改性聚醚砜吸附膜对磷酸盐的去除研究

Study on Phosphate Removal by Modified Polyether Sulfone Adsorption Membrane

为开发一种能够对磷酸盐进行吸附去除的吸附膜,本研究选择聚醚砜(PES)作为膜的基础材料,利用氯乙酰氯和二乙烯三胺对膜材料进行改性接枝,最终成功制成一种能够对磷酸盐进行有效吸附的改性聚醚砜吸附膜。通过FTIR和SEM表征,该膜具有孔状多层结构和明显的氨基吸收峰,结合密度泛函计算和福井函数初步构建了整个反应过程中的各阶段分子结构变化,结果证明通过酰化反应和胺化反应氨基已经成功接枝到聚醚砜膜上。25℃时,该吸附膜的单位面积吸附量在60 min时达到饱和吸附量0.17 mg/cm^(2),且饱和吸附量与温度成正比。共存离子和pH对膜的吸附性能影响较大,该膜在酸性条件下表现出较好的吸附性能,在pH为3时吸附量达到最高值0.19 mg/cm^(2),而SO_(4)^(2-)的存在对膜的吸附性能的影响可达到8%以上。该膜在连续10次脱附循环实验的情况下依旧保持80%的吸附能力,说明该膜具有较好的资源回收以及重复利用的实际价值。

In order to develop an adsorption membrane capable of phosphate adsorption removal,this study selected polyether sulfone(PES)as the basic material of the membrane and modified the membrane material by chloroacetyl chloride and diethylenetriamine.Finally,a modified PES adsorption membrane capable of effective phosphate adsorption was successfully prepared.Through FTIR and SEM characterization,the membrane had a porous multilayer structure and obvious amino absorption peak.Combined with density functional calculation and Fukui function,the molecular structure changes of each stage in the whole reaction process were preliminarily constructed.The results showed that amino groups were successfully grafted onto the polyethersulfone membrane through acylation and amination reactions.At 25℃,the adsorption capacity per unit area of the adsorption film reached the saturation adsorption capacity of 0.17 mg/cm^(2) at 60min,and the saturation adsorption capacity was proportional to the temperature.Coexisting ions and pH had a great influence on the adsorption performance of the membrane.The membrane exhibits good adsorption performance under acidic conditions,and the adsorption capacity reached the highest value of 0.19 mg/cm^(2) when pH was 3.The influence of SO_(4)^(2-) on the adsorption performance of the membrane could reach more than 8%.The membrane still maintains 80%adsorption capacity under the condition of 10 consecutive desorption cycle experiments,indicating that the membrane had good practical value of resource recovery and reuse.