Content of heavy metals in the bottom sediments of the wastewater of the processing enterprise

Abstract

Wastewater contains stable and unstable pollutants. In the process of self-cleaning, a large amount of bottom sediments accumulates, especially in artificially created storage ponds. As a result of the increasing load on this type of water bodies and the accumulation of bottom sediments, the self-purification ability is sharply reduced, which entails an additional load on the environment. The use of bottom sediments for biological reclamation is allowed after the establishment of the hazard class in accordance with the current regulatory documents and taking measures to neutralize them. The purpose of this separate fragment of work was to study the total content of heavy metals in the bottom sediments of storage ponds of a milk processing enterprise and determine the possibility of their further use. As a result of the data obtained, it can be concluded that the lead content was 14.6-17.3 mg/kg, depending on the depth of the bottom sediment sampling layer. At a sampling depth of 0.5-1.0 meters, the lead content was maximum and exceeded the clarke values of the element by 8.1%. There is a 2 time excess of the clarke values for cadmium at a depth of 1.0-1.5 meters. Indicators for zinc and copper were 12.4-14.1 mg/kg and 5.9-9.8 mg/kg, respectively, and did not go beyond the threshold limits of the compared values. The research results allow concluding that the bottom sediments of the storage ponds of the milk processing enterprise are not toxic. Therefore, they can be used in the composition of soil.