“…For beneficial reuse, treatment trains might require a process dedicated to reducing the toxicity of the treated produced water to ensure public and environmental safety. Recently, promising studies have shown that photocatalysis-driven advanced oxidation processes (ozonation, rare metal catalyst, Fenton processes) can greatly reduce produced water toxicity. − Other technologies and processes have shown a potential for reducing toxicity, such as adsorption (granulated activated carbon, powder activated carbon, zeolite), , ion exchange, and biological treatments (activated sludge, MBR) − but require more research to determine their applicability for produced water treatment . Furthermore, if primary, secondary, and tertiary treatments are needed to meet effluent requirements, ensure sustainability, and address public concerns, the resulting treatment system may not be economically viable.…”