The performances of persulfate activators to degrade the persistent organic pollutants in industrial wastewater

Abstract

Over the past few decades, there has been significant research and application of advanced oxidation processes (AOPs) that rely on in-situ radicals as a potential treatment for persistently organic contaminated industrial wastewaters that contain residual pharmaceuticals, dyes … While persulfate (PS) oxidation alone is insufficient for the complete elimination of contaminants in wastewater, combining it with activators such as transition metals, alkalis, heat, microwave (MW), ultrasound (US), ultraviolet (UV), electrochemical (EC) energy, or electron transfer mediators is a promising approach to generate sulfate radical (SO4−•) and facilitate further degradation of persistent organic pollutants (POPs). PS activation methods that rely on reducing agents (metal ions, alkali) and external energy (heat, MW, US, UV, and EC) are highly suitable for treating persistent organic pollutants (POPs) in industrial effluent. Meanwhile, PS activation method that uses activated carbon (AC) materials is deemed the most efficient system for removing residual antibiotics in pharmaceutical wastewater due to their high efficiency and short processing time. Notably, the pH value, reaction temperature, water matrices, ratio of catalyst/PS, and PS concentration are critical factors that exert significant effects on the treatment process. Accordingly, this review offers a broad understanding of sulfate radical oxidation processes (SR-AOPs) to aid in selecting suitable treatment approaches for POPs in industrial wastewater.