Progress in the Remediation of Heterogeneously Co-Contaminated Petrochemical Soils: From Structural Constraint to Multiscale Process Coupling

Abstract

Heterogeneously co-contaminated soils impacted by petrochemical activities are characterized by the coexistence of total petroleum hydrocarbons (TPHs), semi-volatile organic compounds (SVOCs), and their weathered derivatives distributed across multiphase soil domains. Their long-term persistence is primarily governed by pore-scale heterogeneity, strong sorption within soil organic matter (SOM), and severe mass transfer limitations across solid–liquid–gas interfaces.This review synthesizes recent advances in understanding and remediating such complex systems from a multiscale and system-coupling perspective. We focus on three interconnected aspects: (i) the structural evolution of contaminated soil matrices under long-term aging, (ii) interfacial activation mechanisms induced by external physical and chemical energy fields, and (iii) the nonlinear coupling among physical transport, chemical transformation, and biological degradation processes.A conceptual framework is proposed, emphasizing “structural constraint release–interfacial activation–system-level evolution”, providing theoretical support for hierarchical, adaptive, and energy-efficient remediation strategies in highly heterogeneous contaminated sites.