The study was focused on investigating the contribution of a single bacterial strain to lead removal from wastewater through microbial precipitation and adsorption. Previous studies on lead bioremediation have been conducted using a microbial consortium obtained from wastewater at a lead battery recycling plant in Gauteng, South Africa. The successful isolation of an active strain in the consortium was achieved and the strain was identified as a pure culture of Klebsiella pneumoniae. The rate of lead removal and the metabolic activity of the culture was determined over a period of 4 d.
The results indicated that microbial precipitation of Pb(II) by K. pneumoniae is possible with significant Pb(II) removal occurring in under 20 h. The amount of lead in solution was decreased to a value undetectable by the analysis equipment in approximately 63 h. No lead removal by adsorption was observed. It is suspected that a metabolically dependent mechanism was responsible for the precipitation of lead as the metabolic activity increased with increasing lead precipitation, but further studies would be required to confirm this.