Efficient degradation method of emerging organic pollutants in marine environment using UV/periodate process: Case of chlorazol black

Highlights: • UV/IO₄⁻ process was applied for degrading chlorazol black (CB) in seawater. • Photoactivated periodate process is applicable in seawater only for pH solution • Degradation rate increased with increasing periodate and CB concentrations and decreasing pH. • Degradation rate of CB was not affected by liquid temperature rise in the interval 25–55 °C. • SDS surfactant did not affect the degradation rate of CB, making UV/IO₄⁻ process a promising method for treating contaminated seawater. - Abstract: Sea has historically been subject to high anthropogenic pressures of direct and indirect loads of emerging organic pollutants (EOPs) from intensive industrial and agricultural activities. Photoactivated periodate (UV/IO₄⁻) is an innovative oxidation technique that was never tested in seawater as pollutants matrix. In this work, we attempted to investigate the treatment of seawater contaminated with chlorazol black (CB) dye, as a model of EOPs, using photoactivated periodate process. It was found that periodate (0.5 mM) assisted-UV treatment of CB (20 mg L^{− 1}) in seawater resulted in 13.16-fold increase in the initial degradation rate, compared to UV alone, and 82% of CB was removed after 40 min face to 38% under UV alone. The beneficial effect of UV/IO₄⁻ treatment is strongly dependent on operational parameters. More interestingly, SDS surfactant, as an organic matter, did not affect the degradation process, making UV/IO₄⁻ a promising technique for treating seawater contaminated with EOPs.