Evaluation of biological removal of cyanide from waste of gold refuge complex Download PDF

Background and Aim: Cyanide is a highly toxic compound used in many industries. There are several approaches to remove cyanide from the waste. Physical and chemical processes have been successfully used to purify the cyanide-forming elements. Today, cyanide biochemical analysis is considered as a cost-effective and environmentally compatible method compared to conventional chemical methods. The purpose of this study was to evaluate the cyanide removal from wastewater from Muteh golden complex using native bacteria. Methods: After collecting soil samples, enrichment of cyanide degrading bacteria was carried out in a culture medium containing potassium cyanide. The ability of isolated bacteria was investigated using cyanide as the only source of carbon and nitrogen at different pH levels. The cyanide decomposition and production of ammonia and nitrate in the culture medium were measured. Finally, the genetic identification of the superior strain for bio-degradation was carried out. Results: Seven strains were isolated from which 10 strains were able to withstand cyanide to a concentration of 1000 mg/L and use it as the sole source of carbon and nitrogen. The results showed that reduction of cyanide concentration was directly related to increasing the concentration of ammonia in growth medium and growth of isolates. After 72 hours, the cyanide content of the media in Mgt16 decreased from 1000 mg/l to 100 mg / l (90% removal efficiency). The highest efficiency was obtained at pH=10. The 16srDNA analysis indicated that the strain indicated the results of the strain. Conclusion: The results of this study showed that bacteria isolated from Mutee wastewaters are an appropriate alternative for bioassay cyanide in alkaline conditions and can be used to decompose cyanide from industrial wastewater and contaminated sites.