Sereda A. Two-stage purification of landfill infiltrates in aerobic lagoons and municipal wastewater treatment facilities

In the dissertation research an actual scientific and practical task is solved: the increase of hydrosphere environmental safety through two-stage purification of landfill infiltrates in aerobic lagoons and municipal pollution control facilities. The proposed method of avoiding the environmental hazard from the landfill infiltrates will allow to successfully implement technical and biological re-cultivation of landfills. The methodological bases for achievement of environmental safety of landfills in the conditions of transition to modern technologies for solid municipal waste`s utilization in Ukraine were considered. The data of the monitoring of hydrosphere pollution in landfill`s impact zone, on the example of Hrybovytske (Lviv) landfill, of solid municipal waste were collected. It was concluded that solving the problem of introducing innovative technologies for management of solid waste is possible only under the condition of an integrated approach. Pretreatment of Hrybovytske landfill infiltrates was suggested to be applied in aerobic lagoon and the final treatment – on sewerage pollution treatment facilities in Lviv. The aerobic stage was studied in the laboratory conditions (under the static and the dynamic conditions). Under the static conditions the kinetics of concentrations alteration of NH4-N, рН, COD and dissolved oxygen was studied in the process of biological aerobic purification of the infiltrate, as well as the dependence of this kinetics from the air consumption and the addition of active sludge. In dynamic conditions the optimal time of infiltration delay in the aerated lagoon is determined, as well as the dependence of the change in the relative concentration of ammonium nitrogen in the infiltrate for the temperature of the process implementation, the addition of the adjuvant bodies to the system for immobilization on them of biocenosis, the kinetics of the change in the relative concentration of ammonium nitrogen in the infiltrate from the periodicity of aeration. The peculiarities of the biocenosis development of the aerated lagoon were studied. The analysis of technological features of the pre-cleaning stage of dumps infiltration in the aerated lagoon was carried out. Based on conducted research in the pilot plant, that imitates work of Lviv sewerage pollution control facilities, a minimal permissible level of the filtrates dissemination in the municipal sewage was set, aiming the effective work supply of these pollution control facilities. In order to clean the filtrates in municipal sewage treatment plants, the stability of the time clearing indicators has been confirmed in dynamic mode. No systematic statistically significant increase in concentrations of any of the heavy metals in the activated sludge in the process of cleaning the mixture of infiltration and household effluents was observed. During the elemental analysis of the spent active sludge after its biodegradation it was confirmed that it is possible to use it as a fertilizer for damaged lands re-cultivation. As a result of the generalization of these studies, a general strategy for two-stage cleaning of landfill infiltrates is proposed. Keywoards: environmental safety, infiltrates, two-stage purification, aerobic lagoon, biocenosis, sewerage pollution control facilities, dynamic, static regime.