Effect of powder-activated carbon pre-coating membrane on the performance of the UF system for wastewater reclamation: a pilot-scale study

Pretreatment is an indispensable means to alleviate membrane fouling and improve ultrafiltration (UF) performance. In this study, we designed and established a powder-activated carbon pre-coating membrane (PACPM) unit as a pretreatment for the UF system. The effective filtration area of PACPM was 0.5 m2. 300 g/m2 PAC was selected as the optimal dosage in the pilot-scale apparatus according to the laboratory-scale trial. The pre-coating membrane could be formed within 30 min. PACPM could remove different kinds of organic compounds with different molecular weights and hydrophobicity during a certain period of time. During 10 operation cycles, the specific flux decrease rate of PACPM-UF was only 2.8%, which was much lower than that of direct UF (13.4%). PACPM could improve the performance of the UF system, not only for the increase of the initial SF value but also for the increase of the flux recovery thorough backwash. Nevertheless, a regular replace-regeneration process is necessary to maintain PACPM performance.