Bacterial biofilms for sequestration of Cu+2 from CMP wastewater

The process of chemical mechanical planarization (CMP) employed by the semiconductor industry creates large quantities of wastewater containing toxic levels of copper. Use of biomass-based filtration may offer a less expensive and more sustainable means of treating wastewater prior to disposal. We screened a library of microorganisms for ability to bind Cu²⁺ from solution and form biofilm within packed bed filtration columns. Filter beds supporting L. casei/P. pastoris biofilms were found to exhibit a two-phase adsorption behavior during flow-through binding experiments. Bound Cu²⁺ was able to be recovered via acid wash, and the biomass quickly regenerated and could be reused.