John E. Greenleaf
Chemical-free Softening of Hard Water using Ion-Exchange Fibers and Harvested Snow-melt or rain water
The primary objectives of the proposed research are to investigate thedetails of an environmentally attractive process which will very efficiently remove temporary hardness without requiring any chemicals for regeneration or production of sludge. According to information available in the open literature, the proposed process will be the first one to utilize rainwater or snowmelt as an efficient regenerant.
Potential Relevance and Future Applications:
Removal of temporary hardness from water is a treatment or pre-treatment practiced in a wide variety of drinking water plants. With the recent growth in pressure-driven membrane processes (e.g., reverse osmosis, nanofiltration), removal of hardness through pre-treatment has attained special significance for the protection of the relatively delicate membranes. The two universally practiced processes in this regard are lime softening and ion exchange. While lime softening produces voluminous sludge to be disposed of, ion exchange process generates highly concentrated brine or acid as a waste regenerant stream. Residuals management will continue to be a major concern with these processes.