Degradation Of Parathion Research Articles

Carbon Catabolite Repression of Methyl Parathion Degradation in a Bacterial Isolate Characterized as a Cupriavidus sp. LMGR1

Among the mixture of carbon compounds, bacteria have the ability to select energetically efficient substrate as a preferred carbon source. This specific behavior often limits the use of pollutants as a secondary carbon source by bacteria grown with preferred carbon source and the pollutants. Therefore, to develop an efficient bioremediation technology for removal/degradation of organophosphorus pesticide methyl parathion (MP) from agricultural soils, a soil bacterial strain (LMGR1) capable of degrading MP and p-nitrophenol was isolated and identified as a Cupriavidus oxalaticus based on biochemical (carbon utilization pattern) and molecular analysis (16S rRNA gene sequence), but the phylogenetic analysis revealed a distinct position, and the name was designated as Cupriavidus sp. LMGR1. The effect of preferred carbon source on degradation was also investigated. The bacterium assimilated the pesticide as a sole source of carbon and consumes about 100 mg L−1 of MP within 6 to 7 h of incubation. Furthermore, the methyl parathion hydrolase (MPH) enzyme (localized in the periplasm of bacterium) activity was induced by the carbon deficiency instead of substrate. Determination of kinetic parameters, i.e., Vmax and Km for MPH enzyme in the extracted periplasmic protein indicated significant higher affinity towards the substrate. The reduced MPH activity in the bacterium grown in presence of preferred carbon source indicated the role of carbon catabolite repression in regulation of pesticide degradation. Thus, the bacterium has prodigious capability to be used as a bioremediation agent, but the availability of preferred carbon source may affect its potential in field application.

Photodegradation of Organophosphorus Pesticides in Honey Medium by Solar Light Irradiation.

In this study, the photodegradation of organophosphorus (OPs) pesticides in the honey medium was evaluated under sunlight irradiation. Some of the 22 samples collected at different sites contained OPs pesticides (Methyl parathion, Coumaphos and Fenitrothion) with an average of 8ng/g. Moreover, three samples were found with pesticide residue levels exceeding the maximum residue limits (MRL ≥ 50ng/g) imposed by the standard water (WHO). Gas chromatography (GC) combined with a tritium electron capture detector system was used for the analysis of OPs pesticides in honey. Total degradation of the Methyl parathion was obtained in less than 60min of irradiation. Moreover, the elimination of the other OPs found in the samples was also effective with a rate of 85% for Coumaphos and Fenitrothion after 50min of sunlight irradiation. The kinetics of the photodegradation reaction of all OPs pesticides studied followed a pseudo-first order model.

Cascade degradation of organophosphorus pollutant by photoenzymatic integrated nanocatalyst

AbstractBACKGROUNDAs visible‐light photocatalytic semiconductors, BiOBr‐based catalysts have a promising application prospect for the degradation of dyes and pollutants in wastewater. Enzyme catalysis has become a promising technology in the degradation of organophosphorus pollutants due to excellent activity and specificity. Herein, a photoenzymatic integrated nanocatalyst of organophosphorus hydrolase (OPH) immobilized on BiOBr (OPH@BiOBr) was successfully synthesized for the cascade degradation of methyl parathion under visible light.RESULTSThe obtained OPH@BiOBr could degrade methyl parathion into para‐nitrophenol (p‐NP) by hydrolyzing the PS bond using OPH, and then converting the produced p‐NP into a less toxic substance through photocatalysis of BiOBr. After 3 h of reaction, methyl parathion was degraded into hydroquinone and nearly 80% of the produced p‐NP was further degraded at the same time. The OPH@BiOBr nanocatalyst could be recycled five times and still retained 83% of its initial activity.CONCLUSIONSA novel photoenzymatic integrated nanocatalyst was developed for cascade degradation of methyl parathion under visible light. This represents the first attempt at eliminating pesticide residues by combining enzyme with photocatalyst through a cascade reaction. Considering the fact that wastewater may have pesticide residues, photoenzymatic integrated catalysts will be useful for the degradation of pollutants. The unique flower‐like structure of the nanocatalyst could not only improve photocatalytic activity but also protect enzyme molecules so as to complete the cascade degradation. In addition, with the development of enzyme engineering and photocatalysis, the integrated nanocatalysts that combine photocatalyst with enzyme will have more and more application in the fields of energy and the environment. © 2020 Society of Chemical Industry

Sono-coprecipitation synthesis of ZnO/CuO nanophotocatalyst for removal of parathion from wastewater.

Semiconductor photocatalysis is an effective method used to degrade organophosphorus compounds. Here, the potential of a commonly mixed oxide semiconductor, ZnO/CuO, has been examined to degrade methyl parathion. Sono-coprecipitation method was used to provide ZnO/CuO nanocomposites, and it was applied to photocatalytic and sono-photocatalytic degradation of methyl parathion under solar light irradiation. Powder x-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), the Brunauer-Emmett-Teller (BET) surface area, field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM) were used to characterize the synthesized samples. The optimal experimental conditions such as ZnO/CuO photocatalyst 90:10M ratios, the initial concentration of 20mg/L parathion, 1g/L photocatalyst loading, no compressed air sparging, pH of 8, and ultrasonic power (60W and 80kHz) were used to degrade the parathion effectively. The parathion was fully (100% removal) degraded after 60min sono-photoirradiation in the optimal experimental conditions. A real water sample was used to examine the ability of the ZnO/CuO photocatalyst 90:10 to remove the parathion in the water-soluble ions. Graphical abstract.

Synthesis of titanium nanoplate decorated by Pd and Fe3O4 nanoparticles immobilized on graphene oxide as a novel photocatalyst for degradation of parathion pesticide

In this research, the photocatalytic degradation of the pesticide pollutant was investigated using titanium nanoplates decorated by Pd and Fe3O4 nanoparticles immobilization on graphene oxide nanosheets (TNP-Pd-Fe3O4/GO). This nanocatalyst was characterized by XRD, FESEM-EDS-Mapping techniques. As-synthesized TNP-Pd-Fe3O4/GO was tested for photocatalytic activity by the degradation of the pesticide pollutant, parathion under visible light irradiation. The effect of catalyst amount, initial parathion concentration and pH were studied on photocatalytic degradation of parathion by the design of the experimental method in presence of TNP-Pd-Fe3O4/GO nanocomposite. The central composite design modeling, based on response surface methodology, was used for this object. In addition, the kinetics of parathion degradation was studied by the Langmuir- Hinshelwood equation.

Fabrication of Pt-Pd@ITO grown heterogeneous nanocatalyst as efficient remediator for toxic methyl parathion in aqueous media.

In this study, nano-sized ITO supported Pt-Pd bimetallic catalyst was synthesized for the degradation of methyl parathion pesticide, a common extremely toxic contaminant in aqueous solution. On the characterization with different techniques, a beautiful scenario of honeycomb architecture composed of ultra-small nanoneedles or fine hairs was found. Average size of nanocatalyst also confirmed which was in the range of 3-5nm. High percent degradation (94%) was obtained in 30s using 1.5 × 10- 1mg of synthesized nanocatalyst, 0.5mM NaBH4, and 110W microwave radiations power. Recyclability of nanocatalyst was efficient till 4th cycle observed during study of reusability. The supported Pt-Pd bimetallic nanocatalyst on ITO displayed many advantages over conventional methods for degradation of methyl parathion pesticide, such as high percent degradation, short reaction time, small amount of nanocatalyst, and multitime reusability. Graphical abstract Schematic illustration of reaction for degradation of methyl parathion.

Effective oxidation of methyl parathion pesticide in water over recycled glass based-MCM-41 decorated by green Co3O4 nanoparticles

Pieces of glass as solid wastes were recycled in the synthesis of highly order MCM-41 that decorated by green fabricated Co3O4 nanoparticles using the green extract of green tea leaves forming novel green nano-composite. The synthetic Co3O4/MCM-41 exhibit high surface area, low bandgap energy (1.63 eV), and typical spherical morphology decorated by Co3O4 nanoparticles. The composite was evaluated as green photocatalyst in effective oxidation of methyl parathion pesticide in the presence of a visible light source. The degradation results revealed complete removal of 50 mg/L and 100 mg/L after 60 min and 90 min, respectively using 0.25 of the catalyst at pH 8. The detection of the TOC in the treated methyl parathion solution gives strong indications about the formation of organic intermediate compounds during the oxidation steps. The main detected intermediate compound are C6H5OH(NO2), C6H5OH, (CH3O)3P(S), C6H4(OH)2, C6H3(OH)3, C6H4(NH2)OP(O)(OCH3)2, (CH3O)2P(O)OH, (CH2)2C(OH)OH(CHO)OC(O), and HO2C(CH2)2C(O)CHO. The detected intermediate compounds converted into SO42−, PO43−, NO3−, and CO2 under the extensive photocatalytic of them over Co3O4/MCM-41. The oxidizing species trapping test verified the controlling of the methyl parathion degradation pathway by the hydroxyl radicals. Finally, the composite showed significant reusability properties and applied five times in the oxidation of methyl parathion with considerable degradation percentages.

3D Sphere-like Nickel Tungstate Catalyst for Destroying of Organophosphate Pesticide Methyl Parathion

Recently, the appearance of pesticide residues into the environment poses serious risks to the living organisms. In this view, we explored a novel and superior photocatalyst based on nanostructured sphere-like nickel tungstate (NiWO4 NSs) for the degradation of organophosphate pesticide methyl parathion (MP) under visible light irradiation, for the first time. The NiWO4 NSs were tailored through simple precipitation technique and confirmed by several spectroscopic techniques. Fascinatingly, the NiWO4 NSs portrayed superior photodegradation performances towards MP degradation with superior stability.

Synthesis of KIT‐5 decorated by Bi2S3‐Fe3O4 photocatalyst for degradation of parathion pesticide in aqueous media: Offering a degradation model and optimization using response surface methodology (RSM)

AbstractIn this research, a novel KIT‐5/Bi2S3‐Fe3O4 nanocomposite was prepared. The structure and morphology properties of the nanocomposite were well characterized by XRD, FESEM‐EDS‐mapping, TEM, and N2 adsorption–desorption. Benefiting from the visible light, the as‐prepared KIT‐5/Bi2S3‐Fe3O4 nanocomposite exhibit significantly improved photocatalytic performance for the degradation of parathion. The optimum photocatalytic efficiency of KIT‐5/Bi2S3‐Fe3O4 nanocomposite was investigated with the central composite design using Design Expert software. The four critical variables affecting parathion degradation such as the concentration of parathion, pH, irradiation time, and amount of KIT‐5/Bi2S3‐Fe3O4 nanocatalyst. A polynomial function corresponding to degradation percent was obtained for the experimental data. The results showed that this catalyst has a good performance for the degradation of parathion.

2H and 13C isotope fractionation analysis of organophosphorus compounds for characterizing transformation reactions in biogas slurry: Potential for anaerobic treatment of contaminated biomass

The ability of anaerobic digestion (AD) to eliminate organophosphorus model compounds (OPs) with structural elements of phosphate, phosphorothioate and phosphorodithioate esters was studied. The enzymatic mechanism of the first irreversible degradation reaction was characterized using metabolite pattern and kinetic 2H/13C-isotope effect in original, cell-free and heat sterilized biogas slurry. The isotope fractionation study suggests different modes of degradation reactions. Representatives for phosphate ester, tris(2-chloroethyl) phosphate and tris(1,3-dichloro-2-propyl) phosphate, were hydrolyzed in biogas slurry without carbon or hydrogen isotope fractionation. Representatives for phosphorodithioate, Dimethoate and Malathion, were degraded in original slurry yielding carbon enrichment factor (εC) of −0.6 ± 0.1‰ and −5.5 ± 0.1‰ (−0.9 ± 0.1‰ and −7.2 ± 0.5‰ in cell-free slurry), without hydrogen isotope fractionation. Phosphorothioate degradation represented by Parathion and Parathion-methyl yielded surprisingly different εC (−0.7 ± 0.2 and −3.6 ± 0.4‰) and εH (−33 ± 5 and −5 ± 1‰) in original slurry compared to cell-free slurry (εC = −2.5 ± 0.5 and −8.6 ± 1.4‰; εH = -61 ± 10 and −10 ± 3‰) suggesting H-C bond cleavage. Degradation of Parathion and Parathion-methyl in sterilized slurry gave carbon but not hydrogen fractionation implying relative thermostable enzymatic activity with different mechanism. The correlation of 2H and 13C stable isotope fractionation of Parathion in biogas slurry showed distinct pattern (Λoriginal = 31 ± 11, Λcell-free = 20 ± 2), indicating different mechanism from chemical hydrolysis. Overall, AD can be a potential treatment for OPs contaminated biomass or contaminated organic waste material.

Chemically modified electrospun nanofiber for high adsorption and effective photocatalytic decontamination of organophosphorus compounds

AbstractBACKGROUNDOrganophosphorus (OP) pesticides are widely used to prevent the destruction of crops by various pests, including insects and rodents, which can affect the yield. On the other hand, the use of OP pesticides is linked to various disorders in animals and humans who are exposed to pesticides directly or indirectly. The current study deals with the use of lanthanum (La)‐doped zinc oxide (ZnO) crystals grown on electrospun nanofibers for photocatalytic degradation of methyl parathion (MP), an important OP pesticide.RESULTSThe electrospinning process was optimized using various parameters. Similarly, the crystal growth conditions such as La concentration, pH, temperature and time were optimized for further studies. Complete degradation was achieved at 150 min from the start and was supported by a reduction in photoluminescence of the reaction mixture. The total organic carbon content was used to decide the mineralization of the toxin. The degradation followed first‐order kinetics with rate constant 0.018 min−1. Hence MP was successfully degraded using La‐ZnO/polyacrylonitrile (PAN) fibers, and the degraded by‐product was confirmed by gas chromatography/mass spectrometry (GC/MS) analysis.CONCLUSIONChemically modified La‐ZnO/PAN nanofibers were an efficient material to decontaminate the pesticide MP, achieving 100% efficiency. The process may be ecofriendly for upscaling photocatalytic degradation processes. © 2019 Society of Chemical Industry

Fe2O3/Mn2O3 nanoparticles: Preparations and applications in the photocatalytic degradation of phenol and parathion in water

AbstractIn this study, nanoparticles of Fe2O3/Mn2O3 mixture were obtained using the sol–gel method. The synthesis uses the combination of polyvinyl alcohol (PVA) and tartaric acid (TA). Synthesized catalysts prove superior compared to those afforded from previous reports. To be specific, desired catalysts can be received at lower calcination temperature. Furthermore, their structures display higher uniformity in term of particle sizes. Finally, they show better performance for the photocatalytic degradation of model‐persistent organic compounds.

Study the performance of continuous bioreactor for the treatment of wastewater containing methyl parathion by isolated Alcaligenes species

Methyl parathion degradation potential bacterial species was successfully isolated from the agricultural field and identified as Alcaligenes sp. SRG. The coconut coir was used as packing media for the bioreactor. The process parameters were optimized in a batch experiment as pH (7 ± 0.3); temperature (35 ± 3 °C) and methyl parathion concentration as 150 mg/L. The continuous operation was performed under optimized process parameters and at varying flow rate of 10–40 ml/h. The performance of continuous bioreactor was studied and found maximum removal efficiency greater than 90% at a flow rate of 30 mL/h. The residual analysis FT-IR and GC–MS confirmed the biodegradation of methyl parathion. The phenolsulphonic acid, phenylamine, and benzo-1,4-quinone are the confirmed metabolites of methyl parathion. The growth and inhibition kinetic parameters were studied and found μmax; 0.176 per day; Ks; 77.85 mg/L and Ki; 289.01 mg/L.

Transcriptional analysis reveals the metabolic state of Burkholderia zhejiangensis CEIB S4-3 during methyl parathion degradation.

Burkholderia zhejiangensis CEIB S4-3 has the ability to degrade methyl parathion (MP) and its main hydrolysis byproduct p-nitrophenol (PNP). According to genomic data, several genes related with metabolism of MP and PNP were identified in this strain. However, the metabolic state of the strain during the MP degradation has not been evaluated. In the present study, we analyzed gene expression changes during MP hydrolysis and PNP degradation through a transcriptomic approach. The transcriptional analysis revealed differential changes in the expression of genes involved in important cellular processes, such as energy production and conversion, transcription, amino acid transport and metabolism, translation, ribosomal structure and biogenesis, among others. Transcriptomic data also exhibited the overexpression of both PNP-catabolic gene clusters (pnpABA′E1E2FDC and pnpE1E2FDC) present in the strain. We found and validated by quantitative reverse transcription polymerase chain reaction the expression of the methyl parathion degrading gene, as well as the genes responsible for PNP degradation contained in two clusters. This proves the MP degradation pathway by the strain tested in this work. The exposure to PNP activates, in the first instance, the expression of the transcriptional regulators multiple antibiotic resistance regulator and Isocitrate Lyase Regulator (IclR), which are important in the regulation of genes from aromatic compound catabolism, as well as the expression of genes that encode transporters, permeases, efflux pumps, and porins related to the resistance to multidrugs and other xenobiotics. In the presence of the pesticide, 997 differentially expressed genes grouped in 104 metabolic pathways were observed. This report is the first to describe the transcriptomic analysis of a strain of B. zhejiangensis during the biodegradation of PNP.

Application of an enzyme encapsulated metal-organic framework composite for convenient sensing and degradation of methyl parathion

Terbium-BTC (BTC = 1,2,4-Benzenetricarboxylic acid) metal-organic framework (MOF) has been employed for in-situ encapsulation of hexahistidine-tagged organophosphate hydrolase (OPH6His) enzyme. The enzymatic activity and stability of OPH6His were found remarkably enhanced after its encapsulation within the MOF. The potential of this enzyme-MOF composite (OPH6His@Tb-BTC) has been explored as a dual platform to simultaneously detect organophosphate pesticides (OPPs) and catalyze their degradation. The OPH6His@Tb-BTC exhibited improved enzymatic activity (by approximately 30%) and reusability (at least five cycles). It is demonstrated to be a highly sensitive and simple optical bioprobe for the detection of an OPP candidate, methyl parathion with a low limit of detection (2.6 nM). A less toxic metabolite was formed through catalytic conversion of methyl parathion (i.e., upon its incubation with OPH6His@Tb-BTC), further supporting the promising role of this composite in the remediation of pesticide-contaminated environments.

Kinetics and mechanism of the oxidative degradation of parathion by Ferrate(VI)

The degradation of parathion (PTH) by ferrate(VI) was investigated to evaluate the potential application of this iron-based chemical oxidant in water treatment. A series of kinetic experiments were conducted to examine the effects of operational parameters like solution pH, oxidant dose and temperature, and water constituents including anions (Cl−, NO3−, HCO3−), cations (Ca2+, Mg2+, Cu2+, Fe3+), and humic acid (HA). The removal of PTH at an initial concentration of 5 mg/L could reach 99% in 300 s under the conditions of [Fe(VI)]:[PTH] = 15:1; T = 25 °C and pH = 7.0. The presence of HCO3−, Ca2+, Cu2+, Fe3+ and HA decreased the removal efficiency of PTH, while Cl−, NO3− and Mg2+ had no obvious effects on PTH removal. Moreover, real water samples were also used to explore the feasibility of this Fe(VI) oxidation method. Fe(VI) could attack the PS double bond, and the PO single bond connecting the nitrophenol or the ethyl group in PTH molecule, leading to the formation of six products (paraoxon, thiophosphates and phosphates), which were detected by liquid chromatography-time-of-flight-mass spectrometry (LC-TOF-MS). These findings may provide useful information for the environmental elimination of organophosphate pesticides.

Enhanced Degradation of Methyl Parathion in the Ligand Stabilized Soluble Mn(III)-Sulfite System

The ligand-stabilized soluble Mn(III) recognized as active intermediate can potentially mediate the attenuation of contaminants. In this study, the abiotic degradation behaviors of methyl parathion in the ligand stabilized Mn(III)-sulfite system were investigated. The results showed that the yield of soluble Mn(III) produced from the redox reaction of MnO2 and oxalic acid was dependent linearly on the dosage of MnO2 and caused the decomposition of methyl parathion up to 50.1% in Mn(III)-sulfite system after 30 minutes. The fitted pseudo-first-order reaction constants of methyl parathion degradation increased with the increasing of the amount of produced Mn(III) but was not effected linearly by the addition of sulfite. Other ligands, including pyrophosphate and oxalic acid, acted as effective complexing agents to stabilize soluble Mn(III), and exhibited competitive effect on methyl parathion degradation with sulfite. The formation of Mn(III)-sulfite complexes is the critical step in the system to produce abundant reactive oxygen species identified as SO3•- to facilitate methyl parathion degradation. The hydrolysis and oxidation of methyl parathion were acknowledged as two primary transformation mechanisms in Mn(III)-sulfite system. These findings indicate that naturally ligands-stabilized soluble Mn(III) can be generated and could oxidatively decompose organophosphate pesticides such as methyl parathion.

Effects of Interfaces of Goethite and Humic Acid-Goethite Complex on Microbial Degradation of Methyl Parathion.

Microbial degradation plays an essential role in the removal of hydrophobic organic compounds (HOCs) dispersed in soil and sediment, and its performance is greatly affected by mineral particles which regulate HOCs bioavailability by interfacial adsorption. Likewise, bacteria cells attach to the surfaces of mineral particles as well but how bacterial attachment affects biodegradation is largely unknown. Here we report inhibitory effects of goethite and humic acid (HA)-goethite complex addition on microbial degradation of methyl parathion (MP). Using attenuated total reflectance-Fourier transform infrared spectroscopy, we observed that the adhesion of bacterial cells responsible for MP degradation on goethite occurred and the adhesive strength increased over time. We then replaced goethite with phosphate-adsorbed goethite to weaken the goethite-bacteria association and the inhibition of MP biodegradation was alleviated. These results suggested the formation of goethite-bacteria association hinder MP biodegradation. Meanwhile, our results showed that HA coating prevented bacterial attachment on goethite particles along with a drastically increased MP adsorption by goethite. The combined effect would lead to decreased mass fluxes of MP to bacterial cells and could represent another mechanism responsible for the decreased degradation rate observed in the current study.

Electrochemical behaviour and degradation of methyl parathion on platinum electrode

Methyl parathion adsorption from the solution of 0.5 M H2SO4 (M = mol dm−3) on the surface of platinum electrode has be proven. When Pt electrode covered by adsorbed product is cycled between potentials of 0.4 V to −0.23 V, the split of adsorbed molecules of methyl parathion occur and molecules of p-nitrophenol are released. We assume that molecules of methanol are also released besides p-nitrophenol and molecules of methylthiophosphoric acid remain adsorbed on the surface of the platinum electrode. If oxidation of adsorbed product is realized by cycling between potentials of −0.23 V to 1.32 V, the split of adsorbed molecules of methyl parathion occur and molecules p-nitrophenol and methanol are released. The adsorbed methylthiophosphoric acid is completely mineralized. Degradation of methyl parathion was observed in the electrochemical cell with separated electrode compartments. After 12 h of cycling between potentials of −0.23 V to 1.32 V, the concentration of the methyl parathion decreased to 2.5% of starting value (5.3 × 10−5 M).

Degradation of Methyl Parathion, a common pesticide and fluorescence quenching of Rhodamine B, a carcinogen using β-d glucan stabilized gold nanoparticles

Natural carbohydrate polymer β-d-glucan extracted from Tricholoma crassum (Berk.) Sacc. predominantly linked by β-glycosidic bonds have been used to synthesize gold nanoparticles (Au NPs). As glucan is water soluble, the Au NPs are prepared in water medium, a green solvent. The morphology and characterization of the synthesized Au NPs have been confirmed by various techniques, like TEM, EDX, XRD, UV–Vis and FT-IR spectroscopic studies. The obtained Au NPs exhibits chemosensing property against Methyl Parathion, a group of highly toxic organophosphorous pesticide, extensively used as an agricultural chemical. Degradation of parathion using Au NPs lead to water-soluble products thereby reducing the toxicity of Methyl Parathion by disrupting the thiophosphate-ester linkage. The synthesized Au NPs also act as a good fluorescence quencher of Rhodamine B, a common fluorophore and carcinogenic compound, obeying Stern-Volmer equations. The β-d-glucan capped Au NPs are safe having possible medicinal usage.