Gold leaching and recovery from mixed-metal scientific waste. In addition to electronic waste, gold can be found in other waste streams such as scientific and laboratory waste. Three of these mixed-metal waste streams were obtained for the next series of gold recovery experiments (Fig. and Fig. ). The purpose here was to test the gold leaching and sorption on samples of unknown composition and use a single batch of poly-1 in repeated gold sorption for each waste stream. The first sample was an aqueous solution of heavy metal waste from a chemistry laboratory. This 7.5 L sample had a gold concentration of 23 ppm, as determined by AAS. A 100 g sample of poly-1 was added to this solution and stirred for 16 hours at room temperature and then recovered by filtration. The gold concentration in the solution was reduced to <0.4 ppm, indicating >99% of the gold was bound to the sorbent. The same 100 g of sorbent was then added to a second leach solution derived from a different source of mixed-metal scientific waste. Specifically, metal from the inside of a sputter coater was wiped off and then reacted with the TCCA/NaBr leach system, providing a 500 mL solution with a gold concentration of 244 ppm. After 2.5 hours of stirring, the same 100 g of the polymer sorbent removed 96% of the gold, as determined by AAS. The sorbent was recovered by filtration and then added to a third and final leach solution derived from gold scraps and discarded scientific samples coated with gold. These gold-rich samples were similarly leached with TCCA/NaBr to provide a 1.13 L solution with a gold concentration of 6389 ppm. The same 100 g of sorbent was mixed with this third leach solution for 22 hours at room temperature. After this time the gold concentration was reduced to 27 ppm, indicating 99% of the gold was bound by the polymer.