Huge volumes of effluents emanating from food, pharmaceutical and semiconductor industry, for example, have called for strategies based on environmentally benign processing. It was estimated that semiconductor industry, CMP step produce around 450 millions gallons of effluents per year. The continuously growth in semiconductor industry during the last decades come with the increment in the demand of ultra pure water to be used in their processes. 30-40% of the water used on this processes is spend in the CMP step, most of it in the slurry dilution. After CMP this water containing mainly particles and copper is discharge. The CMP process effluent composition and chemicals concentrations are variable depending on the slurry used and will varies process to process. In general, the main components will be dissolved copper in concentrations between 1- 50ppm, Si and/or Al nanoparticles, and concentrations between 50-500ppm and organics contaminants. CMP effluents can be treated in order to help the industry meet the discharge requirements, but also CMP effluents can be treated to be reuse for example in the slurry dilutions. The main benefits would be: 1) economical implications for the industry reusing water and recovering the copper and 2) environmental benefits obtained from reducing hazardous wastes making it a win-win situation for everyone. Previous work from Dr. Ogden group in the University of AZ, demonstrated that the immobilized bacteria Y5 is capable of removing copper when you treat a particle free solution. Immobilized Y5 appears to be a viable technique to treat copper in water solutions but not that good in treating copper in CMP wastewater. From these studies they conclude that the particles affect biotreatment because they broke the grains and expose the cells to direct contact to the contaminants. For this reason, it is necessary pretreatment or particles removal before biotreatment. As part of this research, we propose to develop mass-exchanger based on dual function depth filters and bio-treatment to treat wastewater to remove Silica and Alumina nanoparticles and copper from Chemical Mechanical Planarization (CMP) wastewater. At this moment, the filter is used with membrane RP products 100 series (1 micron 95% efficiency) and we obtained up to 67% of total suspended solid reduction. For the biotreatment, the microorganisms were inoculated in a Virtis Culture Bioreactor up to late logarithmic to early stationary growth phase (optical density OD @600nm ~ 0.9-1.2). Also, we used Kaldnes biocarrier for the batch and continuous reactor studies to provide maximum surface area for the bacteria to colonize and produce biofilm. From preliminary results, we obtained that the bacteria maximum binding capacity for copper solution in ultra pure water (UPW) was 0.16 gram of copper per gram of dried bacteria but further studies are necessary using higher concentration rates. This value is very similar to that obtained by Stanley and Ogden (2003) which report a maximum binding capacity of copper in water using Soil 5Y immobilized in calcium alginate beads of 0.14 gram of copper per gram of dried sorbent. In the case of the actual CMP wastewater obtained from the University of Arizona tool room, the maximum binding capacity was 0.44 g/g. Two continuous column experiments were perform using Soil 5Y and Thriothiox A1 bacteria previously growth in the biocarriers. In the case of 5Y the column that column did not turn blue during the experiment, as expected due to the copper presence, it achieve saturation concentration really fast, and the removal from the beginning of the experiment was lower that expected. In the other hand, using the commercial bacteria the column was visually turning blue, more copper was removed and it takes more time to saturate.

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