ABSTRACT
Extremely saline wastewater resulting from many industrial processes, such as food and agro processing and leather and textile industry, cannot be treated by traditional treatment techniques.
Due to the salinity of wastewater, biological approaches are costly and impractical to implement, and membrane methods can encounter issues such as membrane blocking caused by the presence of organic compounds. Effective methods for removing organic pollutants from salty industrial wastewater are needed. Advanced oxidation processes (AOPs) are regarded as a potential way of oxidizing a broad variety of organic compounds, even in highly saline settings. In contrast to traditional AOPs, which use hydroxyl radicals as primary oxidants, sulphate-based radical AOPs (SR-AOPs) are said to provide a variety of in situ oxidants, including sulphate radicals and singlet oxygen, as well as non-radical oxidation pathways. SR-AOPs have recently gained popularity due to their high redox potential (2.5–3.1 V), wide-operating pH range (2–9), and longer life span of the sulphate radicals produced (30−40 μs). Several methods have shown promising strategies for sulfate radical activation, such as heat, ultrasound, ultraviolet radiation, metal-incorporated transition catalysts, and carbon catalysts. This chapter summarizes the activation methods for the efficient generation of sulphate radicals and evaluates their application and economic feasibility. The mechanism of activation has also been presented.
