Lead Removal from Contaminated Water by a Mixed Microbial Ecosystem

Abstract
The research reported here explored the advantages of using an integrated ecosystem for the uptake of lead and examined some of the possible mechanisms for the transfer of the metal through the system with eventual binding in the microbial biomass. Strategies were applied to (1) stimulate enhanced production of biomass and consequent lead recovery by simple enrichments of the microbial environment, and (2) increase the microbial tolerance and lead uptake capacity by adaptation of the component species. The microbial ecosystem employed here was one which arose spontaneously after pond enrichment with silaged grass clippings and moved through a predictable microbial succession. Ecosystem processes and microbial relationships resulted in the mobilization of metal in the soil bed and water column with ultimate deposition in the surface biomass. The stable silage-microbe biomass, floating at the top of the pond, bound the metal for extended periods of time.