Advanced technology of municipal wastewater treatment
with granular sludge

Summary

Increasing the specific biochemical capacity of the facilities using the so-called granular activated sludge is one of the promising areas for the development of biological wastewater treatment technologies. Granular sludge is microbial biocenosis specializing in the decomposition and mineralization of substances present in wastewater. The main distinction from regular sludge is due to two important factors: the composition of the basic structural unit of granular sludge – granules, and a high sedimentation rate (up to 20 m/h). This provides for developing sludge doses of up to 10 g/l in bioreactors of wastewater treatment. The results of the development of the first biotechnology in Russia for municipal wastewater treatment of using granular activated sludge are presented. The technology has been implemented at the facilities of Mosvodokanal JSC. The technology of aerobic biological treatment in a sequencing batch reactor with sequential nitri-denitrification and an upward flow of wastewater provides for the quality of effluent that meets the standards for maximum permissible concentrations for discharge into fishery bodies. Technical and economic comparison of the developed technology with the technology of removing nutrients in flow-through aeration tank showed that the life cycle costs of the facilities with partially granulated activated sludge are 1.4 times less than the costs of traditional biological treatment technology (for a capacity of 1000 m³/day).

Key words

biological treatment , granulated activated sludge , municipal wastewater , nutrients removal , SBR-reactor