Coupling effect of 17β-estradiol and natural organic matter on the performance of a PAC adsorption/membrane filtration hybrid system

A powdered activated carbon/submerged microfiltration (PAC/SMF) system was investigated to examine the removal efficiency of 17 beta-estradiol (E2) as well as the membrane filterability in the presence of natural organic matter(NOM). The removal of E2 was approximately 92%. but the presence of NOM did not significantly affect the adsorption efficiency of E2 on PAC. When E2 was spiked in the raw water containing NOM, the coupling phenomena did not occur in the rejection of E2 and NOM, but took place in the membrane fouling. Although the reduction of filterability by E2 itself was not so significant, membrane fouling by the river water in the presence of E2 significantly deteriorated in comparison to that generated by filtrating only the river water without E2. This was because E2 induced the additional adsorption of weakly-adsorptive NOM. This coupling phenomenon was related to the initial contact concentration of E2 with the membrane surface. The higher the initial contact concentration, the worse the fouling by NOM.