Abstract:
Mainboard and PCI card of a desktop computer were generated from household, office and hotel/apartment, industry, and import and export. In 2015 2018, More than 68 percent of them were managed by unregistered sectors that cause difficulty in process monitoring and waste treatment regulating. The objectives of this study were to compare the environmental effects between two printed circuit boards recycle processes which used aqua regia and cyanide complexes as gold leaching agents and to provide options for lessening those effects. The impact assessment of aqua regia leaching process was determined under various conditions, while the proper cyanide leaching process was set as a base case. In the aqua regia leaching process, the average yield of gold was 95.25 percent with different purity values. Material flows were analyzed, and the effects on health and environment were investigated by using SimaPro version 9.0.0.35, respectively. The result indicated that the environmental impacts decreased due to wastewater treatment, and the separation of other extracted metals for further recovery. Sludge was suggested to be treated in landfill or hazardous waste incineration. Additionally, the aqua regia leaching process provided lower effects than the cyanide leaching process since three times leaching aqueous recirculation was achieved.