scholarly journals Kinetic Study of the Biodegradation of Acephate by Indigenous Soil Bacterial Isolates in the Presence of Humic Acid and Metal Ions

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 433 ◽  
Author(s):  
Simranjeet Singh ◽  
Vijay Kumar ◽  
Sourav Singla ◽  
Minaxi Sharma ◽  
Dhananjaya P. Singh ◽  
...  
Keyword(s):  
Humic Acid ◽  
Metal Ions ◽  
Contaminated Soils ◽  
Mass Spectrometry Analysis ◽  
Bacterial Strains ◽  
Spectrometry Analysis ◽  
First Order ◽  
First Order Kinetics ◽  
Degradation Rates ◽  
Uv Visible

Many bacteria have the potential to use specific pesticides as a source of carbon, phosphorous, nitrogen and sulphur. Acephate degradation by microbes is considered to be a safe and effective method. The overall aim of the present study was to identify acephate biodegrading microorganisms and to investigate the degradation rates of acephate under the stress of humic acid and most common metal ions Fe(III) and copper Cu(II). Pseudomonas azotoformanss strain ACP1, Pseudomonas aeruginosa strain ACP2, and Pseudomonas putida ACP3 were isolated from acephate contaminated soils. Acephate of concentration 100 ppm was incubated with separate strain inoculums and periodic samples were drawn for UV—visible, FTIR (Fourier-transform infrared spectroscopy) and MS (Mass Spectrometry) analysis. Methamidophos, S-methyl O-hydrogen phosphorothioamidate, phosphenothioic S-acid, and phosphenamide were the major metabolites formed during the degradation of acephate. The rate of degradation was applied using pseudo-first-order kinetics to calculate the half-life (t1/2) values, which were 14.33–16.72 d−1 (strain(s) + acephate), 18.81–21.50 d−1 (strain(s) + acephate + Cu(II)), 20.06 –23.15 d−1 (strain(s) + acephate + Fe(II)), and 15.05–17.70 d−1 (strains + acephate + HA). The biodegradation efficiency of the three bacterial strains can be ordered as P. aeruginosa > P. putida > P. azotoformans. The present study illustrated the decomposition mechanism of acephate under different conditions, and the same may be applied to the removal of other xenobiotic compounds.

Biodegradation rates of aromatic contaminants in biofilm reactors

1995 ◽  
Vol 31 (1) ◽  
pp. 117-128 ◽  
Author(s):  
Jean-Pierre Arcangeli ◽  
Erik Arvin
Keyword(s):  
Aromatic Hydrocarbons ◽  
Competitive Inhibition ◽  
Removal Rate ◽  
First Order ◽  
Biofilm Reactors ◽  
First Order Kinetics ◽  
Reducing Conditions ◽  
Low Concentrations ◽  
Degradation Rates ◽  
Order Surface

This study has shown that microorganisms can adapt to degrade mixtures of aromatic pollutants at relatively high rates in the μg/l concentration range. The biodegradation rates of the following compounds were investigated in biofilm systems: aromatic hydrocarbons, phenol, methylphenols, chlorophenols, nitrophenol, chlorobenzenes and aromatic nitrogen-, sulphur- or oxygen-containing heterocyclic compounds (NSO-compounds). Furthermore, a comparison with degradation rates observed for easily degradable organics is also presented. At concentrations below 20-100 μg/l the degradation of the aromatic compounds was typically controlled by first order kinetics. The first-order surface removal rate constants were surprisingly similar, ranging from 2 to 4 m/d. It appears that NSO-compounds inhibit the degradation of aromatic hydrocarbons, even at very low concentrations of NSO-compounds. Under nitrate-reducing conditions, toluene was easily biodegraded. The xylenes and ethylbenzene were degraded cometabolically if toluene was used as a primary carbon source; their removal was influenced by competitive inhibition with toluene. These interaction phenomena are discussed in this paper and a kinetic model taking into account cometabolism and competitive inhibition is proposed.

Biodegradation of phorate by bacterial strains in the presence of humic acid and metal ions

2021 ◽  
Author(s):  
Simranjeet Singh ◽  
Vijay Kumar ◽  
Amith G. Anil ◽  
Romina Romero ◽  
Praveen C. Ramamurthy ◽  
...  
Keyword(s):  
Humic Acid ◽  
Metal Ions ◽  
Bacterial Strains

scholarly journals Composition of Soil Microbial Communities Enriched on a Mixture of Aromatic Hydrocarbons

2000 ◽  
Vol 66 (12) ◽  
pp. 5282-5289 ◽  
Author(s):  
E. Anne Greene ◽  
Jason G. Kay ◽  
Karim Jaber ◽  
Les G. Stehmeier ◽  
Gerrit Voordouw
Keyword(s):  
Aromatic Hydrocarbons ◽  
Contaminated Soils ◽  
Soil Microbial Communities ◽  
Time Dependent ◽  
Community Members ◽  
First Order ◽  
Soil Microbial ◽  
Benzene Degradation ◽  
First Order Kinetics ◽  
Genomic Dnas

ABSTRACT Soil contaminated with C5+, which contained benzene (45%, wt/wt), dicyclopentadiene (DCPD) plus cyclopentadiene (together 20%), toluene (6%), styrene (3%), xylenes (2%), naphthalene (2%), and smaller quantities of other compounds, served as the source for isolation of 55 genomically distinct bacteria (standards). Use of benzene as a substrate by these bacteria was most widespread (31 of 44 standards tested), followed by toluene (23 of 44), xylenes (14 of 44), styrene (10 of 44), and naphthalene (10 of 44). Master filters containing denatured genomic DNAs of all 55 standards were used to analyze the community compositions of C5+ enrichment cultures by reverse sample genome probing (RSGP). The communities enriched from three contaminated soils were similar to those enriched from three uncontaminated soils from the same site. The compositions of these communities were time dependent and showed a succession of Pseudomonas andRhodococcus spp. before convergence on a composition dominated by Alcaligenes spp. The dominant community members detected by RSGP were capable of benzene degradation at all stages of succession. The enrichments effectively degraded all C5+ components except DCPD. Overall, degradation of individual C5+ hydrocarbons followed first-order kinetics, with the highest rates of removal for benzene.

Improvement in carbofuran degradation by different Fenton’s reagent dosing processes

2011 ◽  
Vol 27 (10) ◽  
pp. 934-944 ◽  
Author(s):  
Ying-Shih Ma
Keyword(s):  
Rate Constants ◽  
Degradation Products ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Fenton’S Reagent ◽  
Fenton's Reagent ◽  
Spectrometry Analysis ◽  
Toc Removal ◽  
First Order Kinetics ◽  
Made In

Attempts were made in this study to examine the efficiency of Fenton’s reagent with different dosing processes and H2O2 and Fe2+ concentrations for the treatment of carbofuran wastewater. Carbofuran degradation, total organic carbon (TOC) removal and H2O2 consumption were determined during the experiments. Increases in H2O2 and Fe2+ concentrations led to an increase in the degradation of carbofuran. Almost 100% of carbofuran could be degraded at pH 3, 120 mg L-1 H2O2, 24 mg L-1 Fe2+ and 30 minutes reaction time; removals of TOC were among 48.8%–53.3% under different dosing processes. A continuous dosing process was beneficial to improve the removal of TOC by Fenton’s reagent. Rate constants of carbofuran degradation could be calculated by the first-order kinetics; increase in the Fenton’s reagent generally increased the rate constants. Gas chromatography-mass spectrometry analysis found five degradation products by hydroxyl radicals attack. Thus, this study might offer an effective dosing way for carbofuran wastewater treatment by Fenton’s reagent.

scholarly journals Isolation, Screening, and Characterization of Antibiotic-Degrading Bacteria for Penicillin V Potassium (PVK) from Soil on a Pig Farm

2019 ◽  
Vol 16 (12) ◽  
pp. 2166 ◽  
Author(s):  
Xuanjiang Yang ◽  
Miao Li ◽  
Panpan Guo ◽  
Hualong Li ◽  
Zelin Hu ◽  
...  
Keyword(s):  
Contaminated Soils ◽  
Antibiotic Sensitivity ◽  
Animal Husbandry ◽  
Farm Animals ◽  
Bacterial Strains ◽  
Penicillin V ◽  
Degradation Rates ◽  
Antibiotic Susceptibility Test ◽  
Degrading Bacteria ◽  
Pig Farm

(1) Background: Antibiotics are frequently used on farm animals, making animal husbandry a relatively large source of antibiotic pollution of the environment. The present study aims to isolate and acclimatize antibiotic-degrading bacterial strains for penicillin V potassium (PVK) from the contaminated soil of a pig farm. (2) Methods: Bacterial strains were isolated and acclimatized by continuous enrichment of cultures with PVK as the sole carbon source. The antibiotic susceptibility test, thiol mercury salt ultraviolet spectrophotometry (TMSUS), morphological observations, and 16S rDNA sequence analysis were used to identify and characterize the isolated strains. (3) Results: Four bacterial isolates (denoted as LM-1, LM-2, LM-3, LM-4) were obtained, and two of them (LM-1, LM-2) with the highest degradation rates were identified to belong to the same genera as Bacillus. These two isolates were found to be resistant to PVK antibiotic in an antibiotic sensitivity test. The TMSUS indicated that the strains LM-1 and LM-2 had good performance in PVK degradation (68% for LM-1, 66% for LM-2 in 48 h) when the initial PVK concentration was about 100 μg/mL. (4) Conclusions: Two bacterial strains isolated from the soil on a pig farm are effective in degrading PVK and can be potentially used for bioremediation of PVK antibiotic-contaminated soils.

scholarly journals Efficient degradation of naproxen by persulfate activated with zero-valent iron: performance, kinetic and degradation pathways

2020 ◽  
Vol 81 (10) ◽  
pp. 2078-2091
Author(s):  
Shuyu Dong ◽  
Xiaoxue Zhai ◽  
Ruobing Pi ◽  
Jinbao Wei ◽  
Yunpeng Wang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Hydroxyl Radical ◽  
Rate Constants ◽  
Zero Valent Iron ◽  
Degradation Pathways ◽  
First Order ◽  
First Order Kinetics ◽  
Degradation Rates ◽  
Initial Ph ◽  
Pseudo First Order

Abstract Degradation of naproxen (NAP) by persulfate (PS) activated with zero-valent iron (ZVI) was investigated in our study. The NAP in aqueous solution was degraded effectively by the ZVI/PS system and the degradation exhibited a pseudo-first-order kinetics pattern. Both sulfate radical (SO4•−) and hydroxyl radical (HO•) participate in the NAP degradation. The second-order rate constants for NAP reacting with SO4•− and HO• were (5.64 ± 0.73) × 109 M−1 s−1 and (9.05 ± 0.51) × 109 M−1 s−1, respectively. Influence of key parameters (initial pH, PS dosage, ZVI dosage, and NAP dosage) on NAP degradation were evaluated systematically. Based on the detected intermediates, the pathways of NAP degradation in ZVI/PS system was proposed. It was found that the presence of ammonia accelerated the corrosion of ZVI and thus promoted the release of Fe2+, which induced the increased generation of sulfate radicals from PS and promoted the degradation of NAP. Compared to its counterpart without ammonia, the degradation rates of NAP by ZVI/PS were increased to 3.6–17.5 folds and 1.2–2.2 folds under pH 7 and pH 9, respectively.

scholarly journals Modeling the Effect of Plants and Peat on Evapotranspiration in Constructed Wetlands

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Florent Chazarenc ◽  
Simon Naylor ◽  
Yves Comeau ◽  
Gérard Merlin ◽  
Jacques Brisson
Keyword(s):  
Phragmites Australis ◽  
Constructed Wetlands ◽  
Typha Latifolia ◽  
Growth Conditions ◽  
First Order ◽  
First Order Kinetics ◽  
Hydraulic Behaviour ◽  
Degradation Rates ◽  
Wide Range ◽  
Main Effect

Evapotranspiration (ET) in constructed wetlands (CWs) represents a major factor affecting hydrodynamics and treatment performances. The presence of high ET was shown to improve global treatment performances, however ET is affected by a wide range of parameters including plant development and CWs age. Our study aimed at modelling the effect of plants and peat on ET in CWs; since we hypothesized peat could behave like the presence of accumulated organic matter in old CWs. Treatment performances, hydraulic behaviour, and ET rates were measured in eight 1 m2CWs mesocosm (1 unplanted, 1 unplanted with peat, 2 planted withPhragmites australis, 2 planted withTypha latifoliaand 2 planted withPhragmites australiswith peat). Two models were built using first order kinetics to simulate COD and TKN removal with ET as an input. The effect of peat was positive on ET and was related to the better growth conditions it offered to macrophytes. Removal efficiency in pilot units with larger ET was higher for TKN. On average, results show for COD ak20value of 0.88d-1and 0.36d-1for TKN. We hypothesized that the main effect of ET was to concentrate effluent, thus enhancing degradation rates.

scholarly journals Diversity of 4-Chloro-2-nitrophenol-Degrading Bacteria in a Waste Water Sample

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Pankaj Kumar Arora ◽  
Alok Srivastava ◽  
Vijay Pal Singh
Keyword(s):  
Waste Water ◽  
Water Sample ◽  
Mass Spectrometry Analysis ◽  
Contaminated Site ◽  
Gas Chromatography Mass Spectrometry ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Spectrometry Analysis ◽  
Waste Water Sample ◽  
Degrading Bacteria

Eighteen bacterial strains, isolated from a waste water sample collected from a chemically contaminated site, Patancheru (17°32′N 78°16′E/17.53°N 78.27°E), India, were able to decolorize 4-chloro-2-nitrophenol (4C2NP) in the presence of an additional carbon source. These eighteen 4C2NP-decolorizing strains have been identified as members of four different genera, includingBacillus,Paenibacillus,Pseudomonas, andLeuconostocbased on the 16S rRNA gene sequencing and phylogenetic analysis. Most of the bacteria (10) belonged to the genusBacillusand contributed 56% of the total 4C2NP-degrading bacteria, whereas the members of generaPaenibacillusandPseudomonasrepresented 22% and 17%, respectively, of total 4C2NP-degrading isolates. There was only one species ofLeuconostoccapable of degrading 4C2NP. This is the first report of the diversity of 4C2NP-decolorizing bacteria in a waste water sample. Furthermore, one bacterium,Bacillus aryabhattaistrain PC-7, was able to decolorize 4C2NP up to a concentration of 2.0 mM. Gas chromatography-mass spectrometry analysis identified 5-chloro-2-methylbenzoxazole as the final product of 4C2NP decolorization in strain PC-7.

scholarly journals Biodegradation of Polyethoxylated Nonylphenols

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yassellis Ruiz ◽  
Luis Medina ◽  
Margarita Borusiak ◽  
Nairalith Ramos ◽  
Gilberto Pinto ◽  
...  
Keyword(s):  
Degradation Products ◽  
Life Time ◽  
Viscosity Data ◽  
Natural Environments ◽  
Maximal Growth ◽  
Bacterial Strains ◽  
Kinetic Rate Constant ◽  
Kinetic Rate ◽  
First Order ◽  
First Order Kinetics

Polyethoxylated nonylphenols, with different ethoxylation degrees (), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native and its derivatives. In this paper, the isolation of five bacterial strains, capable of using , as unique carbon source, is described. The most efficient degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% medium. The degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant () and half life time () for this biotransformation were estimated to be 0.0072 h−1 and 96.3 h, respectively.

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