Removal of heavy metals using a brewer's yeast strain of Saccharomyces cerevisiae: application to the treatment of real electroplating effluents containing multielements

Abstract

BACKGROUND: Yeast cells have been recognized as an effective type of biomass for the treatment of wastewaters containing heavy metals. However, its capability to treat efficiently complex effluents loaded with several metals ions (Cr, Cu, Ni and Zn) has never been reported. The aim of this work was to study the feasibility of a hybrid technology, which combines chemical precipitation at pH 6.0 with a subsequent biotechnological-based process (using heat-killed cells of a flocculent brewing strain of Saccharomyces cerevisiae), to remove simultaneously several metals from real electroplating effluents.

RESULTS: Two effluents containing Cu, Ni and Zn (effluent A) or Cr, Cu and Ni (effluent B) were treated. In both effluents, pH was adjusted to 6.0; in effluent B, Cr(VI) was previously reduced to Cr(III). Chemical speciation studies allowed defining the amount of biomass to be employed with a minimum number of batches. Subsequently to pH adjustment to 6.0, effluents were fully treated with a serial batch of biomass. After the third batch, metal concentrations were lowered to below the legal limits of discharge; removals ≥ 89, 91, 92 and 94% were attained for Ni, Cu, Cr and Zn, respectively.

CONCLUSIONS: In the present work, the usefulness of using flocculent brewing yeast cells to treat complex industrial effluents loaded with several heavy metals was demonstrated. The hybrid process developed was shown to be an efficient alternative for the treatment of real electroplating effluents. Copyright © 2010 Society of Chemical Industry