Biochars and Biochar Composites: Low-Cost Adsorbents for Environmental Remediation

Abstract The industrial revolution in the 20th century led to the evolution of numerous anthropogenic pollutants. Biochar, solid residue obtained from the pyrolysis of naturally available biomass, has attracted the attention of researchers due to its ability to remove these pollutants through adsorption from water and soil backed by various physicochemical properties. In this chapter, adsorptive removal of the pollutants involved is summarized in terms of the mechanisms that control the remediation. Research on heavy metals, organic contaminants, nutrients, oxyanions, and toxic gases considering the precise chemistry of polluted media and the biochar employed has been conducted. Functional improvement of biochar as adsorbent upon further chemical functionalization or fabrication of biochar composite is also discussed, with a focus on these pollutants. Finally, current challenges in biochar adsorptive remediation and future research opportunities required to overcome those challenges have been compiled.