A novel CuO–CeO 2 –Co 3 O 4 nanocatalyst loaded on Al 2 O 3 ceramic composite membrane (CCM-S) was synthesized through spraying-calcination method, which can be beneficial to the engineering application of scattered granular catalyst. BET and FESEM-EDX testing revealed that CCM-S possessed a porous character with high BET surface area of 22.4 m 2 /g and flat modified surface with extremely fine particle aggregation. The CCM-S calcined above 500 °C presented excellent anti-dissolution effect due to the formation of crystals. XPS indicated that the composite nanocatalyst possessed the variable valence states, which were conducive to exert the catalytic effect of Fenton-like reaction. Subsequently, the effects of experimental parameters including fabricate method, calcination temperature, H 2 O 2 dosage, initial pH value, and CCM-S amount were further investigated considering the removal efficiency of Ni(II)-complex and COD after decomplexation and precipitation (pH = 10.5) treatment within 90 min. Under the optimal reaction condition, the residual Ni(II)-complex and Cu(II)-complex concentration from actual wastewater was all lower than 0.18 mg/L and 0.27 mg/L, respectively; meanwhile, the removal efficiency of COD was all higher than 50% in the mixed electroless plating effluent. Besides, the CCM-S could still maintain high catalytic activity after a six-cycle test, and the removal efficiency was slightly declined from 99.82% to 88.11%. These outcomes indicated that CCM-S/H 2 O 2 system was provided with a potential applicability on treatment of real chelated metal wastewater.
Juan Liu,Xia Wu,Jingjing Liu,Conglu Zhang,Qi Hu,Xiaohong Hou
In this work, ofloxacin degradation was investigated by using Fe 3 O 4 -CeO 2 /activated carbon (AC) as heterogeneous Fenton catalyst. Response surface methodology based on central composite design (CCD) was used to investigate individual and interactive effects of three parameters on the ofloxacin degradation, i.e., solution pH, H 2 O 2 dosage and initial ofloxacin concentration. Optimal conditions were determined to be pH 3.3, H 2 O 2 20.0 mM, ofloxacin 12.0 mg L −1 and catalyst 0.5 g·L −1 . The ofloxacin degradation efficiency and the total organic carbon (TOC) removal was 95% and 54% within 60 min, respectively. The obtained results agreed well with the modeling prediction ( R 2 = 0.9826, and Adj- R 2 = 0.9783). The kinetic analysis implied that the reaction followed first-order kinetic with R 2 = 0.9965. According to mass spectrometry qualitative analysis, eight intermediates of ofloxacin were detected and two possible degradation pathways were proposed. The catalyst still showed degradation efficiency of 82.4% toward ofloxacin after five runs.