DK型纳滤膜对水中微量邻苯二甲酸酯的吸附及截留特性

Adsorption dynamics and rejection characteristics of phthalic acid esters in DK nanofiltration membrane

邻苯二甲酸酯(PAEs)是一类典型的环境激素,对人体健康具有较大的危害。本文采用DK型纳滤膜去除水中微量邻苯二甲酸酯,分析了水中微量邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸正二丁酯(DNBP)和邻苯二甲酸异二丁酯(DIBP)等在DK型纳滤膜表面的吸附行为,考察了4种邻苯二甲酸酯的辛醇/水分配系数(logKow)和相对分子质量(Mw)对其在DK型纳滤膜表面的吸附和膜的截留特性的影响。结果表明Freundlich吸附方程能较好地描述4种邻苯二甲酸酯在DK型纳滤膜表面的动态吸附行为;DK型纳滤膜对水中微量邻苯二甲酸酯的截留特性表现为膜面吸附作用和膜孔筛分效应,吸附平衡后的截留机理取决于膜孔的筛分效应,DK型纳滤膜对DMP、DEP、DNBP、DIBP的截留率分别为55%、78%、96%和96.8%(0.5 MPa,30℃,DMP、DEP、DNBP、DIBP浓度均为300μg/L),表明DK型纳滤膜能高效去除水中的DNBP和DIBP。

The removal of trace phthalic acid esters （PAEs） in water used DK nanofiltration membrane has been investigated. The adsorption behavior of dimethyl phthalate （DMP）,dieth yl phthalate （DEP）,di n butyl phthalate （DNBP） and di iso butyl phthalate （DIBP） were ana lyzed. Influence of Mw and logKow of PAEs on the equilibrium adsorption capacity and rejection characteristics of DK nanofiltration membrane was also explored. It was found that adsorption isotherms of PAEs in DK nanofiltration membrane fit the Freundlich adsorption equation well. The rejection characteristics of PAEs involved the retention of adsorption and the retention of membrane pore before adsorption reaches saturation. After adsorption reaches saturation,the re jection mechanisms of PAEs could be described by pore model,and rejection rate （R） of DMP, DEP,DNBP and DIBP were 55%,78%,96%and 96.8%（0.5 MPa,30℃,PAEs’concen trations are 300μg/L）,respectively. The results indicated that the trace DNBP,DIBP in water could been rejected very effectively by DK nanofiltration membrane.