Degradation of hexacyanoferrate (III) ion by the coupling of the ultraviolet light and the activation of persulfate at basic pH

The ultraviolet light activation of persulfate (PS) under alkaline conditions was evaluated for treating hexacyanoferrate (III) ion ([Fe(CN)6]3-). effect the wavelength type (i.e., UVA and UVC), initial PS concentration (0.3, 0.6, 0.9 g L−1), pH value (11 13) on degradation 50 mg L−1 [Fe(CN)6]3- were studied. Finally, role main degrading agents (SO4•-, O2•-, or HO•) involved in process determined using scavengers a pathway proposed. Results show that can be decomposed by UVC light, while is not effective neither photolysis nor PS. Alkaline alone at 13 also degrade cyanocomplex. However, combination with (0.3 L−1) showed high efficiency elimination [Fe(CN)6]3-, achieving 93.3% removal after 125 min treatment. highest CN- release Fe dissolved occurs 0.3 Further increases concentrations may lead to an excess radicals solution, resulting detrimental recombination reactions affect process. Quenching tests importance follows order: HO• > O2•- >>> 1O2 SO4•-, allowed demonstrate singlet oxygen could participate [Fe(CN)6]3-. All these results suggest feasibility this technology treat industrial wastewater efficiently.