Photocatalytic ozonation of dyes using multiwalled carbon nanotube

In this paper, photocatalytic ozonation (UV/O3) of dyes using multiwalled carbon nanotube (MWCNT) was investigated. Reactive Red 198 (RR198) and Direct Green 6 (DG6) were used as dye models. UV–vis and ion chromatography (IC) analyses were employed to study dye degradation. The effect of operational parameters such as MWCNT dosage, dye concentration, salt (inorganic anions) and pH on dye degradation was studied. Formate, acetate and oxalate anions were detected as dominant aliphatic intermediates during the degradation of dyes by UV/O3/MWCNT, UV/O3 and O3/MWCNT processes. In addition, nitrate, sulfate and chloride anions were detected as the mineralization products of dyes during the degradation processes. Results showed that the dye degradation using photocatalytic ozonation with MWCNT (UV/O3/MWCNT) was a very effective method for dye degradation.