Photocatalytic Degradation Of Pesticides Research Articles

Sustainable production of graphene quantum dots from rice husk for photo‐degradation of organochlorine pesticides

AbstractThe controlled synthesis of two‐dimensional nanocrystals of graphene particles instead of amorphous carbon quantum dots is highly challenging and requires tremendous efforts to optimize the reaction conditions. It has been observed that as a significant bio‐compatible zero‐dimensional material, graphene quantum dots are considered as a novel material for opto‐electronics, energy, biological and environmental applications. However, very few are known about their utilization in photocatalytic degradation of pesticides, especially organochlorine pesticides which are resistant to removal by conventional wastewater treatment methods. In this work, graphene quantum dots were produced from rice husk at relatively low temperatures, resulting in an average particle size of 3.3 nm. The high resolution transmission electron microscopy clearly showed the formation of spherical quantum dots having lattice fringes and the selected area electron diffraction pattern showed the crystallinity of the graphene quantum dots. A study of photodegradation of three highly toxic organochlorine pesticides namely, dichlorodiphenyl trichloro ethane, cypermethrin and fenvalerate were carried out using as‐synthesized graphene quantum dots from rice husk. Interestingly, all these pesticides were found to be degraded around 60 % to 70 % under visible light conditions. It confirmed that synthesized graphene quantum dots from rice husk can act as prominent photocatalyst for the degradation of pesticides and other pollutants.

Utilization of the copper recovered from waste printed circuit boards as a metal precursor for the synthesis of TiO2/magnetic-MOF(Cu) nanocomposite: Application in photocatalytic degradation of pesticides in aquatic solutions

In this study, a number of leaching solutions (H2SO4, CuSO4 and NaCl) and an electrochemical method were used together for the separation of Cu from waste printed circuit boards. Secondly, the magnetic-MOF(Cu) was synthesized using the Cu recovered from waste printed circuit boards. Thereafter, TiO2/mag-MOF(Cu) composite was prepared and its photocatalytic activity was assessed in the photo degradation of two prominent organophosphorus pesticides, namely malathion (MTN) and diazinon (DZN). The catalytic structure of the MOF-based composite was fully characterized by various analyses such as XRD, SEM, EDAX, FT-IR, VSM and UV–vis. The obtained analyses confirmed the successful synthesis of TiO2/mag-MOF(Cu) composite. The synthesized composite exhibited highly efficient in the degradation of both pollutants under the following conditions: pH 7, contaminant concentration 1 mg/L, the catalyst dosage of 0.4 g/L, visible light intensity 75 mW/cm2 and reaction time of 45 min. First order kinetic model was best suited with the experimental results (R2: 0.97–0.99 for different MTN and DZN concentrations). Trapping studies revealed that superoxide radicals (O2•−) played an important role during the degradation process. Furthermore, the catalyst demonstrated a superb recovery as well as high stability over five cyclic runs of reuse. In addition, the total organic carbon (TOC) analysis showed over 83% and 85% mineralization for MTN and DZN, respectively. The combined system of TiO2/mag-MOF(Cu)/Vis also exhibited a great level of efficiency and feasibility in the treatment of tap water and treated wastewater samples. It is concluded that TiO2/mag-MOF(Cu) could be used as an excellent catalyst for the photodegradation of MTN and DZN in aqueous solution.

Bi-functional biochar-g-C3N4-MgO composites for simultaneously minimizing pollution：Photocatalytic degradation of pesticide and phosphorus recovery as slow-release fertilizer

Significant progress has been made in the development of phosphorus recovery adsorbents and photocatalysts for degradation of pesticides. However, the bifunctional materials for phosphorus recovery and photocatalytic degradation of pesticides have not been designed, and the mechanism of the interaction between photocatalysis and P adsorption remains unexplored. Herein, we develop biochar-g-C3N4-MgO composites (BC-g-C3N4-MgO) with bi-function application to minimize water toxicity and eutrophication. The results show phosphorus adsorption capacity of the BC-g-C3N4-MgO composite reaches 111.0 mg·g-1, and its degradation ratio of dinotefuran reaches 80.1% within 260 min. The mechanism studies show that MgO can play variety roles in BC-g-C3N4-MgO composite, in which can improve the adsorption capacity of phosphorus, enhance the utilization efficiency of visible light and the separation efficiency of photoinduced electron-hole pairs. The biochar existed in BC-g-C3N4-MgO serves as charge transporter with a good conductivity, which promotes the fluent transfer of photo-generated charge carriers. The ESR indicates that both •O2− and •OH generated from BC-g-C3N4-MgO are responsible for dinotefuran degradation. Finally, pot experiments reveal that P laden BC-g-C3N4-MgO promotes the growth of pepper seedlings with high P utilization efficiency of 49.27%.

Photocatalytic Degradation and Adsorptive Removal of Emerging Organic Pesticides Using Metal Oxide and Their Composites: Recent Trends and Future Perspectives

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.

Titanium-based metal-organic framework capsulated with magnetic nanoparticles: Antimicrobial and photocatalytic degradation of pesticides

Pesticide residues create an ecological ecosystem that is incredibly dangerous and presents major risks to human health. To solve this issue, scientists are concentrating on creating extremely effective composites with superior photocatalytic performance. Even if several efforts have been made to remove pesticides and dangerous compounds using adsorption, the development of novel adsorbents with large adsorption capabilities is still very desirable. Here, the photocatalytic of carbamate pesticides in aqueous solution under simulated sunlight irradiation in the existence of Fe3O4, CuO/Cu2O, MIL-125-NH2, Fe3O4@MIL-125-NH2 and CuO/Cu2O@MIL-125-NH2 were investigated. The photocatalytic process may be credited with the effective electron-hole separation and wider area of light response. Moreover, the mechanism of pesticide photocatalytic process was discovered as mineralization of pesticides to carbon dioxide, water, sulphate, and ammonia. Total organic carbon (TOC) analysis was used to quantify the mineralization of pesticides while UV spectroscopy was used to measure the rates of pesticides photocatalytic activity. CuO/Cu2O@MIL-125-NH2 and Fe3O4@MIL-125-NH2 composite demonstrated the maximum pesticide photocatalytic efficiency and outstanding cycle stability. The antimicrobial potency was increased and the inhibition zone was minimised when treated by a parent MIL-125-NH2 and its composites, which is surprising data when employing CuO/Cu2O@MIL-125-NH2 and Fe3O4@MIL-125-NH2 nanocomposite as an anti-bacterial material.

Potential Applications of Chitosan-Coated Zinc Oxide Nanoparticles for Degrading Pesticide Residues in Environmental Soils

The precipitation process was applied to synthesize chitosan-coated zinc oxide nanoparticles (chitosan-ZnO NPs). Then, various characterization tools were used such as XDR, SEM, TEM, FTIR, and EDX. The use of these 50 nm chitosan-ZnO NPs in soil decontamination of thifluzamide and difenoconazole pesticide residues is being investigated. In two distinct soils, the effect of catalytic decontamination on pesticide residues was examined (sandy loam and sandy clay soils). The studies required two sets of pesticide concentrations. One set of samples was added to the chitosan-ZnO NPs catalyst, and the other set was studied without the addition of a catalyst. Photocatalytic studies were conducted under the sunlight in July. The soil samples were hand-spread in a glass dish to a height of 5 mm and sprayed with an aqueous solution of pesticide. From 8 a.m. to 5 p.m., these samples were exposed to sunlight in October 2021. We found that the best concentration of catalyst was 0.05%. The acquired samples were quantified using validated Ultra-Fast Liquid Chromatography (UFLC) with Photo Diode Array (PDA) detection. Kinetic parameters such as rate constant k and the degradation rate of pesticides DT50 have been calculated using Pesticide Residue Dissipation Data. The findings showed that the tested fungicides degenerate according to pseudo-first-order kinetics. Based on the findings, we concluded that photocatalytic degradation of pesticides in soils are faster than photolysis.

Adsorption and Photocatalytic Degradation of Pesticides into Nanocomposites: A Review.

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 Critical Review on the Photo Degradation of Diazinon, A Persistent Organic Pesticides

Broad production, utilization, and scrapping of pesticides worldwide increase the health concern of humans and animals, due to their bio-persistent and bio-accumulating nature. Among the present treatment methods, metaloxide based photocatalysis is the emerging technology for pesticide removal in aqueous medium, and has gained the interest of many researchers in the past years due to its feasibility, cost efficiency and higher degradation rate. This review briefly discusses the mechanism of metaloxide based photocatalytic degradation, reaction kinetics of pesticides degradation, optimization of operational parameters to enhance the degradation process, and different modifications such as binary, ternary or metal/non-metal dopped metaloxide photocatalysts to improve the effectiveness of degradation has also been analyzed. The effect of operational parameters like effect of catalyst dosage, pH, initial pesticide concentration, UV/sunlight, and irradiation time on the photocatalytic degradation of pesticide has been reviewed. The comparison of various photocatalysts for the degradation of diazinon from aqueous medium is summarized. However additional research is required to achieve fast and maximum degradation to keep the environment safe.

Bi-Functional Biochar-G-C3n4-Mgo Composites for Simultaneously Minimizing the Pollution：Photocatalytic Degradation of Pesticides and Phosphorus Recovery as Slow-Release Fertilizer

Bi-Functional Biochar-G-C3n4-Mgo Composites for Simultaneously Minimizing the Pollution：Photocatalytic Degradation of Pesticides and Phosphorus Recovery as Slow-Release Fertilizer

Abatement of organic and inorganic pollutants from drinking water by using commercial and laboratory-synthesized zinc oxide nanoparticles

ZnO nanoparticles have been synthesized and applied for the removal of different environmental pollutants in the present study. Combustion method is used for the preparation of ZnO NPs. X-Ray diffraction pattern reveals the crystallinity of the nanoparticles, where SEM and TEM images displayed that ZnO NPs were of size less than 100 nm and nearly spherical in shape. UV–Vis and IR spectra revealed the formation of ZnO NPs. Adsorption and advanced oxidation processes were employed for the removal/degradation of trace elements/pesticide. UV reactor containing 1 UV rod of 11 W (Philips) was used for the photocatalytic degradation of pesticide. ICP–OES and GC–MS techniques were used for the further quantitative analysis of trace elements and OP pesticide—monocrotophos, respectively. The analysis shows the 88% degradation of monocrotophos when subjected to UV light in the reaction chamber for 120 min at a pH 4 when 2 g of nanocatalyst is applied. However, the removal of trace element Arsenic shows linear adsorption as compared to Cd and Se. The removal efficiency of ZnO nanoparticles for Cd and Se was 36% and 64%, respectively, after 120 min. The synthesized nanoparticles are more effective than the commercially available ones.

Synthesis and structure of a bismuth-cobalt bimetal coordination polymer for green efficient photocatalytic degradation of organic wastes under visible light

A novel BiCo-based bimetal coordination polymer (BiCo-MCP) with a molecular formula Bi2Co2C42H36N6O33 was synthesized by a mild hydrothermal method. BiCo-MCP was characterized via single crystal X-ray diffraction, SEM and XRD. BiCo-MCP is crystallized in a two-dimensional structure. The energy gap of BiCo-MCP is ~1.65 eV, which indicates that this material can absorb light both in visible and UV regions. This work is the first report on photocatalytic degradation of pesticide by a bismuth-containing bimetallic coordination polymer. The multiplication effect of pH and H2O2 together with BiCo-MCP on the degradation of imidacloprid pesticide wastewater showed that the catalyst system with 1< pH <3.5 and H2O2 (0.18 × 10−3 mmol/L) give the best degradation rate of 81% comparing to 35.4%(BiCo-MCP) under visible light for 5 h. The most interesting feature is that using BiCo-MCP as catalyst for photocatalytic degradation of imidacloprid can obtain the final environmentally friendly inorganic species decreasing the possible formation of a variety of organic intermediates. The influences of different pH on BiCo-MCP as photocatalyst to degradation of Rhodamine B (RhB) has also been investigated indicating the enhanced degradation properties of RhB by BiCo-MCP in acidic or alkaline aqueous solution.

Photocatalytic degradation of pesticides by nanofibrous membranes fabricated by colloid-electrospinning

Photocatalytic degradation of organic pollutants is a promising way to clean wastewater. Herein, we develop and compare two processes for fabricating nanofibrous membranes with photocatalytic properties. Hybrid nanofibers are produced by colloid-electrospinning and composed of metal oxide nanoparticles on sintered SiO2 nanoparticles. The latter serves as support for the photocatalyst and preserves the structural integrity of nanofibers. Adsorption of metal salts on crosslinked polymer/SiO2 fibers followed by calcination allows for the obtention of fibers with large amounts of metal oxide. Nanofibrous membranes with supported ZnO, In2O3, or mixture of both, display photocatalytic activity upon UV irradiation. The membranes can degrade a dye and an organophosphate pesticide more effectively than membranes directly fabricated from the calcination of metal oxides.

Recent advances on TiO2-based photocatalysts toward the degradation of pesticides and major organic pollutants from water bodies

ABSTRACTPesticides and organic waste constitute a group of environmental pollutants that are widely distributed in our environment due to various human activities. Adsorptive removal and photocatalytic degradation of these pollutants from water have emerged as energy and cost-effective technologies. However, advanced oxidation technologies are gaining attention as an effective method for wastewater treatment capable of degrading a diverse spectrum of organic contaminants. Photocatalysis is a promising advanced oxidation technology to alleviate water pollution problems. Titanium dioxide (TiO2) is the most popular photocatalyst due to its low cost, nontoxicity, high oxidizing abilities, and easy immobilization on various surfaces. The current review aims to highlight recent advancements in photocatalytic degradation of pesticides and major organic pollutants using TiO2-based photocatalysts. Indeed, most of the methods, which employed potent catalysts, showed and exhibited successful degradation of the pesticides under various conditions. We believe this topic of research is extremely vital and will continue to grow in recent years, reaching ultimate desirable results and find more applications in different fields of study.

Biodegradation Aspects of Carbendazim and Sulfosulfuron: Trends, Scope and Relevance

A large amount of pesticides are being used now-a-days in crop protection which has resulted in buildup of such harmful compounds in the environment, proving a menace to humans, animal life as well as to soil microbes. Residues of these pesticides have been reported in soil, water and foods. Carbendazim and sulfosulfuron are among the most widely used pesticides for treating fungal diseases and unwanted herbs in crops respectively. Carbendazim is a benzimidazole fungicide which can harm liver as well as the endocrine system and suspected to have mutagenic and tumorigenic effects. On similar lines sulfosulfuron, a sulfonylurea herbicide may result in the development of resistant herbs displaying its carry-over effects to the next crop cultivated. These pesticides possess large half-lives and thus remain persistent in the environment which may lead to harmful consequences in near future. Besides chemical and photo-catalytic degradation of pesticides, microbial degradation has now been evolved as a much effective and safer way to eradicate these harmful compounds from the environment. However a limited literature is available on the microbial degradation of such compounds. The present review emphasizes mainly upon the chemical properties of Carbendazim and Sulfosulfuron, detection of their residues, harmful effects and insights into their degradation studies. Further, the use of efficient microbes for remediation of pesticides from the environment has been discussed.

Photo catalytic degradation of pesticides in immobilized bead photo reactor under solar irradiation

The discharge of wastewaters containing pesticides from industries, agricultural applications and surface run off are toxic, which is one of the major cause of water pollution and is responsible for a variety of adverse environmental impacts. Heterogeneous photo catalysis has proved to be an effective treatment method for removal of toxic pollutants from industrial wastewaters owing to its ability to convert them in to innocuous end products such as CO2, H2O and mineral acids. The photo catalytic degradation of three pesticides, widely used in India, viz., Monocrotophos (MCP), Endosulfan (ES) and Chlorpyriphos (CPS) was studied in sunlight using Immobilized Bead Photo Reactor (IBPR) under solar radiation. TiO2 coated on the polymeric bead was characterized using SEM, XRD, UV–Vis spectrophotometer and FT-IR. Batch degradation of pesticides were studied to establish the photo catalytic activity of immobilized beads under solar irradiation.

SOLAR PHOTOCATALYTIC DECONTAMINATION AND DISINFECTION OF WATER

Photocatalysis using TiO2 for detoxification of contaminated water is most extensively been studied and developed today as of its practical applications to treat water contaminants. Photocatalytic treatment can be useful for addressing hazardous contaminants such as phenols, agricultural wastes, pesticides and etc. The objective of this study was to demonstrate whether detoxification of pesticide contaminated water by TiO2 photocatalysis process is possible. The performance of photocatalytic degradation of pesticide contaminated groundwater has been studied at pilot scale with the TiO2 photocatalyst. The study showed that 80 % and 54 % mineralization has been attained after 24 hours of UV and solar radiation, respectively.

Zinc(II) phthalocyanines immobilized in mesoporous silica Al-MCM-41 and their applications in photocatalytic degradation of pesticides

In the present study the authors investigated a set of three new zinc(II) phthalocyanines (zinc(II) tetranitrophthalocyanine (ZnTNPc), zinc(II) tetra(phenyloxy)phthalocyanine (ZnTPhOPc) and the tetraiodide salt of zinc(II)tetra(N,N,N-trimethylaminoethyloxy) phthalocyaninate (ZnTTMAEOPcI)) immobilized into Al-MCM-41 prepared via ship-in-a-bottle methodology. The samples were fully characterized by diffuse reflectance-UV–vis spectroscopy (DRS-UV–vis), luminescence, thermogravimetric analysis (TG/DSC), N2 adsorption techniques and elemental analysis. A comparative study was made on the photocatalytic performance upon irradiation within the wavelength range 320–460nm of these three systems in the degradation of pesticides fenamiphos and pentachlorophenol. ZnTNPc@Al-MCM-41 and ZnTTMAEOPcI@Al-MCM-41 were found to be the most active systems, with the best performance observed with the immobilized cationic phthalocyanine, ZnTTMAEOPcI@Al-MCM-41. This system showed high activity even after three photocatalytic cycles. LC–MS product characterization and mechanistic studies indicate that singlet oxygen (1O2), produced by excitation of these immobilized photosensitizers, is a key intermediate in the photocatalytic degradation of both pesticides.

Impact of Operating Conditions and Recent Developments in Heterogeneous Photocatalytic Water Purification Process

The heterogeneous photocatalytic water purification process has gained significant attention due to its effectiveness in degrading and mineralizing biorecalcitrant organic compounds. This author reviews and summarizes the recently published works on the photocatalytic oxidation of various organic compounds in wastewater with particular emphasis on the impact of various parameters on the photocatalytic degradation of pesticides, dyes, and phenols in wastewater. Recent developments using modified TiO2 and ZnO photocatalytic system for the enhanced degradation of various organic compounds are also highlighted.

Photocatalytic Degradation of Pesticides in Natural Water: Effect of Hydrogen Peroxide

The aim of this paper is to evaluate the effectiveness of photocatalytic treatment with titanium dioxide in the degradation of 44 organic pesticides analyzed systematically in the Ebro river basin (Spain). The effect of the addition of hydrogen peroxide in this treatment is studied, and a monitoring of effectiveness of photocatalytic processes is carried out by measurements of physical-chemical parameters of water. The application of photocatalytic treatment with 1 g L−1of TiO2during 30 minutes achieves an average degradation of the studied pesticides of 48%. Chlorine demand, toxicity, and dissolved organic carbon (DOC) concentration of water are reduced. If hydrogen peroxide is added with a concentration of 10 mM, the average degradation of pesticides increases up to 57%, although chlorine demand and toxicity of water increase while DOC concentration remains unchanged with this treatment. The application of either photocatalytic treatments does not produce variations in the physical-chemical parameters of water, such as pH, conductivity, colour, dissolved oxygen, and hardness. The pesticides which are best degraded by photocatalytic treatments are parathion methyl, chlorpyrifos, α-endosulphan, 3,4-dichloroaniline, 4-isopropylaniline, and dicofol while the worst degraded are HCHs, endosulphan-sulphate, heptachlors epoxide, and 4,4′-dichlorobenzophenone.

Photocatalytic degradation of pesticides by titanium dioxide and titanium pillared purified clays

Titanium dioxide was synthesized by the sol–gel method and titanium pillared purified clay was prepared with two titanium contents: 1.15 and 10.5mmol of Ti per gram of clay. The composites were synthesized by immobilizing TiO2 onto surfactant-pillared clay via ion exchange reaction between clay with cation surfactant, cetyl-trimethyl ammonium bromide (CTMABr). The composition and texture of the prepared photocatalysts were characterized with X-ray powder diffraction (XRD), FT-IR spectroscopy, transmission electron microscopy (TEM) and energy-dispersive spectroscopy (EDX). The adsorption performance and photocatalytic activities of the prepared samples were investigated using 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenoxypropionic acid (2,4-DP) as models of organic pollutants. The results were obtained that these photocatalysts can effectively degrade selected pesticides. The removal efficiency increases with the Ti content in the pillared clay.