Harmful concentrations of metals enter the environment in significant quantities via numerous industrial activities. They are not readily detoxified by natural processes and pose lasting environmental hazards. This project's long-term application enhances public health by lessening exposure to toxic metals by reducing their release into the environment. To accomplish this, a novel, versatile, and improved electrowinning technology to remove and reclaim a variety of target hazardous and persistent metal contaminants from dilute sources such as Acid Mine Drainage (AMD) is being developed. Phase I successfully demonstrated concept technical viability and experimentally verified the new technology. The technology exhibits dramatically better performance than competing electrowinning technologies, allowing it to economically treat dilute metal streams that are currently impractical to address by existing methods. Objectives: Phase II will extend the Phase I work and seek to create a complete pilot-scale 10 gallon per minute (GPM) water treatment system incorporating the new technology, demonstrate its operation under service conditions, and position the technology for commercialization. Accomplishing these goals will provide an example of the technology of sufficient size and technical maturity for commercial utility while also showing real-world practical utility. A metal removal business will be developed around this technology. Proposed Activity: The Phase II objectives will be achieved by completing the following activities stepwise. ? Create a 10 GPM electrowinning cell element as the fundamental technology building block. ? Create a 10 GPM multi-stage treatment module using the cell elements. ? Verify the multi-stage module performance and select preferred operation parameters. ? Incorporate the multi-stage module into a portable pilot-scale prototype metal recovery system. ? Design and implement a short-term field demonstration of the prototype metal recovery system. ? Evaluate the field test results to refine the business model, pursue follow-on funding (private and public), and prepare a marketing strategy. Methods Employed: The proposed activities will be accomplished using the following methods. ? The cell design will be refined and scaled using performance trends determined in Phase I. ? Laboratory batch and flow-through tests optimizing the electrowinning of selected contaminant metals from synthetic and actual AMD using the technology will be utilized. ? Plating efficiency, metal removal rate, system power consumption, plus physical and performance stability will be determined as a function of selected module operating parameters. ? The field-trial will mirror flow-through laboratory tests and employ relevant protocols adapted from the EPA Mine Waste Technology Program (MWTP) Quality Assurance Project Plan (QAPP) 2006. Project Narrative The mature version of the new technology that was successfully proved under Phase I will enhance public health by lessening the amounts of toxic metals entering the environment. The technology works with a variety of metals singly or in mixtures, can be used to treat a wide range of contaminant sources, and allows the practical removal and reclamation of low concentrations of metals in water that competing technologies can not address. The metal reclamation achieved provides an economic incentive to treat sources currently allowed to contaminate the environment.
