Removal of C.I. Reactive Red 2 by low pressure UV/chlorine advanced oxidation
Qianyuan Wu
,
Yue Li
,
Wenlong Wang
,
Ting Wang
,
Hongying Hu
DOI:10.1016/j.jes.2015.06.013
Received March 09, 2015,Revised June 19, 2015, Accepted June 23, 2015, Available online September 01, 2015
Volume 28,2016,Pages 227-234
Azo dyes are commonly found as pollutants in wastewater from the textile industry, and can cause environmental problems because of their color and toxicity. The removal of a typical azo dye named C.I. Reactive Red 2 (RR2) during low pressure ultraviolet (UV)/chlorine oxidation was investigated in this study. UV irradiation at 254 nm and addition of free chlorine provided much higher removal rates of RR2 and color than UV irradiation or chlorination alone. Increasing the free chlorine dose enhanced the removal efficiency of RR2 and color by UV/chlorine oxidation. Experiments performed with nitrobenzene (NB) or benzoic acid (BA) as scavengers showed that radicals (especially 
OH) formed during UV/chlorine oxidation are important in the RR2 removal. Addition of HCO3− and Cl− to the RR2 solution did not inhibit the removal of RR2 during UV/chlorine oxidation.
OH) formed during UV/chlorine oxidation are important in the RR2 removal. Addition of HCO3− and Cl− to the RR2 solution did not inhibit the removal of RR2 during UV/chlorine oxidation.
