Cu-Co/γ-Al_(2)O_(3)催化臭氧氧化深度处理维生素废水研究

Treatment of vitamin wastewater by Cu-Co/γ-Al_(2)O_(3)catalyzed ozonation process

为解决维生素C废水经二级生化处理后仍不能达到排放标准的问题,以γ-氧化铝为载体,采用化学浸渍法工艺制备出一种高效稳定的Cu-Co/γ-Al_(2)O_(3)催化剂,构成臭氧催化氧化体系。采用XRD、BET、SEM对催化剂进行表征,并探究不同条件下对维生素C废水深度处理效果的影响。结果表明,在反应初始溶液pH=9、臭氧浓度20 mg/L、臭氧流量1 L/min、催化剂投加量为16 g/L、过氧化氢投加量6 mL/L、在反应时间持续90 min的条件下,COD去除率、UV 254去除率、TOC去除率分别达到83.25%,92.14%,79.39%。EPR测试表明臭氧催化氧化体系遵从羟基自由基作用机理,Cu-Co/γ-Al_(2)O_(3)催化剂重复使用10次后,COD去除率、UV 254去除率、TOC去除率仍达到76.37%,86.15%和74.29%,且负载金属离子浸出维持在较低水平,表明该催化剂是一种优异稳定的非均相臭氧催化剂。

In order to solve the problem that vitamin C wastewater can not reach the discharge standard after secondary biochemical treatment,a kind of efficient and stable Cu-Co/γ-Al_(2)O_(3)catalyst was prepared by chemical impregnation process withγ-alumina as the carrier,which constituted the ozone catalytic oxidation system.XRD,BET and SEM were used to characterize the catalyst,and the effect of different conditions on the advanced treatment of vitamin C wastewater was explored.The results show that under the conditions of initial reaction pH=9,ozone concentration of 20 mg/L,ozone flow rate of 1 L/min,catalyst dosage of 16 g/L,hydrogen peroxide dosage of 6 mL/L,and reaction time of 90 min,the removal rate of COD,UV 254 and TOC can be achieved respectively 83.25%,92.14%,79.39%.EPR test showed that the ozone catalytic oxidation system followed the hydroxyl radical action mechanism.After repeated use of Cu-Co/γ-Al_(2)O_(3)catalyst for 10 times,the COD removal rate,UV 254 removal rate and TOC removal rate still reached 76.37%,86.15%and 74.29%,and the supported metal ion leaching maintained at a low level.The results show that the catalyst is an excellent and stable heterogeneous ozone catalyst.