Removal of sulfamethizole from aqueous solution using advanced oxidation processes: effects of pH and salinity

This study investigates the removal of sulfamethizole (SFZ) in ozone (O ), O /Na S O (sodium persulfate), UV/Na S O , UV/O , and UV/O /Na S O systems. The effects of pH and salinity on SFZ mineralization were evaluated. The mineralization of SFZ followed pseudo-first-order kinetics. At pH 5, the rate constants of SFZ mineralization in O , O /Na S O , UV/Na S O , UV/O , and UV/O /Na S O systems were 0.576, 0.924, 0.702, 1.26, and 5.21 h , respectively. The SFZ mineralization rate followed the order pH 5 > pH 7 > pH 9 in all tested advanced oxidation processes. Salinity increased the rate of SFZ mineralization in O and O /Na S O systems and decelerated it in UV/Na S O , UV/O , and UV/O /Na S O systems. UV/O /Na S O was the best system for mineralizing SFZ, and sulfate radicals were the predominant species in UV/O /Na S O .