Application of Photo-Fenton Process to Highly Saline Water Matrices: Effect of Inorganic Ions on Iron Speciation

The photo-Fenton process has been widely studied for the treatment of organic pollutants and disinfection in a wide range of scenarios. Nevertheless, its efficiency decreased when applied to complex matrices, as in the case of most advanced oxidation processes. Despite the interferences caused by different anions, the photo-Fenton is able to obtain good degradation values for pollutants and microorganisms, especially in combination with other methods; however, it depends on the matrix to be treated. Due to the lack of studies and reviews in this field, this paper reviewed the outcome of the inorganic ions present on highly saline water matrices (more than 1 g L^-1 of chlorides, fluorides, bromides, sulphates, carbonates or bicarbonates, borates, phosphates and nitrates/nitrites) on the Fenton-based processes, focusing on their outcome on iron speciation and their scavenger effect. Also, the most relevant works so far for the abatement of microcontaminants and disinfection by this process on highly saline matrices have been revised. Special emphasis is on the efficiency of the process, considering the relevant industries referred to.