Biodegradation of free cyanide by bacterial species isolated from cyanide-contaminated artisanal gold mining catchment area in Burkina Faso

Autor: Koffi Marcelin Kouakou, L.C. Razanamahandry, Hamma Yacouba, Hela Karoui, Harinaivo A. Andrianisa
Rok vydání: 2016
Předmět:
Gold mining
Environmental Engineering
Health
Toxicology and Mutagenesis
Cyanide
education
0211 other engineering and technologies
02 engineering and technology
010501 environmental sciences
01 natural sciences
Mining
chemistry.chemical_compound
Bioremediation
Burkina Faso
Environmental Chemistry
Cyanates
Soil Microbiology
health care economics and organizations
0105 earth and related environmental sciences
021110 strategic
defence & security studies
Cyanides
Bacteria
Waste management
business.industry
Public Health
Environmental and Occupational Health
social sciences
General Medicine
General Chemistry
Contamination
Biodegradation
Pollution
Biodegradation
Environmental
Wastewater
chemistry
Environmental chemistry
Environmental science
Gold
Catchment area
Environmental Pollution
business
Water Pollutants
Chemical
Zdroj: Chemosphere. 157:71-78
ISSN: 0045-6535
DOI: 10.1016/j.chemosphere.2016.05.020
Popis: Soil and water samples were collected from a watershed in Burkina Faso where illegal artisanal gold extraction using cyanidation occurs. The samples were used to evaluate cyanide contamination and the presence of cyanide degrading bacteria (CDB). Free cyanide (F-CN) was detected in all samples, with concentrations varying from 0.023 to 0.9 mg kg(-1), and 0.7-23 μg L(-1) in the soil and water samples, respectively. Potential CDB also were present in the samples. To test the effective F-CN degradation capacity of the isolated CDB species, the species were cultivated in growth media containing 40, 60 or 80 mg F-CN L(-1), with or without nutrients, at pH 9.5 and at room temperature. More than 95% of F-CN was degraded within 25 h, and F-CN degradation was associated with bacterial growth and ammonium production. However, initial concentrations of F-CN higher than 100 mg L(-1) inhibited bacterial growth and cyanide degradation. Abiotic tests showed that less than 3% of F-CN was removed by volatilization. Thus, the degradation of F-CN occurred predominately by biological mechanisms, and such mechanisms are recommended for remediation of contaminated soil and water. The bacteria consortium used in the experiment described above exist in a Sahelian climate, which is characterized by a long hot and dry season. Because the bacteria are already adapted to the local climate conditions and show the potential for cyanide biodegradation, further applicability to other contaminated areas in West Africa, where illegal gold cyanidation is widespread, should be explored.
Databáze: OpenAIRE
Externí odkaz: