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用死端过滤法考察纳滤膜Desal5DK处理水中内分泌干扰物双酚A(BPA)和四溴双酚A(TBBPA)的效率,并研究吸附对纳滤截留有机分子的影响.结果表明,纳滤膜Desal5DK对BPA的表观截留率随累积吸附量的增加而降低,从初始的89%降至达到平衡状态时的47%,BPA累积吸附量相应达到约30μg·m-2.较高压力时,吸附层较高的溶质浓度引起膜通量下降.虽然Desal5DK对TBBPA累积吸附量达到50μg·m-2,但由于分子量较大和分子结构复杂,截留率较高(>95%).5×105Pa压力下解吸时TBBPA分子由于位阻效应几乎不能透过纳滤膜;而BPA则扩散通过纳滤膜,并且在流出30mL时浓度达到峰值,流出的BPA总量约占总吸附量的30%.
The effect of nanofiltration membrane Desal5DK on the concentration of BPA and TBBPA in water and the effect of adsorption on organic molecules entrapped by nanofiltration were investigated by dead end filtration.The results showed that nanofiltration The apparent rejection rate of Desal5DK to BPA decreased with the increase of cumulative adsorption amount from 89% to 47% at the equilibrium state, and the cumulative adsorption capacity of BPA reached about 30μg · m-2. At higher pressure , And the higher solute concentration of the adsorbed layer caused the decrease of membrane flux.While Desal5DK accumulated 50μg · m-2 of TBBPA, the rejection was higher (> 95%) due to its larger molecular weight and complex molecular structure. When desorbed under pressure, TBBPA molecules hardly permeate the nanofiltration membrane due to the steric effect. However, BPA diffused through the nanofiltration membrane and peaked at 30 mL. The total amount of BPA flowing out was about 30% of the total adsorbed amount.