Effect of various factors on the kinetics of linked ammonia removal from industrial wastewaters

Work of industrial enterprises results in large amounts of wastewaters. Both domestic and industrial wastewaters contain elements, which are capable even at low concentrations of causing harm to human health and environment. Metallurgical and coke chemical enterprises wastewaters are among the most dangerous and toxic pollutants. The group of the most dangerous pollutants in-cludes ammonium nitrogen. It is usually contained in industrial wastewaters in the linked and free ammonia form. These compounds are capable of provoking not only a disorder in the human nervous system, but also of the development of oncological diseases and even of causing death. For our investigations wastewater samples from one of the largest Ukrainian metallurgical enterprises have been used – AZOVSTAL IRON & STEEL WORKS (Metinvest Holding, Mariupol, Ukraine). As a result of our investigations it has been found that the contents of ammonia nitrogen in AZOVSTAL IRON & STEEL WORKS wastewaters was equal to 300 mg/l, of which the linked ammonia was 190 mg/l. We investigated the possibility of removing linked ammonia from industrial wastewaters depending on the temperature. It has been found that upon heating the contents of linked ammonia in wastewaters is reduced by about 25%. These results are not sufficient to achieve the level of maximum permissible concentration (MPC of ammonia is 2 mg/l). The perspective direction for better removal of linked ammonia is using strong bases (NaOH).