切削液废水含有大量乳化油,如未经处理直接排放,会造成环境污染、水生态系统破坏等.为了实现水包油乳化废水的高效分离、降低膜污染,以成膜性好、力学性能稳定、耐化学性能佳的聚偏氟乙烯(PVDF)中空纤维膜为基膜,将胱胺的氨基引入到膜表面,再与甲基丙烯酸的羧基发生酰胺化反应,然后通过自由基聚合反应形成环状聚合物功能层,从而得到亲水性好、通量大且油水分离率高的PVDF基复合膜.通过红外光谱(IR)、扫描电镜(SEM)、水接触角等测试对改性前后的膜样品的物化性能进行表征;采用自制错流过滤装置测试正己烷油水混合乳液、切削液废水的分离效果.研究结果表明,原膜(M0)的水接触角(WCA)为 91.95°,改性后的膜M1,M2 和M3 的WCA分别降低至 65.78°,51.08°,71.70°,说明改性膜的亲水性提高.M0与M1,M2和M3在正己烷油水乳液分离中各自的渗透通量分别为37.34,58.40,81.57,44.55 L·m-2·h-1;对切削液废水分离的渗透通量分别是7.41,11.96,24.36,10.80 L·m-2·h-1.原膜和改性膜在分离高浓度的切削液废水时,渗透通量都有所下降,但改性膜的渗透通量明显高于原膜水渗透通量,其中M2改性膜的分离通量最佳,说明改性膜的亲水性和抗污染性最佳,有望用于工业含油废水处理.
Cutting fluid wastewater contains a large amount of emulsified oil.If it is discharged directly without treatment,it will cause environmental pollution and water ecosystem destruction.In order to efficiently separate oil-in-water emulsion wastewater and reduce membrane fouling,polyvinylidene fluoride(PVDF)hollow fiber membrane with good membrane-forming property,stable mechanical properties and good chemical resistance was used as the support,the amino group of cysteamine was introduced to the membrane surface,and then amidated with the carboxyl group of methacrylic acid,and followed by forming a cyclic polymer functional layer through a free radical polymerization reaction,thus PVDF-based composite membrane with good hydrophilicity,large flux and high oil-water separation rate was obtained.The physical and chemical properties of the modified films were characterized by infrared spectroscopy(IR),scanning electron microscopy(SEM)and water contact angle.The separation effect of n-hexane-in-water emulsion and cutting fluid wastewater was tested by self-made cross-flow filtration device.The results show that the water contact angle(WCA)of the original membrane(M0)is 91.95°,while the WCA of the modified membrane M1,M2 and M3 decrease to 65.78°,51.08° and 71.70°,respectively,indicating that the hydrophilicity of the modified membrane is improved.The permeation fluxes of M0,M1,M2 and M3 for n-hexane-in-water emulsion are 37.34,58.40,81.57,44.55 L·m-2·h-1,respectively.The water fluxes for cutting fluid and wastewater separation are 7.41,11.96,24.36,10.80 L·m-2·h-1,respectively.The fluxes of the original membrane and the modified membrane in separating high concentration cutting fluid wastewater decrease,but the permeation flux of the modified membrane is obviously higher than that of the original membrane,and the permeation flux of M2 modified membrane is the best,which indicates that the modified membrane has the best hydrophilicity and anti-pollution ability,and is expected to be used in the treatment of industrial oily wastewater.
刘耀威;黄坤;张博君;付维贵;杜润红;赵义平
天津工业大学 材料科学与工程学院 省部共建分离膜与膜过程国家重点实验室,天津 300387
化学工程
聚偏氟乙烯;胱胺;甲基丙烯酸;油水分离;切削液废水
polyvinylidene fluoride;cystamine;methylacrylic acid;oil-in-water separation;cutting fluid wastewater
《材料工程》 2024 (002)
227-234 / 8
国家重点研发计划资助政府间国际科技创新合作重点专项(2017YFE0114200)
10.11868/j.issn.1001-4381.2022.001079
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