Ion exchange strategies along the water lifecycle
Treavor Boyer, Ph.D.
Department of Environmental Engineering Sciences
University of Florida
Access to clean water is a critical social, environmental, and economic challenge for the 21st century. Our vision is to develop robust ion exchange approaches to the treatment of water at various stages in its lifecycle so as to maximize water conservation, recover valuable materials, sequester harmful contaminants, minimize the production of waste byproducts, and advance the water-energy nexus. This presentation will highlight recent research in our group that uses ion exchange to recover phosphorus from natural systems, selectively remove groups of chemical contaminants during drinking water treatment, minimize the volume of waste residuals produced by membrane processes, and improve the function of waterless urinals. These topics are of intrinsic importance to water supply planning and wastewater management, and also encapsulate the key technical issues for a number of different water recycling strategies. The insights developed from the ion exchange research presented here are expected to lead to exciting new ideas for treatment and beneficial uses of water at various stages in its lifecycle.
Dr. Treavor Boyer is an Assistant Professor in the Department of Environmental Engineering Sciences at the University of Florida. He joined the faculty in 2008 after receiving his Ph.D. from the University of North Carolina at Chapel Hill. Dr. Boyer completed his M.S. in environmental engineering at the University of North Carolina at Chapel Hill and his B.S. in chemical engineering at the University of Florida. The focus of Dr. Boyer¹s research is aquatic chemistry and water treatment. The long-term goals of his research program are (i) to understand the effect of DOM on physical, chemical, and biological processes and (ii) to apply the principles of ion exchange to natural and engineered systems. Website: Treavor Boyer's Webpage
Ion exchange can be applied to maximize water conservation, recover materials, minimize waste byproducts, and so on. Ion exchange utilizes resins from the solution which exchanges their mobile ions for ions of similar charge. Dr. Boyer’s results demonstrated that the best way to apply ion exchange is to use a combination anion and cation ion resins. The results of his study showed that this technique had a conspicuously high ability to reduce dissolved organics from raw river water as compared with conventional treatment. So if ion exchange can be applied to a conventional treatment system, it will reduce the size of the treatment system (multi-process steps to only single step) with higher water quality. Dr. Boyer mentioned in his data that the removal of disinfection by-products (DBPs) also had high efficiency. Thus, application of this technology was able to remove DBPs as well as hardness. Also, the data surprisingly showed very stable removal efficiency with a high water quality, even though it was conducted by regenerating resins for a year. Lastly, it can be applied with a membrane process such as the application of uric treatment. The combination of the membrane process and the ion exchange can not only result in the improvement of water quality but also minimize of water residuals.
ReplyDeleteI was not well-informed on ion exchange technology, so Dr. Boyer's talk was especially interesting for me.
ReplyDeleteI found it very intriguing that he says the resin used as the ion exchange medium can be tailored to target removal of certain ions with high specificity. In my research, there is a potential problem in water systems of BaSO4 scaling; one of the examples Dr. Boyer gave is that an ion exchange system can be designed that would be very effective at removing Ba2+ ions, so I should consider incorporating an ion exchange system in addition to other options such as adding anti-scalant polymers.
I was moved by Dr. Boyer's extensive coverage of what can actually be achieved using ion exchange - from restoring lakes to landfill leachate color removal. The research on different types of resins, and what kind of DOC removal efficiencies can be obtained was extremely informative. The change in lead removal efficiencies with constant CSMR ratio but higher magnitudes of feed water chloride and sulfate was also a good find and is worth mentioning. However the part that interested me personally was the possibility of using the high osmotic pressure ion exchange brine as a draw solution for an osmotic membrane bioreactor (OsMBR) - which is a classical MBR process driven by water motion created by an osmotic gradient through a forward osmosis membrane. For more information on OsMBR and forward osmosis in general please refer to:
ReplyDeletehttp://dx.doi.org/10.1016/j.memsci.2006.05.048
http://dx.doi.org/10.1016/j.desal.2008.02.022