Leaching of Heavy Metals from Personal Computer Components: Comparison of TCLP with a European Leaching Test

The objective of this work was to quantify the leaching of nine heavy metals from four desktop personal computer components (PCCs), namely, integrated drive electronics (IDE) cables, video cards, random-access memory (RAM), and CPUs, using two different leaching tests. One test was the toxicity characteristic leaching procedure (TCLP), which is widely used in the United States. The TCLP was augmented using a five-step sequential leaching procedure to further investigate the influence of increasing liquid-to-solid (L/S) ratios on the amount of metals leached. The other leaching test was based on European standards following the requirements of a European decision regarding acceptance of waste at landfills. The European leaching test was performed at the natural pH of the materials. Results showed that the masses of some metals leached during the TCLP were up to two orders of magnitude greater than the corresponding masses measured by the European leaching test. Lead and zinc were the dominant metals leached from all four PCCs. Video cards, RAM, and CPUs were classified as hazardous wastes according to the U.S. EPA's TCLP limit for lead. Based on the limits of the European decision, IDE cables, video cards, and RAM chips were classified as nonhazardous and should be disposed of to nonhazardous waste landfills. CPUs should be disposed of to hazardous waste landfills. The amount of metals leached increased with an increasing liquid-to-solid ratio. (C) 2013 American Society of Civil Engineers.