage (80.2%) of 2,4-D was achieved. The experimental data were in good agreement with the Thomas and Yoon–Nelson models. For the Yoon–Nelson model, the rate constant increased with an increase in the flow rate, initial ion concentration, and bed height. The time required for a 50% breakthrough decreased with an increase in the flow rate, bed height, and initial ion concentration. For the Thomas model, the rate constant increased with an increase in the flow rate but decreased with an increase in bed height and initial concentration. Overall, the study showed that termite mound soil in a fixed-bed column adsorption system presents an excellent potential for removing 2,4-D from aqueous solutions.

Hydroxyapatite (HAp) granules were fabricated successfully from HAp powder and polyvinyl alcohol (PVA) additive by sintering method. The characterization of material was analyzed by color, durability in the water, XRD, EDX, SEM and BET. The obtained HAp granules were white, single phase of HAp, with specific surface area of 73 m2/g, size of granule about (2 × 10) mm. HAp granules were used for the removal of Zn2+ ions from aqueous solution. The effect of factors on the Zn2+ adsorption property was investigated. The adsorption efficiency and capacity obtained 77.15 % and 2.57 mg/g, respectively at suitable batch adsorption condition: HAp granule mass of 0.5 g/ 50mL solution, initial concentration of 20 mg/L Zn2+, contact time 40 minutes and pH0 5.7 at 30 oC. The adsorption efficiency reached about 99.55 % at suitable column adsorption condition: contact time of 3,5 min, flow rate of 14 mL/min, adsorption zone height of 4Ф (Ф = 2.5 cm), initial concentration of 20 mg/L Zn2+, HAp granule mass of 11.9 g/ 2L solution, pH0 5.7 at 30 oC. 

In this study, a ternary MgO-impregnated eggshell–kaolin (EKM) composite was synthesized and evaluated for fluoride removal from water under fixed-bed column adsorption. The composite, prepared by co-precipitation and wet impregnation, was characterized using XRD, FTIR, SEM–EDX, and Brunauer–Emmet–Teller analyses. Results confirmed successful integration of the three components, yielding a mesoporous structure with a surface area of 158.5 m 2  g −1 . The composite exhibited good defluoridation performance under varying operational conditions. Higher bed depth and lower flow rate enhanced adsorption capacity, achieving up to 6.35 mg g −1 at 10 mg L −1 influent fluoride concentration. Breakthrough data were well described by the Thomas, Clark, and Yoon–Nelson models ( R 2 ≥ 0.94 ) at lower influent concentration, moderate flow rate, and greater bed depth, while the bed depth service time model confirmed a linear increase in service time with bed depth. The adsorbent maintained good regeneration ability across four cycles. Co-existing anions showed interference with the uptake of F − , with inhibitory effects following the order: PO 4 3 − > SO 4 2 − > NO 3 − > Cl − . The study estimated that 11.11 g of EKM composite yields 2 L of safe water for less than USD1. These results highlight the EKM composite as an efficient and sustainable adsorbent for practical defluoridation applications.

Deoxynojirimycin (DNJ) is an α-glucosidase inhibitor with high food values. However, the complex and costly enrichment processes have greatly prevented its application. Herein, this study aimed to propose a simple and efficient enrichment process for DNJ from Morus alba L. extracts using cation exchange resins. The LSI and D113 resins were chosen due to their excellent adsorption and desorption properties. The adsorption characteristics agreed with the pseudo-first-order kinetic model and the Langmuir isotherm model. This adsorption was chemisorption, spontaneous, endothermic and entropy-driven. Furthermore, the concentration and pH of the extracts, desorption solvent, breakthrough and elution curves, sample loading and elution rate were investigated to optimize the enrichment process by resin column chromatography. The results also showed that the purity of DNJ was improved to 44.00 % with a total recovery of 78.21 % using the LSI-D113 combination strategy. This research demonstrated the industrial feasibility of DNJ enrichment using cation exchange resins.

In the current work, the behavior of a fixed bed column (FBC) containing an innovative nanocomposite, Fe3O4-ZIF8@eggshell membrane matrix (F-ZIF8@EMM), was investigated in the concurrent elimination of arsenic and nitrate, as two potentially harmful elements (PHEs) in drinking water. Flow rate (6-10 mL/min), column height (10-20 cm), reaction time (30-180 min), pH (5-10), primary content of arsenic (25-100 µg/L), primary content of nitrate (100-200 mg/L), and nanocomposite dose (0.25-1 mg/L) were examined as different operational effects on the simultaneous uptake of arsenic and nitrate from actual water via the as-fabricated novel nanocomposite through various experiments. Characteristics of F-ZIF8@EMM were analyzed via X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and Brunauer-Emmett-Teller (BET) analyses. The consequences illustrated that the optimal parameters were: flow rate (6 mL/min), primary content of arsenic (100 µg/L), primary content of nitrate (150 mg/L), bed height (20 cm), and pH (7). The simultaneous elimination efficiency of nitrate and arsenic was 90 % under optimal conditions. The FBC fed with water containing arsenic and high nitrate could operate for 440 min with a qm of 226 mg/g. After fitting, different models were identified, with the concurrent uptake of nitrate and arsenic was the optimum fit with the Thomas model (R2 = 0.9998). Analysis of the cost of the process displayed that it should be estimated to be approximately 0.005$ per liter of safe drinking water. This study demonstrates the stability and high efficiency of the newly structured adsorbent after 10 consecutive adsorption cycles. It also validates the significant capacity of the as-made composite F-ZIF8@EMM in the concurrent uptake of nitrate and arsenic. Consequently, the application of FBC technology has shown promise in enhancing this process.

Herein, magnetite nanoparticles (NPs), zeolite A and magnetite-zeolite A (MAGZA) composite was developed by green methods. The produced nanomaterials were characterized and the effect of process parameters such as flow rate, adsorbent bed height and adsorbate inlet concentration was evaluated for the removal of biological oxygen demand (BOD), chemical oxygen demand (COD) and total organic carbon (TOC) in a column. The characterization results demonstrated the successful synthesis of magnetite NPs, zeolite A and MAGZA composite. The performance of the MAGZA composite in the fixed-bed column was superior to zeolite A and magnetite NPs. The parametric influence indicates that an increase in bed height and a decrease in the flow rate and inlet adsorbate concentration improved the performance of the adsorption column. The adsorption column demonstrated maximum performance at a flow rate (4 mL/min), bed height (5 cm) and inlet adsorbate concentration (10 mg/L). Under these conditions, the highest percent removal of BOD, COD and TOC were 99.96, 99.88 and 99.87%. Thomas and Yoon-Nelson's model suitably fitted the breakthrough curves. After five reusability cycles, the MAGZA composite demonstrated removal percent of BOD (76.5%), COD (55.5%) and TOC (64.2%). The produced MAGZA composite effectively removed BOD, COD and TOC from textile wastewater in a continuous operating mode.

In this work, we developed five solid adsorbents such as calcium alginate beads (CG), Araucaria gum (AR) extracted from Araucaria heterophylla tree by chemical precipitation procedures, and Araucaria gum/calcium alginate composite beads (CR21, CR12, and CR11) prepared with different calcium alginate: Araucaria gum ratios (2:1, 1:2, and 1:1, respectively). The synthesized solid adsorbents were characterized utilizing TGA, XRD, nitrogen adsorption/desorption analysis, ATR-FTIR, pHPZC, swelling ratio, SEM, and TEM. Through the batch and column adsorption strategies, we evaluated the effect of adsorbent dose, pH, initial Pb (II) concentration, shaking time, bed height, and flow rate. The data of batch technique indicated that CR11 demonstrated a maximum batch adsorption capacity of 149.95 mg/g at 25 °C. Lead ions adsorption was well fitted by pseudo-second order and Elovich according to kinetic studies, in addition to Langmuir and Temkin models based on adsorption isotherm studies onto all the samples. Thermodynamic investigation showed that Pb (II) adsorption process is an endothermic, physical, and spontaneous process. The highest column adsorption capacity (161.1 mg/g) was achieved by CR11 at a bed height of 3 cm, flow rate of 10 mL/min, and initial Pb+2 concentration of 225 mg/L with 68 min as breakthrough time and 180 min as exhaustion time. Yoon-Nelson and Thomas models applied well the breakthrough curves of Pb (II) column adsorption. The maximum column adsorption capacity was decreased by 11.4 % after four column adsorption/desorption processes. Our results revealed that CR11 had an excellent adsorption capacity, fast kinetics, and good selectivity, emphasizing its potential for its applications in water treatment.

Water pollution has remained a pressing concern in recent years, presenting multifaceted challenges in search of effective mitigation strategies. Our study, which targets mitigating pollution caused by 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), a significant aquatic pollutant, is innovative in its approach. We have identified adsorption as a promising, cost-effective method for its removal. Our research strategy involves dynamic adsorption utilizing a peristaltic pump and composite beads containing activated carbon and sodium alginate (CA/Alg), a novel combination that mimics industrial processes. To optimize column adsorption, we examine bead stability under varied pH conditions and optimize parameters such as concentration, adsorption time, and pH through batch adsorption experiments, employing experimental design techniques. Additionally, we optimize column adsorption factors, including bead height, circulation time, and flow rate, crucial for process efficiency, and under these optimum conditions (C2,4,5-T = 80 ppm. pH = 2, t = 27h30min, H = 30 cm and D = 0.5 mL/min) the capacity of adsorption equal to 748.25 mg/g. Characterization techniques like SEM, EDX, BET analysis, XRD, and FTIR provide insights into the morphology, composition, surface area (331 m2/g), pore volume (0.11 cm3/g), crystal structure, and functional groups of the CA-P/Alg adsorbent. Theoretical analysis elucidates the adsorption mechanism and interaction with pollutants. Economic analysis, encompassing CAPEX and OPEX estimation, evaluates the feasibility of implementing this cleanup method at an industrial scale, considering initial investment and ongoing operational costs, indicating potential savings of 64 % compared with the activated carbon normally used on the Moroccan market. This comprehensive and innovative approach addresses water pollution challenges effectively while ensuring economic viability for industry-scale implementation.

Industrial wastewater contains a wide range of pollutants that, if released directly into natural ecosystems, have the potential to pose serious risks to the environment.This study aims to investigate sustainable and efficient approaches for treating tannery wastewater, employing a combination of hyphenated Fenton oxidation and adsorption processes. Rigorous analyses were conducted on wastewater samples, evaluating parameters like COD, sulphide, NH3-N, PO43-, NO3-, and Cr(VI). The performance of this adsorbent material was gauged through column adsorption experiments. A comprehensive characterization of the adsorbent was undertaken using techniques such as SEM, EDX, BET, FTIR, XRD, and LIBS. The study delved into varying operational parameters like bed depth (ranging from 3.5 to 9.5 cm) diameter (2.5 cm) and influent flow rate (ranging from 5 to 15mLmin-1). The experimental outcomes revealed that increasing the bed depth and decreasing the influent flow rate significantly bolstered the adsorption column's effectiveness. Breakthrough curves obtained were fitted with different models, including the Thomas and Yoon-Nelson models. The most optimal column performance was achieved with a bed height of 10.5 cm and a flow rate of 5mLmin-1. The combined process achieved removal efficiencies of 94.5% for COD, 97.4% for sulphide, 96.2% for NH3-N, 83.1% for NO3-, 79.3% for PO43-, and 96.9% for Cr(VI) in tannery effluent. This research presents a notable stride toward the development of sustainable and efficient strategies for tannery wastewater treatment.

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This study focused on the use of a fix-bed column in the removal of amoxicillin from an aqueous solution by the application of silver nano-based adsorbents. The silver nanoparticle and nanocomposite were produced by a green synthetic approach. Column adsorption was performed at a flow rate of 5.88 mL/min, bed height of (5.0–7.0 cm), and amoxicillin concentration of 20–40 mg/L. Adsorption data were fitted to Thomas, Adams-Bohart, and Yoon-Nelson models. The color change from light yellow to dark brown showed that silver ions have been reduced to silver atoms. Energy dispersive spectroscopy (EDS) analysis showed the characteristic silver peak of the nano-adsorbents at 3.0 keV containing 57.29% silver in the synthesized silver nanoparticle. Analysis of silver nanoparticles-maize leaf composite revealed its pore distribution to be uneven with an average pore size of 7.44 nm. The data were best fitted to the Thomas model more than Adams-Bohart and Yoon-Nelson’s models. Thomas’s model showed that an increase in concentration and flow rate led to an increase in qo (maximum adsorption capacity) and kTH (Thomas rate constant), However, the increase in bed height led to a decrease in both qo and kTH. The correlation coefficients were in the range 0.6528–0.9797. The results revealed that the silver nanoparticles-maize leaf combo is suitable for the continuous adsorption of amoxicillin in aqueous media with the best performance at a lower concentration, higher bed height, and flow rate.

Triclosan (TCS), a common antibacterial agent found in numerous personal care products, has been detected in wastewater and surface water and is now of significant environmental concern due to its health impacts. To mitigate this issue, various treatment methods have been explored. This study investigated the efficacy of Macadamia nut shell activated carbon (MAC) as an economical adsorbent for triclosan removal. A pulsed-bed column adsorption technique was applied to enhance adsorption capacity and prolong the operational lifespan of the column. Batch experiments were conducted to explore various parameters and adsorption capacity. Column experiments were carried out to investigate breakthrough curves and various associated parameters. In batch experiments, MAC exhibited a high TCS adsorption capacity of 119.05 mg/g, and optimal adsorption conditions were determined. Adsorption kinetics followed the pseudo-second-order model, and equilibrium data were well-fitted by both the Langmuir and Freundlich isotherm models. A pulsed-bed column adsorption showed superior performance compared to a fixed-bed column under specific conditions (flow rate: 10 mL/min, TCS initial concentration: 60 mg/L, bed column height: 10 cm) and removal bed height of only 6 cm, successfully enhancing TCS adsorption capacity to 53.40 mg/g and extending the operational lifespan of the column to 5,280 minutes. Adapting pulsed-bed columns for TCS removal from wastewater in the personal care product industry led to the extension of column life with increased adsorption capacity and minimized the use of adsorbents as a practical and environmentally friendly method. Doi: 10.28991/CEJ-2024-010-05-019 Full Text: PDF

In this study, chromate adsorption onto red peanut skin (RPS) was investigated in a fixed-bed column; FTIR, PZC, SEM, DLS, and BET were used to evaluate its adsorption properties. The experiments were conducted to determine the effect of physical parameters, including the inlet initial Cr(VI) concentration (100–500 mg L−1), bed height (10–20 cm), and feed flow rate (13.59–23.45 mL min−1). They were carried out to predict breakthrough curves. The adsorption capacity coefficients were determined using the most widely used Bohart–Adams model. It was tested to fit experimental data, for a better understand the dynamic behavior, and for further optimize column performance. It was found that the Cr(VI) uptake decreases when increasing the flow rate and that high chromate concentration and bed height consequently increase the column’s life span. A high column adsorption capacity can be achieved with a higher Cr(VI) concentration due to the higher driving force. The results indicated that the Bohart–Adams model provides a good description (R2 > 0.98) of the experimental data of the Cr(VI)’s removal from the aqueous solution on the RPS suggesting that the surface diffusion is the rate-limiting step in the continues adsorption process.. Breakthrough adsorption capacity is crucial for comparing RPS with other similar materials. Indeed, possible mechanisms have been suggested for illustrating adsorption onto RPS. The obtained results showed significant potential of 26.23 mg g−1 of RPS on Cr(VI) elimination at a natural pH of 5.35. Furthermore, this global investigation allowed for the design of a promising low-cost material for the future scale-up of cleaning wastewater polluted by metal and determine the properly conditions for operating column adsorption. This material provides an economical, efficient means of eliminating pollutants, thus meeting the main aims of the UN Sustainable Development Goals (UN SDGs).

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The reduction of chemical oxygen demand (COD) from palm oil mill effluent (POME) is very significant to ensure aquatic protection and the environment. Continuous adsorption of COD in a fixed bed column can be an effective treatment process for its reduction prior to discharge. Adsorption capacity of bone derived biocomposite synthesized from fresh cow bones, zeolite, and coconut shells for the reduction in the organic pollutant parameter was investigated in this study in a fixed bed column. The effect of influent flow rate (1.4, 2.0, and 2.6 mL/min) was determined at an influent pH 7. The optimum bed capacity on the fabricated composite of surface area of 251.9669 m2/g was obtained at 1.4 mL/min at breakthrough time of 5.15 h influent POME concentration. The experimental data were fitted to Thomas, Adams–Bohart, and Yoon–Nelson models fixed bed adsorption models. It was revealed that the results fitted well to the Adams Bohart model with a correlation coefficient of R2 > 0.96 at different influent concentration. Adsorption rate constant was observed to increase at lower flow rate influent concentration, resulting in longer empty bed contact time (EBCT) for the mass transfer zone of the column to reach the outlet of the effluent concentration. In general, the overall kinetics of adsorption indicated that the reduction in COD from POME using a bone-biocomposite was effective at the initial stage of adsorption. The pore diffusion model better described the breakthrough characteristics for COD reduction with high correlation coefficient. Shorter breakthrough time compared to EBCT before regeneration indicated that the bone composite was suitable and effective for the reduction in COD from POME using fixed bed column adsorption.

Abstract A continuous-flow adsorption/desorption process for the recovery of phenolic compounds (PCs) from olive mill wastewaters (OMWs) was developed in a 0.53 m packed column, using a previously selected resin (Amberlite XAD16) and an actual OMW. The main goals of the study were (i) to evaluate the PC adsorption/desorption performances of XAD16 by means of adsorption isotherms and adsorption/desorption breakthrough tests, and (ii) to develop a reliable model of the process. A combination of centrifugation and microfiltration resulted necessary to attain a high suspended solid removal (98.5%) and thus avoid clogging of the packed bed. The quality of two packing procedures was evaluated by means of frontal analysis tests. XAD16 performed well in terms of both adsorption yield at 20% breakthrough (87–88%) and PC/COD selectivity (PC/COD adsorption constant = 7–9). The desorption solvent (acidified ethanol) was effectively regenerated by vacuum distillation. The adsorption breakthrough curves were successfully simulated with a 1-D convection/dispersion model with mass-transfer ( R 2  = 0.95–0.99; k L a  = 0.8–2.5 · 10 −3 1/s), whereas an equilibrium adsorption model with dispersion failed to predict the experimental data. In the perspective of a process scale-up, the simulation of the best-performing operational condition was used to evaluate the process performances for different column lengths (0.5–10 m). A precise and automated HPLC method for total PC measurement was developed and compared to the traditional Folin–Ciocalteu methodology. Further research is needed to optimize the desorption step, to scale up the process and to evaluate the long-term resin performances.

: The objectives of this study were to isolate and purify blueberry anthocyanin by combination of macroporous resin and Sephadex LH-20 and identify anthocyanin composition after isolation and purification. The static adsorption/desorption experiments of anthocyanin on ten different types of resins were compared. The results showed that the highest AB-8 macroporous resin adsorption rate of 97.73 % and desorption rate of 81.52 % from blueberry were achieved under optimal conditions (Adsorption conditions: a flow rate of feed 1.0 mL/min, anthocyanin concentration of 1.0 mg/mL, pH of 3.0; Desorption conditions: an eluent flow rate of 1.5 mL/min, ethanol concentration of 60 %, pH of 3.0). The anthocyanin purity increased 19.86-fold from 4.58 % to 90.96 % after one run treatment with macroporous resin combined Sephadex LH-20 method. Delphinidin-3-glucoside and cyanidin-3-glucoside were identified by HPLC-ESI-MS/MS. The results of this study may effectively promote the purification of anthocyanin from most blueberry varieties as well as from other plant materials.

Abstract Black glutinous rice bran (BGRB) serves as a plentiful natural pigment source. However, limited research has been conducted on the extraction, purification, and characterization of the anthocyanins present in BGRB. This work aims to provide an eco-friendly process for industrial anthocyanin extraction and purification. Following green chemistry principles, safe solvents and recyclable purification materials were used in the experiment. And waste production and energy consumption were limited. Optimal extraction conditions: ethanol–water ratio 40:60 (v/v, pH 2.5), solvent-feed ratio 80:1 (mL/g), 50 °C, and 40 min yielded 19.79 ± 0.14 mg/g anthocyanin, and 32 anthocyanins were identified in the BGRB anthocyanin extract. Optimal purification conditions: employing a D101/AB-8 mixed resin (7:3 w/w), the volume, pH value, and flow rate of BGRB anthocyanin extract were 1.5 Bed Volumes (BV), pH 3.0, and 0.5 BV/hr, respectively; desorption was performed successively with 40:60 (v/v, pH 2.5) ethanol–water of 6 BV, 0.5 BV/hr. Purification achieved 65.97% anthocyanin recovery. After purification, total anthocyanins (67.70 ± 5.43 mg/g to 171.27 ± 7.99 mg/g) and color value (33.48 ± 2.91 to 84.58 ± 1.41) were both 2.5 times higher than in the extract. The metabolite expression of purified anthocyanins showed 4.2 times increase by liquid chromatography–mass spectrometry (LC–MS). Graphical Abstract The workflow of this study.

In our previous study, as natural food colorants and antioxidants, the color and content stabilities of Schisandra chinensis (S. chinensis) anthocyanins were investigated. In this work, the purification process parameters of S. chinensis anthocyanins using a macroporous resin and gel filtration chromatography were evaluated. The optimized parameters of static adsorption and desorption were as follows. The selected resin is HPD-300 (nonpolar copolymer styrene type resin), and the anthocyanins adsorption saturation capacity of HPD-300 resin was 0.475 mg/g dry resin. Adsorption time was 4 h, and 0.517 mg/mL of S. chinensis anthocyanins was adsorbed on the resin column with a flow rate of 39 mL/h (3 BV/h). After adsorption, the anthocyanins were completely desorpted with 2.5 BV of 90% (v/v) ethanol solution, and the desorption flow rate was 13 mL/h (1 BV/h). After purification by dynamic adsorption and desorption, the anthocyanins content in the effluent increased from 47.6 mg/g to 128.4 mg/g, the purity of anthocyanins increased six-fold from 5.08% to 30.43%, and the anthocyanins recovery was 96.5%. The major constituent of S. chinensis anthocyanins was isolated with Bio-Gel P2 gel filtration chromatography, and it was detected by liquid chromatography electrospray ionisation tandem mass spectrometry (LC-ESI-MS) as cyanidin-3-O-xylosylrutinoside. Moreover, the antioxidant activities of S. chinensis anthocyanins were investigated. After purification using the HPD-300 resin, the antioxidant activities of anthocyanins were increased 1.2-fold (FRAP) and 1.7-fold (ABTS).

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Pomegranate juice (PJ), rich in anthocyanins (ACNs), was efficiently concentrated using a nonionic acrylic polymeric adsorbent resin to develop ACNs-rich fraction aim to develop natural pH-sensitive indicators for real-time food deterioration detection. The ACNs-rich fraction was incorporated into fiber films made from two hydrocolloid matrices composed of polyvinyl alcohol, chitosan, and starch. Optimal adsorption conditions (94.0 %) were achieved at pH 2.5, with a 40-minute contact time and a PJ-to-resin ratio of 30 ml/0.7 g. Desorption reached 93.3 % using a 6-bed volume solvent and 8-minute contact time. HPLC analysis showed an 82-fold increase in anthocyanin content and a 6.2-fold rise in antioxidant activity compared to raw PJ. Isotherm and kinetic studies showed good fits with the Freundlich (R2 = 0.96) and pseudo-second-order (R2 = 0.99) models, respectively. FTIR-ATR and molecular docking analyses revealed hydrogen bonding between ACNs and the polymer matrix. The developed fiber films based on chitosan and polyvinyl alcohol exhibited ultrafine average diameters, pronounced color changes in response to ammonia exposure, and antioxidant activities that were 51.0 and 72.5 times higher than those of the unloaded control. This study introduces a novel natural indicator for real-time food deterioration and proposes optimized, scalable preparation methods with commercial potential for food packaging.

This study focuses on enhancing anthocyanin concentration in natural blue colorant powder from butterfly pea flowers (BPFs) (Clitoria ternatea L.) using an adsorption–elution method with AB‐8 macroporous resin. Based on the experimental results, optimal processing conditions were identified as BPF extract concentration of 0.3 mg/mL, adsorption time of 90 min with circulating flows, volume ratio between BPF extract solution and AB‐8 resin was 3.5:1 (v/v), elution solvent was 60% ethanol, and elution flow rate of 1 mL/min. The total monomeric anthocyanin content, determined via the pH differential method, reached 14.77 ± 0.23 mg/g in the final powder‐a more than six‐fold increase compared to the crude extract. The powder exhibited vivid violet‐blue coloration, low moisture content (9.27 ± 0.14%), and high antioxidant activity (IC 50 = 75.69 ± 0.12 ppm), which is substantially improved compared to the unpurified extract (IC 50 = 248.40 ± 0.35 ppm). Furthermore, the AB‐8 resin maintained high efficiency over three reuse cycles, demonstrating its stability and potential for scalable production. These findings confirm that macroporous resin purification is a practical approach for producing anthocyanin‐rich powders with enhanced functional properties, making it highly suitable for applications in the food, cosmetic, and nutraceutical industries.

Spent hops after supercritical CO2 extraction contain valuable bioactive compounds such as xanthohumol (XN). Due to its low water solubility and high thermal and light sensitivity, traditional purification remains challenging. This study investigates a sequential purification strategy using a three-liquid-phase extraction system followed by macroporous resin chromatography. A three-liquid-phase extraction system consisting of n-hexane-ethanol-NaH2PO4-water was employed to fractionate the crude extract. XN partitioned into the middle ethanol-rich phase, effectively separating it from non-polar lipids and polar impurities. Further purification was conducted using Diaion HP-20 resin. Adsorption data followed the Langmuir isotherm (R2 = 0.9989) and pseudo-second-order kinetics (R2 = 0.9999), indicating a monolayer chemisorption mechanism. The process significantly improved the XN purity, representing a 5.6-fold enrichment. UV–VIS and HPLC analysis confirmed that the resin-purified fraction closely matched the XN standard profile. Simultaneously performing anti-solvent precipitation also resulted in XN-enriched extracts; however, with slightly lower purity. These results demonstrate that combining a three-liquid-phase extraction system with macroporous resins provides a scalable, efficient, and reproducible method for high-purity XN recovery from industrial residues, contributing to the sustainable valorisation of brewery waste.

In order to enrich and separate three coumarins (columbianetin acetate, osthole and columbianadin) from Angelicae Pubescentis Radix (APR), an efficient method was established by combining macroporous resins (MARs) with preparative high-performance liquid chromatography (PHPLC). Five different macroporous resins (D101, AB-8, DA-201, HP-20 and GDX-201) were used to assess the adsorption and desorption characteristics of three coumarins. The result demonstrated that HP-20 resin possessed the best adsorption and desorption capacities for these three coumarins. Moreover, the adsorption dynamics profiles of three coumarins were well fitted to the pseudo second order equation (R2 > 0.99) for the HP-20 resin. The adsorption process was described by the three isotherms models including Langmuir (R2 > 0.98, 0.046 ≤ RL ≤ 0.103), Freundlich (R2 > 0.99, 0.2748 ≤ 1/n ≤ 0.3103) and Dubinin Radushkevich (R2 > 0.97). The contents of columbianetin acetate, osthole and columbianadin in the product were increased 10.69-fold, 19.98-fold and 19.68-fold after enrichment, respectively. Three coumarins were further purified by PHPLC and the purities of them reached above 98%. Additionally, the anti-inflammatory effects of these three coumarins were assessed by Lipopolysaccharide (LPS)-induced RAW 264.7 cells. It was found that the production of NO and MCP-1 was obviously inhibited by three coumarins. Columbianetin acetate, osthole and columbianadin could be used as potentially natural anti-inflammatory ingredients in pharmaceutical products. It was concluded that the new method combining MARs with PHPLC was efficient and economical for enlarging scale separation and enrichment of columbianetin acetate, osthole and columbianadin with anti-inflammatory effect from the APR extract.

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To address the challenge of purifying bioactive polyphenols from the complex matrix of Ziziphus jujuba Mill. var. spinosa pulp, this study established an integrated purification protocol combining Deep Eutectic Solvent (DES) extraction with macroporous adsorption resin (MAR) enrichment. Among five screened resins, AB-8 exhibited superior selectivity, achieving a maximum adsorption capacity of 62.48 mg polyphenols/g dry resin and a desorption ratio of 83.40%. Kinetic analysis revealed that the adsorption process strictly followed a pseudo-second-order model (R2 = 0.999), indicating a mechanism dominated by chemisorption. Through dynamic optimization, optimal column parameters were determined as a loading concentration of 2.4 mg/mL, a flow rate of 1.0 mL/min, and elution with 70% (v/v) ethanol. Structural characterization via UV-Vis and FT-IR confirmed the effective removal of polysaccharide and protein impurities, while High-Performance Gel Permeation Chromatography (HPGPC) indicated a low-molecular-weight distribution (Mw approx. 1073 Da). Furthermore, HPLC-MS profiling definitively identified eight key constituents, including chlorogenic acid, catechin, rutin, and quercetin. Collectively, this work elucidates the adsorption mechanism and provides a scalable, efficient technical foundation for the high-purity preparation of jujube polyphenols.

Abstract Salvia miltiorrhiza Bunge leaves, a crop waste, have potential as a source of bioactive phenolics. In this work, ultrasound-assisted extraction (UAE) was employed as a green extraction technology to extract phenolics from S. miltiorrhiza leaves. UAE parameters were optimized using response surface methodology (RSM) based on Box-Behnken design, achieving the total phenolics from S. miltiorrhiza leaves (SMLTP) yield of 71.16 ± 0.57 mg gallic acid equivalent per g of dry material (mg GAE/g DM) under optimal conditions. Afterwards, NKA-2 resin was selected to enrich SMLTP, the data for adsorption of SMLTP on NKA-2 resin fitted well with pseudo-second-order and Langmuir models. A NKA-2 resin-based chromatography procedure was optimized by studying breakthrough curves and desorption curves to enrich SMLTP from crude extract. A lab-scale enrichment experiment was performed under optimal conditions, the content of SMLTP in the product was 78.33 ± 0.61 %, which was 3.7 times higher than that in the crude extract, the recovery yield of SMLTP was 82.14 ± 1.62 %. Finally, HPLC-DAD analysis showed the contents of five major phenolic compounds including caffeic acid, rutin, isoquercitrin, rosmarinic acid, and salvianolic acid B significantly increased through enrichment. Certainly, this study will enhance S. miltiorrhiza industry to be more ecologic and economic.

Background Eucommia ulmoides Oliv. (EUO) was a traditional Chinese herb, its leaves were abundant in China, and polyphenol compounds were considered to be an important active ingredient in Eucommia ulmoides Oliv. leaves (EUOL). However, previous research mainly focused on compound identification and extraction process, there were few reported on the efficient enrichment process and biological activity evaluation of polyphenols in EUOL. Methods The adsorption and desorption characteristics of twelve different resins (HPD-100, HPD-300, HPD-600, D-3250, X-5, D-140, NKA-9, NKA-II, D-101, AB-8, S-8 and Polyamide) were investigated to develop an efficient method for the enrichment of polyphenol from EUOL, and the static adsorption, kinetics, isotherm and thermodynamics of the polyphenol from EUOL were analyzed. The eluted component was obtained through dynamic elution, and its main polyphenol compounds were detected by high-phase liquid chromatography (HPLC) and the inhibitory effects on the enzyme activity of α-amylase and α-glucosidase was also evaluated for different elution components. Meanwhile, the binding of main polyphenol compounds to enzyme was also evaluated. Results The selected resins (HPD-300, HPD-600, D-3250, X-5, D-140, NKA-9, D-101 and AB-8) showed adsorption patterns that fitted well to the pseudo second-order kinetics. The intra-particle diffusion model demonstrated that the diffusion of polyphenol compounds on these resins were divided into three processes. For HPD-300, HPD-600 and NKA-9, the Freundlich model better described the adsorption isotherm behavior than the Langmuir model, and the adsorption of polyphenol was a physical, exothermic, and spontaneous process. Subsequently, dynamic elution was performed yielding a higher polyphenol content in a 60% ethanol-water elution component, and it also exhibited a higher inhibitory effect on α-amylase and α-glucosidase activity. Furthermore, as the main polyphenol compounds, chlorogenic acid, rutin, quercetin and kaempferol were used to simulate the binding to the enzyme protein through molecular docking technology. The results showed that quercetin had a higher docking score for α-amylase, while rutin displayed superior binding to α-glucosidase. Conclusions Therefore, polyphenols of EUOL could be enriched through macroporous resins and have the potential to be effective enzyme inhibitor.

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This study evaluated Osmanthus fragrans fruit (OFF) peel as a potential source of anthocyanin-based natural colorants. Anthocyanins were extracted using acidified ethanol and purified by macroporous resin adsorption, yielding a pigment-rich extract with a recovery of 10.4 ± 0.2% from dried peel. HPLC–MS/MS analysis indicated that cyanidin-3-O-rutinoside (C3R) was the predominant anthocyanin in the extract. The molar absorptivity of C3R was experimentally determined to enable more accurate quantification of C3R-rich systems. The purified extract exhibited typical pH-dependent color behavior, maintaining a stable red coloration under acidic conditions (pH 2.0–4.0). Thermal stability experiments showed that C3R degradation was strongly influenced by temperature and pH, and the degradation behavior followed first-order kinetics. In addition, the extract displayed measurable antioxidant capacity in DPPH and FRAP assays. These results demonstrate that O. fragrans fruit peel is a promising source of C3R-rich anthocyanins with potential applications as natural colorants in acidic food systems.

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This work described the purification and enrichment of flavonoids from baobab (Adansonia digitata) fruit pulp (BFP) by ultrasound-assisted adsorption/desorption procedure using macroporous resins. Four resins were tested and HPD-500 polar resin exhibited the best adsorption/desorption properties. Based on preliminary experiments and literature reports, the effects of various ultrasonic conditions including high power short time (HPST, 540 W for 5 min), medium power medium time (MPMT, 270 W for 15 min) and low power long time (LPLT, 45 W for 30 min) as well as different temperatures (T = 25-45 °C) on the adsorption of Total Flavonoids Content (TFC) were investigated in comparison with orbital shaking/no sonication (NS). Also, the effect of ultrasound on the desorption capacity and recovery of TFC was determined at different concentrations of ethanol (30-100%). Remarkably, ultrasonic treatment significantly increased the adsorption/desorption capacity and recovery and shortened the equilibrium time. The pseudo-second-order kinetic and Freundlich isotherm models better delineated the adsorption process under ultrasound. Moreover, the adsorption process was both spontaneous and thermodynamically favourable with physical adsorption and multilinear intraparticle diffusion being the predominant mechanisms of the whole process. HPST treatment at 25 °C with 80% ethanol as the desorption solvent most noticeably enhanced the adsorption/desorption of flavonoids and contributed to the highest recovery of TFC, Total Phenolic Content (TPC), and antioxidant capacity in addition to a 5-8-fold reduction in total sugar and acid contents when compared with NS treatment. Moreover, HPLC analysis revealed that the content of nine out of thirteen phenolic compounds from the HPST treatment was the highest, and the individual flavonoids content increased by 2-3-fold compared with the other treatments. Our analyses suggested that ultrasound can be employed as a practical approach to intensify the adsorption and desorption of functional compounds in BFP.

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The contamination of aquatic environments with hexavalent chromium (Cr(VI)) poses significant environmental and public health risks, necessitating the development of high-performance adsorbents for its efficient removal. This study evaluates the potential of green-synthesized nanoscale zero-valent iron-modified sludge biochar (TP-nZVI/BC) as an effective adsorbent for Cr(VI) removal through isothermal adsorption experiments, fixed-bed column studies, and artificial neural network (ANN) modeling. Fixed-bed experiments demonstrated that breakthrough time, exhaustion time, and unit adsorption capacity increased with bed height. Conversely, these parameters decreased with higher influent concentrations and flow rates. Breakthrough curve analysis revealed that the Thomas model provided the best fit for the experimental data (R2 = 0.992–0.998). An ANN model, developed using the Levenberg–Marquardt algorithm, employed a single hidden layer with six neurons and exhibited excellent predictive performance (R2 = 0.996, MSE = 0.520). The ANN model was validated for its ability to predict adsorption behavior under untested conditions, demonstrating its applicability for process optimization. This study highlights the superior performance of TP-nZVI/BC as an adsorbent for Cr(VI) and establishes a theoretical basis for optimizing and scaling up fixed-bed adsorption systems using ANN modeling. The findings provide valuable insights into the practical application of sustainable materials in environmental remediation.

Achieving effective separation of lignin and protic ionic liquids from sugarcane straw liquor is essential for adding value to the biomass. In this study, layered double hydroxides were used to adsorb lignin at different superficial velocities and temperatures, with the aim of optimizing breakthrough time, exhaustion time, adsorption efficiency, and productivity. The results revealed that superficial velocity significantly influenced adsorption parameters, whereas temperature did not exert significant effects within the studied range. Empirical models were validated with a relative error of <5 %, confirming their reliability in predicting process performance. Under optimized conditions, layered double hydroxides achieved effective lignin separation, with high adsorption efficiency and desorption capacity, enabling the recovery of protic ionic liquids. Nuclear magnetic resonance spectroscopy was used to assess the structural integrity of the purified protic ionic liquids and lignin. In conclusion, layered double hydroxides were effective in separating lignin and recovering protic ionic liquids from the pretreatment liquor. The findings also provide insights into the interactions between lignin, protic ionic liquids, and layered double hydroxides, supporting the design of cost-effective and efficient adsorption processes. Thus, this study contributes to the development of green technologies for separation processes, underscoring the potential of layered double hydroxides.

The experimentally investigation for dehydration of gas streams in a fixed-bed adsorption column using a 4A molecular sieve was reported for the first time. Different operating conditions of the adsorption system were performed, such as flow rate (2.0, 5.0 and 8.0 L min.-1) and bed depths (10, 20 and 30 cm). A significantly decreased (p ≤ 0.05) in exhaustion time of the adsorption column was verified as a result of the increase in the flow rate. On the other hand, a significantly increase (p ≤ 0.05) in the rupture time and the mass transfer zone (MTZ) were observed when the bed depths rise. Furthermore, the experimental data were satisfactory described by the Yoon-Nelson model due to high values of correlation coefficient (R2). These results suggested the suitability of 4A zeolite molecular sieve for the dehydration of gas streams in continuous operating mode. Moreover, it could be interesting for the scientific communities and industry.

A continuous adsorption study in a fixed-bed column using baobab fruit shell activated carbon (BF-AC) was investigated for phenol removal from an aqueous solution. Baobab fruit shell (BFS) was chemically activated using potassium hydroxide (KOH) at 700 °C in a nitrogen (N2) atmosphere. Scanning electron microscope (SEM), X-ray diffraction (XRD), and BET surface area analyses were performed for the characterization of BF-AC. Fixed-bed experiments were carried out and the effect of feed flowrate (10, 15, 20 mL/min) and bed height (5, 10, 15 cm) on the adsorption were investigated by evaluating the breakthrough curves. BET surface area of BF-AC was 1263 m2/g, indicating its well-developed pores and its good quality as an adsorbent. The findings showed that the exhaustion time (t????) and breakthrough time (tb) reduced as the flowrate augmented, while they increased as the bed height augmented. With the increase in the bed height and the flowrate, phenol solution volume treated was augmented. Also, BF-AC with bed height of 15 cm provided better elimination of phenol with carbon usage rate (CUR) of 1.74 g/L and empty bed contact time (EBCT) of 9.9 minutes. According to the findings, BF-AC is an effective adsorbent for removing phenol from aqueous solutions. ABSTRAK: Kajian penjerapan berterusan menggunakan kulit buah baobab diaktifkan karbon (BF-AC) telah dikaji mengguna pakai kolum lapisan tetap bagi penyingkiran fenol daripada larutan cecair. Kulit buah Baobab (BFS) diaktifkan secara kimia menggunakan kalium hidroksida (KOH) pada suhu 700 °C dalam atmosfera nitrogen (N2). Imbasan mikroskop elektron (SEM), pembelahan sinar-X (XRD, dan analisis permukaan BET dijalankan bagi pencirian BF-AC. Eksperimen kolum lapisan tetap bagi mengkaji kesan penjerapan pada aliran suapan (10, 15, 20 mL/min) dengan ketinggian (5, 10, 15 cm) dinilai melalui lengkung bulus. Kawasan permukaan BET BF-AC adalah 1263 m2/g, menunjukkan liang yang elok terbentuk dan berkualiti baik sebagai penyerap. Penemuan ini menunjukkan bahawa puncak masa maksima (t????) dan masa terbaik (tb) berkurangan pada kadar aliran bertambah, sebaliknya ianya meningkat pada ketinggian bertambah. Dengan penambahan ketinggian katil dan kadar aliran, jumlah larutan fenol yang dirawat telah bertambah. Selain itu, BF-AC pada ketinggian 15 cm menunjukkan penghapusan fenol terbaik pada kadar penggunaan karbon (CUR) 1.74 g/L dan masa sentuhan kolum kosong (EBCT) 9.9 minit. Ini menunjukkan, BF-AC adalah penyerap yang berkesan bagi menyingkirkan fenol daripada larutan cecair.

Ammonium contamination in wastewater poses serious risks to aquatic environments and requires efficient continuous treatment strategies. This study evaluates a Garcinia-derived biosorbent for NH4+ removal in a laboratory-scale fixed-bed column and quantitatively examines the influence of flow rate, influent concentration, and bed height on dynamic adsorption behavior. Breakthrough and exhaustion were defined at Ct/Co = 0.05 and Ct/Co = 0.95, respectively. Decreasing the flow rate from 2.0 to 0.5 mL min−1 increased the Thomas capacity from 10.5 to 18.5 mg g−1 and extended breakthrough time from < 100 to ~ 240 min. Increasing bed height from 5 to 20 cm enhanced qmax from 12.0 to 23.5 mg g−1. Model validation using the Thomas and Yoon–Nelson equations showed good agreement with experimental data (R2 = 0.89–0.99, RMSE = 0.021–0.065, MAE = 0.018–0.054). The mass transfer zone (MTZ) length and empty bed contact time (EBCT) were estimated to provide additional insight into column hydrodynamics. The results demonstrate the potential applicability of Garcinia-based biosorbent for laboratory-scale continuous ammonium removal and provide useful operational insights for fixed-bed adsorption systems.

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To attain efficient removal of hexavalent chromium (Cr6+) from aqueous solutions, a novel polyurethane foam-activated carbon (PUAC) adsorbent composite was developed. The composite material was synthesized by the binding of coconut shell-based activated carbon (AC) onto a coconut oil-based polyurethane matrix. To thoroughly characterize the physicochemical properties of the newly developed material, various analytical techniques including FTIR spectroscopy, SEM, XRD, BET, and TGA analyses were conducted. The removal efficiency of the PUAC composite in removing Cr6+ ions from aqueous solutions was evaluated through column experiments with the highest adsorption capacity of 28.41 mg g−1 while taking into account variables such as bed height, flow rate, initial Cr6+ ion concentration, and pH. Experimental data were fitted using Thomas, Yoon-Nelson, and Adams-Bohart models to predict the column profiles and the results demonstrate high breakthrough and exhaustion time dependence on these variables. Among the obtained R2 values of the models, a better fit was observed using the Thomas and Yoon-Nelson models, indicating their ability to effectively predict the adsorption of Cr6+ ions in a fixed bed column. Significantly, the exhausted adsorbent can be conveniently regenerated without any noteworthy loss of adsorption capability. Based on these findings, it can be concluded that this new PUAC composite material holds significant promise as a potent sorbent for wastewater treatment backed by its excellent performance, cost-effectiveness, biodegradability, and outstanding reusability.

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In this study, fixed-bed adsorption of Pb(II) from an aqueous solution using chitosan-coated bentonite (CCB) was investigated. Characterization of CCB was performed using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The effects of varying bed height (1.3 to 4.3 cm), flow rate (0.20 to 0.60 mL/min), and initial concentration (500 to 1500 mg/L) on the length of mass transfer zone (Zm) and adsorption capacity at breakthrough (qb) and exhaustion (qe) were examined. Low flow rate and high bed height were determined to cause a longer time to reach breakthrough and exhaustion. Meanwhile, the fixed-bed system was observed to quickly attain breakthrough and exhaustion under high initial concentrations. Kinetic column models such as the Thomas, Yoon–Nelson, and Clark models were used to predict the breakthrough curves. High R2 values (0.9758 ≤ R2 ≤ 0.8087) were attained for the Thomas model, which indicates that there is good agreement between experimental data and linear plots generated by the Thomas model. Moreover, the Thomas model is best in describing the breakthrough curves of Pb(II) removal under a fixed-bed system.

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ABSTRACT A novel ternary composite (RGO-βCD-ECH) consisting of epichlorohydrin (ECH) cross-linked beta-cyclodextrin polymer (βCD-ECH) with reduced graphene oxide (RGO) as a carrier was synthesised and used for the removal of malachite green (MG) dye from water. The adsorption performance was systematically investigated in batch mode, and the optimised parameters were as follows: initial MG dye concentration 100 mg/L, solution pH 8.0, contact time 90 min, adsorbent dosage 0.4 g/L, and temperature 30°C. The adsorption data follow the Langmuir model (R2 = 0.998) and the maximum sorption capacity (qm) was 902.125 mg/g. The kinetic data of adsorption follows the pseudo-second-order kinetic model (R2 = 0.999). The positive value of ΔHo = 102.047 kJ/mol indicates the endothermic nature of the adsorption process. The effects of bed height (2–4 cm) and MG dye flow rate (5–15 mL/min) were investigated in the fixed-bed column study. The exhaustion time (te), breakthrough time (tb), and bed capacity (qbed) of the column increases with bed height increases, and the value decreases with flow rate increases. The most important feature of this adsorbent is it could efficiently and easily regenerate from the MG dye loaded composite with a negligible effect on percentage removal. These characteristics of these novel composites could exhibit a bright future in the application of MG dye removal from wastewater.

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This study aims to develop a chitosan-zinc oxide nano-adsorbent–coated sand (CZOCS) filter bed for getting rid of milk processing industry wastewater (MPIW) in a safe way. Chitosan zinc oxide nano-adsorbent (CZnO) of 88.35 ± 2.89 d.nm size was used to coat naturally available sand through a calcination process at 200 °C for a heating rate of 5 °C/min. The characteristics of the diffraction peaks and functional groups are attributed to the nature of CZnO loading on the sand surface. The increase in breakthrough and exhaustion times is caused by the biological oxygen demand (BOD) and chemical oxygen demand (COD) of influent having more time to interact with the adsorbent as bed height increases, resulting in higher reduction efficiencies. Lower bed heights (10 cm) which saturate faster than higher bed heights (40 cm) result in a shorter mass transfer time. Adsorption capacity at the 95% column exhaustion point increased from 611.04 to 1089.63 mg/g for BOD and from 4512.29 to 5600.81 mg/g for COD. Different kinds of kinetic models have been used to forecast breakthrough curves employing experimental data. Statistical and error function parameters were used to choose the best-fit model. Among the models investigated, the Thomas model was shown to be the best-fit with the highest R-square values of 0.9942 and 0.9939. The CZOCS has high reusability and could be used for up to six cycles of organic pollutant adsorption. Aside from that, novel CZOCS could be used to clean real MPIW, and making it one of the most promising adsorbents. Graphical Abstract

In this study, a Methyl Green (MG) dye pollutant was separated by Mobil Composition Matter No. 41 (MCM-41) in a fixed-bed continuous column with investigated three parameters, namely a bed height (2–6 cm), initial MG concentration (10–30 mgL-1) and a process flow rate (0.8–1.6 mL min−1). Results indicated that the highest bed capacity of 20.97 mg/g was obtained with respective to optimal values such as; 6 cm for a column height, 0.8 mL min−1 for flow rate, and an initial MG concentration 20 mgL-1. Furthermore, a quantity of the adsorbed pollutant decreased as the flow rate increased, while increasing the initial MG concentration yielded the opposite effect. The column apparatus was performed properly at the low flow rate, whereas both the breakthrough and exhaustion time increased with the bed depth. Thomas and Yoon-Nelson models were applied for predicting the breakthrough curves and calculating the characteristic factors of the laboratory fixed-bed adsorption column, which were beneficial for process design. Based on regression coefficient analyses, results of employing the Yoon-Nelson model was found to be superior to the Thomas one. Breakthrough performance indicated that MCM-41 was suitable for applications in continuous adsorption regimes for MG dye. The mesoporous MCM-41 was recovered effectively by calcinations and employed again for four times in the continuous system successfully.

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Anthocyanin content is one of the limiting factors in the production of cranberry juice cocktail, yet the press cake contains approximately 40% of the pigment of the berries. The pigment can be recovered by extracting the pomace with methanol containing 0.03% HCl. Other solvents are less effective. A single extraction from whole ground pomace at a 5:1 solvent:pomace ratio will extract approximately 50% of the pigment. A multiple extraction will remove over 90%. Grinding the pomace reduces the time of extraction from several hours to less than ½ hr. The methanol in the pigment solution can be removed by distillation under vacuum and the resulting aqueous solution absorbed on an Amberlite C G-50 resin. The resin absorbs the anthocyanin and many of the impurities can be rinsed off the column with water. The pigments can be eluted with 0.0001% HCl in ethanol and concentrated to provide a concentrate for addition back to the juice.

Blueberries are rich in anthocyanins and are commonly processed into blueberry juice, jam, and other blueberry derivatives. During such deep processing, a substantial amount of anthocyanins remains in the peel residue. In this study, the adsorption of anthocyanins by seven macroporous resins (X‐5, DM‐21, SP‐207, XAD‐16, XAD‐7HP, LS‐305, and AB‐8) was evaluated to develop a simple and efficient process for large‐scale separation and purification of blueberry anthocyanins from the peel residue. Static screening experiments indicated that DM‐21, SP‐207, and LS‐305 resins exhibited favorable adsorption/desorption performance. The adsorption isotherm data fitted well with the Langmuir model, and the adsorption kinetics followed the pseudo‐second‐order model. Dynamic column adsorption and desorption tests further demonstrated that LS‐305 resin is a promising adsorbent for industrial applications in the recovery of blueberry anthocyanins from peel residue. After one round of operation, the resulting dried pigment products contained 33.5% blueberry anthocyanins, which corresponded to a 12.6‐fold increase over the crude extract.

Abstract Macroporous resin technology has unique advantages in the effective separation and purification of components from natural product. Evaluation of adsorption and desorption ability of chlorogenic acid on ten kinds of macroporous resins (AB-8, D4020, HPD-722, HPD-300, HPD-100, NKA, NKA-Ⅱ, NKA-9, S-8, X-5) from Eucommia ulmoides Oliv. leaves extraction was carried in this study. Resin NKA-Ⅱ exhibited the highest adsorption and desorption capacity and recovery. The adsorption parameters of NKA-Ⅱ resin for chlorogenic acid can be accurately calculated with the Freundlich equation. The adsorption process was observed following a pseudo-second-order kinetic model. Dynamic testing was performed on a NKA-Ⅱ resin-packed column where the breakthrough point was identified at four bed volumes of extract was loaded, and five bed volumes of 70% ethanol was required for complete desorption. After enrichment with macroporous adsorbent resin, the content of chlorogenic acid from extract increased 6.21-fold from 1.9% to 11.8%. The recovery of chlorogenic acid reached 87.9%.

This study aimed to extract anthocyanins from dried and semi-defatted açaí pulp using green technologies based on the coupling of pressurized liquid extraction (PLE) with in-line purification through solid-phase extraction (SPE) and on-line analysis by high-performance liquid chromatography (HPLC). Critical parameters that affect the extraction efficiency and purification were investigated and optimized by response surface methodology (RSM). PLE was performed with acidified water at different pH (2.0, 4.5, and 7.0) and temperatures (40, 80, and 120 °C) at 15 MPa, 2 mL/min, and solvent-to-feed mass ratio equal to 40. SPE was optimized in a column packed with the adsorbent PoraPak™ Rxn. Different ethanol concentrations (50, 75, and 100 %) and temperatures (30, 40, and 50 °C) were evaluated for the anthocyanin's elution. The optimal conditions of the two experimental designs were determined by the RSM, firstly for PLE: 71 °C and pH 2; then using this PLE condition, the optimization of the SPE was obtained: 30 °C and 50 % ethanol. The developed PLE method provided similar anthocyanin yield to other techniques, and the coupling with SPE in-line produced an extract 5-fold more concentrated than PLE alone. Therefore, the system (PLE-SPE × HPLC-PDA) proved to be a powerful tool for monitoring the extraction process in real-time.

ABSTRACT Ginkgo biloba leaves (GBL), a traditional Chinese medicinal resource, are recognised for their rich flavonoid content with diverse bioactivities. This study optimised the purification of total flavonoids from GBL using macroporous adsorption resin and quantified the compounds via LC-MS. Among six tested resins, AB-8 exhibited superior performance, with an adsorption capacity of 92.54 ± 0.85 mg/g and a desorption capacity of 71.03 ± 1.83 mg/g. The adsorption process followed the Langmuir isotherm and pseudo-first-order kinetics, indicating favourable, spontaneous, and exothermic physical adsorption. Scale-up column chromatography under optimised conditions (adsorption: 6 BV of GBLF extract at 1.5 BV/h; desorption: 5.5 BV of 60% ethanol at 3 BV/h) increased flavonoid purity by 5-fold (from 7.08% to 36.20 ± 0.45%) with a recovery rate of 36.20 ± 0.45%. LC-MS analysis identified 17 major flavonoids, 14 of which showed significant enrichment after purification. These findings establish a robust framework for industrial-scale flavonoid purification from GBL.

The aim of this study was to valorize liquid effluent from the sunflower protein isolate process by extracting phenolic compounds it contains. To do so, XAD7 resin was used. A multicriteria optimization methodology based on design of experiments showed the optimal conditions were adsorption flow rate of 15 BV/h at pH 2.7, a desorption flow rate at 120 BV/h with ethanol/water 50% (v/v). The best trade-off between purity and recovery yields resulted in the production of a fraction containing 76.05% of chlorogenic acid (CGA) whose biological properties were evaluated. DPPH and ABTS tests showed that this fraction had a higher radical scavenging capacity than vitamin C. In vitro assays have shown that this fraction, when used at a concentration corresponding to 50 or 100 µM of CGA, does not present any cytotoxicity on human THP-1 cells differentiated into macrophages. In addition, this fraction when added prior to the inflammatory stimulus (LPS) can reduce tumor necrosis factor-alpha (TNF-α) production by 22%, thereby highlighting its protective properties against future inflammation.

In the present study, enactments and separation characteristics of five extensively utilized adsorbents for enhancement and purification of Grewia asiatica Anthocyanins (ACNs) extracts were analysed. Among five tested resins (AB-8, Sepabeads Sp-700, C18SPE Cartridge, Sepabeads Sp-207 and AB-80), AB-8 resin exhibited the best adsorbent ability for Grewia asiatica ACNs (84.24mg/mL resin). Results of static adsorption tests revealed that AB-8 resin selected for kinetics and isotherm experiments followed a pseudo 2nd order model along with Langmuir isotherm. In order to improve operational procedure, dynamic adsorption and desorption tests were done on a packed column of AB-8 resin. Optimum factors for subsequent adsorption-desorption experiments; processing volume 20ml, flow rate 2 mL/min with elution solvent of acidified methanol (1%v/v) were used. HPLC and LC-MS/MS profiles of the purified extract confirmed seven ACNs in Grewia asiatica samples, out of which cyanidin-3-O-(6"acetylglucoside) comprises 44-63% (695 μg/g) of total ACNs composition. Moreover, pigment purification using AB-8 resin did not alter ACNs mixture composition after purification but enhance the peak intensity and gives effective purification. Hence present work reveals that the separation procedure established through column chromatography providing an effective methodology to enhance the purification of ACNs from Grewia asiatica.

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The dynamic adsorption and desorption of anthocyanins of black beans with AB-8 macroporous resin was studied. The research results showed that: the concentration of sample solution was 1.0mg/mL and the pH was 2.0, adsorption flow rate was 1mL/min, the highest absorption ratio was 93.65%. The elution solvent was 4BV of 70% ethanol and the desorption flow rate can be reached up to 1mL/min. AB-8 macroporous resin could be separated and purified of anthocyanins from black beans. The anthocyanins produced by the above conditions was black powder, the color value of purified anthocynins was 17.72 times higher than that of the beginning. This study laid foundation for the industrial production of anthocyanin in black hulls of natural pigments, and had a positive role in the development of health care products.

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This study developed an environmentally friendly method for extracting polyphenols and rubusoside from Rubus suavissimus leaves. Under optimal extraction conditions, the contents of polyphenol and rubusoside reached 91.89 ± 2.39 mg/g and 47.03 ± 1.45 mg/g, respectively. The extract was purified by twelve types of macroporous resins, among which the ADS-7 resin had the highest static adsorption and desorption capacities. Optimized purification parameters for ADS-7 resin were determined by static and dynamic adsorption-desorption experiments and found to be: loading flow rate, 3 BV/h; loading concentration, 10 mg/mL; loading volume, 24 BV; elution solvent, 80 % (v/v) ethanol; elution speed, 3 BV/h; and elution volume, 20 BV. After purification, the content of polyphenols and rubusoside increased by 2.63 and 2.32 times, respectively. Kinetic and thermodynamic analyses revealed distinct adsorption mechanisms: polyphenols followed a pseudo-second-order model, whereas rubusoside followed a pseudo-first-order model; both exhibited spontaneous (ΔG < 0) and endothermic (ΔH > 0) physisorption. Ultrafiltration-assisted centrifugal fractionation combined with UPLC-ESI-qTOF-MS/MS identified eight potential α-glucosidase inhibitors, including quercetin, apigenin, rutin, ellagic acid, kaempferol-3-O-rutinoside, kaempferol, rubusoside, and steviol. Molecular docking simulations revealed the molecular interactions between these compounds and α-glucosidase. The enriched extract demonstrated enhanced bioactivity, with a 3.35-fold higher α-glucosidase inhibition, and its IC₅₀ values for DPPH and ABTS+ radical scavenging decreased from 142.03 μg/mL to 88.45 μg/mL and from 197.63 μg/mL to 107.63 μg/mL, respectively. These results substantiate the effectiveness of the extraction-purification approach for producing R. suavissimus leaf extracts and suggest their potential application as functional hypoglycemic and antioxidant food ingredients.

The present study presents an attempt to modify the surface properties of macroporous resins (MRs) in order to improve anthocyanin adsorption and desorption from Pyrus communis var Starkrimson fruit peel extract. A number of MRs were tested to optimise the ultrasonic-assisted adsorption (UAA) conditions; including ultrasonic power (100-400 W), resin-to-extract ratio (1-3 g/50 mL) and temperature (20-40 °C). Similarly, varying ultrasonic-assisted desorption (UAD) conditions were optimised; including ultrasonic power (200-600 W), resin-to-solvent ratio (1-4 g/50 mL), ethanol concentration (60-90% v/v) and temperature (20-40 °C). The Amberlyst 15 (H) cationic resin was found to be superior to the other tested resins. The maximum adsorption capacity (659 µg/g) of cyanidin 3-galactoside (Cy 3-gal) was achieved under the optimised UAA conditions (400 W, 20 °C and 1 g/50 mL), while 616 µg/g of Cy 3-gal was recovered under the optimised UAD conditions (582 W, 1 g/50 mL, 60% and 20 °C). Moreover, titratable-acid and total-sugar contents were found to be significantly lower under UAA than under conventional-assisted adsorption (CAA). ANOVA revealed that process factors had significant effects on the Cy 3-gal purification, as depicted by their linear, quadratic and interactive effects. While anthocyanin adsorption was found to be significantly improved at lower ultrasonic power, higher power promoted the desorption process. Adsorption under optimized UAA conditions followed pseudo second-order kinetics and multilayer adsorption (Freundlich isotherm) onto the Amberlyst 15 (H) resin surface was observed. The particle-size distribution curve and scanning electron microscopic images also revealed higher resin-surface roughness, peeling and the appearance of pores on the surface under ultrasonication.This is the first study to use ultrasonication to modify a cationic exchange resin for the improvement of Cy 3-gal purification from a fruit extract. This study can recommend the use of ultrasonication as a low-cost green technique that can improve macroporous resin characteristics for better purification of compounds from an extract.

Recycling food waste to extract valuable bioactive compounds (BAC) offers a groundbreaking solution to mitigate environmental challenges. The isolation and purification of BAC from food waste are getting more attention to maintain environmental sustainability. The therapeutic potential of these compounds highlights the need for innovative approaches to extracting and purifying them from by-products. In this context, the chlorogenic (CG) acid is extracted from watermelon (Citrullus lanatus) rind (WMR) using ultrasound-assisted extraction (USAE) technique and purified using the macroporous adsorption resin (MPAR) method. The extraction and purification were carried out with water, 70 % v/v ethanol/water (70 % Et), and 90 % v/v ethanol/water (90 %-Et) solvent to analyze the impact of solvent on extraction efficiency, purity, and recovery. The extracted CG acid was qualitatively analyzed via UV spectrometry and HPLC and underwent FESEM analysis while purified CG acid was characterized via FTIR and thermal analysis. The implementation of the MPAR method notably increased the yield to 4.6 mg/g of raw material using solvents comprising 90 % ethanol than water and 70 % ethanol. The recovery of CG acid significantly escalated to 88 %, enhancing the purity percentage from an initial range of 70–94 %.

A novel approach for extraction and purification of the anthocyanins from Purple-heart Radish was developed by microwave-assisted deep eutectic solvent extraction (MAE-DES) coupled to macroporous resin separation (MRS). Citric acid-based DES as the extractant was screened and characterized from 13 synthesized deep eutectic solvents due to the excellent performance. Through RSM optimization of MAE-DES process, the anthocyanin yield reached 6.442 ± 0.135 mg/g, demonstrating that MAE-DES significantly superior to that of conventional methods. With AB-8 MRS purification, the anthocyanin purity was increased by 63-fold. By UHPLC-Q-TOF-MS/MS, the anthocyanins obtained from Purple-heart Radish were dominantly composed of pelargonins. Based on composition analysis, pH differential method was first modified by introducing weighting factors, avoiding serious underestimation of the anthocyanins content in Purple-heart Radish. MAE-DES and the modified spectrophotometry were successfully applied for assessment of anthocyanin extraction and sample drying methods, providing an efficient alternative to development and application of the anthocyanins from Purple-heart Radish.

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In this study, high-performance liquid chromatography was used to determine four components of Shaoyao Gancao Decoction (SGD), and the effect of purification was evaluated using fingerprints, similarity analysis and cell experiments. An effective method for isolation and purification of SGD was established. The adsorption/desorption properties of SGD were evaluated using resin screening, isothermal analysis, adsorption kinetics, and dynamic adsorption-desorption experiments. It was shown that the Langmuir equation fitted the isotherm data well and that a pseudo-second-order model accurately described kinetic adsorption on AB-8 resin. Analysis of thermodynamic parameters showed that the adsorption process was exothermic. Under the optimal process conditions, the concentrations of albiflorin, paeoniflorin, liquiritin and ammonium glycyrrhizinate in the product were 73.05, 134.04, 45.04 and 75.00 mg/g, respectively. The yields of the four components were 71.89 %-86.19 %. Cell experiments showed that the purified SGD retained anti-inflammatory activity. This research lays the foundation for the separation and purification of SGD and subsequent preparation research.

Cocoa is a rich source of health-promoting polyphenols such as flavanols. These compounds can be separated from other matrix constituents using various adsorbents or resins. Seven different macroporous resins (Amberlite® XAD-2, XAD-4, XAD-7, XAD-7HP, XAD-16, SepabeadsTM SP207, and Diaion® HP2-MG) were evaluated for their adsorption and desorption properties for the enrichment of flavonoids from an aqueous cocoa (Theobroma cacao L.) extract. The influence of adsorption and desorption temperatures and the concentration of the desorption solvent (a hydroalcoholic solution) were investigated by static adsorption and desorption methods. The results of the resin comparison showed that the adsorbent XAD-7HP had the best adsorption characteristics, with an adsorption capacity of 39.8 mg ECE/g. XAD-7HP was found to be the most suitable adsorbent, and 70% ethanol was the best desorbing solvent, based on static experiments. In addition, the optimal conditions for the adsorption of flavonoids were obtained at a temperature of 30 °C, where equilibrium was reached after 80 min. The static adsorption process was well-described by a pseudo-second-order kinetics model, while the adsorption isotherm data were fitted well by the Freundlich isotherm model. Further dynamic adsorption and desorption characteristics were evaluated on a packed glass column, and it was shown that XAD-7HP could enrich the flavanol content by 5.03-fold, with a dry matter content of 456.05 mg/mL (as estimated by the degree of DP1–DP7 procyanidin polymers using ultra-pressure liquid chromatography).

Vaccinium corymbosum berries represent a source of anthocyanins and polyphenols studied and tested for their healthy potential. The present study was aimed at isolating, characterizing, and quantifying the anthocyanin‐enriched fraction obtained from blueberry and at assessing its biological and protective effects against head and neck cell lines and under inflammatory‐related conditions. V. corymbosum berries extract was subjected to colorimetric analysis, antioxidant evaluation, and HPLC‐DAD analysis. This extract was characterized by chlorogenic acid and 12 glycosylated anthocyanins, being the most abundant delphinidin‐3‐O‐galactoside, delphinidin‐3‐O‐arabinoside, malvidin‐3‐O‐galactoside, malvidin‐3‐O‐glucoside, and malvidin‐3‐O‐arabinoside. The blueberry extract (BL) was further used in extensive biological evaluation. Head and neck cell lines, namely CAL27 and A253, were treated at different concentrations in order to evaluate cell migration ability and ErbB receptors and antioxidant enzymes gene expression.The gene expression analysis highlighted the capability of BL to reduce ErbB receptors expression in CAL27 cell lines. The same treatments induced an opposite effect in A253 cell line for ErbB2/ErbB3 receptors. Moreover, in A253 cell line, BL increased SOD2 levels and reduced cell migration. The action of BL was also studied in an ex vivo experimental model of colon inflammation and was effective both in reducing the lipopolysaccharide‐induced gene expression of different proinflammatory biomarkers involved in colon inflammation, among which tumor necrosis factor α, interleukin (IL)‐6, and in stimulating the gene expression of the anti‐inflammatory cytokine IL‐10.The content of specific anthocyanins and chlorogenic acid can be considered responsible of such biological activities providing a new food supplement as coadjuvant of standard therapies.