DETERMINATION OF THE DISINFECTANT ACTION OF CAUSTIC LIME ON THE MICROFLORA OF SLUDGE OF WASTEWATER OF CLEANING FACILITIES FOR SEWERAGE AND CATTLE-BREEDING COMPLEXES

Abstract

Introduction. The main task of treating sewage sludge is to obtain the final product, the properties of which would ensure the possibility of its utilization and minimize the damage to the environment. The sanitary and hygiene characteristics of the sediment are assessed by the presence of pathogenic microorganisms and helminths eggs. The degree of disinfection of the sediments is controlled according to SanPiN 2.1.7.573 - 96. The objective of the work. Determination of optimal doses of caustic lime for disinfection of microbial contamination of sewage sludge of household wastewater of sewerage cleaning facilities (SCF) and liquid manure of the swine complex. Material and methods. The object of the study were microbial communities of the sludge of the SCF household wastewater and liquid manure of the swine complex. Standard microbiological research methods were used in the work according to MU 2.1.5.800 - 99 and MR N FTs/4022. For representativeness, analyses were performed in triplicate. Results. Caustic lime was added in the amount of 1 to 10% of the volume (mass) of the sludge under study into the sludge of household wastewater (humidity of 97 - 98%). The contact time was 0.5 hours, 1 hour, 3 hours. At a concentration of caustic lime of 5 and 6%, the absence of microflora was noted after 1 hour, at a concentration of caustic lime 8 - 10% - after 0.5 hours. After 3 hours, for any amount of caustic lime (from 1 to 10%) in the native sludge of wastewater sewerage, all the microorganisms under study were not shown. Into the liquid manure (humidity less than 85%), caustic lime was added in the amount of 4 - 10% of the volume (mass) of the material being examined. The exposure was of 1 and 3 hours. The complete death of microbes at any exposure was observed at a concentration of caustic lime 9 and 10%. Conclusion. The investigations have shown the dynamics of death of microorganisms in studying the impact of caustic lime on both native and sterilized material to be the same. The total death of microorganisms during the treatment of sludge from household wastewater was observed at a concentration of caustic lime of 7 - 9%. The complete death of microbes in liquid manure (native and sterilized) at any exposure was observed at a concentration of caustic lime 9 and 10%.