Biochars and Engineered Biochars for Water and Soil Remediation: A Review

Biochars (BCs) are considered as ecofriendly and multifunctional materials with significant potential for remediation of contaminated water soils, while engineered biochars (E-BCs) enlarged surface areas abundant functional groups can perform even better in environmental remediation. This review systematically summarizes the key physical chemical properties BCs that affect their pollutant sorption capacities, major methods employed modification E-BCs, performance BCs/E-BCs removing types organic (e.g., antibiotics pesticides) inorganic pollutants heavy metals), corresponding removal mechanisms. The BCs—such ash or mineral contents, aromaticity, structures, pH, C=O, -COOH, -OH, -NH2)—depend primarily on feedstock sources (i.e., plant, sludge, fecal) pyrolysis temperature. Ion exchange, precipitation, electrostatic attraction, complexation main mechanisms involved adsorption BCs/E-BCs, whereas hydrogen bonding, pore filling, hydrophobic interaction, van der Waals forces driving uptake pollutants. Despite promises, more pilot field scale investigations necessary to demonstrate practical applicability viability soil