The Treatment Of Chromium-contained Wastewater Produced In Chromium Slag Contaminated Sites

Chromium is one of the important elements of industrial production, with the wide using in industry; but chromium compounds have great impact on the environmental pollution. In producing of chromium salt, there are the number of waste chromium residue which is occupied much of the land resources and most of waste chromium residue were accumulated in the open-air, but there are not necessary waterproof, dustproof and impermeable performance. Chromium residues of pollutants were flushed by snow and rain. The pollutants infiltrated in soil and water, which can cause serious damage to plants and living beings. In the management process of chromium salt, leaching method is usually chosen, but a lot of chromium-containing waste water will be generated, so the chromium-containing waste water also should be treated.There are many kinds of technologies in treating the wastewater containing chromium, including physical method, chemical method, physical and chemical method and biological method. The chemical method is the main one, and it plays a very important role in engineering practice.This paper uses chemical precipitation process and scrap iron column respectively to deal with the high and low concentration chromium wastewater. In dealing with high concentration of chromium-contained wastewater, by contrasting treat effects of the three common reductive agents, the best treatment effect of reductive and optimize technological conditions would be chosen to make wastewater meet the effluent standard. In dealing with low concentration of chromium-contained wastewater, scrap iron column would be chosen to treat chromium-contained wastewater and gain the operation process parameters to make wastewater meet national discharge standards.In accordance with the process parameters by the lab, the chromium-contained wastewater of Qinghai chromium slag contaminated sites was selected to treat. By debugging, the chromium-contained wastewater by treatment chromium slag contaminated site producing could meet national discharge standards.