The influence of metals on sulfate-reducing activity and metal removal from synthetic mine wastewater using sulfate reducing bacteria.

Nine metals (Cd, Cu, Co, Fe, Pb, Mn, Ni, Sn and Zn) were studied to determine their influence on sulfate reducing activity. There were three types of metal influences. Fe and Mn did not affect the sulfate reducing activity within 20mM. Co, Sn, Cd and Pb caused a lag in the sulfate reducing reaction that depended on the concentration of each metal. Zn, Ni and Cu had significant influence on the sulfate reducing bacteria compared the other metals. When their concentration exceeded 5mM, the sulfate reducing reaction was completely inhibited.The model wastewater containing 1.0mM-Fe or 0.5 mM-Zn was continuously treated in an anaerobic reactor, and the metal was not detected in the treated water. It appeared that the metal was held in the form of a metal sulfide in the reactor.