Faculty Publications
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Publications by NITK Faculty
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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 Sustainable replacement of EDTA–Biojarosite for commercial iron in the Fenton’s and UV–Fenton’s degradation of Rhowedamine B – a process optimization using Box–Behnken method(IWA Publishing, 2022) Bhaskar, S.; Rashmishree, K.N.; Manu, B.; Sreenivasa, M.Y.Biojarosite as a replacement for commercial iron catalyst in the oxidative degradation of the dye Rhodamine B was confirmed and established. Investigations on the oxidative degradation by Fenton’s oxidation and UV–Fenton’s oxidation with EDTA at neutral pH were conducted and degradation of target compound was evaluated. UV–Fenton’s oxidation was shown to be efficient over Fenton’s oxidation in the degradation of Rhodamine B with removal efficiency of 90.0%. Design of Experiments was performed with Box–Behnken design. Investigation was conducted for the predicted values separately for both Fenton’s oxidation and UV–Fenton’s oxidation and the Rhodamine B removal was taken as response. Variable parameters biojarosite, H2O2 dosage and EDTA were optimized in the range of 0.1–1 g/L, 2.94–29.4 mM and 10–100 mM, respectively. A quadratic regression model is fitted for both Fenton’s and UV–Fenton’s oxidation. Analysis of variance (ANOVA) is performed and model fit is discussed. © 2022 The Authors.Item Extraction of iron from laterite soil and green synthesis of laterite nano iron catalyst (GLaNICs) for its application as Fenton's catalyst in the degradation of triclosan(IWA Publishing, 2022) Rashmishree, K.N.; Bhaskar, S.; Shrihari, S.; Thalla, A.K.Laterite based nano iron particles were synthesized using natural laterite extract as a precursor and Psidium guajava plant extract for its application as Fenton's catalyst in the degradation of triclosan. Chemical digestion method was used for the extraction of iron from laterite soil. Synthesized nano iron catalyst was characterized using SEM-EDS, XRD and FTIR and evaluated for its catalytic application in the Fenton's oxidation of triclosan. Maximum triclosan degradation of 69.5% was observed with nano iron catalyst dosage of 0.1 g/L and hydrogen peroxide dosage of 200 mg/L at acidic pH of 3. Hydrogen peroxide influence on the process was observed with Fenton's oxidation. Role of iron in the process has been accessed by control experiment with no nano catalyst addition in which degradation is considerably low. Fenton's oxidation was compared with conventional Fenton's oxidation driven by a green nano iron catalyst. Study claims the usage of natural laterite iron as a replacement for commercial iron in Fenton's degradation of triclosan. Regeneration and reusability studies on catalyst were studied and synthesized catalyst was observed to be reusable in three consecutive cycles. Degradation of triclosan in Fenton's oxidation follows pseudo-second order reaction with linear fit. © 2022 The Authors.Item Green synthesis of granular activated carbon/zinc ferro nanocomposites-based bioleached laterite iron (BLaFe) for the removal of Rhodamine B in water using adsorption–Fenton’s oxidation process(IWA Publishing, 2023) Bhaskar, S.; Rashmishree, K.N.; Manu, B.; Sreenivasa, M.Y.Novel cost-effective catalyst granular activated carbon (GAC)-based zinc ferro nanocomposites for the heterogeneous Fenton’s oxidation of dye were synthesized using bioleached laterite iron (BLFe) as a precursor and Psidium gujava leaf extract. Synthesized nanocomposites were characterized using SEM, EDS, XRD and BET surface area analysis. The degradation of Rhodamine dye was carried out with nanocomposites using adsorption–Fenton’s oxidation process. The catalytic role of nano-composites in Fenton’s oxidation of Rhodamine B (RhB) was investigated and reported. The maximum dye removal of 96.2% was observed with 64.2% COD removal within 200 min of treatment. An increase in nanocomposite dosage has a positive effect on dye removal marking 5 g/L as an optimum dosage. Adsorption studies reveal that RhB removal using BLFe-based GAC/zinc ferro composites fits the Freundlich Adsorption Isotherm model with an adsorption capacity of 47.81 mg/g. A com-bination of adsorption and Fenton’s oxidation has resulted in higher removal efficiency with nanocomposite material. Reusability studies confirm that the spent catalyst can be reused for five cycles. © 2023 The Authors.Item Synthesis of plant-based biogenic jarosite nanoparticles using Azadirachta indica and Eucalyptus gunni leaf extracts and its application in Fenton degradation of dicamba(Editorial Office of Water Science and Engineering, 2024) Bhaskar, S.; Manu, B.; Sreenivasa, M.Y.; Manoj, A.Bio-jarosite, an iron mineral synthesized biologically using bacteria, is a substitute for iron catalysts in the Fenton oxidation of organic pollutants. Iron nanocatalysts have been widely used as Fenton catalysts because they have a larger surface area than ordinary catalysts, are highly recyclable, and can be treated efficiently. This study aimed to explore the catalytic properties of bio-jarosite iron nanoparticles synthesized with green methods using two distinct plant species: Azadirachta indica and Eucalyptus gunni. The focus was on the degradation of dicamba via Fenton oxidation. The synthesized nanoparticles exhibited different particle size, shape, surface area, and chemical composition characteristics. Both particles were effective in removing dicamba, with removal efficiencies of 96.8% for A. indica bio-jarosite iron nanoparticles (ABFeNPs) and 93.0% for E. gunni bio-jarosite iron nanoparticles (EBFeNPs) within 120 min of treatment. Increasing the catalyst dosage by 0.1 g/L resulted in 7.6% and 43.0% increases in the dicamba removal efficiency for EBFeNPs and ABFeNPs with rate constants of 0.025 min−1 and 0.023 min−1, respectively, confirming their catalytic roles. Additionally, the high efficiency of both catalysts was demonstrated through five consecutive cycles of linear pseudo-first-order Fenton oxidation reactions. © 2023 Hohai University