Ecologically safe nickel concentrations in soils of the Central Ciscaucasia and the Caucasus

An extensive number of enterprises are located on the territory Central Ciscaucasia and Caucasus. Emissions from these industrial facilities enter atmosphere, settle soil, drain into reservoirs. Among main pollutants is heavy metal nickel (Ni). Nickel at same time a vital chemical element, and, time, it can act as toxicant that cause mutations. Its biological role depends concentration in soil. The aim study to establish ecologically safe concentrations for soils Materials methods research. oxides were added soil samples dose 100, 1000, 10000 mg/ kg incubated plastic vessels temperature 20-22 °C 55-60% moisture. In this work, parameters determined basis generally accepted science ecology (phytotoxicity soils, total bacteria, catalase activity, dehydrogenase abundance Azotobacter changes cellulolytic activity). According indicators microbiological, biochemical phytotoxic parameters, we calculated IIBS - an integral indicator state results obtained their discussion. Based analysis Caucasus, following ranked according resistance contamination: ordinary chernozem (91) >chernozem podzolized (mountain) (84) ≥ typical (83) chernozems leached (82) = mountain-meadow chernozem-likes sod-peaty (80) mountain meadow-steppe (78) sod-calcareouses (76) dark gray forest(75) soddy (71) brown forest weakly unsaturated(68).The greater IPBS, more resistant type contamination. made possible calculate regional maximum permissible (rMPC) Ni Сentral For purpose, regression equations constructed reflecting dependence each studied content it. rMPC 170 mg/kg, meadow chernozem-like — 160 150 turf-peat 130 sod—carbonate 120 kg, 145 turf 140 slightly unsaturated 100 mg/kg.