臭氧氧化耦合陶瓷膜过滤处理煤制气废水研究

构建了臭氧氧化耦合陶瓷膜过滤小试反应器,通过连续流实验进行深度处理煤制气废水研究。结果表明,臭氧投加量≥100 mg/L,COD和UV₂₅₄的去除率分别≥54.4%和71.1%,出水BOD_5/COD> 0.3,TMP增长缓慢,膜污染得到有效控制;反应器HRT的优选时间为40～60 min,延长HRT对COD去除率的提高不显著。曝空气后,COD去除率无明显变化,TMP稍降低但不显著。与pH分别为5和10相比,pH=8时系统COD的去除率分别提高27.1和20.1个百分点;UV₂₅₄去除率分别提高提高20.4和6.7个百分点。NaHCO3(羟基自由基清除剂)对照实验证明,系统对COD的去除,除膜过滤(23.5%)和臭氧分子氧化作用外,羟基自由基反应(17.8%～31.9%)也是主要贡献因素。

Study on Ozonation Coupled with Ceramic Membarane Filtration on the Treatment of Coal Gasification Wastewater

An ozonation coupling ceramic membarane filtration reactor was built in lab-scale, advanced treatment of coal gas gasification wastewater was studied by continuous experiments. The results showed that, the removal efficiencies of COD and UV254 were above 54.4% and 71.1%, respectively, when the ozone dosage was above 100 mg/L, and the value of BOD5/COD of effluent were above 0.3. In addition, the TMP of membrane increased slightly,and the mitigation of membrane fouling was effectively controlled. The optimized HRT was 40~60 min, and the improvement of COD removal was not significant by prolonging HRT. After aeration, there was no significant change in COD removal rate, and the TMP of membrane was slightly reduced but not significant. Compared with pH was 5 and pH was 10, the removal rate of COD increased by 27.1 percent and 20.1 percent respectively, on the condition of influent pH was 8, and the removal rate of UV254 increased by 20.4 percent and 6.7 percent respectively. The results of COD removal with and without NaHCO3(which is a kind of inorganic hydroxyl radical scavenger) further indicated that, for the removal of COD, the hydroxyl radical reaction was another predomiant contributor(17.8%~31.9%), except for membrane filtration(23.5%) and ozone molecular oxidation.