Extracting noble metals from industrial solutions and waste waters with biosorbents

Abstract

The chemical composition of various industrial solutions of the Shchelkovo Plant of Secondary Noble Metals is evaluated. It is established that the excess content of heavy metals with respect to gold and silver is larger by a factor of more than 1000. The microbial biomasses of various systematic groups are approved for extracting Au and Ag from solutions with a high salt background. The appropriateness of selectively extracting heavy metals from such complex solutions is shown. The behavior of heavy metals is investigated for sorption on biosorbents from individual solutions within the pH limits of 1.0–6.0 for the medium. The decisive significance of the pH of the solution (within the limits 1.0–3.0) on selectively extracting Ag from industrial solutions is determined. The notion that silver and heavy metals are attributed to different groups of metals by varying the degree of sorption with microorganisms, depending on the pH medium, is confirmed. The specific behavior of the biomass cells in the acidic medium also promotes the separation of these elements. Testing the biosorbed extraction of silver from the industrial solution on a granulated lincomycin biomass is approved under industrial conditions. The average degree of extraction was Cu ≤ 8.1, Ni 4.2, Zn 4.0, Fe 15.5%. The losses of biosorbent are about 70 g/m3 of the solution.