Faculty Publications
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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 UniversityItem 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.