WAYS OF RESTORATION OF THE TERRITORIES OF FILTRATION FIELDS OF COMMUNAL SEWAGE TREATMENT PLANTS AFTER RECONSTRUCTION

Abstract

Finding safe ways to dispose of sewage sludge generated at treatment facilities is one of the main problems for operating organizations. The filtration fields of the communal treatment facilities of the city of Kropyvnytskyi, located near the village of Pervozvanivka, were decommissioned in 2004. The territory of buildings, part of which is in a dry state, and the other is covered with water, is not used, the accumulated layer of silt deposits pollutes the environment, releasing harmful substances. To determine ways to restore the territory of the filtration fields using it in economic activities, soil samples were taken in the interval 0-0.5 m and 1-1.5 m using the drilling method. Analysis of the physical and chemical parameters of the soil samples showed that plant nutrients (nitrogen, phosphorus, potassium) are present in sufficient quantities, and the upper sludge layer can be used as fertilizer. However, in some areas, 2-5 times the maximum permissible concentration of cadmium, lead, zinc, and copper, makes it impossible to use the territory for growing agricultural products. The analysis of the situation showed that the removal of the upper silt layer of the soil with its further disposal at the landfill is economically impractical. The two most effective options for restoring the dry area of the filtration fields together with the accumulated sludge are proposed: the cultivation of bioenergy crops for the production of biofuel (willow, poplar, miscanthus, etc.) and the creation of a nursery for seedlings of forest species of trees and plants for landscaping cities. In order to dewater and clean the areas covered with water from heavy metals, for the purpose of their further use, it is proposed to plant them with higher aquatic plants, in particular reeds. The proposed ways of restoring the territory of the filtration fields after reclamation will ensure the economic effect of the activity and create additional jobs for the local population.