Efficacy of agricultural waste derived biochar for arsenic removal: Tackling water quality in the Indo-Gangetic plain

Santanu Mukherjee; Alok Kumar Thakur; Ritusmita Goswami; Payal Mazumder; Kaling Taki; Meththika Vithanage; Manish Kumar

doi:10.1016/j.jenvman.2020.111814

Efficacy of agricultural waste derived biochar for arsenic removal: Tackling water quality in the Indo-Gangetic plain

J Environ Manage. 2021 Mar 1:281:111814. doi: 10.1016/j.jenvman.2020.111814. Epub 2021 Jan 2.

Authors

Santanu Mukherjee¹, Alok Kumar Thakur², Ritusmita Goswami³, Payal Mazumder⁴, Kaling Taki⁵, Meththika Vithanage⁶, Manish Kumar⁷

Affiliations

¹ Discipline of Earth Sciences, Indian Institute of Technology Gandhinagar, Gujarat, 382355, India; School of Agriculture, Shoolini University of Biotechnology and Management Sciences, Solan, 173229, India.
² Discipline of Earth Sciences, Indian Institute of Technology Gandhinagar, Gujarat, 382355, India.
³ Department of Environmental Science, The Assam Royal Global University, Guwahati, 781035, Assam, India; Centre for Ecology, Environment and Sustainable Development, Tata Institute of Social Sciences, Guwahati, 781013, Assam, India.
⁴ Center for the Environment, Indian Institute of Technology, Guwahati, Assam, 781039, India.
⁵ Discipline of Civil Engineering, Indian Institute of Technology, Gandhinagar, 382355, Gujarat, India.
⁶ Ecosphere Resilience Research Center, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, 10250, Sri Lanka.
⁷ Discipline of Earth Sciences, Indian Institute of Technology Gandhinagar, Gujarat, 382355, India. Electronic address: manish.env@gmail.com.

PMID: 33401117
DOI: 10.1016/j.jenvman.2020.111814

Abstract

Arsenic (As), a geogenic and extremely toxic metalloid can jeopardize terrestrial and aquatic ecosystems through environmental partitioning in natural soil-water compartment, geothermal and marine environments. Although, many researchers have investigated the decontamination potential of different mesoporous engineered bio sorbents for a suite of contaminants, still the removal efficiency of various pyrolyzed agricultural residues needs special attention. In the present study, rice straw derived biochar (RSBC) produced from slow pyrolysis process at 600 °C was used to remove As (V) from aqueous medium. Batch experiments were conducted at room temperature (25 ± 2 °C) under different initial concentrations (10, 30, 50, 100 μg L^-1), adsorbent dosages (0.5-5 μg L^-1), pH (4.0-10.0) and contact times (0-180 min). The adsorption equilibrium was established in 120 min. Adsorption process mainly followed pseudo-second order kinetics (R² ≥ 0.96) and Langmuir isotherm models (R² ≥ 0.99), and the monolayer sorption capacity of 25.6 μg g^-1 for As (V) on RSBC was achieved. Among the different adsorbent dosages and initial concentrations used in the present study, 0.2 g L^-1 (14.8 μg g^-1) and 100 μg L^-1 (13.1 μg g^-1) were selected as an optimum parameters. A comparative analysis of RSBC with other pyrolyzed waste materials revealed that RSBC had comparable adsorption ability (per unit area). These acidic groups are responsible for the electron exchange (electrostatic attraction, ion-exchange, π-π/n-πinteractions) with the anionic arsenate, which facilitates optimum removal (>60%) at 7 < pH < pH_PZC. The future areas of research will focus on decontamination of real wastewater samples containing mixtures of different emerging contaminants and installation of biofilter beds that contains different spent adsorbents/organic substrates (including biochar) for biopurification study in real case scenario.

Keywords: Adsorption; Arsenic; Electrostatic; Ion-exchange; Langmuir; Rice straw biochar.

MeSH terms

Adsorption
Arsenic*
Charcoal
Ecosystem
Hydrogen-Ion Concentration
Kinetics
Wastewater
Water Pollutants, Chemical*
Water Purification*
Water Quality

Substances

Waste Water
Water Pollutants, Chemical
biochar
Charcoal
Arsenic