阵列平板膜在MBR系统中的运行效能分析

OPERATING PERFORMANCE ANALYSIS OF ARRAYED FLAT SHEET MEMBRANES IN AN MBR SYSTEM

以北京市某市政污水处理厂为例,分析介绍了阵列平板膜组器在该厂膜生物反应器中的运行情况。运行数据表明:阵列平板膜在平均通量25 L/(m^(2)·h),气水比8.5的条件下,具有良好的运行稳定性。通过对同一条廊道内不同位置的组器进行污染差异性及原因分析,发现污泥浓度差异与组器间膜污染程度呈正相关。组器浓缩效应导致污泥浓度呈梯度递增,回流端与进水端的平均污泥浓度比为1.09(最大可达到1.22),浓度的差异直接影响组器间的膜污染程度差异。在平均通量为15~25 L/(m^(2)·h)下运行时,组器两极通量比值仅为1.13~1.15,表明阵列平板膜组器的管路损失较小且通量分布均匀性较好。经与同类型产品相比,阵列平板膜在运行能耗及维护费用方面具有明显优势。

This article gave an introduction to the application of arrayed flat sheet membranes in membrane bioreactors(MBRs)by taking a municipal sewage treatment plant in Beijing as an example.The operating data showed that the arrayed flat sheet membranes were operated stably at a flux of 25 L/(m^(2)·h)and a gas-to-water ratio of 8.5.Differences in fouling performances among the membrane cassettes and their influencing factors were analyzed.The sludge concentration in the membrane tank was positively related to membrane fouling.The sludge concentration increased gradually due to the concentration effect of membrane rejection of the solids.The local sludge concentration along the membrane tank was concentrated by 1.09 times on average(with a maximum of 1.22 times),which directly affected the fouling of membrane cassettes at different positions of the tank.At the overall flux of 15 to 25 L/(m^(2)·h),the spatial uniformity of flux on each membrane unit of a membrane cassette was outstanding,enabling a maximum-to-minimum ratio of only 1.13 to 1.15,which fully proved the low frictional loss through the membrane channel and pipeline.The arrayed flat sheet membranes exhibits a prominent advantage of relatively lower operating energy consumption than other similar products.