AbstractThe paper describes a novel chemical-microbiological method for the selective removal of cadmium, tellurium and silver from the thin film CdTe photovoltaic modules. The chemical component of the process utilizes dissolution of metals with nitric acid. The metal solution is subjected to selective biosorption of silver and cadmium by passing through biosorbent columns. The adsorbed cadmium and silver are desorbed and recovered by chemical precipitation. Tellurium in solution coming out of the biosorbent columns is converted microbiologically to its metallic form in a bioreactor. The combined chemical-microbiological treatment ensures recovery of silver, cadmium and tellurium with 86%, 80% and 99% efficiency, respectively. The treated waste can be discharged safely in the environment.
Read full abstract