摘要:
以聚砜超滤膜为基膜,通过聚酰胺-胺(PAMAM,G0)与均苯三甲酰氯(TMC)的界面聚合反应制备了复合纳滤膜.通过正交实验优化了纳滤膜的制备条件,并通过傅里叶变换红外光谱仪(FTIR-ATR)、场发射扫描电镜(FESEM)进行膜表面结构及形貌分析,测试了纳滤膜的盐截留能力.结果表明:纳滤膜制备条件确定为聚酰胺-胺(PAMAM,G0)浓度为0.25%,均苯三甲酰氯(TMC)浓度为0.3%,界面聚合时间为90 s,热处理温度为80°C,热处理时间15 min.界面聚合后在超滤膜表面形成了一层致密的聚酰胺(PA)活性皮层,所制得的复合纳滤膜盐截留顺序为Na2SO4>MgSO4>MgCl2 >NaCl,表明纳滤膜表面带有负电荷.纳滤膜处理采油废水时,存在过滤初期的通量快速下降、随后的缓慢下降以及最后的通量稳定3个阶段,且压力为0.7 MPa,0.9 MPa和1.1 MPa时所对应的通量由10 L/(m2·h)逐渐升高到22 L/(m2·h),其对采油废水的盐截留率处在12.6 %~14%之间.%Composite NF membrane was prepared by interfacial polymerization with poly (amidoamine) (PAMAM,G0) and trimesoyl chloride (TMC) on the substrate of PSF UF membrane.The prepared conditions were optimized and the surface structure and morphology of the resulting membrane were characterized with FTIR-ATR and FESEM,then the separation performance for kinds of salt using resulting membrane was studied.The results indicated that the preparation conditions were PAMAM(G0) concentration 0.25%,TMC concentration 0.30%,interfacial polymerization time 90 s,heat treatment temperature 80 °C,heat treat time 15 min.The surface analysis results indicated that the dense active skin layer was formed on the substrate after interfacial polymerization.The order of salts rejection rate is Na2SO4>MgSO4 >MgCl2 >NaCl,which showed that theresulting membrane was negatively charged.When nanofiltration membrane treated with produced water,the flux decline includes three stages,such as beginning drop fast,slow down and flux stability period.And the corresponding flux increased from 10 L/(m2 · h) to 22 L/(m2 · h) when operating pressure is 0.7 MPa,0.9 MPa and 1.1 MPa,respectively,meanwhile the salt rejection rate is between 12.6% and 12.6%.