Waste-Derived Functional Carbon for Rapid PAHs Removal: A Sustainable Pathway for Co-Remediation and Resource Valorization of Oily Sludge

Abstract

Oily sludge (OS) and polycyclic aromatic hydrocarbons (PAHs) in wastewater represent two of the most hazardous contaminants at petroleum-polluted sites, necessitating integrated strategies for simultaneous solid–liquid phase remediation. This study proposes a sustainable waste-to-resource approach by converting OS into functionalized 3-aminopropyltriethoxysilane/co-pyrolytic carbon (APTES/CPC) for the rapid removal of PAHs from wastewater. Results indicate that the adsorption capacity of APTES/CPC is 2.11 times higher than that of co-pyrolytic carbon (CPC). Rapid anthracene adsorption occurs within 1 min, and adsorption equilibrium is reached within 10 min. This demonstrates its potential for emergency treatment of petroleum-contaminated wastewater. Mechanistic studies using density functional theory (DFT) revealed that ethoxy functional groups played a pivotal role by inducing electron relaxation, promoting sp³-like hybridization, and facilitating stable C─C bond formation with anthracene. This shift from physical to chemical adsorption underpins the exceptional kinetics of APTES/CPC. These findings offer a promising strategy for in situ treatment of petroleum-contaminated wastewater using pyrolysis residues derived from OS.

Keywords

anthracene adsorption / APTES functionalization / co-pyrolysis char / petroleum-contaminated wastewater / rapid adsorption / synchronous removal

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