正渗透膜生物反应器膜过滤实验研究

Experimental Study on Membrane Filtration Characteristics in Forward Osmosis Membrane Bioreactor

为研究正渗透膜生物反应器膜过滤特性,在明确正渗透膜生物反应器工作原理与研究难点的前提下预设实验,使用氯化钠为污水模拟驱动介质,并基于OMBR通用处理技术进行生活污水处理方式模拟。充分记录关键性元件正渗透膜分离过程中驱动液浓度、膜朝向、错流速率、活性污泥浓度等可测物理量,以标定分析相应因素对膜过滤性能的关联影响程度。研究表明:(1)实验预设NaCl浓度由0.5 mol/L上升至3 mol/L过程中,相应可测物理量水通量(Jw)增长速度明显,数据显示由4.97 L/(m^2·h)递增至13.33 L/(m^2·h),同样当NaCl浓度由0.5 mol/L上升至3 mol/L过程中,反向盐通量Js的数量级由9.26 g/(m^2·h)递增至42.58 g/(m^2·h);(2)相关的Jw和Js可测物理量在活性层朝向驱动液条件下(AL-DS)较活性层朝向原料液(AL-FS)条件下略大;(3)水通量Jw和反向盐通量Js可测物理量成正相关趋势;(4)相应水通量Jw数量级与活性污泥浓度成反比,进一步可以看出活性污泥浓度由3000 mg/L上升至5000 mg/L过程中水通量Jw数量级下降趋势缓慢。

In order to study the membrane filtration characteristics of the forward osmosis membrane bioreactor,the experiment was designed on the premise of clarifying the working principle and research difficulties of the forward osmosis membrane bioreactor.Sodium chloride was used as the driving medium of sewage simulation,and the domestic sewage treatment was simulated based on OMBR general treatment technology.The measurable physical parameters were fully recorded,such as driving fluid concentration,membrane orientation,cross flow rate and activated sludge concentration in the process of forward osmosis membrane separation of key components,so as to calibrate and analyze the relevant influence degree of corresponding factors on the membrane filtration performance.The results showed that:(1)In the process of increasing NaCl concentration from 0.5 mol/L to 3 mol/L,the growth rate of measurable physical water flux(Jw)was obvious,and it increased from 4.97 L/(m^2·h)to 13.33 L/(m^2·h).Similarly,when the concentration of NaCl increased from 0.5 mol/L to 3 mol/L,the reverse salt flux Js increased from 9.26 g/(m^2·h)to 42.58 g/(m^2·h);(2)The related measured physical quantities of JW and JS were slightly larger when the active layer was oriented to the driving fluid(AL-DS)than when the active layer was oriented to the feed fluid(AL-FS).(3)There was a positive correlation between the water flux Jw and reverse salt flux Js.(4)The corresponding water flux Jw was inversely proportional to the activated sludge concentration,furthermore the water flux Jw decreased slowly in the process of increasing the concentration of activated sludge from 3000 mg/L to 5000 mg/L.