焦化废水中水回用工艺中反渗透膜污染清洗应用

Reverse Osmosis Membrane Fouling Cleaning in Recycling Technology of Coking Wastewater

采用双膜法工艺处理焦化废水,实现中水回用。项目选用型号DOWTM BW30XFR-400/34i卷式反渗透膜,初始运行通量16 LMH,经过6月运行后,通量下降>95%。膜元件采用浸泡方式能极大程度地提高清洗效果,采用LC-07强酸型清洗剂对膜通量恢复和截留率的提升效果显著,膜元件截留率可以由清洗前的57.23%稳定恢复至>90%。SEM结果显示,清洗后膜表面仍然残留有少量的污染物,ATR-FTIR谱图显示经化学清洗后,聚砜支撑层的O=S=O对称伸缩振动峰发生明显红移,酰胺I和酰胺II特征峰整体发生蓝移,可能是膜面污染物的存在导致特征基团的电子跃迁。

Double-membrane process was used for coking wastewater reuse,the DOWTM BW30XFR-400/34i series reverse osmosis membrane was selected in the project.In comparison with new BW30XFR membrane module,the flux decreased more than 95%for the fouled membrane module.It was found that the recovery of membrane capability required repeated and long-term chemical cleaning.The soaking method could improve the cleaning effect greatly.LC-07 could remarkable effect on membrane characteristics with more than 95%flux recovery.The rejection of membrane increases to more than 90%after chemical cleaning,contrast with 57.23%of fouled membrane.As shown in SEM results,there were still membrane foulants on the membrane surface.ATR-FTIR spectra showed that after chemical cleaning,the O=S=O symmetrical stretching vibration peak of the support layer of polysulfone had obvious red shift,and the characteristic peaks of amide I and amide II had blue shift,which might be that the presence of pollutants in the membrane surface led to the electronic transition of the characteristic groups.