Photocatalytic degradation of Rhodamine-B dye using composite prepared from drinking water treatment sludge and nano TiO2

In this study, composite Sludge adsorbent (ASN)/TiO2 was prepared from the drinking water treatment sludge ASN (activated with nitric acid) and nanoparticle TiO2 by the sol-gel method, followed by using it to remove Rhodamine-B (RB) dye from polluted water. The prepared composite was characterized by transmission electron microscopy, X-ray fluorescence spectrometry, X-ray diffraction, and surface area N-2-adsorption/desorption analysis. Photocatalytic degradation of RB dye was investigated by UV and UV/hydrogen peroxide (H2O2) irradiation. Parameters such as composite dosage, initial dye concentration, UV irradiation time, and solution pH were applied to obtain the optimum conditions for high RB dye degradation. The results showed that the highest RB dye degradation (96.7%) was using a 2:1 ratio of ASN/TiO2. High degradation of dye was achieved within 4 h at pH 7, 50 ppm dye concentration, and 0.125 g/50 ml composite dose. The maximum degradation of RB dye using the prepared composite under UV irradiation with H2O2 (99.85%) was higher than that with UV irradiation only (96.85%). The rate of the dye photocatalytic degradation followed the first-order kinetics.