摘要
以某煤化工厂两级反渗透浓水为研究对象,采用纳滤膜进行分盐,考察了不同操作压力下纳滤膜对水中主要组分截留效果的影响。试验结果表明,纳滤膜对于SiO_2和COD的去除率分别为35.2%和54.8%;膜产水侧电导率和TDS明显下降,浓水侧电导率和TDS明显升高,且膜对TDS的截留率随着操作压力的增加逐渐升高;膜对Cl-呈负截留,负截留效果随压力增加而效果越显著;膜对SO_4~(2-)的平均截留率高达98.7%;产水侧Cl-和SO_4~(2-)质量浓度比明显升高,平均可达58.24,分盐效果较好。纳滤产水经蒸发结晶所得NaCl达到GB/T 5462—2015《工业盐》标准中工业干盐一级品要求;纳滤浓水经冷冻结晶所得Na2SO4达到GB/T 6009—2014《工业无水硫酸钠》标准中Ⅰ类工业无水Na_2SO_4一等品要求。
Taking two-stage reverse osmosis brine from a coal chemical plant as the research object,nanofiltration membrane was adopted to separate salt from the brine, the effect of nanofiltration membrane on interception of main components in water under different operating pressures was investigated. The results showed that, the removal rates of SiO2 and COD were 35.2% and 54.8% respectively; The conductivity and TDS of the membrane production water decreased significantly, the conductivity and TDS of the concentrated water side increased obviously, and the rejection rate of the membrane to TDS was gradually increased with the increase of operating pressure; the membrane showed negative interception for Cl-, ant the negative interception effect was more obvious with the increase of pressure; the average rejection rate of membrane to SO42-was as high as98.7%, the mass ratio of Cl-to SO42-in water production side was significantly improved, which was 58.24 in average, the salt separation effect was better. The quality of the NaCl obtained from evaporation crystallization of nanofiltration production water met the requirement of top quality industrial dry salt in GB/T 5462—2015 Industrial Salt. The Na2 SO4 obtained from freezing crystallization of nanofiltration brine reached the requirement of top quality industrial anhydrous Na2 SO4 of class I in GB/T 6009—2014 Anhydrous Sodium Sulfate for Industrial Use.
引文
[1]纪钦洪,于广欣,张振家.煤化工含盐废水处理用探讨[J].水处理技术, 2014, 40(11):8-12.
[2]黄开东,李强,汪炎.煤化工废水“零排放”技术及工程应用现状分析[J].工业用水与废水, 2012, 43(5):1-6.
[3]韩勇涛,冯杰,周海,等.煤化工高含盐废水零排放处理工程实例[J].工业用水与废水, 2014, 45(2):62-63.
[4]杨善远,孙继涛,于峥.煤化工废水再生及浓盐水处理工艺[J].工业用水与废水, 2018, 49(5):45-49.
[5]周厚方,施武斌,丁志刚,等.煤化工高浓盐水分质资源化利用[J].煤炭加工与综合利用, 2017,(12):23-26.
[6]陈富强,池勇志,田秉晖,等.高盐工业废水零排放技术研究进展[J].工业水处理, 2018, 38(8):1-5.
[7]吴雅琴,申屠勋玉,杨波,等.膜集成技术在煤化工高盐废水资源化中的应用[J].煤化工, 2016, 44(4):6-9.
[8]张莉娜.纳滤膜脱盐及其在海水软化中的应用[D].上海:华东理工大学, 2011.
[9]许振良,汤永健,周秉武,等.纳滤膜功能层构筑及其应用[J].水处理技术, 2015, 41(12):3-9.
[10]何启贤,刘久清,颜果春,等.纳滤膜结构特征对纳滤过程分离性能的影响[J].工业水处理, 2010, 30(7):22-25.
[11]赛世杰.纳滤膜在高盐废水零排放领域的分盐性能研[J].工业水处理, 2017, 37(9):75-78.