In this study the applicability of the microsieve technology together with coagulation and flocculation for advanced phosphorus removal was investigated. A pilot unit including a microsieve with 10 µm mesh size is operated continuously with secondary effluent. By applying a pretreatment of 0.07-0.09 mmol/L coagulant and 1.5-2 mg/L cationic polymer total phosphorus values below 80 µg/L were achieved. Coagulation with polyalumium chloride (PACl) produced better effluent quality compared to FeCl3 as less suspended solids and less residual coagulant were found in the microsieve effluent. Also the transmittance of UV radiation through the water is improved by using PACl. The amount of backwash water was very low (< 3 %). Results after rebuilding the chemical pre-treatment showed that under optimized mixing conditions polymer doses << 1 mg/L are possible without losses in water quality and filtration performance. In total microsieving with chemical pretreatment is a viable option for high quality effluent polishing.

In this study the applicability of the microsieve technology together with coagulation and flocculation for advanced phosphorus removal was investigated. A pilot unit including a microsieve with 10 µm mesh size is operated continuously with secondary effluent. By applying a pretreatment of 0.036 – 0.179 mmol/L coagulant and 2 mg/L cationic polymer total phosphorus values below 100 µg/L were easily achieved. Values below 50 µg/L were possible at high metal dosing, but the higher suspended solid load reduced the capacity of the pilot unit. Coagulation with polyalumium chloride (PACl) produced better effluent quality compared to FeCl3 as less suspended solids and less residual coagulant were found in the microsieve effluent. Also the transmission of UV radiation through the water is improved by using PACl. The amount of backwash water was very low (< 3 %). In total, if combined with UV disinfection, microsieving with chemical pretreatment is a viable option for high quality effluent polishing.

In this study the applicability of the microsieve technology together with coagulation and flocculation for advanced phosphorus removal was investigated. A pilot unit including a microsieve with 10 µm mesh size is operated continuously with secondary effluent. By applying a pretreatment of 0.036 – 0.179 mmol/L coagulant and 2 mg/L cationic polymer total phosphorus values below 100 µg/L were easily achieved. Values below 50 µg/L were possible at high metal dosing, but the higher suspended solid load reduced the capacity of the pilot unit. Coagulation with polyalumium chloride (PACl) produced better effluent quality compared to FeCl3 as less suspended solids and less residual coagulant were found in the microsieve effluent. Also the transmission of UV radiation through the water is improved by using PACl. The amount of backwash water was very low (< 3 %). In total, if combined with UV disinfection, microsieving with chemical pretreatment is a viable option for high quality effluent polishing.