Ecofriendly recovery of copper from spent telecommunication printed circuit boards using an indigenous cyanogenic bacterium

A comprehensive review of bioleaching optimization by statistical approaches: recycling mechanisms, factors affecting, challenges, and sustainability

“…They produce cyanide using HCN synthase and decarboxylated glycine at the end of the growth logarithmic phase of cyanogenic bacteria. 42,43 As illustrated in eqn (2), cyanide can be secreted in two forms, including the hydrocyanic acid (HCN) and the cyanide anion (CN − ), in a reversible reaction in equilibrium. Noteworthy is that due to the p K a of HCN, metal-cyanide complexes' generation occurs at high pH values.…”