膜蒸馏法浓缩反渗透浓水的试验研究  

Study on Concentration of Reverse Osmosis Concentrate by Membrane Distillation

作　　者：孙项城[1] 王军[1] 侯得印[1] 王宝强[2] 栾兆坤[1] 

机构地区：[1]中国科学院生态环境研究中心,北京100085 [2]中国矿业大学化学与环境工程学院,北京100083

出　　处：《中国给水排水》2011年第17期22-25,30,共5页China Water & Wastewater

基　　金：国家高技术研究发展计划(863)项目(2009AA063901);国家自然科学基金资助项目(20907066)

摘　　要：采用直接接触式膜蒸馏法浓缩处理反渗透浓水,系统研究了未经预处理、酸化预处理和阻垢预处理后的反渗透浓水在膜蒸馏浓缩过程中产水电导率、产水通量和膜污染的变化规律。试验结果表明,在三种膜蒸馏试验中,膜蒸馏的脱盐率均稳定。未经预处理的反渗透浓水在膜蒸馏过程中产水通量下降迅速,膜表面CaCO3污染是其主要原因。酸化预处理在一定程度上延缓了膜蒸馏浓缩过程产水通量的衰减,但随着浓缩过程的进行,仍然有沉积物在膜表面形成,导致通量下降。经阻垢预处理后膜蒸馏浓缩过程的膜通量比较稳定。这是因为阻垢预处理在一定程度上预防了难溶盐在膜表面的沉积,减缓了膜污染。对经阻垢预处理后的反渗透浓水保持浓缩倍数为3,在112 h的长周期运行中产水电导率稳定在5μS/cm以下,且产水通量下降缓慢,至试验结束时产水通量为13.9 kg/(m2.h),较初始通量只下降了10.9%。Direct contact membrane distillation （MD） was applied in concentration of reverse osmosis （RO） concentrate. RO concentrates without pretreatment, with acidification pretreatment and antisealant pretreatment were employed as the feed of MD concentration process to investigate the differences in permeate conductivity, permeate flux and membrane fouling. The results show that in all the MD processes, the salt rejection rate is stable. When reverse osmosis concentrate is used directly as feed, the permeate flux is diminished rapidly, and CaCO3 scaling is the major reason of permeate flux decline. Acidification pretreatment prevents permeate flux decline to some extent. However, with increasing of concentration factor, the flux declines seriously, this is also caused by scaling in MD process. Antisealant pretreatment can relieve permeate flux decline by reducing deposition of insoluble salts on membrane surface. A 112 h continuous MD desalination experiment of RO concentrate with antiscalant pretreatment was carried out with concentration factor at constant 3, the permeate conductivity is less than 5 μS/cm,and the permeate flux is decreased slowly. At the end of the experiment, the permeate flux is 13.9 kg/ （m2·h） , which is decreased by 10.9% compared with the initial flux.

关 键 词：膜蒸馏 反渗透浓水 膜污染 阻垢 浓缩 

分 类 号：X703[环境科学与工程—环境工程]