Mn-N共掺杂TiO_(2)/ZSM-5复合材料及光催化降解含氰废水

Mn-N co-doped TiO_(2)/ZSM-5 composite and its photocatalytic degradation of cyanide-containing wastewater

为了高效降解含氰废水并探究其降解行为,采用溶胶凝胶法制备了Mn-N共掺杂TiO_(2)/ZSM-5复合材料光催化剂,采用低温N_(2)吸附-脱附技术、SEM、XRD、UV-Vis等分析手段对其进行表征。以高压汞灯为光源,探讨了焙烧温度和TiO_(2)/ZSM-5质量比对复合材料的物性参数和光催化活性的影响。结果表明:在400℃焙烧且TiO_(2)/ZSM-5质量比为78.65%时,复合材料具有最佳的光催化活性。复合材料添加量为2.5g/L、溶液初始pH值为9.5时,经过3 h暗吸附和2.5 h光催化后,氰化物、铜和锌的去除率分别为98.15%、92.17%和100%。复合材料具有较高的稳定性,再生4次后,其对氰化物的去除率为96.02%。氰和锌的暗吸附过程符合伪二级吸附动力学,氰的光催化降解过程符合Langmuir-Hinshelwood模型。

In order to efficiently degrade cyanide-containing wastewater and explore the degradation behavior,the photocatalyst of Mn-N co-doped TiO_(2)/ZSM-5 composite was prepared by sol-gel method.The prepared composite was characterized by low-temperature N_(2)adsorption-desorption technology,SEM,XRD,UV-Vis.The effects of calcination temperature and mass ratio of TiO_(2)/ZSM-5 on the physical parameters and photocatalytic activity were investigated by using high-pressure mercury lamp as light source.The results show that the composite has the best photocatalytic activity at the calcination temperature of 400℃and the mass ratio for TiO_(2)/ZSM-5 of 78.65%.When the composite dosage is 2.5 g/L and the solution initial pH value is 9.5,the removal efficiencies of cyanide,copper and zinc are 98.15%,92.17%and 100%,respectively,after 3 h of dark adsorption and 2.5 h of photocatalytic reaction.The composite has high stability.After the composite regenerated for 4 times,the removal efficiency of cyanide is 96.02%.The dark adsorption process of cyanide and zinc conforms to the pseudo-secondary adsorption model,and the photocatalytic degradation process of cyanide conforms to the Langmuir-Hinshelwood model.