Influence of intrinsic properties of lignocellulosic feedstock on adsorptive properties of biochar

Abstract

Biochar, which is rich in aromatic carbon and minerals, is a product of biomass pyrolysis at temperatures ranging from 350 to 1,000°C in oxygen-limited environments. In recent years, biochar has generated much interest in the field of water treatment in view of low production costs, availability of the feedstock (e.g., lignocellulosic biomass waste), and adsorptive properties. In this study, lignocellulosic feedstock from control and contaminated sites was pyrolyzed under 450°C for 2 h. The novelty of this study was consideration of the natural modifications of biochar and their influence on principal adsorptive characteristics of the biochar. The aim of this study was to determine the influence of intrinsic properties of lignocellulosic feedstock on adsorptive properties of biochar. Intrinsic properties of lignocellulosic feedstock, such as lignin, C, O, H, N, moisture and ash content, and Pb, Zn, Cu, Cr, Ni, Cd, Mg, and Fe concentrations, were analyzed. Adsorptive properties of biochar, such as cation exchange capacity (CEC), Brunauer–Emmett–Teller (BET) surface area, surface functionality, carbon, oxygen, hydrogen, nitrogen (COHN), moisture and ash content, and Pb, Zn, Cu, Cr, Ni, Cd, Mg, and Fe concentrations, were investigated. It was found that a larger amount of lignin (54–59%), ash (11.8–13.9%), nitrogen (0.4%), and Zn (182 mg/kg) and a lower carbon content (75–76%) in lignocellulosic feedstock may favor the adsorptive characteristics of biochar.