THE USE OF HOLLOW-FIBER CROSS-FLOW MICROFILTRATION IN BIOACCUMULATIONAND CONTINUOUS REMOVAL OF HEAVY-METALS FROM SOLUTION BY SACCHAROMYCES-CEREVISIAE

Cross-flow microfiltration was shown to retain Saccharomyces cerevisia e biomass utilized for heavy metal bioaccumulation. The passage of met al-laden influent through a series of sequential bioaccumulation syste ms allowed for further reductions in the levels of copper, cadmium, an d cobalt in the final effluent than that afforded by a single bioaccum ulation process. Serial bioaccumulation systems also allowed for parti al separation of metals from dual metal influents. More than one eleme ntal metal cation could be accumulated simultaneously and in greater q uantities than when a single metal was present in the effluent (Cu2+ 0 .43 mmol, Cu2+ + Cd2+ 0.67 mmol, and Cu2+ + Co2+ 0.83 mmol/g yeast dry mass when the initial concentration of each of the metal species was 0.2 mmol L(-1)). Co-accumulation of two different metal cations allowe d higher total levels of bioaccumulation than found with a single meta l. The flux rate was 2.9 x 10(2) L (.) h(-2) (.) m(-2) using a polypro pylene microfiltration membrane (0.1 mu m pore size) at 25 degrees C. (C) 1994 John Wiley and Sons, Inc.