 |
    |
|
|
|
The uses for natural zeolites, can be generally categorized into three functional classifications, and within each function exists a broad range of applications. 1. GAS ADSORPTION:
2. WATER ADSORPTION/DESORPTION:
3. ION EXCHANGE:
GAS ADSORPTIONThe ability of activated zeolites to adsorb many gases on a selective basis is in part determined by the size of the channels ranging from 2.5 to 4.3A in diameter (according to zeolite type). Specific channel size enables zeolites to act as molecular gas sieves and selectively adsorb such gases as ammonia, hydrogen sulfide, carbon monoxide, carbon dioxide, sulfur dioxide, water vapor, oxygen, nitrogen, formaldehyde, and others. CABSORB ZS/ZC 500A has about 47% void space and a surface area about 500 square meters per gram which is larger than any other natural zeolite mineral. This means the rate of both sorption and ion exchange are higher than in any other natural zeolite. The ability of zeolites to adsorb certain gases readily lends them to odor control applications. Public toilets, horse stables, chicken houses, and feed lots all release offensive ammonia fumes causing distress to the animals as well as human beings. These problems can be arrested by the application of ZS403H, ZK406H zeolite products. Homeowners with pets often have pet litter trays which cause to unpleasant and offensive odors. Zeolite placed in the litter tray with the normal litter can eliminate these odors by adsorbing ammonia and volatile organic compounds. The potential use of zeolites in many industries for select removal of gases from composite gaseous mixtures is seemingly endless. See Data Sheet #6 for a partial listing of the gases that can be adsorbed. WATER ADSORPTION/DESORPTIONNatural zeolites possess a high affinity for water and have the capability of adsorbing and desorbing it without damage to the crystal structure. This property makes them useful in desiccation as well as other unique commercial systems, such as in heat storage. In many industrial and commercial applications, zeolites have been found highly effective in controlling moisture levels particularly in low humidity ranges where other desiccants are less effective. GSA Resources, Inc. produces ZS/ZC500A as cost effective molecular sieve products. The capability to adsorb/desorb water without change in matrix, coupled with a high heat of adsorption, allows natural zeolites to effectively and efficiently store heat energy for later use. A problem of many alternative heat energy systems utilizing non-zeolite heat storage media has been low efficiency and high cost. Natural zeolites provide a low cost, efficient media for heat storage (to include storage of waste and/or off-peak heat energy) and solar refrigeration applications. ION EXCHANGEThe highly selective cation exchange capacity makes zeolites especially beneficial in controlling specific cationic levels in water systems, agriculture and many other areas. Heavy metal ion uptake capabilities of ZS500H are superior to those of the synthetic zeolites 3A, 4A, 5A and equivalent to 13X for the removal of Cu+2, Pb+2, and Zn+2 from solution. ZS500RW is qualified for radioactive waste treatment for the removal of both Sr90 and Ce137. As an example of selective cation removal, radioactive strontium can be removed from nuclear effluents by passing it through a zeolite filtration column. The efficiency of strontium removal is dependent upon many factors, including the relative concentrations of other competing cations in the effluent . Sewage breaks down into ammonium. This cation can be removed from secondarily treated waste water in much the same way as is strontium. ZS403H is a high crystallinity clinoptilolite also suitable for this application. When fish feed, their normal biological processes quickly contaminate the water in which they live with ammonium. Natural zeolites can be used to ensure removal of ammonium in fish farms, fish aquaria, and fish transport. Crop growers often use an ammonium based fertilizer to supply nitrogen as an essential nutrient. Too high a concentration ammonium supplied to emerging crops can be toxic and can lead to "burning" of the root systems. This means that fertilizer levels have to be rigorously controlled, often requiring successive application of plant nutrients. Ideally, a one time treatment with an ammonium based fertilizer without root "burning" would be more cost effective than the extra labor and time involved for several applications. Proper use of natural zeolites many help solve this problem. The clinoptilolite product ZK406H has proven to be very useful in these applications. The correct type of zeolite application to soils may be expected to do the following:
Zeolites properly applied to soils not only control high nitrogen levels but also can have a significant impact upon reducing water pollution caused by field runoff. High nitrogen levels in river water reduce the waters ability to adsorb oxygen. Adequate oxygen levels are imperative to fish and aquatic life. Regulatory agencies are concerned about the increasing levels of undesirable pollutants in water and the financial resources of companies and municipalities that have to invest in equipment required to achieve increasingly more stringent standards. Chemical effluents from various chemical waste dumps are often sources of water pollution where zeolites can be of benefit by sequestering the substances prior to migration into the water system.
|
|
|
