浸没式厌氧膜生物反应器处理垃圾渗滤液的连续运行性能

厌氧消化是垃圾渗滤液处理的重要技术,常规厌氧工艺在处理过程中存在微生物易流失和出水水质较差等问题。采用厌氧膜生物反应器在中温条件下处理垃圾渗滤液,考察了废水降解性能和膜过滤性能。连续100 d的反应器运行实验表明:在水力停留时间为10 d,COD容积负荷平均为5.63 kg/(m3·d)的条件下,系统运行稳定,平均COD去除率达到92%,膜出水总挥发性脂肪酸浓度低于200 mg/L,pH稳定在7.95左右。在膜通量为6 L/(m2·h)下,连续62 d内的膜压增长缓慢,未出现明显的膜污染。批次产甲烷试验结果表明:渗滤液产甲烷潜能达到305 mL/g TS,与连续运行实验296 mL/g TS的产气效果接近,沼气中甲烷浓度可高达70%~80%。产气达到90%和95%的潜能分别用时2.5,3.1 d,说明反应器有进一步缩短水力停留时间的可能性。反应器驯化的厌氧活性污泥对乙酸有较好的耐受性,在乙酸浓度为10000 mg/L时,产气迟滞期仅为1.4 d。综合来看,长期运行厌氧膜生物反应器处理垃圾渗滤液具有较好的COD去除效果、运行稳定性和膜过滤性。

PROCESS PERFORMANCE OF A SUBMERGED ANAEROBIC MEMBRANE BIOREACTOR IN TREATING LEACHATE FROM ORGANIC FRACTION OF MUNICIPAL SOLID WASTE

Anaerobic digestion is an important technology for landfill leachate treatment. There are some problems in the conventional anaerobic process, such as easy loss of microorganisms and poor effluent quality. In this paper, landfill leachate was treated by an anaerobic membrane bioreactor at medium temperature, and the degradation performance and membrane filtration performance of wastewater was investigated. The experimental results showed that the system ran stably under the conditions of hydraulic retention time of 10 days and volume load of 5.63 kg/(m3·d). The average COD removal rate reached 92%, the total volatile fatty acid concentration of membrane effluent was less than 200 mg/L, and the pH value was stable at about 7.95. At a membrane flux of 6 L/(m2·h), the membrane pressure increased slowly in 62 consecutive days without obvious membrane fouling. Batch methane production test results showed that the methane production potential of leachate reached 305 mL/g TS, being close to the gas production effect of 296 mL/g TS in the continuous running experiment. Methane concentration in biogas was high, up to 70%~80%. It took 2.5 days to reach 90% and 3.1 days to reach 95% of the total potential, respectively, indicating that the reactor had the possibility of further shorting the hydraulic retention time. The acclimated anaerobic activated sludge in the reactor had a good tolerance to acetic acid. When the acetic acid concentration was 10000 mg/L, the gas production lag period was only 1.4 days. In general, the long-term operation of the anaerobic membrane bioreactor has good COD removal effect, operation stability and membrane filtration performance when treating landfill leachate.