Metal leaching from cathode ray tube waste using combination of Serratia plymuthica and EDTA

Bioassisted processes have been continuously expanding its applications for the discovery of new eco friendly, economic and efficient technique for the metal extraction from e-waste scrap, as a valuable mineral resource. Proposed hybrid combination is expanding the application of metal bioleaching from waste CRT by using Serratia plymuthica and EDTA. To the best of our knowledge, this is the first report to use microbe (S. plymuthica) and chemical (EDTA) combination for the improvement of metal leaching from waste CRT. Microbe for this study is isolated through the soil collected from CRT collection/recycling site at Dehradun (India). The selected combination is capable to enhance the leaching rate as compared to the leaching with individual microbe or chemical. Mechanistically it can be explained by: (i) enhancement in metal mobility by the formation of metal hydrous oxide and; (ii) mononuclear to multinuclear complex shifting. A second order mechanism for leaching is also proposed to predict the rate constant for the leaching.