Detoxification of Cyanide Wastewater by Cyanotrophic Organisms: the case of Phanerochaete chrysosporium

  • Grace Ofori-sarpong University of Mines and Technology,Tarkwa, Ghana
  • Ahmed-Salim Adam Golden Star Prestea/Bogoso Resources, Bogoso Mine, Ghana.
  • Richard Kwasi Amankwah University of Mines and Technology, Tarkwa, Ghana

Abstract

Cyanide, a carbon-nitrogen radical, is a major building block in many industries including pharmaceuticals, petrochemical and gold processing. In the gold extraction industry, cyanide has been the universal lixiviant for over a century due to better understood process chemistry, among others. Industries that discharge cyanide-laden effluents are mandated to keep concentrations below 0.2 mg/L to prevent death by cyanide-intoxification, which occurs when cyanide binds to key iron-containing enzymes and prevent them from supplying oxygen-containing blood to the tissues. Techniques used to attenuate cyanide in wastewater can broadly be grouped into chemical, physical and biological methods.  In recent times, attention has been placed on biotechnological methods, which make use of cyanotrophic microorganisms to clean up cyanide-contaminated environments. This paper reports on studies set out to assess the ability of Phanerochaete chrysosporium to degrade cyanide under different conditions including changes in cyanide concentration, culture mass, time, closed and open system. At the end of 24-hour contact in an open agitated system, a control experiment using 100 mg/L cyanide revealed a natural attenuation of 15% with pH decreasing to 9.88, while the best myco-detoxification of 85% was achieved by contacting 100 mg/L cyanide with 0.5 g culture mass, translating into degradation capacity of 17.2 mg/g (milligram of cyanide per gram of culture) with pH reducing to 8.4 in 24 hours. The degradation could be based on a number of mechanisms including hydrolysis to HCN, oxidation to cyanyl radical and cyanate due to natural attenuation through atmospheric contact, and secretion of organic acid, oxidative enzymes, and hydrogen peroxide by the fungus.

Author Biographies

Grace Ofori-sarpong, University of Mines and Technology,Tarkwa, Ghana

Grace Ofori-Sarpong is an Associate Professor of Minerals Engineering at the University of Mines and Technology, Tarkwa. She holds PhD in Energy and Mineral Engineering from Pennsylvania State University, MSc in Environmental Resources Management and BSc in Metallurgical Engineering, both from the Kwame Nkrumah University of Science and Technology, KNUST, Kumasi, Ghana. Her areas of research interest include microbial-mineral interaction, environmental biohydrometallurgy, acid mine drainage issues and precious minerals beneficiation. She is a member of the Society for Mining, Metallurgy and Exploration Engineers (SME), Society of Petroleum Engineers (SPE) and the Founder and President of Ladies in Mining and Allied Professions in Ghana. She is also a Fellow of Ghana Academy of Arts and Sciences and West African Institute of Mining, Metallurgy and Petroleum (WAIMM)

Ahmed-Salim Adam, Golden Star Prestea/Bogoso Resources, Bogoso Mine, Ghana.

Ahmed-Salim Adam is the General Manager of Golden Star Resources Ltd, Bogoso Mine. He holds Master of Science and Bachelor of Science Degrees in Mineral Engineering at University of Mines and Technology (UMaT), Tarkwa. He has Processing Supervisors and Metallurgical Superintendent certificates of competency from the inspectorate Division of Minerals Commission. His areas of research interest include microbially enhanced recovery of minerals, precious metal beneficiation, biotechnology of industrial waste. He is a member of Ghana Institution of Engineers and Society for Mining, Metallurgy and Exploration Engineers (SME).

Richard Kwasi Amankwah, University of Mines and Technology, Tarkwa, Ghana

Richard K Amankwah is a Professor of Minerals Engineering at the University of Mines and Technology (UMaT), Tarkwa, Ghana. He holds a PhD degree in Mining Engineering from Queen’s University, Canada, and MPhil and BSc in Metallurgical Engineering from the Kwame Nkrumah University of Science and Technology, KNUST, Kumasi, Ghana.  His research interests include gold beneficiation, water quality management, microwave processing of minerals, small-scale mining, medical geology, microbial mineral recovery and environmental biotechnology. He is a Fellow of the West African Institute of Mining, Metallurgy and Petroleum (WAIMM), a member of the Ghana Institution of Engineers and the Society for Mining, Metallurgy and Exploration Engineers (SME).

Published
2020-06-30
Section
Minerals Eng. Articles