An evaluation of mer-specified reduction of ionic mercury as a remedial tool of a mercury-contaminated freshwater pond

Abstract

The potential for mer-mediated reduction/volatilization of ionic mercury as a tool in the decontamination of a freshwater pond was evaluated using laboratory incubations and a microcosm simulation. In flask assays inoculations with ionic mercury-resistant bacteria (105-107 cells ml-1) isolated from the pond, significantly increased the rate of mercury loss (MANOVA, P≤0.05) relative to uninoculated controls. The effects of cell density, mercuric mercury concentration, addition of nutrients and supplementation with the sulfhydryl reagent β-mercaptoethanol on the rate of mercury loss, were investigated. Inoculation (by 105 cells ml-1) of a flow-through microcosm that simulated the cycling of mercury in the contaminated pond, stimulated by more than 4-fold the formation of volatile elemental mercury. Thus, biological formation of volatile mercury may hold a promise as a remedial tool of contaminated natural waters. © 1995 Society for Industrial Microbiology.