The desirable physical characteristics of lead are responsible for its widespread use in water distribution systems plumbing systems, even though very low levels of lead may pose a significant health hazard and cause learning disabilities in children. Though municipal water supplies generally have very low lead levels, they frequently become contaminated with lead from the distribution system and/or domestic plumbing. Proposed Environmental Protection Agency regulations will reduce the problem through corrosion control, but not entirely cure it.Clinoptilolite zeolite, a naturally occurring mineral with a high ion-exchange capacity, can selectively remove lead from water. Current research at the U.S. Bureau of Mines and the Idaho National Engineering Laboratory shows that ion-exchange columns containing clinoptilolite can reduce lead levels to well below the drinking water standard from relatively high initial concentrations. This, and other research, indicates that clinoptilolite zeolite may provide an effective media for use in filters to treat drinking water.However, detailed data are needed to develop effective, low-cost filters using clinoptilolite for lead removal. Most importantly, this study will address questions such as the contact time needed for lead removal, the effective capacity at relatively high flow rates, and parameters such as the optimum particle size to maximize efficiency while maintaining good flow characteristics.Results of this research will be used to develop drinking water filters for domestic use at the tap and for use in schools and other public places.The investigators expect to reduce the lead in contaminated water from relatively high levels such as lppm to significantly less than 50ppb, the current drinking water standard, through ion- exchange with clinoptilolite zeolite. It may be possible to achieve levels of 10ppb or less. If successful, this will allow the investigators to proceed with Phase II, development of an inexpensive water filtration cartridge for home use either as an under the sink type filter cartridge or a counter top unit. Following Phase II, the investigators intend to procure venture capital for commercial production of a filtration unit containing clinoptilolite zeolite for home use. Secondarily, they intend to develop filtration units for use with drinking fountains used in public and industrial places.
