Mechanism study and performance evaluation of pharmaceuticals and personal care products removal by nanofiltration and reverse osmosis

• Main Authors: Chung-hsiang Lee, 李仲翔
• Other Authors: Yi-li lin
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/73220488075775973912

碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程研究所 === 99 === In this study, two commercial nanofiltration membranes (NF90 and NF270) and one reserse osmosis membrane (XLE) were used to evaluate the removal of six pharmaceuticals and personal care products (PPCPs) (Carbamazepine, Ibuprofen, Sulfadiazine, Sulfamethazine, Sulfamethoxazole and Triclosan) in the aqueous environment in the pH range of 3-10 with or without the presence of alginate fouling layer. The membranes were also characterized by physical-chemical properties of molecular weight cut-off, hydrophobicity, membrane surface charge, morphology and roughness to validate the rejection mechanisms of the PPCPs. It was found that the removal efficiencies of PPCPs by the chosen membranes were affected by the interactions of the physical-chemical properties of membranes and PPCPs as well as solution pH. At low pH values, steric hindrance exclusion (and adsorption) are two dominnt mechanisms for the rejection of unionized PPCPs, while electrostatic repulsion contributes to PPCPs rejection at high pH values because the dissociation of functional groups of membranes and PPCPs both increase as pH increases. The results of static batch adsorption tests suggested that the adsorption of PPCPs onto membrane surface depends on the hydrophobicity of PPCPs instead of the pressurized advective flow to transport the PPCPs into the active polymer of membranes surface. The results of fouling tests using sodium alginate indicated that the alginate fouling layer on the membrane surface could provide an additional structural barrier so that the rejection of PPCPs was enhanced. The simplified charge concentration polarization model was validated to be effective for the prediction of PPCPs removal by tight membrane with the contribution of electrostatic repulsion based on the removal effieiency of non-ionic PPCPs.