CuO/γ-Al_2O_3催化双氧水处理聚乙烯醇废水的研究

Treatment of polyvinyl alcohol solution by hydrogen peroxide catalyzed with CuO/γ-Al_2O_3

采用浸渍—煅烧法制备CuO/γ-Al_2O_3催化剂,并用其催化双氧水处理聚乙烯醇(PVA)废水,对比了不同煅烧温度下CuO/γ-Al_2O_3的催化性能以及催化剂投加量、双氧水投加量、PVA初始质量分数对PVA去除率的影响。结果表明,煅烧温度为450℃时得到的CuO/γ-Al_2O_3催化性能最好,增加CuO/γ-Al_2O_3和双氧水的投加量均有助于降低PVA降解产物黏均分子量,而PVA初始质量分数越高,PVA降解产物的黏均分子量越高。当PVA初始质量分数为1.0%,双氧水投加量为60 mL/L,CuO/γ-Al_2O_3投加量为1.0g/L,反应温度为60℃,溶液初始pH=3时,反应2h后PVA去除率达90%以上,PVA降解产物的黏均分子量从100 773降至3 194,下降了近97%,CuO/γ-Al_2O_3的催化性能随着重复使用次数的增加有一定下降。

CuO/γ-Al2O3 nanoparticles were prepared by wet impregnation-calcination method,the obtained catalyst was used to catalyze hydrogen peroxide for the treatment of polyvinyl alcohol solution.The effect of calcination temperature on CuO/γ-Al2O3 property and CuO/γ-Al2O3 dosage,hydrogen peroxide dosage,initial PVA concentration on the removal efficiency of PVA were investigated.Results revealed that the CuO/γ-Al2O3 nanoparticles calcinated at 450℃ exhibited the best catalytic capability.Besides,the degradation of PVA was promoted by increasing hydrogen peroxide as well as CuO/γ-Al2O3 dosage,while higher initial PVA concentration going against the effective degradation,leading to a higher viscosity-average molecular weight of degradation products.In this paper,more than90% of PVA was removed after 2 h of treatment under conditions of initial PVA concentration of 1.0%,temperature of 60 ℃,pH=3,hydrogen peroxide dosage of 60 mL/L and CuO/γ-Al2O3 dosage of 1.0 g/L,average molecular weight of PVA degradation products was decreased by 97%,from 100 773 to 3 194.The nano catalyst could be recycled by filtration and calcination,but the catalytic ability was slightly decreased in four-times utilization.