Degradation of Acid Orange 7 in a persulphate-bisulfite system under visible light
Heng Zhong, Jia Fang, Lei Sun, Hui Zhao, Aihua Xu, Dongsheng Xia, A. V. Nevsky
Section: Nature management and natural resources consumption
Textile industry is one of the most significant manufacturing sectors that produce large volumes of highly polluted and toxic wastewater. Dyes represent an important part of waste effluents. In this study, the degradation of Acid Orange 7 dye (AO7) in a persulfate-bisulfite (PS-BS) system under visible (Vis) light (wavelength more than 420 nm) was performed. All batch experiments were conducted in a 100 mL undivided glass beaker containing 50 mL solution at about 25 оC without irradiation or under irradiation by a direct exposure visible light power supply (CHF-XM-500W) from
Beijing Trusttech Co. (China). After the desired amounts of AO7 and PS in 50 mL of the aqueous solution were added into the reactor, the reaction was initialized by adding BS. To monitor the degradation process of AO7, solution samples were taken out at given reaction time intervals and measured immediately on a METASH UV-5500PC spectrophotometer under the maximum absorption wavelength (484 nm) to record the temporal UV-vis spectral variations of the dye. The related reaction progress was monitored using the UV-vis absorption spectra of AO7 in terms of the percentage of
degraded azo-dye. The activities of different systems including BS/Vis, PS/BS, PS/Vis and BS/PS/Vis were evaluated. It was found that the efficiency of PS/Vis system was negligible, and almost 29 and 40% of AO7 was oxidized by BS/Vis and BS/PS within 30 min, and it was further improved to almost 94% within 30 min by BS/PS/Vis system at room temperature. Various operational parameters, such as PS concentration, BS concentration and initial pH were investigated to optimize the process.
ISSN 1995-4301
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