Browsing by Author "Kenchannavar, P."

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    Application of circular economy in wastewater treatment using biochar based adsorbent derived from sewage sludge
    (Institute of Physics, 2022) Kenchannavar, P.; Surenjan, A.
    The Circular Economy intends to reuse wastewater and recover resources and energy from the sludge in the wastewater sector. The conversion of sewage sludge into biochar by pyrolysis technique is a sustainable, environmentally friendly option for sewage sludge management. In the current work, biochar was produced by co-pyrolyzing sewage sludge and coconut shell, and it was then utilized as an adsorbent to eliminate methylene blue (the model pollutant) from wastewater. The sewage sludge is abundant in functional groups and metal ions, and the addition of coconut shells increased the porosity of the adsorbent. The biochar produced by mixing coconut shell and sewage sludge in the ratio1:1 showed higher adsorption capacity compared to biochar obtained from pure sewage sludge; hence the co-pyrolyzed biochar was used for further studies. The morphology and functional groups present on biochar were examined using SEM and FTIR analysis. The kinetics and mechanism of methylene blue adsorption was adequately explained by the pseudo-second-order kinetic model. Using the Langmuir isotherm model, the maximal adsorption capacity of the methylene blue dye on biochar was observed to be 31.64 mg/g. © Published under licence by IOP Publishing Ltd.
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    Exploring the potential of cashew nut shell biochar for chlorpyrifos pesticide removal
    (Elsevier B.V., 2025) Pandey, P.; Kenchannavar, P.; Surenjan, A.
    India generates over 620 million metric tons of agricultural waste yearly. Agricultural wastes have limited economic worth and are underutilized. Agro-waste recycling into circular economy products is essential for environmental health. In small-scale cashew industries, shell waste generation is 67.5 % of the seed weight. Cashew nut shells (CNS), a residual product of the industry, are burned following the extraction of pulp and oils, resulting in negative environmental impacts. This study focuses on the application of CNS biochar for the removal of chlorpyrifos, a highly toxic organophosphate pesticide. Prepared biochar was analyzed using SEM, BET, and FTIR. After adsorption, the specific surface area of biochar decreased from 111.62 m²/g to 14.00 m²/g. For an initial chlorpyrifos concentration of 15 mg/L, the highest removal efficiency of 94.2 % was obtained with a 120-minute contact time, a biochar dose of 0.5 g/L and a pH of 6. Adsorption studies demonstrated a maximum adsorption capacity of 31.34 mg/g, with results following the Langmuir isotherm and pseudo-second-order kinetics, indicating monolayer chemisorption. The findings highlight CNS biochar as a promising alternative to conventional adsorbents, offering an environmentally friendly solution for water purification. © 2025 Elsevier B.V.