Bioleaching of copper from low grade scrap TV circuit boards using mesophilic bacteria

article i nfo In this study, the extraction of copper from manufacturing scrap TV circuit boards (STVB) by bacteria-assisted leaching was studied using a mixed culture of mesophilic bacteria. Initial availability of soluble iron appeared to be of prime importance for the extraction of copper from STVB, which contains 43 g/ton Fe. In this respect, the addition of 1-8 g/L Fe(II) significantly improved (by up to 54%) the extraction of copper from STVB at the expense of the increased acid consumption. A new approach for the bioleaching process was adopted, which is based on the addition of pyrite (5-50 g/L pyrite concentrate (PyC)) as a source of iron and sulphur. Copper extraction was observed to enhance from 24% to 84% in the presence of 50 g/L PyC with a significant decrease (62%) in the consumption of acid. An increase in the size of inoculum from 10% to 50% v/v was also observed to improve the bioleaching rate of copper. The findings in the current study highlight the practical impor- tance of the availability of iron (and hence, iron content of wastes) for the successful development of a bioleaching process for e-waste and the potential for utilisation of pyrite as a suitable source of iron and sul- phur in bioleaching of e-waste.