Removal of cyanide from alumina smelter wastewater using precipitation and filtration technique

• Published in: IOP conference series. Earth and environmental science 2021-11, Vol.896 (1), p.12075
• Main Authors: Huda, M F, Helmy, Q
• Format: Article
• Language: English
• Subjects: Aluminum; Aluminum oxide; Cyanide process; Cyanides; Efficiency; Environmental health; Ferrous sulfate; Filtration; Iron sulfates; Metallurgy; pH effects; Pollutants; Smelters; Smelting; Sulfates; Wastewater; Water pollution
• ISSN: 1755-1307; 1755-1315
• DOI: 10.1088/1755-1315/896/1/012075

Aluminum is a metal that is used in many products because of its good conducting properties. However, in the production process, aluminum is not obtained easily but through a long process. In aluminum smelting process, wastewater that is produced indicates the existence of pollutants as determined by several indicators of water pollution, one of which is cyanide that will threaten human and environmental health if not treated properly. This study was conducted to determine the optimal dose of ferrous sulfate to remove cyanide, the precipitation and filtration process efficiency in reducing cyanide, and its effect on pH of wastewater. Data were collected from an aluminum smelting company, and experiments were conducted in the laboratory. Based on results, ferrous sulfate dose of 93 mg/l is the most optimal dose in removing cyanide with an efficiency of 58.74±0.51%, while filtration process provides an efficiency of 81.65±0.42%. Precipitation with ferrous sulfate makes pH value of wastewater decrease, but filtration process increases the value again. Throughout the whole process, cyanide can be reduced by a combination of precipitation and filtration process with the efficiency of 92.43±0.26% and an average final effluent concentration of 0.78 mg/L from an initial concentration of 10.3 mg/L.