Environmental fate and transformation mechanisms of chlorinated organic pollutants from the petrochemical industry: Insights for pollution control and remediation

Chlorinated organic pollutants (Cl-OPs), highly toxic and environmentally persistent, have become the spotlight, particularly from petrochemical industry. This study focuses on environmental fate of Cl-OPs from petrochemical industry, and transformation mechanisms in multi-media, aiming to enhance pollution control and remediation strategies. Emitted from leakage and waste discharge, Cl-OPs, encompassing chlorinated volatile organic compounds (Cl-VOCs), traditional and emerging persistent organic pollutants (POPs), were prevalent with average concentrations of 10(-6)-10(3) mu g/m(3) in the atmosphere, 10(-2)-10(5) mu g/kg in soil and 10(0)-10(5) mu g/L in groundwater. Significantly, emerging POPs, particularly hexachlorobutadiene (HCBD) and short-chain chlorinated paraffins (SCCPs), with concentrations comparable to Cl-VOCs, urgently need attention. Once into the environment, ClOPs are naturally transformed primarily through atmospheric oxidation and water photolysis induced by hydroxyl radical ( OH), and microbial degradation. Despite challenges in atmospheric complete degradation, OH in water effectively photolytically degrade chlorinated benzenes and paraffins facilitated by dissolved oxygen and organic matter. Microbial degradation, influenced by oxygen, temperature, and pH, is essential for Cl-OPs removal from water and soil, where oxidation make complete mineralization possible whereas dechlorination may generate higher toxic intermediates. Hence, Cl-OPs control necessitates an attentive to leakage and waste management. Furthermore, advanced OH oxidation and microbial treatment are of effective remediation prospect.