Influence of Agricultural Feedstock on the Physicochemical Properties and Performance of Biochar

Abstract

Limited understanding exists of how pyrolysis conditions affect the physicochemical properties of biochar derived from specific agricultural feedstocks. This study investigates coconut shell–derived biochar produced via oxygen-limited pyrolysis at 600 °C with a heating rate of 5 °C min⁻¹. X-ray diffraction revealed a predominantly amorphous structure (crystallinity index: 30.3%) with broad peaks at 2θ ≈ 23.15° and 43.80°, indicating high structural disorder that is favorable for adsorption. Dynamic light scattering showed a unimodal particle size distribution centered at ~1550 nm, while zeta potential measurements indicated a mean surface charge of −17 mV, confirming moderate colloidal stability and affinity for cationic contaminants. BET and BJH analyses demonstrated a hierarchical pore structure, with the cumulative pore volume reaching ~77 cc g⁻¹ in the 40–51 nm range and a micropore volume of ~0.13 cc g⁻¹. FTIR analysis confirmed the presence of –OH, C=O, and aromatic C=C functional groups, contributing to surface reactivity. Collectively, these structural, chemical, and electrokinetic properties position coconut shell biochar as a low-cost, high-performance material for environmental remediation and wastewater treatment, comparable in key characteristics to commercial activated carbon.