Study On Treatment Of The Simulation Wastewater With Acid Scarlet-3R By The Catalytic Wet Peroxide Oxidation

The dye is a kind of stable organic matter, which retaining in environment for a long time. Some matirials of dye wastewater are harmful to human health. Mutagenicity and carcinogenicity substances had been discovered in azo-dyes, anthraquinone dye and triphenylmethane dye. The dye wastewater ingredients are complex, which have influence on the aquatic zoology and botany growth after entering water body. It includes lead, chromium and manganese heavy metal ions. Catalytic wet peroxide oxidation (CWPO) is an important method to treat refractory compounds. Under normal temperatures and pressures, the method mainly relies on H₂O₂ as oxidant, which produce hydroxyl radicals with strong oxidizing property. In this way, majority of organic matter are easily oxidized with a higher oxidation rate. As the key of CWPO, catalyst is definitely important. So the research on new high-efficiency catalysts to treat difficult degradation matters with CWPO is imperative.The experimental take the acid scarlet-3R synthetic wastewater as the processing objects, and prepared supported catalyst by impregnation method. We discussed the degradation of supported catalyst to the acid scarlet-3R synthetic wastewater. The important results were as follow:1. The single component supported catalyst CuO/γ-Al₂O₃ was used to treat acid scarlet-3R. In this process, the degradation efficiency of acid scarlet-3R was 78.13%, the loss amount of copper was 8.53 mg·L^-1 as reaction time was 3h. The degradation activity decreased by 35% after recycles use of catalyst for three times.2. The Ce-modified on supported Catalyst CuO/CeO₂/γ-Al₂O₃ was also used to treat acid scarlet-3R. Compared with catalyst CuO/γ-Al₂O₃, the degradation efficiency of the latter raised form 78.13% to 98.16% as reaction time was 3h, while the loss amount of copper decreased from 8.53mg·L^-1 to 2.76 mg·L^-1。3. Composite oxide catalyst of cerium and zirconium was prepared to treat acid scarlet-3R. Compared with catalyst CuO/CeO₂/γ-Al₂O₃, Catalyst CuO/CeO₂/γ-Al₂O₃ had higher activity and stability. With the loss amount of copper was 0.12 mg·L^-1, the degradation efficiency of acid scarlet-3R reached 93.96% in two hours, whereas the degradation efficiency was up to 96.26% in three hours.4. The XRD characterization results concluded that there weren't crystalline phase of CuO and CuAl2O4 spinel structure for catalyst CuO/γ-Al₂O₃ and Cu-Ce-Zr-O/γ-Al₂O₃. This showed highly dispersed copper oxide on vector for catalyst CuO/γ-Al₂O₃. Compared Cu-Ce-Zr-O/γ-Al₂O₃ with Ce-Zr-O/γ-Al₂O₃, diffraction peak position of Ceria-Zirconia solid solution shifted a large angle with the addiction of copper, which indicated Cu-Ce-Zr solid solution has formed through entering Cu into Ce-Zr solid solution.5. We choose Cu-Ce-Zr-O/γ-Al₂O₃ catalyst to treat acid scarlet-3R synthetic wastewater by CWPO and investigate the effect of temperature, wastewater pH, H₂O₂ and catalyst dosage on degradation effectiveness. The results showed:(1) Temperature had obvious influence on catalyst reaction. Degradation rate increased as temperature increased in the same time. When the temperature was 30℃and 60℃, as well as catalyst reaction time was 0.5h, The Degradation rate of acid scarlet-3R were 67.33% and 95.52%.(2) Acid scarlet-3R degradation rate increased and then decreased as pH increased. Catalyst had higher catalytic activity when pH varies from 4 to 10, which showed that the modified catalyst had better acid-base suitability.(3) When H₂O₂ dosage less than 10 g·L^-1, acid scarlet-3R degradation rate increased as H₂O₂ dosage increased. The degradation rate reached 93.96% as H₂O₂ dosage was 6 g·L^-1 and reaction time was 2h. The optimal dosage of H₂O₂ was 6 g·L^-1.(4) Acid scarlet-3R degradation rate increased as catalyst dosage increased. Acid scarlet-3R degradation rate reached 93.96% as catalyst dosage was 16.0 g·L^-1 and reaction time was 2h.