Removal of 17β-estradiol by powdered activated carbon—Microfiltraion hybrid process: The effect of PAC deposition on membrane surface

Abstract

The removal of 17β-estradiol (E2) was investigated in a powdered activated carbon-submerged microfiltration (PAC-MF) hybrid system to better understand the effect on the system performance of PAC deposition on the membrane. A series of experiments were carried out under various operating conditions. Although the rejection or adsorption of E2 by MF membrane itself was almost negligible, the concentration of E2 in the permeate was always lower than it was in the reactor. This is because E2 was further removed as it passed through the PAC layer deposited on the membrane. As the E2 removal efficiency by the deposited PAC was lower than that by the PAC in the bulk phase, the overall E2 removal was largely dependent on the fraction of the deposited PAC on the membrane which were influenced by operating parameters such as permeate flux, hydraulic retention time (HRT) and mixing intensity in a PAC-MF system. The effect of these parameters on the overall E2 removal rate were also determined quantitatively using model equations developed in this study.