Mechanism and kinetics of Cr(VI) adsorption on biochar derived from Citrobacter freundii under different pyrolysis temperatures

Singh, S and Anil, AG and Naik, TSSK and U, B and Khasnabis, S and Nath, B and Kumar, V and Subramanian, S and Singh, J and Ramamurthy, PC (2022) Mechanism and kinetics of Cr(VI) adsorption on biochar derived from Citrobacter freundii under different pyrolysis temperatures. In: Journal of Water Process Engineering, 47 .

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Abstract

The use of bacterial biochar for Cr(VI) removal opens room for new research in terms of cost-effectiveness, better performance and high selectivity. This work reports the synthesis, physicochemical characterization and performance evaluation of bacterial biochar synthesized at 200 °C and 400 °C. To examine the removal mechanism and behaviour, batch mode experiments were conducted by modifying different parameters such as dosage, pH, initial ion concentration and temperature. The capacity of the biochar for removing Cr(VI) was found to be qmax = 19.43 mg/g (200 °C) and 29.73 mg/g (400 °C). The BET surface area of bacterial biochar (400 °C) is also seen to decrease from 22.09 m2/g to 3.17 m2/g. The decrease in pore volume and surface area makes successful adsorption evident. In addition to this, the adsorption data were adequately simulated with Langmuir, Freundlich and Temkin and pseudo-second kinetics suggesting that the adsorption process were the combination of external mass transfer and chemisorption. Electrostatic interactions were determined to be the dominant removal mechanism. Biochar pyrolyzed at 400 °C serves as good adsorbent material to remove Cr(VI) from aqueous solutions. It can also be a suitable material for removing emerging contaminants from aqueous solutions.

Item Type:	Journal Article
Publication:	Journal of Water Process Engineering
Publisher:	Elsevier Ltd
Additional Information:	The copyright for this article belongs to the Elsevier Ltd.
Keywords:	Adsorbent; Biochar; Citrobacter freundii; Cr(VI) removal; Isotherms; Sensors
Department/Centre:	Division of Interdisciplinary Sciences > Interdisciplinary Centre for Energy Research Division of Interdisciplinary Sciences > Interdisciplinary Centre for Water Research Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	22 Jun 2022 05:19
Last Modified:	22 Jun 2022 05:19
URI:	https://eprints.iisc.ac.in/id/eprint/73613

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