STUDY OF CYANIDE REMOVAL EFFICIENCY WITH PRECIPITATION AND FILTRATION TECHNOLOGY IN ALUMINIUM SMELTING WASTEWATER

• Main Author: Farhan Huda, Muhammad
• Format: Final Project
• Language: Indonesia
• Subjects: Teknik saniter dan perkotaan; teknik perlindungan lingkungan
• Online Access: https://digilib.itb.ac.id/gdl/view/61556
• Institution: Institut Teknologi Bandung

Aluminium is a metal used in many ways, mainly because of its good conductor properties. However, in the production process, aluminium is not obtained easily, but through a long refining process. In the aluminium smelting process, wastewater is produced which contains several parameters of water pollution, one of which is cyanide which if not treated properly it will threaten human and environmental health. This research was conducted to determine the type of precipitant that is most efficient in reducing cyanide level in aluminium smelting wastewater, the optimal dose of the most efficient precipitant, the efficiency of the filtration process in reducing cyanide level, the effect of precipitation and filtration processes on the pH value of wastewater, as well as the correlation between the doses of the precipitants and wastewater temperature. Secondary data were collected from an aluminium smelting company while primary data were obtained from experiments conducted in the laboratory. Based on the results of the study, ferrous sulfate was the best precipitant to reduce cyanide level, while the ferrous sulfate dose of 93 mg/l was the most optimal dose in removing cyanide with an average efficiency of 58.74±0.51%, while the filtration process provided an average efficiency of 81.65±0.42%. As for precipitation with ferrous sulfate and aluminium sulfate, the pH value of wastewater decreased to an average of 5.16±0.25 and 3.96±0.03 from the initial pH value of 9.09, while calcium hydroxide made the pH value of wastewater rise to 10.27±0.18, then the filtration process also increased the pH value of wastewater. The doses of ferrous sulfate and aluminium sulfate had a significant inverse correlation with wastewater temperature with a correlation coefficient (?) of -0.929 and -0.485, while doses of calcium hydroxide had no significant correlation. Overall, cyanide can be removed with a combination of precipitation and filtration techniques by 92.43±0.26% with an average final effluent concentration of 0.78±0.03 mg/l from an initial concentration of 10.3 mg/l.