| Abstrakt: |
Electrical and electronic waste (e-waste) is currently one of the largest growing wastes with complex hazardous nature to treat in an environmentally sound manner. This study was carried out to suggest a cheaper and safer means of leaching copper from electronic waste and developing an electrolytic process for its extraction. In an experimental study design with laboratory analysis, printed circuit boards (5kg) of obsolete television were ground and sieved to obtain 2mm particle size. Chemical leaching of copper using different concentrations of nitric acid (1M, 3M, 5M and 7M) was carried out at varying time intervals (0 hour, 12 hours, 24 hours and 48 hours). Leachate obtained was subjected to electrolysis to recover copper using a prototype electrolytic cell designed and fabricated locally. Bioleaching was carried out through composting process for four weeks using market wastes and cow dung under mesophilic conditions. Chemical leaching yielded higher copper (236,187.6 ± 0.4 mg/kg) than that leached biologically (74.4 ± 0.1 mg/kg). Electrolytic extraction showed that the mean weight of copper deposited at 1M acid extraction (683.3 ± 2.6 mg) was significantly higher than that deposited at 3M concentration of electrolyte (366.7 ± 2.6 mg). Also, copper extracted electrolytically from chemical leachate (366.7 ± 2.6 mg) was higher than that extracted from bioleachate (36.8 ± 1.8 mg) at 3M of electrolyte. Bioleaching is a very slow process and the yield depends on method of leaching, current, voltage, electrolyte concentration, time and electrode types. These factors play an important role in electrolytic recovery of copper from e- wastes. [ABSTRACT FROM AUTHOR] |
