New advances in copper biomachining by iron-oxidizing bacteria

Abstract

The machining of copper contained in oxygen-free copper workpieces by extremophile bacteria has been studied. The effect of the main parameters affecting the continuity of the process and which decrease the removal rate were analysed during the incubation, biomachining and regeneration phases. The presence of copper affected the bacterial culture, while the enhancement of process performance due to the simultaneous presence of A. ferrooxidans and L. ferrooxidans was relatively limited. pH was maintained below 1.80 to avoid Fe3+ losses in the form of jarosite precipitates. Measurement of the redox potential allowed a rapid monitoring of the process status.