A pilot-scale hybrid municipal wastewater reclamation system using combined coagulation and disk filtration, ultrafiltration, and reverse osmosis: Removal of nutrients and micropollutants, and characterization of membrane foulants

• Particulate materials are effectively removed by CC–DF process.
• Removal of micropollutants by RO is governed by the MW, Log D, and charge characteristics.
• EfOM with small MW contributes to fouling formation of the UF and RO membranes.
• Hydrophilic fractions are responsible for fouling formation of UF and RO membranes.
• Residual coagulants after CC–DF contribute to fouling formation of UF membrane.

A pilot-scale municipal wastewater reclamation system using combined coagulation and disk filtration (CC–DF), ultrafiltration (UF), and reverse osmosis (RO) membrane has been built to investigate removal of water contaminants and fouling mitigation. The reclaimed water using the pilot system could meet draft regulations on wastewater reuse of the California Department of Public Health (DOC: 0.5 mgC/L; TN: 5 mgN/L). The removal of micropolluants by the CC–DF process and UF could not be evaluated by their MW, Log D, and charge characteristics. However, they were identified as governing factors affecting the removal of micropollutants by the RO. The CC–DF process might effectively remove particulate materials capable of contributing to cake layer formation on the UF membrane surfaces but the residual coagulants provided a strong effect on fouling formation of the UF membrane. Thus, hydrophobic fractions of the desorbed UF membrane foulants were higher than those of the desorbed RO membrane foulants.