Wastewater treatment of mining enterprises from nitrogen compounds in the Arctic

Abstract

Open pit mining using explosives based on ammonium nitrate leads to wastewater pollution with nitrogen compounds. In case of insufficient wastewater treatment, pollutants enter surface-water bodies. Excessive concentration of nitrogen compounds in water leads to the development of the process of eutrophication, which adversely affects the vital activity of aquatic organisms and humans. At the moment, a common method of wastewater treatment from nitrogen compounds is a biological treatment method using devices such as aeration chambers, oxidation tanks and slim filters. An alternative option for biological treatment is the introduction of algae into wastewater. In the conditions of the Arctic, it is difficult to carry out biological treatment using algae due to low temperatures throughout the year. In this study, the feasibility of using the frost-resistant strain Chlorella kessleri VKPM A1-l1ARW for the effluents treatment from nitrogen compounds was tested. Model solutions with a known nitrates concentration were used. Experiments were carried out at two specified temperatures for comparison. The results showed that by the end of the 10-day experiment, the nitrates extraction efficiency at standard temperature (20 °C) was from 40.3% to 71.8%, at low temperature (3 °C) was from 30.4% to 73.6%.