UV/H_2O_2/TiO_2联合水解酸化+MBR工艺处理亚砜废水

Treatment of DMSO wastewater by UV /H_2O_2/TiO_2 combined with hydrolytic acidification-MBR process

二甲基亚砜(DMSO)废水因其COD高、可生化性差的特性而较难处理。本实验以采用硫酸二甲酯法生产DMSO的某化工厂废水为研究对象,设计并建立了组合式光催化氧化装置联合水解酸化+MBR工艺的中试系统,探讨了组合式光催化氧化装置、氧化剂投加量、pH、反应时间和水力停留时间对系统处理效果的影响。结果表明,组合式光催化氧化装置可有效提高DMSO废水的可生化性。最优工艺参数为:按H2O2与原水COD质量浓度比为2∶1投加H2O2,在pH值为4、反应时间为6 h、水力停留时间为4 h的条件下,该系统对原水COD(5 000 mg/L)去除率大于98%,出水COD达到《污水综合排放标准》(GB 8978-1996)一级要求。

The dimethyl sulfoxide(DMSO) wastewater is difficult to be treated because of the high chemical oxygen demand( COD) and the poor biochemical degradability. In this study,we used the wastewater from a plant that produced DMSO by the dimethyl sulfate as raw water. A pilot system of UV /H2O2/TiO2 combined with hydrolytic acidification-membrane bioreactor(MBR) process was designed and established. Then,the influences of UV /H2O2/TiO2,total dosage of oxidizers,pH,reaction time and hydraulic retention time on treatment effect were discussed. The result showed that the biodegradability of DMSO could be greatly improved by UV /H2O2/TiO2. The optimum process parameters were that the mass concentration ratio of H2O2 and COD was 2∶ 1,the pH was 4,the reaction time of hydrolytic acidification was 6 hours and the hydraulic retention time of MBR was 4hours. Under the above conditions,the removal efficiency for COD( 5 000 mg /L) was above 98 % and the effluent COD could meet the first criteria specified in Integrated Wastewater Discharge Standard( GB8978-1996).