The Experts below are selected from a list of 2553 Experts worldwide ranked by ideXlab platform
Dirk Springael - One of the best experts on this subject based on the ideXlab platform.
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targeted metagenomics demonstrates the ecological role of is1071 in bacterial community adaptation to Pesticide Degradation
Environmental Microbiology, 2018Co-Authors: Vincent Dunon, Karolien Bers, Rob Lavigne, Dirk SpringaelAbstract:: IS1071, an insertion element that primarily flanks organic xenobiotic Degradation genes in cultured isolates, is suggested to play a key role in the formation and distribution of bacterial catabolic pathway gene clusters. However, in environmental settings, the identity of the IS1071 genetic cargo and its correspondence to the local selective conditions remain unknown. To respond, we developed a long-range PCR approach amplifying accessory genes between two IS1071 copies from community DNA followed by amplicon sequencing. We applied this method to Pesticide-exposed environments, i.e. linuron-treated agricultural soil and on-farm biopurification systems (BPS) treating complex agricultural wastewater, as to non-treated controls. Amplicons were mainly recovered from the Pesticide-exposed environments and the BPS matrix showed a higher size diversity compared to the agricultural soil. Retrieved gene functions mirrored the main selection pressure as (i) a large fraction of the BPS amplicons contained a high variety of genes/gene clusters related to the Degradation of organics including herbicides present in the wastewater and (ii) in the agricultural soil, recovered genes were associated with linuron Degradation. Our metagenomic analysis extends observations from cultured isolates and provides evidence that IS1071 is a carrier of catabolic genes in xenobiotica stressed environments and contributes to community level adaptation towards Pesticide bioDegradation.
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Establishment of multiple Pesticide bioDegradation capacities from Pesticide‐primed materials in on‐farm biopurification system microcosms treating complex Pesticide‐contaminated wastewater
Pest Management Science, 2014Co-Authors: Kristel Sniegowski, Dirk SpringaelAbstract:BACKGROUND On-farm biopurification systems (BPSs) treat Pesticide-containing wastewater at farms by bioDegradation and sorption processes. The inclusion of Pesticide-primed material carrying a Pesticide-degrading microbial community is beneficial for improving bioDegradation, but no data exist for treating wastewater containing multiple Pesticides, as often occurs on farms. In a microcosm set-up, an examination was carried out to determine whether multiple Pesticide Degradation activities could be simultaneously established in the matrix of a BPS by the simultaneous inclusion of different, appropriate Pesticide-primed materials. The microcosms were fed with a mixture of Pesticides including the fungicide metalaxyl and the herbicides bentazon, isoproturon, linuron and metamitron, and Pesticide-degrading activities were monitored over time. RESULTS The strategy immediately provided the microcosms with a multiple Pesticide Degradation/mineralisation capacity, which improved during feeding of the Pesticide mixture. Not only did the Degradation of the parent compound improve but also that of the produced metabolites and compound mineralisation. The time to achieve maximum Degradation/mineralisation capacity depended on the Pesticide Degradation capacity of the Pesticide-primed materials. CONCLUSIONS The data obtained show that the addition of Pesticide-primed materials into the matrix of a BPS as an approach to improve bioDegradation can be extended to the treatment of Pesticide mixtures. © 2014 Society of Chemical Industry
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minimal Pesticide primed soil inoculum density to secure maximum Pesticide Degradation efficiency in on farm biopurification systems
Chemosphere, 2012Co-Authors: Kristel Sniegowski, Karolien Bers, Jaak Ryckeboer, Peter Jaeken, Pieter Spanoghe, Dirk SpringaelAbstract:Abstract Addition of Pesticide-primed soil containing adapted Pesticide degrading bacteria to the biofilter matrix of on farm biopurification systems (BPS) which treat Pesticide contaminated wastewater, has been recommended, in order to ensure rapid establishment of a Pesticide degrading microbial community in BPS. However, uncertainties exist about the minimal soil inoculum density needed for successful bioaugmentation of BPS. Therefore, in this study, BPS microcosm experiments were initiated with different linuron primed soil inoculum densities ranging from 0.5 to 50 vol.% and the evolution of the linuron mineralization capacity in the microcosms was monitored during feeding with linuron. Successful establishment of a linuron mineralization community in the BPS microcosms was achieved with all inoculum densities including the 0.5 vol.% density with only minor differences in the time needed to acquire maximum Degradation capacity. Moreover, once established, the robustness of the linuron degrading microbial community towards expected stress situations proved to be independent of the initial inoculum density. This study shows that Pesticide-primed soil inoculum densities as low as 0.5 vol.% can be used for bioaugmentation of a BPS matrix and further supports the use of BPS for treatment of Pesticide-contaminated wastewater at farmyards.
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monod kinetics rather than a first order Degradation model explains atrazine fate in soil mini columns implications for Pesticide fate modelling
Environmental Pollution, 2010Co-Authors: Karlien Cheyns, Jan Mertens, Jan Diels, Erik Smolders, Dirk SpringaelAbstract:Pesticide transport models commonly assume first-order Pesticide Degradation kinetics for describing reactive transport in soil. This assumption was assessed in mini-column studies with associated batch Degradation tests. Soil mini-columns were irrigated with atrazine in two intermittent steps of about 30 days separated by 161 days application of artificial rain water. Atrazine concentration in the effluent peaked to that of the influent concentration after initial break-through but sharply decreased while influx was sustained, suggesting a Degradation lag phase. The same pattern was displayed in the second step but peak height and percentage of atrazine recovered in the effluent were lower. A Monod model with biomass decay was successfully calibrated to this data. The model was successfully evaluated against batch Degradation data and mini-column experiments at lower flow rate. The study suggested that first-order Degradation models may underestimate risk of Pesticide leaching if the Pesticide Degradation potential needs amplification during Degradation.
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inverse modeling of Pesticide Degradation and Pesticide degrading population size dynamics in a bioremediation system parameterizing the monod model
Chemosphere, 2009Co-Authors: Kristel Sniegowski, Jan Mertens, Jan Diels, Erik Smolders, Dirk SpringaelAbstract:Abstract Pesticide Degradation models are compared which simulate the response of biofilters for treatment of Pesticide-contaminated waste water to time-irregular Pesticide supply in which the Pesticide is used for growth and mineralized. Biofilter microcosms containing a mixture of straw, peat and soil and harboring micropopulations which uses the herbicide linuron for growth, were irrigated with linuron for 28 weeks with a stop in its supply between week 12 and 17. Matrix samples were regularly taken to assay linuron mineralization. A first-order approximation of the Monod model was used to simulate the observed mineralization data, while an inverse modeling framework combining a sensitivity analysis (Morris Sensitivity Analysis) with an inverse modeling approach (Shuffled Complex Evolution Metropolis) adopted to parameterize the model. Lag times in linuron mineralization decreased during the initial weeks of linuron irrigation but increased after supply of linuron ceased. The model well-simulated the lag time dynamics which were related to the dynamics of the predicted linuron-degrading population size in the microcosms. It was predicted that the population size decreased at a rate of 0.031 d −1 after Pesticide supply ceased to reach its initial population size after 25 weeks. We conclude that modeling Pesticide Degradation in biofilters should incorporate biomass dynamics in case the Pesticide is used as C-source. First-order approaches without incorporating biomass dynamics could lead to underestimation of the risk of Pesticide leaching.
M Subrahmanyam - One of the best experts on this subject based on the ideXlab platform.
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an efficient and novel porous nanosilica supported tio2 photocatalyst for Pesticide Degradation using solar light
Journal of Hazardous Materials, 2009Co-Authors: Mangalampalli Phanikrishna V Sharma, Gullapelli Sadanandam, A Ratnamala, Valluri Durga Kumari, M SubrahmanyamAbstract:Abstract A latex polymer of styrene–acrylic acid emulsion is used as a template for the synthesis of novel porous nanosilica (PNS) material. TiO 2 is dispersed over PNS by solid state dispersion and the composite materials are characterized by XRD, nitrogen adsorption–desorption isotherms, SEM and TEM measurements. The photocatalytic activities of the composite TiO 2 /PNS catalysts are evaluated for Degradation of isoproturon Pesticide in water with different parameters under solar light. Furthermore, commercial Pesticide solutions containing imidacloprid and phosphamidon were also degraded successfully with the composite system using the same developed conditions for isoproturon Degradation. The 5 wt% TiO 2 /PNS is found to be active in the present investigation.
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tio2 supported over sba 15 an efficient photocatalyst for the Pesticide Degradation using solar light
Chemosphere, 2008Co-Authors: M Phanikrishna V Sharma, Durga V Kumari, M SubrahmanyamAbstract:Abstract Photocatalytic Degradation and mineralization of Pesticides are studied over TiO2 supported mesoporous SBA-15 composite system using solar light. TiO2 is immobilized over SBA-15 by solid sate dispersion method. The catalysts are characterized by XRD, surface area, UV–Vis diffused reflectance spectra, SEM and TEM. The detailed photocatalytic Degradation studies are carried out over TiO2, SBA-15 and different TiO2 wt% supported SBA-15. The activity evaluation parameters such as catalyst amount, pH, and pollutant initial concentration are studied taking isoproturon as a model compound and established conditions for Pesticide Degradation. The optimum Degradation is achieved over 10 wt% TiO2/SBA-15 within 30 min and the reaction is following pseudo-first order kinetics. The isoproturon mineralization is monitored with TOC reduction and it takes around 9 h for disappearance. The commercial Pesticide solutions containing imidacloprid and phosphamidon are also successfully degraded over these composites with the established conditions. The data indicates that 10 wt% TiO2/SBA-15 composite is an effective and highly active system for the Pesticide Degradations.
Angel Montoya - One of the best experts on this subject based on the ideXlab platform.
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development of an enzyme linked immunosorbent assay for 3 5 6 trichloro 2 pyridinol 2 assay optimization and application to environmental water samples
Journal of Agricultural and Food Chemistry, 1996Co-Authors: Juan J Manclus, Angel MontoyaAbstract:A monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) for 3,5,6-trichloro-2-pyridinol (TCP), the major Degradation product of chlorpyrifos, chlorpyrifos-methyl, and triclopyr Pesticides, was optimized for the analysis of this hydrophilic compound in water. A direct ELISA format was chosen, and the concentration of immunoreagents was first selected to provide the highest sensitivity. Next, the influence of several physical (temperature, time) and chemical (pH, salt, detergent) conditions was studied. Under optimized conditions, the TCP concentration giving 50% reduction of the maximum ELISA signal (I 50 ) in the competitive standard curve was 0.62 nM (0.12 μg/L), and the assay was very specific for TCP. Preliminary evaluation of assay performance in water samples showed the absence of significant matrix effects for the waters tested, whenever the ionic strength of samples was approximately adjusted to that of standards. The assay provides a limit of detection of 0.04 μg/L and a working range of 0.09-0.91 μg/L TCP and allows for a precise and accurate determination of this Pesticide Degradation product in water at levels as low as 0.1 μg/L without sample cleanup.
N N Misra - One of the best experts on this subject based on the ideXlab platform.
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Atmospheric Pressure Cold Plasma as a Potential Technology to Degrade Carbamate Residues in Water
Plasma Chemistry and Plasma Processing, 2020Co-Authors: Rkia Moutiq, S. K. Pankaj, Aubrey Mendonca, Kevin Keener, N N MisraAbstract:Cold plasma technology is an advanced oxidation process (AOP), which has shown significant potential for Pesticide Degradation. The aim of this study was to determine the Degradation efficacy and transformation products for cold plasma treated carbamates in water. The dissipation of three carbamates, namely, carbaryl, methiocarb and aminocarb were evaluated as a function of treatment voltage (70, 80, and 90 kV) and duration (1 to 5 min) using a dielectric barrier discharge. Significant and rapid reduction in the concentrations of carbaryl, methiocarb and aminocarb were observed after cold plasma treatment. A maximum Degradation of 50.5% in carbaryl, 99.6% in methiocarb and 99.3% in aminocarb was achieved after 5 min of treatment at an applied voltage of 90 kV. The plasma light emission was evaluated using optical emission spectroscopy revealing the production of reactive oxygen and nitrogen species, besides gas temperatures closer to ambient. The reaction intermediates were identified mostly as oxidation products from the respective carbamates, and reaction pathways were proposed. The toxicity of the Degradation products, where available, was reviewed. Overall, this study shows the potential of cold plasma technology as an alternative approach for rapid dissipation of agrochemicals and other micro-pollutants in water and wastewater.
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Pesticide Degradation in water using atmospheric air cold plasma
Journal of water process engineering, 2016Co-Authors: Chaitanya Sarangapani, N N Misra, Vladimir Milosavljevic, Paula Bourke, Finbarr Oregan, P J CullenAbstract:Abstract A high voltage dielectric barrier discharge plasma reactor using atmospheric air as the inducer gas was studied for the Degradation of Pesticides (dichlorvos, malathion, endosulfan) in water. The Degradation kinetics of the Pesticides were studied using GC–MS as a function of plasma control parameters. Electrical characterisation of the plasma revealed that the plasma discharge consisted of filamentary streamers. Excited nitrogen, reactive oxygen species and OH radicals generated in the dielectric barrier discharge (DBD) plasma reactor were identified using optical emission spectroscopy. Ozone, used as an indicator for metastable oxygen species, was quantified within the reactor at concentrations of 1600, 2200, 2800 ppm after 8 min of plasma treatment for applied voltages of 60, 70, and 80 kV respectively. The Degradation efficacy of Pesticides after 80 kV and 8 min of plasma treatment were found to be 78.98 ± 0.81% for dichlorvos, 69.62 ± 0.14% for malathion and 57.71 ± 0.58% for endosulfan. Degradation was found to follow first order kinetics. GC–MS analyses showed that the degraded compounds and intermediates formed were less toxic than the parent Pesticide. A proposed mechanism of Degradation of these Pesticides is suggested.
Samina Iqbal - One of the best experts on this subject based on the ideXlab platform.
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bioDegradation of chlorpyrifos and its hydrolysis product 3 5 6 trichloro 2 pyridinol by bacillus pumilus strain c2a1
Journal of Hazardous Materials, 2009Co-Authors: Samina Anwar, Fauzia Liaquat, Qaiser M Khan, Zafar M Khalid, Samina IqbalAbstract:Abstract A bacterial strain C2A1 isolated from soil was found highly effective in degrading chlorpyrifos and its first hydrolysis metabolite 3,5,6-trichloro-2-pyridinol (TCP). On the basis of morphology, physiological characteristics, biochemical tests and 16S rRNA sequence analysis, strain C2A1 was identified as Bacillus pumilus . Role of strain C2A1 in the Degradation of chlorpyrifos was examined under different culture conditions like pH, inoculum density, presence of added carbon/nutrient sources and Pesticide concentration. Chlorpyrifos was utilized by strain C2A1 as the sole source of carbon and energy as well as it was co-metabolized in the presence of glucose, yeast extract and nutrient broth. Maximum Pesticide Degradation was observed at high pH (8.5) and high inoculum density when chlorpyrifos was used as the sole source and energy. In the presence of other nutrients, chlorpyrifos Degradation was enhanced probably due to high growth on easily metabolizable compounds which in turn increased Degradation. The strain C2A1 showed 90% Degradation of TCP (300 mg L −1 ) within 8 days of incubation.