Removal of natural estrogens and synthetic compounds considered to be endocrine disrupting substances [EDs] by coagulation and nanofiltration

Our paper presents the evaluation of retention coefficient of such natural estrogens as estrone (E1), estradiol (E2) and estriol (E3) as well as synthetic compounds considered to be endocrine disrupting substances (EDs) – ethynylestradiol (EE2), mestranol (MeEE2) and diethylstilbestrol (DES) in water treatment processes, i.e. coagulation and nanofiltration. Estrogens were retained in effect of the adsorption on the particles of humic acids and on floccules of Al(OH)₃ and Fe(OH)₃. The efficiency of coagulation process was not good enough to remove these compounds completely from water. As a second stage of water treatment, nanofiltration was proposed. In this process, estrogens were adsorbed on membranes in their pores (Jv/Jw<1), and their retention was dependent on hydrophobility of micropollutants (logKow). The best treatment results were obtained for polyamide membrane (NF-DS5DK) within the range 93.5-99.9%.