Mn-Co-Ce/γ-Al_(2)O_(3)臭氧催化氧化奶牛养殖废水及其机理

Catalytic ozonation of dairy wastewater using Mn-Co-Ce/γ-Al_(2)O_(3) and its mechanism

奶牛养殖废水中因存在难生化降解有机物而难以处理。本研究采用浸渍法制备了一种三元催化剂(Mn-Co-Ce/γAl_(2)O_(3)),以经三级好氧处理后的奶牛养殖废水为对象,探究了催化剂的焙烧温度和焙烧时间、催化反应时间、pH、臭氧投加量和催化剂用量等对臭氧催化氧化的效果及其影响。结果表明,Mn-Co-Ce/γ-Al_(2)O_(3)用量为15 g·L^(-1)、pH=9、臭氧投加量为12.5 mg·L^(-1)·min-1、反应时间30 min时,CODCr去除率达到50%左右。XRD、SEM、BET和XPS对催化剂的表征表明,金属氧化物可成功负载在球状γ-Al_(2)O_(3)上且高度分散。循环试验表明,催化剂在5次循环后仍保持了较高的活性,催化剂稳定性较好。活性氧淬灭试验表明,体系中可以生成O_(2)·、HO·、^(1)O_(2),且1 O_(2)起主导作用。

Certain organic compounds are hardly biodegradable in dairy wastewater,rendering it difficult to treat.In this study,a ternary catalyst(Mn-Co-Ce/γ-Al_(2)O_(3))was prepared using an impregnation method.By selecting tertiary aerobic dairy wastewater as the treatment object,the effects of roasting temperature,roasting time,catalytic reaction time,pH,ozone dosage,and catalyst dosage on the catalytic oxidation effect were investigated.The results showed that the removal rate of CODCr reached approximately 50%in 30 min under optimal reaction conditions:catalyst dosage of 15 g·L^(-1),pH=9,and ozone dosage of 12.5 mg·L^(-1)·min^(-1).The catalysts were characterized via XRD,SEM,BET,and XPS,which showed that the metal oxides were successfully supported on sphericalγ-Al_(2)O_(3) and highly dispersed.A cycle test was performed and showed that the catalyst maintained high activity even after 5 cycles,indicating its good stability.Reactive oxygen quenching revealed that O-·2,HO·,and ^(1)O_(2) could be generated in the system,while ^(1)O_(2) plays a dominant role.