含腐殖酸类有机物模拟废水超滤过程研究

Studies on ultrafiltration membrane process of simulated wastewater containing humic acid organic substances

研究了用中空纤维超滤膜组件净化含腐殖酸类有机物模拟废水的过程.考察了料液中Ca2+浓度、离子强度和pH值对超滤过程的影响.实验结果表明,由于Ca2+与腐殖酸分子发生络合反应,随着料液中Ca2+浓度的增大,膜污染程度加剧;料液离子强度的变化改变了腐殖酸分子的构型和溶质分子之间以及溶质分子与膜面之间的相互作用,随着溶液离子强度的增大,膜通量下降程度增大;料液pH值的降低减少了腐殖酸分子链上官能团中H+的离解度,随着pH值的降低,膜污染程度增大;同时,随着料液中Ca2+浓度、离子强度的增大以及pH值的降低,膜对腐殖酸的脱除率降低.

The purified process of simulated wastewater fiber ultrafiltration membrane module was studied. The containing humic acid （HA） substances by using hollow effects of Ca^2＋ concentration, ionic strengh and pH value on the membrane process were investigated. The experiment results indicate that the membrane flux decrease is accelerated with increasing Ca^2＋ concentration due to its complex formation with the functional groups of HA. The change of the ionic strengh can influence the configuration of the HA macromolecule, and also affect the interaction between the solutes as well as between the solutes and the membrane surface. The decreasing extent of membrane flux increases with the increasing ionic strengh. Furthermore, decreasing pH value reduces the disso- ciation degree of H^＋ in the functional group of HA macromolecule chain, therefore the membrane fouling in- creases with decreasing solution pH. The results also show that the rejection of HA decreases with increasing Ca^2＋ concentration and ionic strengh, and with decreasing pH value.