Rejection of endocrine disrupters contained in biologically treated sewage by nanofiltration

摘要

Two commercial nanofiltration membranes, NF-1 (low salt rejection) and NF-3 (medium salt rejection), were used for basic experiments on the rejection of endocrine disrupters of 17βestradiol, p-nonylphenol, bisphenol A and their mixed solution. Nanofiltration membrane experiments were carried out under low trans-membrane pressure of 0.5 MPa as the operating condition. For the two nanofiltration membranes, the rejection factor was high when the pH of each feed solution was not adjusted. Based on the results of the nanofiltration membrane experiments, four commercial nanofiltration membranes-NF--1, NF-2 (medium salt rejection), NF-3 and NF-4 (high salt rejection)-were used for the rejection of endocrine disrupters contained in biologically treated sewage. The biologically treated sewage concentration of 0.039-0.055 μg/Las 17βestradiol equivalent was reduced by each nanofiltration membrane to 0.026 μg/ L(NF-1), 0.025 μg/L(NF-2), 0.003 μg/L(NF-3) and 0.009 μg/L(NF-4), as 17βestradiol equivalent, respectively. The rejection efficiency of endocrine disrupters showed the same tendency as the TOC rejection efficiency. The permeate flux of nanofiltration membranes was high in the order of NF-1, NF-3, NF-2 and NF-4.