Faculty Publications
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Item 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 LtdItem Bioleaching of iron from laterite soil using an isolated Acidithiobacillus ferrooxidans strain and application of leached laterite iron as Fenton’s catalyst in selective herbicide degradation(Public Library of Science, 2021) Bhaskar, S.; Manu, B.; Sreenivasa, M.Y.A novel isolated strain Acidithiobacillus ferrooxidans BMSNITK17 has been investigated for its bioleaching potential from lateritic soil and the results are presented. System conditions like pH, feed mineral particle size, pulp density, temperature, rotor speed influences bioleaching potential of Acidithiobcillus ferrooxidans BMSNITK17 in leaching out iron from laterite soil. Effect of sulfate addition on bioleaching efficiency is studied. The bioleached laterite iron (BLFe’s) on evaluation for its catalytic role in Fenton’s oxidation for the degradation of ametryn and dicamba exhibits 94.24% of ametryn degradation and 92.45% of dicamba degradation efficiency. Fenton’s oxidation performed well with the acidic pH 3. The study confirms the role of Acidithiobacillus ferrooxidans in leaching iron from lateritic ore and the usage of bioleached lateritic iron as catalyst in the Fenton’s Oxidation. © 2021 S et al.Item Fenton and Sono-Fenton degradation of selective herbicides in water using bioleached Fe-Cu bimetallic nanoparticles (BFe-CuNPs)(Springer Science and Business Media Deutschland GmbH, 2025) Bhaskar, S.; Ashraf, S.; Apoorva, K.V.Bimetallic nanoparticles offer an innovative solution for treating water and wastewater systems using a heterogeneous Fenton-like process. This study investigates the synthesis of iron-copper bimetallic nanoparticles using bioleached iron and copper as precursors and evaluates their performance in the degradation of selective herbicides ametryn and dicamba by Fenton’s oxidation and Sono-Fenton’s oxidation. Bioleaching experiments were conducted separately for iron and copper leaching from laterite ore and chalcocite ore, respectively, using isolated Acidithiobacillus ferrooxidans bacterial strain. Acidothiobacillus ferrooxidans, a chemolithoautotrophic bacterium oxidizes ferrous iron and reduced sulfur compounds, generating sulfuric acid playing a crucial role in the solubilization of iron from laterite ore and copper from chalcocite. In the case of laterite ore, the bacterium’s iron oxidation activity helps release iron from the mineral matrix, making it more accessible for extraction. Similarly, with chalcocite, A. ferrooxidans facilitates the dissolution of copper from chalcocite (Cu2S) through its sulfur-oxidizing capabilities. The synthesized bimetallic nanoparticles were characterized using various techniques, including SEM, XRD, EDS, FTIR, and BET analysis. Fenton’s oxidation and Sono-Fenton’s oxidation of mixture ametryn and dicamba in a solution catalyzed by the bioleached Fe-Cu bimetallic nanoparticles were found to be effective, with ametryn degradation reaching 96.4% and 94.2%, and dicamba degradation reaching 98.1% and 99.3%, respectively, at a catalyst loading of 0.5 g/L. The removal efficiency increased with increasing catalyst loading up to 0.5 g/L and increasing H2O2 dosage up to 500 mg/L. Sono-Fenton’s oxidation led to higher COD reduction of 78.41% compared to conventional Fenton oxidation 70.42% with a reaction rate of 0.039/Min and 0.0053/Min respectively. The study demonstrates the potential of bioleached iron-copper bimetallic nanoparticles as a sustainable replacement for commercial catalysts in the oxidative degradation of herbicides. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2025.