Environmental assessment of the quality of the Elek and Or rivers in the zone of influence of enrichment waste and metallurgical production

Abstract

The greatest threats for the environment are the dusts and sludges of ferrous metallurgy industry dispersed by wind during storage. For the Elek river, the threat is the ferro-dust, and for the Or, the main hazard is the sludge tailings. The performed survey has shown that the Elek and Or waters belong to the 4th class with the water pollution index of 4.15 for the Elek and 4.10 for the Or, which is interpreted as “polluted waters”. Throughout the entire length of the Elek and Or rivers the water quality class varies from 4 (polluted water) to 6 (very filthy water). The hexavalent chromium (Cr6+) content in the Elek River is 4.2 of the threshold limit value; the trivalent chromium (Cr3+) content exceeds the threshold limit value by 3.0 times; for the Or, these values exceed the threshold limit value by 2.2 and 1.5, respectively. Hexavalent chromium belongs to Group 1 carcinogenic substances. In both rivers, the boron threshold limit value value was also found to be exceeded; for example, boron B3+ (trivalent boron) content in the Elek river was found to exceed the threshold limit value value by 7.8 times, and in the Or, by 2.8 times. The present paper is intended to demonstrate that the recycling of large-tonnage wastes, such as the ferro-dust and sludge tailings, in the production of such stock commodities as ceramic bricks may facilitate the proper industrial waste disposal and protection of the industrial environment.