Efficiency of microfiltration in disk filters with plane and volume filtration in the process of removing phytoplankton from water from surface sources

Summary

«Mosvodokanal» JSC has completed testing DynaCloth automatic self-cleaning fiber disc microfilter for the Moskva River water. The tests were carried out during the periods of intensive phytoplankton growth eliminating the use of chemicals. The filtration surface area of the filter was 0.45 m². At 4–8 m³/h water flow rate the hydraulic load was 9–18 m/h. Wash water flow was 1.1–3.3% of the water flow in the unit depending on the type of the filter cloth. Different types of algae dominated in the Moskva River water in different periods. In general, at the peak diatom number their concentration during filtration decreased less than by 53%. The decrease in the number of green algae at the peak of their growth occurred by 56–60%, and that of blue-green algae – by 36%. Cells of diatoms and green algae coenobia are larger than blue-green cells; accordingly, the efficiency of their capture by the filter was higher than that of blue-green algae. The results of the studies carried out for the Moskva River water showed that microfiltration in disk filters with fiber filter cloth can be a promising method for removing phytoplankton (about 50%) from low-turbid eutrophicated waters.

Key words

phytoplankton , river water , microalgae , disk filtration , disk fiber microfilter