The ways of intensification of domestic wastewater treatment processes at small wastewater treatment plants with capacity of 40 m3/day due to modernization of process scheme and application of bioaugmentation technology are considered. The directed selection of community with the introduction of fungal culture Penicillium brasilanum, which presumably plays the role of "biological framework" in the formation of aerobic sludge granule, was carried out. It is found that the isolated fungal culture contributes to the improvement of sedimentation properties. It is concluded that the introduction of fungal culture into the activated sludge community of wastewater treatment plants reduces the sludge index. © 2025 Izdatel'stvo Kalvis. All rights reserved.