光催化 降解 农残

The extensive use of pesticides in agriculture has significantly impacted the environment and human health, as these pollutants are inadequately disposed of into water bodies. In addition, pesticides can cause adverse effects on humans and aquatic animals due to their incomplete removal from the aqueous medium by conventional wastewater treatments. Therefore, processes such as heterogeneous photocatalysis and adsorption by nanocomposites have received special attention in the scientific community due to their unique properties and ability to degrade and remove several organic pollutants, including pesticides. This report reviews the use of nanocomposites in pesticide adsorption and photocatalytic degradation from aqueous solutions. A bibliographic search was performed using the ScienceDirect, American Chemical Society (ACS), and Royal Society of Chemistry (RSC) indexes, using Boolean logic and the following descriptors: “pesticide degradation” AND “photocatalysis” AND “nanocomposites”; “nanocomposites” AND “pesticides” AND “adsorption”. The search was limited to research article documents in the last ten years (from January 2012 to June 2022). The results made it possible to verify that the most dangerous pesticides are not the most commonly degraded/removed from wastewater. At the same time, the potential of the supported nanocatalysts and nanoadsorbents in the decontamination of wastewater-containing pesticides is confirmed once they present reduced bandgap energy, which occurs over a wide range of wavelengths. Moreover, due to the great affinity of the supported nanocatalysts with pesticides, better charge separation, high removal, and degradation values are reported for these organic compounds. Thus, the class of the nanocomposites investigated in this work, magnetic or not, can be characterized as suitable nanomaterials with potential and unique properties useful in heterogeneous photocatalysts and the adsorption of pesticides.

A zinc oxide (ZnO)/reduced graphene oxide (rGO) nanocomposite was synthesized via a hydrothermal synthesis method and used for the photocatalytic degradation of dimethoate. In the synthesis process of the ZnO/rGO nanocomposite, hexamethylenetetramine (HMT) was used as both a mineralizer and reducing agent. When the ZnO nanoparticles formed on the surfaces of graphene oxide sheets, the sheets were simultaneously reduced by HMT to form rGO. The photodegradation rate and photodegradation efficiency of dimethoate by the ZnO/rGO nanocomposite were 4 and 1.5 times, respectively, higher than those of bare ZnO. The ZnO/rGO nanocomposite possessed a high surface area of 41.0 m2 g−1 and pore volume of 4.72 × 10−3 cm3 g−1, which were conducive to the adsorption and mass transfer of pesticides and oxygen. The enhanced photocatalytic performance of the ZnO/rGO nanocomposite was attributed to the decrease in electron–hole recombination rate and effective carrier transport caused by the presence of rGO. Photoelectrochemical measurements confirmed that the nanocomposite exhibited a high charge transfer rate at the ZnO/rGO interface. These results indicate that ZnO/rGO nanocomposites have great application potential in pollutant degradation.

… In this study, we systematically reviewed all the articles about the photocatalytic degradation of pesticides using TiO 2 /UV process. Figure 1 shows the PRISMA flow diagram of the …

… The decrease of the pesticide concentration in the presence of TiO 2 was mainly due to the photocatalytic degradation. Photocatalysis experiments were carried out on the two …

… pesticides are also studied. The possible mechanisms of photocatalytic degradation of phosphate ester pesticides are … , there is no significant loss of the photocatalytic activity of TiO 2 …

… higher degradation efficiency. This paper presents the study of photocatalytic degradation of organochlorine pesticides … The photocatalytic efficiency of a few organochlorine pesticides …

Abstract Assessment of reaction pathways, kinetics and water toxicity during the photocatalytic degradation of glyphosate and myclobutanil pesticides has been performed in different aqueous matrices of increasing complexity, from the single pesticides to the mix of their commercial formulations. Using Aeroxide® TiO2-P25 as reference UV-A (Ultraviolet A) light photocatalyst, the ability of photocatalysis to degrade glyphosate and myclobutanil pesticides in water was evidenced independently of the aqueous matrix complexity, complete mineralization into CO2, phosphate and chloride ions being achieved. Further, an unusual volcano-like TOC evolution profile resulting from the proposed glyphosate degradation pathway was observed whatever the aqueous matrix. Increasing the water matrix complexity from single pesticides to the commercial formulation mix reduced the degradation kinetics and consequently extended the time necessary for complete mineralization but, did not influence the overall pesticide fate profiles. This behavior was associated to the competitive adsorption of the organic matter onto the catalyst and to the presence of ions and inorganic matter. The co-presence of glyphosate and to lesser extent of Roundup® formulation additives strongly impacted the myclobutanil fate profile, due to preferential adsorption/degradation of glyphosate. By contrast, despite the impact in the degradation pathway, the inorganic additives of the Systhane® formulation influenced less both the myclobutanil removal duration and the TOC removal than the glyphosate pesticide and its organic additives from Roundup® do. The treatment allowed for most of the cases a strong reduction of acute toxicity to aquatic invertebrate test organisms (D. magna) whatever the water matrix complexity, while the ecotoxicity was reduced by half for the complex formulation mix.

Abstract Alarming level water pollution is a serious concern in heavily industrialized countries. The development of advanced waste water treatment techniques and their utilization is sought for effective removal of pollutants especially pharmaceutical and pesticide compounds (PPCs). Doped TiO2 nanomaterials mediated photocatalytic degradation of waste water has shown great potential in removing these complex organic pollutants. Improvement in properties of doped TiO2 nanomaterials resulted in the effective utilization of visible light and solar light as light source. Doped TiO2 nanomaterials show great potential to water and energy concerns by fulfilling two key features i.e., effective in removing pollutants which are persistent in nature and cost-effective energy consumption. In this context, doped TiO2 nanomaterials mediated waste water treatment process and its role in water energy nexus is briefly addressed. Application of doped TiO2 nanomaterials against PPCs under different light sources are also discussed in this review.

For applications involving water cleanup, metal oxide nanoparticles are exceptionally successful. They are useful for the adsorption and photocatalytic destruction of organic pollutants due to their distinctive qualities, which include their wide surface/volume area, high number of active sites, porous structure, stability, recovery, and low toxicity. Metal oxide nanomaterials have drawn a lot of attention from researchers in the past ten years because of their various production pathways, simplicity in surface modification, abundance, and inexpensive cost. A wide range of metal oxides, such as iron oxides, MgO, TiO2, ZnO, WO3, CuO, Cu2O, metal oxides composites, and graphene–metal oxides composites, with variable structural, crystalline, and morphological features, are reviewed, emphasizing the recent development, challenges, and opportunities for adsorptive removal and photocatalytic degradation of organic pollutants such as dyes, pesticides, phenolic compounds, and so on. In-depth study of the photocatalytic mechanism of metal oxides, their composites, and photocatalytically important characteristics is also covered in this paper. Metal oxides are particularly effective photocatalysts for the degradation of organic pollutants due to their high photodegradation efficiency, economically sound methods for producing photo-catalytic materials, and precise band-gap engineering. Due to their detrimental effects on human health, pesticides—one of the highly hazardous organic pollutants—play a significant part in environmental contamination. Depending on where they come from and who they are targeting, they are categorized in various ways. Researchers focusing on metal oxides and their composites for the adsorptive and photocatalytic degradation of pesticides would find the review to be a beneficial resource. Detailed information on many pesticides, difficulties associated with pesticides, environmental concentration, and the necessity of degradation has been presented.

Abstract Pesticides are the most hazardous among the various organic pollutants and possess a great human and environmental threat. The pesticide is considered among the top deadly pollutants mankind is ever exposed to. Pesticide pollution becomes one of the leading environmental concerns because of their bioaccumulation and bio-persistence in the environment. At present, membrane separation, surface adsorption, and biodegradation are the conventional methods used for pesticide removal, but still, pesticides are found prominent in the atmosphere. By utilizing the advancement in nanotechnology, the researcher tried to solve the lethal problem of pesticide pollution to overcome the drawbacks associated with conventional methods. In past decades, nanoscience and technology have emerged as a tool for the detection, removal, and remediation of pesticides using advanced nanomaterials such as nanoparticles, nanocomposites, nanofiltration membranes. The present review attempt to summarize the recent research carried out on Zinc oxide based photocatalytic degradation of various pesticides. The basic principle of semiconductor mediated photocatalysis, process optimization, factors affecting, experimental conditions and degradation mechanism has been discussed. The kinetic of pesticide degradation has also been reviewed. Photocatalytic degradation has proved to be a fast, cost-effective and eco-friendly technique for the clean-up of the environment from persistent pollutants.

The widespread application of pesticides in modern agriculture has significantly boosted crop production; however, their inherent toxicity, persistence, and resistance to conventional cleanup methods have led to serious environmental and public health concerns. Advanced oxidation processes (AOP), especially those utilizing visible light for photocatalysis, have recently emerged as promising eco-friendly alternatives for the degradation of pesticides. In particular, zinc oxide (ZnO) based nanophotocatalysts have garnered considerable attention due to their wide band gap (∼3.37 eV), strong oxidative capability, high electron mobility, low electron–hole recombination rates, and natural antibacterial properties, which enhance their photocatalytic activity under sunlight. This review provides a comprehensive overview of recent progress in ZnO-mediated photocatalytic degradation of pesticides, focusing on synthesis methods, structural modifications such as doping and defect engineering, and material hybridization aimed at improving photocatalytic efficiency. Furthermore, the study critically examines the influence of key factors, including catalyst concentration, surface morphology, and particle size, on degradation performance. This review aims to offer a thorough understanding of the versatility of ZnO as a tunable photocatalyst for mitigating pesticide contamination in wastewater by combining mechanistic insights with experimental observations. This integration not only highlights the potential of ZnO in this context but also establishes a foundation for creating scalable and eco-friendly remediation approaches.

Abstract Contamination of natural resources by unwanted harmful chemical species is increasing day by day. After the use of pesticides in agricultural fields, some harmful residues are always left behind which become the major source of pollution. Among all the pollutants, toxic residues of agricultural pesticides cause numerous diseases as they directly pollute soil and water. Biodegradation by microorganisms is a natural process for eliminating pesticides whereas physical adsorption, membrane separation and advanced oxidation process are also used for removing pesticides. These methods are time consuming and unable to attain complete degradation of pesticide residues. Recently, various organic and inorganic compounds have been synthesized to achieve the targeted goal. Semiconductor materials have a tendency to generate electron-hole charge carriers which further contribute towards oxidation and reduction of pesticides. Large band gap value and fast recombination rate of charge carriers in basic semiconductor materials reduces their catalytic properties. Advancement in this field has been achieved by fabricating a composite by combination of two semiconductors having different band gap values. This newly formed composite exhibited excellent results for photocatalytic degradation of pesticides. The present review focuses on discussion of heterojunctions used for pesticide degradation and their catalytic efficiency in UV or visible radiations. Various investigations have proved that these synthesized materials are cost effective and efficient for utilization as photocatalysts for abating the pollution caused by pesticides.

TiO2 doped with C, N and S (TCNS photocatalyst) was prepared by hydrolysis process using titanium iso-propoxide and thiourea. The prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photo electron spectroscopy (XPS), BET surface area, FTIR and diffuse reflectance spectra (DRS). The results showed that the prepared catalysts are anatase type and nanosized par-ticles. The catalysts exhibited stronger absorption in the visible light region with a red shift in the adsorption edge. The photocatalytic activity of TCNS photocatalysts was evaluated by the photocatalytic degradation of isoproturon pesticide in aqueous solution. In the present study the maximum activity was achieved for TCNS5 catalyst at neutral pH with 1 g L-1 catalyst amount and at 1.14 x 10-4 M concentration of the pesticide solution. The TCNS photocatalysts showed higher phtocatalytic activity under solar light irradiation. This is attributed to the synergetic effects of red shift in the absorption edge, higher surface area and the inhibition of charge carrier recombination process.

… photocatalytic degradation and mineralization of pesticides on … activities could be decontaminated by photocatalysis [1], [2], [… of pesticides degraded by photocatalysis, the …

Abstract Widespread use of pesticides in agricultural and domestic sectors and their long half-life have led to their accumulation in the environment beyond permissible limits. Advanced chemical oxidation methods including photocatalytic degradation are being widely investigated for their mineralization. Photocatalytic degradation is the most promising method for degrading pesticides as well as other organic pollutants. Titanium dioxide with or without modification has been widely used as the photocatalyst. Some research groups have also tried other photocatalysts. This review presents a critical summary of the research results reported during the past two decades as well as the scope for future research in this area.

… pesticides in aquatic environments causes serious problems to human beings and other organisms. Photocatalytic degradation … In view of this, TiO 2 photocatalyst was prepared by sol–…

… organocholorine pesticide, hexachlorocyclohexane (HCH), was totally degraded and … The model and mechanism for the photocatalytic degradation of HCH on the Mg 12 Al 6 (OH…

… existing studies on pesticide degradation using a combination of ultrasonic and photocatalysis technologies, which is critical for reducing environmental problems related to pesticides. …

… are one of the best fields of application of photocatalytic … , we describe the photocatalytic degradation of a pesticide, … of the photocatalytic degradation using coated TiO 2 for degrading …

A series of monometallic and bimetallic cocatalyst(s), comprising FeOx, CuOx, CoOx, FeOx–CuOx, and FeOx–CoOx loaded TiO2 catalysts prepared by the surface impregnation method, were investigated for the photocatalytic mineralization of the widely used four herbicides: 2,4-dichlorophenol (2,4-DCP), 2,4,6-trichlorophenol (2,4,6-TCP), 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). It was found that FeOx–CoOx/TiO2 showed the highest photocatalytic efficiency toward mineralization of selected herbicides. FeOx–CoOx/TiO2 achieves 92% TOC removal in 180 min, representing nearly three time activity of the benchmark PC50 TiO2. From XPS analysis, FeOOH, CuO, and CoO were determined to be loaded onto the TiO2 surface. The outstanding photocatalytic performance of the optimized FeOx–CoOx/TiO2 sample for herbicides mineralization is due to an increased charge separation and enhanced hydroxyl radicals production monitored by diverse spectroscopies. Based on the proposed charge transfer mechanism, FeOx–CoOx cocatalyst species accelerate the transfer of photogenerated holes on TiO2, thus facilitating hydroxyl radicals production.

… The observed non-complete mineralisation is more likely owing to the formation of cyanuric acid product from the oxidation of the triazine part of the pesticide. Efficient photocatalytic …

… could easily be achieved, mineralisation was not complete, … Sevnol with TiO2-mediated solar photocatalysis in a solar wastewater … Photocatalytic transformation of pesticides in aqueous …

… The presence of pesticides in the effluent of pesticide … in the general group of carbamate derivative pesticides. It is an active … Complete mineralisation of carbofuran with TiO 2 was …

… photocatalytic degradation of pharmaceutical and pesticide pollutants has been discussed. … and water are the result of mineralisation of isoproturon’s photocatalytic breakdown [66, 67]. …

… photocatalytic study and evaluated in terms of mineralisation … Photocatalysis with TiO 2 can be efficiently applied for complete … , still registered insecticide from group of OP pesticides. …

… 5) versus treatment time during the degradation of the individual pesticides or commercial mixtures studied. Pyrimethanil and triadimenol were readily mineralised during the first 90 min …

… pesticides, which are widely used in agriculture, from the environment using semiconductor photocatalysis. It provides … pesticides, their occurrence, classifications, and an introduction to …

The amount of organochlorine pesticides in soil and water continues to increase; their presence has surpassed maximum acceptable concentrations. Thus, the development of different removal strategies has stimulated a new research drive in environmental remediation. Different techniques such as adsorption, bioremediation, phytoremediation and ozonation have been explored. These techniques aim at either degrading or removal of the organochlorine pesticides from the environment but have different drawbacks. Heterogeneous photocatalysis is a relatively new technique that has become popular due to its ability to completely degrade different toxic pollutants—instead of transferring them from one medium to another. The process is driven by a renewable energy source, and semiconductor nanomaterials are used to construct the light energy harvesting assemblies due to their rich surface states, large surface areas and different morphologies compared to their corresponding bulk materials. These make it a green alternative that is cost-effective for organochlorine pesticides degradation. This has also opened up new ways to utilize semiconductors and solar energy for environmental remediation. Herein, the focus of this review is on environmental remediation of organochlorine pesticides, the different techniques of their removal from the environment, the advantages and disadvantages of the different techniques and the use of specific semiconductors as photocatalysts.

… Triazine and chloroacetanilide herbicides are among the most commonly used pesticides in … resources, semiconductor-induced photocatalysis (heterogeneous photocatalysis) has …

Two TiO2-rGO nanocomposites were prepared by hydrothermal method from commercial TiO2 (P25 and Hombikat UV100, HBK). In both cases TiO2 nanoparticles appeared intimate and homogeneously distributed on rGO surface, but forming a dense network in P25-rGO nanocomposite, and a more open structure in HBK-rGO. Zeta potential and particle size distribution favored the ease of HBK-rGO nanocomposite to form stable suspensions. A comparative analysis of these two photocatalysts was performed on the pilot plant scale solar assisted photodegradation of a 200 μg·L-1 or 5 mg·L-1 mixture of persistent and biorecalcitrant pollutants in deionized water (methomyl, pyrimethanil, isoproturon and alachlor, all used as pesticides). Complete removal of pesticides was achieved, though faster with P25-rGO when O2 was the oxidant. However, the use of hydrogen peroxide (H2O2) dosage as oxidant speeded up pesticides removal, but HBK-rGO performance resulted much improved. Finally, at realistic very low concentrations of 200 μgeach pesticide·L-1, the complete removal of pesticides was achieved at very short times (<25 min), showing the efficiency of the synthetized TiO2-rGO nanocomposites in this pilot-plat scale solar process to mitigate refractory and biorecalcitrant contaminants on effluents as a sustainable and efficient process.

Structural design in a semiconductor photocatalyst is significant to improve the photocatalytic efficiency to solve current energy or environmental problems. In this study, we developed a …

Abstract ZnO/SnO2 nano-composites with different compositions were synthesized by co-precipitation method and further characterized by XRD and TEM. Synthesized photocatalysts were employed for the degradation of a persistent pesticide, Triclopyr (TC). Triclopyr is a well-known herbicide and fungicide. Coupled ZnO/SnO2 photocatalysts showed better degradation of TC than the pure ZnO or SnO2. The nanocomposite containing the 10% of SnO2 content (ZS-2) exhibited highest photo catalytic activity towards degradation of TC. Higher activity of the coupled oxides is attributed to the reduced recombination of photogenerated charged species due to formation of hetro-junctions between ZnO/SnO2.

… to comprehensively understand the behavior and impact of various semiconductor photocatalysts on pesticide degradation. The subsequent section outlines specific studies that shed …

Pesticide pollution is a major issue, given their intensive use in the 20th century, which led to their accumulation in the environment. At the international level, strict regulations are imposed on the use of pesticides, simultaneously with the increasing interest of researchers from all over the world to find methods of neutralizing them. Photocatalytic degradation is an intensively studied method to be applied for the degradation of pesticides, especially through the use of solar energy. The mechanisms of photocatalysis are studied and implemented in pilot and semi-pilot installations on experimental platforms, in order to be able to make this method more efficient and to identify the equipment that can achieve the photodegradation of pesticides with the highest possible yields. This paper proposes a brief review of the impact of pesticides on the environment and some techniques for their degradation, with the main emphasis on different photoreactor configurations, using slurry or immobilized photocatalysts. This review highlights the efforts of researchers to harmonize the main elements of photocatalysis: choice of the photocatalyst, and the way of photocatalyst integration within photoreaction configuration, in order to make the transfer of momentum, mass, and energy as efficient as possible for optimal excitation of the photocatalyst.

… photocatalyst, showed that both the oxidants are able to cause photo-oxidation of the pesticide. … the presence of the catalyst or UV light showed a negligible degradation of the pesticide. …

… pesticides… pesticide removal is the solar-driven photocatalysis, which is the use of sunlight to produce hydroxyl ( • OH) radicals by photocatalysis and its application to remove pesticides …

The discharge of pesticide residues (PRs) from agricultural activities into water bodies has raised concerns about their toxicity to humans and the ecosystem. Traditional methods such as adsorption, membrane filtration, biological treatment, and conventional filtration usually result in incomplete removal of PRs. Currently, removal of PRs using advanced oxidation processes, particularly metal oxide-based photocatalysts, is considered a promising way. This review provides a comprehensive overview of recent advances in the photocatalytic degradation of PRs using TiO2-based photocatalysts (T-BPs), the most widely investigated metal-oxide photocatalyst systems. First, we discuss the distribution, types, and negative impacts of major PRs on humans and the ecosystem. Next, we explore modification methods to enhance the properties of T-BPs, including light absorption behavior, charge separation rate, and photocatalytic degradation performance toward PRs. Afterward, this review carefully examines current challenges, such as complex water matrices, T-BP stability, energy supply for photocatalysis, and toxicity reduction. Finally, we highlight key future research directions, like the development of visible light-driven photocatalysts, enhanced mineralization efficiency, reduced secondary environmental risks, and the design of highly reliable catalyst and reactor systems for sustainable large-scale applications.

… as adsorbents and photocatalysts for the degra dation of pesticides with good efficiency. … In this chapter, we will provide an overview of different types of semiconductor materials and …

… pesticide degradation are of five types: (a) hydroxylated products and derivatives usually after dehalogenation of the parent pesticide… (c) ring opening products for aromatic pesticides (d) …

… drugs, hormones, and sunscreen to pesticides and dyes, are being … , heterogeneous photocatalysis employing semiconductor … In this process, a semiconductor is activated with UV-Vis …

Abstract Pesticides are chemicals that are meant to be effective against various pests and weeds that cause economic damage to various crop systems. They are also hazardous to the health of aquatic and terrestrial organisms. Moreover, pesticides have the tendency to leach out directly into the soil system and thus contaminate the quality of the surface and groundwater. The metabolites of pesticides are also highly persistent in the environment and have harmful effects on soil fertility as well as aquatic and terrestrial ecosystems. Various advanced oxidation processes have been employed to remove pesticides from water such as photolysis, Fenton and photo-Fenton, electrocatalytic oxidation, membrane filtration, heterogeneous photocatalysis, chemical oxidation, ozonation, etc. Heterogeneous photocatalysis is found to be the most-efficient and cost-effective technique for the removal of pesticides as well as their complete mineralization. This chapter, therefore, is considered the first of its kind that summarizes and highlights the use of heterogenous photocatalysis to improve the quality of wastewater for agricultural purposes for promising sustainable agricultural technology.

Pesticides have revolutionized the modern day of agriculture and substantially reduced crop losses. Synthetic pesticides pose a potential risk to the ecosystem and to the non-target organisms due to their persistency and bioaccumulation in the environment. In recent years, a light-mediated advanced oxidation processes (AOPs) has been adopted to resolve pesticide residue issues in the field. Among the current available semiconductors, titanium dioxide (TiO2) is one of the most promising photocatalysts. In this study, we investigated the photocatalytic degradation of profenofos and triazophos residues in Chinese cabbage, Brassica chinensis, using a Cerium-doped nano semiconductor TiO2 (TiO2/Ce) under the field conditions. The results showed that the degradation efficiency of these organophosphate pesticides in B. chinensis was significantly enhanced in the presence of TiO2/Ce. Specifically, the reactive oxygen species (ROS) contents were significantly increased in B. chinensis with TiO2/Ce treatment, accelerating the degradation of profenofos and triazophos. Ultra-performance liquid chromatography–mass spectroscopy (UPLC-MS) analysis detected 4-bromo-2-chlorophenol and 1-phenyl-3-hydroxy-1,2,4-triazole, the major photodegradation byproducts of profenofos and triazophos, respectively. To better understand the relationship between photodegradation and the molecular structure of these organophosphate pesticides, we investigated the spatial configuration, the bond length and Mulliken atomic charge using quantum chemistry. Ab initio analysis suggests that the bonds connected by P atom of profenofos/triazophos are the initiation cleavage site for photocatalytic degradation in B. chinensis.

… waste solutions polluted with 24 emerging pollutants (13 pharmaceuticals and 11 pesticides) using a coupled biological-photocatalytic … followed by a photocatalytic process using the …

This study aims to demonstrate a technically feasible alternative to remove pesticide residues from agro-waste water produced in farms from remnants in containers and treatment tanks, rinse in tanks after treatments, and cleaning of machines and equipment. For this, the photocatalyzed degradation of 12 pesticides commonly used on vegetables, vines, citrus and fruit crops was investigated in aqueous suspensions of TiO2 in tandem with Na2S2O8 at pilot plant scale under natural sunlight in Murcia (SE of Spain) during summer and winter seasons. Previously, preliminary experiments were carried out at laboratory scale using a photoreactor to optimize the photocatalyst (200 mg L-1) and oxidant (250 mg L-1) concentrations on the rate constants of the studied pesticides. The photodegradation of all pesticides can be modelled assuming a pseudo-first-order kinetics. The time needed for disappearance of 90% (DT90) of the studied pesticides, was lower than 4 h in summer in all cases with the exception of cyproconazole (4.9 h), while, cyproconazole (8.9 h), metalaxil (6.1 h) and propyzamide (7.9 h) showed DT90 higher than 6 h in winter. The reaction rate was enhanced 3-fold in summer season, which is directly correlated to the higher accumulated fluence per time received during this season (about a factor of 2.9 higher than in winter). In both cases, the higher and lower degradation rates were obtained for cyprodinil and cyproconazole, respectively. The total fluence to get a 90% reduction (H90) ranged from 4.6 to 5.2 J cm-2 (cyprodinil) to 71.5-76 J cm-2 (cyproconazole).

… can efficiently degrade residual OPPs. Herein, a chiral TiO 2 photocatalyst was developed by … for applying chiral TiO 2 nanomaterials for the photocatalytic degradation of OPPs in foods. …

Photocatalytic mitigation of triazinone herbicide residues using titanium dioxide in slurry … Photocatalytic oxidation of metamitron and metribuzin herbicides in water was studied. …

… Pesticide residues remain a major threat to ecosystems and food security, warranting novel … photocatalytic nanocomposites serve as a transformative platform, repurposing waste …

This work assesses the behavior (adsorption, degradation and leaching) of four insecticides (chlorantraniliprole, thiametoxam, imidacloprid and pirimicarb) and their main reaction intermediates in a clay-loam textured soil (1.6% OM). Following the batch equilibrium method, the KOC (as log values) ranged from 1.2 to 3.9 (thiametoxam and pirimicarb, respectively). All the insecticides were moderately persistent (t½ = 39-100 days) in the following order: thiametoxam > imidacloprid > pirimicarb > chlorantraniliprole. Two major transformation products, desmethyl-formamido pirimicarb and desmethyl pirimicarb, were formed as consequence of dealkylation of the parent compound. Using disturbed soil columns only thiametoxam (93% of the initial amount) and imidacloprid (42% of the initial amount) were recovered from leachates. In the case of pirimicarb and chlorantraniliprole, 74% and 30%, respectively, were recovered from the soil. Thiametoxam and imidacloprid can be catalogued as mobile compounds, while pirimicarb and chlorantraniliprole are classified as immobile according to the screening indices used (GUS and ELI). Leachates containing thiametoxam and imidacloprid were subjected to photocatalytic treatment for 240 min using TiO2/Na2S2O8 with the help of a photochemical reactor equipped with LED lamp. Both compounds had a very fast degradation rate (half-lives ≤ 0.5 min) in deionized water, while their half-lives were 112 min and 178 min, respectively, in leaching water. This implies a strong effect of the water matrix composition, mainly due to organic matter dissolved (quenching). Only traces of thiametoxam urea and hydroxy imidacloprid were detected during the photocatalytic experiment.

Metal oxide nanoparticles and their composites have garnered significant attention in water treatment and environmental cleanup due to their unique physicochemical properties. These materials exhibit distinct crystalline structures, tunable morphologies, large surface areas, versatile surface chemistry, and widespread availability. These features make nanostructured metal oxides and their composites highly effective for the selective removal of organic pollutants from the environment, either by adsorption or photodegradation. This article focuses on recent advances, challenges, and opportunities in the use of metal oxides and their composites for the targeted removal of organic contaminants, including insecticides, phenolic compounds, organic dyes, and similar pollutants. The discussion encompasses a broad range of metal oxides and their composites, highlighting their diverse structural, crystallographic, and morphological characteristics that influence their adsorption and photocatalytic performance. Emphasis is placed on the photocatalytic and adsorptive capabilities of these materials, including their photo-stimulation properties and mechanisms. Metal oxides are highlighted as outstanding photocatalysts due to their high photodegradation efficiency, cost-effective synthesis methods, and optimized bandgap engineering. This review serves as a valuable resource for researchers exploring the photocatalytic and adsorptive applications of metal oxide-based materials, particularly in the remediation of hazardous organic pollutants such as pesticides.

… The toxicit: (inhibition, %) suddenly increased as soon as the photocatalytic oxidation started. This indicates that toxil products were formed as the toxic parent compound was …

… of the pesticides. UV/TiO 2 /H 2 O 2 photocatalysis is effective in degradation of pesticides chlorpyrifos… UV/TiO 2 /H 2 O 2 photocatalysis may be applied as pretreatment of a chlorpyrifos, …

Pesticide residues, when present in agricultural wastewater, constitute a potential risk for the environment and human health. Hence, focused actions for their abatement are of high priority for both the industrial sectors and national authorities. This work evaluates the effectiveness of the photocatalytic process to decompose two frequently detected pesticides in the water effluents of the fruit industry: thiamethoxam-a neonicotinoid compound and flonicamid-a pyridine derivative. Their photocatalytic degradation and mineralization were evaluated in a lab-scale photocatalytic batch reactor under UV-A illumination with the commercial photocatalyst Evonik P25 TiO2 by employing different experimental conditions. The complete degradation of thiamethoxam was achieved after 90 min, when the medium was adjusted to natural or alkaline pH. Flonicamid was proven to be a more recalcitrant substance and the removal efficiency reached ~50% at the same conditions, although the degradation overpassed 75% in the acidic pH medium. Overall, the pesticides’ degradation follows the photocatalytic reduction pathways, where positive charged holes and hydroxyl radicals dominate as reactive species, with complete mineralization taking place after 4 h, regardless of the pH medium. Moreover, it was deduced that the pesticides’ degradation kinetics followed the Langmuir-Hinshelwood (L-H) model, and the apparent rate constant, the initial degradation rate, as well as the L-H model parameters, were determined for both pesticides.

In this study, copper and tin doped TiO2 nanocomposite (NCs) (Cu-Sn-TiO2) were sunthesized using a precipitation method and their potential for nanoremediation of pesticide residues in soil was investigated. To characterize the physicochemical properties of the Cu-Sn-TiO2 NCs, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy were used. To assess their antibacterial activity against Escherichia coli and Staphylococcus aureus, bacterial growth inhibition and bacterial membrane damage were measured. The photocatalytic experiment was conducted under natural climatic sunlight. The soil samples were hand-spread to a height of 5 mm in a glass tray and sprayed with an aqueous pesticide solution. The catalyst concentration that worked best was 0.01%. Validated UFLC with PDA detection was used to quantify the samples. Kinetic parameters such as rate constant (k) and DT50 were calculated using pesticide residue dissipation data. After 20 h of exposure, the Cu–Sn–TiO2 NCs demonstrated significant antibacterial activity, reducing bacterial viability by more than 70%. Based on the formation of reactive oxygen species and the disruption of the bacterial membrane, the mechanism of the antibacterial and photocatalytic action of the Cu–Sn–TiO2 NCs was discussed. The agricultural and environmental sectors may benefit from the Cu–Sn–TiO2 NCs promising potential for the nanoremediation of pesticide residues in soils.

In the present study, the photocatalytic oxidation and detoxification of aqueous matrices contaminated with boscalid using g-C3N4 catalyst and UV-A light was investigated. The UV-A/g-C3N4 process was found to achieve higher than 83% removal of boscalid in both matrices, with h+ and O2•− being the main species. UHPLC-HRMS analysis allowed the identification of five TPs, while the main degradation pathways involved hydroxylation, cyclization, and dechlorination. Scenedesmus rubescens microalgae species was exposed to boscalid solutions and lake water spiked with the fungicide before the photocatalytic treatment and inhibition in the growth rate was observed. An increase in the toxicity was also observed during the first stages of the treatment. The results from the in silico study correlate with the observed evolution of ecotoxicity during the application of the process, as some of the identified TPs were found to be toxic or very toxic for aquatic organisms. However, prolonged application of the process can lead to detoxification. It was also observed that the g-C3N4 catalyst can retain its photochemical stability and activity after at least three cycles. However, a slight decrease in the activity was observed when repeated another two times. This study demonstrated that the suggested photocatalytic process can both decrease the harmful effects of boscalid as well as effectively lower its concentration in water.

Abstract Combination approaches involving sonolysis and photolysis with catalysts like CuO, ZnO and TiO2 have been applied for the treatment of commercial Flonicamid solution. The effect of ultrasonic power, initial loading of flonicamid and pH on COD reduction was studied for individual sonolysis and photolysis. The optimal conditions were established as initial concentration of 75 ppm, US power of 100 W and pH as 2. The impact of catalyst concentration has been subsequently examined and optimized loading were established for different catalysts as CuO (1 g/l), ZnO (0.75 g/l) and TiO2 (0.75 g/l). The extent of COD reduction achieved using ultrasound combination with catalyst at optimum loading was found to be 62.07 %, 73.73 % and 77.59 % for CuO, ZnO and TiO2 catalysts respectively. The efficiency of sonocatalytic treatment process was greater (COD removal as 77.59 % for specific case of TiO2 catalyst) than sonolysis (39.23 %) operated individually. Similar trend was also seen for comparison of photocatalysis with photolysis. Sonophotocatalytic oxidation with maximum COD reduction as 98.36 % for the case of TiO2 was found as best approach compared to sonocatalysis and photocatalysis. The sonophotocatalytic oxidation followed pseudo first-order kinetics for all the catalysts. Overall, the sonophotocatalytic combination involving TiO2 has been demonstrated as the most effective approach for COD reduction of commercial flonicamid solution.