Keywords: metal ions, metal chelates, SRB, sulphate–reducing bacteria, precipitation, remediation, CDTA, DTPA, EDTA, NTA, metal sulphides, lead, copper, heavy metals, soil pollution, environmental pollution, chelate washing, hydrogen sulphide
Treatment of metal ions and metalchelate complexes in water with biologically produced H2S
The possibility to precipitate Pb and Cu as metal sulphides has been investigated. The metals are present as metal chelates, a situation that will appear after soil washing for remediation of polluted soil. Sulphide for the precipitation step is obtained via a bioreactor containing Sulphate–Reducing Bacteria (SRB). The effects on the precipitation process for copper and lead were studied in the presence of four different chelating substances (EDTA, NTA, CDTA, DTPA), with a precipitation of more than 98% for both Pb
2+. The results clearly indicate that chelate washing and the subsequent precipitation is a viable technology.