Biotreatment of copper and isopropyl alcohol in waste from semiconductor manufacturing

The generalized use of copper chemical-mechanical planarization (CMP) in integrated circuits manufacturing is increasing as the industry moves from previous technology to copper technology. With CMP being one of the main water consumers and producers of wastewater in the fab, more low energy/cost effective methods are being developed to avoid a future risk of violating discharge regulations for copper-containing wastewater. In addition, with the expected increase in water consumption, there is an incentive to find better ways to treat and recycle wastewaters. The possibility of using biological organizms to treat copper and organic-containing wastewater is studied. Two different approaches are combined to create a treatment strategy: adsorption on immobilized cells to treat copper and biodegradation by immobilized cells to treat organics [specifically isopropyl alcohol (IPA)]. Two previously developed bacterial systems are used. In addition, predictive models for the two cases developed in previous work are evaluated in this combined treatment. Continuous flow experiments were performed. Copper adsorbed to the immobilized cells and the binding capacity is comparable to other systems found in the literature. The IPA was totally degraded.