Adsorption of polycyclic aromatic hydrocarbons (PAHs) in soil and water on pyrochars: A review

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants that pose severe environmental and human health risks. Given their chemical stability and hydrophobicity, PAHs tend to accumulate in soil and water, leading to long-term contamination. Effective remediation strategies are urgently required to mitigate these risks. Pyrochars have gained increasing attention due to their high adsorption capacity, cost-effectiveness, and environmental sustainability. This review systematically examines the application of pyrochars in PAHs removal, focusing on their adsorption mechanisms and influencing factors. Pyrochars exhibit adsorption capacities ranging from 2.0 mg/g to 384 mg/g under optimal conditions. Their adsorption is primarily governed by pore filling, π–π interactions, and hydrogen bonding, with variations depending on PAHs molecular structure and pyrochars surface properties. Additionally, the review highlights the potential applications of pyrochars in environmental remediation and provides insights for future research on enhancing their performance. This study contributes to the development of sustainable and efficient strategies for PAHs pollution control.