Conventional wastewater treatment considers the source to contain undesirable concentration of pollutants. If this waste stream is discharged to a water-receiving body without any treatment, it can be a threat to public health and can also damage the environment. Therefore, regulatory agencies typically provide maximum pollutant concentration that is allowable in the discharged water, and wastewater treatment plants are designed to meet these discharge limits. Regulatory compliance by the wastewater treatment plants is observed by removing pollutants from the source streams through a variety of physical, chemical, and biological processes. A new paradigm, however, considers the aqueous stream to be rich in resources which can be recovered. While the overall goal of meeting regulatory limits is not compromised, this paradigm allows the added benefit of extraction of resources from the waste stream, thus providing twin benefits of: (1) reducing the need to produce fresh supplies of precious resources which typically consume high amounts of energy and also adversely impact the environment, and (2) offsetting the cost of treatment. Although this is a win-win situation, its implementation requires a deeper understanding of principles of selective separation. The resource-species typically are present in trace concentration and in the background of competing species with much higher concentration. Therefore, removal and eventual recovery of the resource is a challenging separation problem. Moreover, the purity of the recovered resource is a major criterion in its marketability and the efficiency of the entire process. This short course will provide a road map in support of this new paradigm through case studies.
The primary objectives of the course are as follows:
• Providing participants with the scientific, environmental, and economic framework of the resource-recovery paradigm,
• Covering the physical-chemical principles of selective separation,
• Exposing the participants to modifications of conventional wastewater treatment processes to accommodate resource recovery, and • Conducting Life Cycle Analyses of proposed resource-recovery schemes.