Degradation of Reactive Brilliant Red X-3B Dye by Microwave Electrodeless UV Irradiation

Degradations of reactive brilliant red X-3B solution by both conventional UV irradiation and microwave electrodeless UV irradiation were investigated. Degradation processes were studied by UV-VIS spectrophotometry, total organic carbon (TOC), high performance capillary electrophoresis (HPCE), conductivity, pH value, and ion chromatography. The results of color removal (%) and TOC removal (%) showed that the degradation by microwave electrodeless UV irradiation was more effective than by conventional UV irradiation. The results of UV-VIS absorption spectra and HPCE analyses indicated that the degradation of reactive brilliant red X-3B was occurred at the conjugation system first, the benzene ring and the naphthalene ring later. The reactive brilliant red X-3B was cleaved into some new small compounds and eventually most of the organic substances were mineralized to CO2 and H2O. The results of the conductivity analysis suggested that the degradation has mainly occurred in the first 40 min of reaction. The pH value of reactive brilliant red X-3B solution was decreased first and then was increased. The results of inorganic anions analysis hinted that many of the N, Cl, and S elements from reactive brilliant red X-3B were still attached in organic molecules.