Removing suspended solids from effluent in the process of tertiary treatment by microfiltration in disk filters with flat and volumetric filtration

Summary

Mosvodokanal JSC carried out tests of a pilot microfiltration plant based on a disk filter with a fabric filter cloth. The pilot plant supplied by Mediana-Filter RPC JSC has been designed for removing suspended solids from effluent in the process of tertiary treatment. Disk microfiltration with fabric filter cloth (volumetric filtration type) provides for removing suspended solids to 4 mg/l in the effluent after biological treatment while using fabric filter cloth of 10 µm typical size and to 2 mg/l while using 5 µm filter cloth. At 8.5 m/h filtration rate the consumption of wash water for the pilot plant for 10 µm filter cloth was 0.7–1.4% of the water flow, and 5.8–6.8% for 5 µm filter cloth. Beside suspended solids present in the suspension, COD, BOD₅, total nitrogen and total phosphorus are also removed. Microfiltration plants of volumetric type are similar to the plants of flat type and can be used to ensure high quality tertiary treatment of effluent after biological treatment to remove suspended solids.

Key words

wastewater treatment , dragged particles , microscreening , disc filter , pile fiber filter cloth