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Author: search.filters.author.Manu, B.Subject: search.filters.subject.bacterium

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    Bacteriological synthesis of iron hydroxysulfate using an isolated Acidithiobacillus ferrooxidans strain and its application in ametryn degradation by Fenton's oxidation process
    (Academic Press, 2019) Bhaskar, S.; Manu, B.; Sreenivasa, M.Y.
    The investigation reports the application of biogenic jarosite, an iron hydroxy sulfate mineral in Fenton's Oxidation process. Ametryn, a herbicide detrimental to aquatic life and also to human is treated by Fenton's oxidation process using synthesized iron mineral, jarosite. The jarosite synthesis was carried out by using an isolated Acidithiobacillus ferrooxidans bacterial strain with ferrous as an iron supplement. The isolated strain was characterized by molecular techniques and biooxidation activity to ferrous to ferric iron was checked. On Fenton's treatment ametryn degradation upto 84.9% and COD removal to the extent of 56.1% was observed within 2 h of treatment and the reaction follows the pseudo first order kinetics with the curve best fit. The slight increase in kinetic rate constant on jarosite loading rate increase from 0.1 g/L to 0.5 g/L with H2O2 dosage of 100 mg/L confirms that jarosite has a catalytic role in the removal of ametryn. Mass spectroscopy analysis of treated synthetic ametryn solution at various intervals reveal the degradation follows dealkylation and hydroxylation pathway with the formation of three major intermediate compounds discussed here. © 2018 Elsevier Ltd
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    Biological Treatment of 3,6-Dichloro-2-Methoxybenzoic Acid Using Anaerobic-Aerobic Sequential Batch Reactor
    (Springer Basel info@birkhauser-science.com, 2019) Mahesh, G.B.; Manu, B.
    A sequential anaerobic-aerobic batch reactor was used to treat 3,6-dichloro-2-methoxybenzoic acid (dicamba) during a long operation period of 340 days in the presence of disodium anthraquinone-2,6-disulphonate (AQS) as redox mediator. The sludge activity was evaluated for different dosages of dicamba over constant hydraulic retention time (HRT), neutral pH (6.5–7.5) and at ambient reactor temperature. Effects of increased dicamba concentration, solids retention time (SRT) and oxidation reduction potential (ORP) on the biodegradation of dicamba was monitored and compared with control reactor containing no dicamba. Results revealed that long operation period, long SRT and ORP were playing important role in the breakdown of dicamba to its transformation products and subsequent removal in the system. The system was capable of degrading the compound completely during long operation period, long SRT and at low ORP in the presence of AQS. Reducing condition in the anaerobic reactor significantly contributed to the treatment process through demethylation, dehalogenation and dechlorination reactions in the presence of different reducing bacteria. The results of GC-HRMS identified the anaerobic transformation products of dicamba as oleic acid (C18H34O2), 9-Octadecenoic acid (Z), 2-hydroxy-1-(hydroxymethyl)ethyl ester (C21H40O4), trans-13-Ocatadecenoic acid (C18H34O2) compounds which were then oxidised in the aerobic reactor. © 2019, Springer Nature Switzerland AG.