Optimizing environmental remediation: Thermal tunability of bone char for selective remediation of water, soil, and mine waste

Abstract Bone char (BoC) is a bio-hydroxyapatite material derived from the pyrolysis of animal bones. It has been extensively studied for its applications in water, soil, and industrial waste remediation. Unlike other biological and mineral adsorbents, BoC exhibits pH, electrical conductivity, porosity, and crystallinity properties that vary proportionally with the pyrolysis temperature. This variability allows BoC to be a tunable, reproducible, and sustainable material suitable for targeted remediation efforts, including the removal of specific anions and cations from contaminated water, enhancing soil quality, and mitigating the adverse effects of mine tailings. This study evaluates the chemical and physical properties of BoC produced at pyrolysis temperatures ranging from 400 to 1000°C, proposing its use for targeted remediation applications. Our findings indicate that both physical and chemical properties of BoC vary proportionally positively or negatively with increasing pyrolysis temperature. The main key characteristics for remediation include ion exchange capacity, pH, and stability. We recommend using BoC pyrolyzed at low temperatures ( 800°C) pyrolyzed BoC is effective for remediation in both water and soil under extremely acidic conditions.