The zeolite mineral is a naturally occurring mineral that was formed when ash from volcanoes was deposited in alkaline/saline lakes millions of years ago. Over time, the interaction of the volcanic ash with the salts in the lake water altered the ash creating the mineral zeolite. Zeolite is an amazing crystalline mineral capable of adsorbing and absorbing over a dozen different types of gases, moisture, petrochemicals, heavy metals, low-level radioactive elements and a multitude of various solutions.

Since their classification by the Swedish mineralogist Baron Cronstedt in 1756, many naturally occurring zeolite minerals have been identified. The name "zeolite" literally means boiling stones. Derived from the Greek "Zeo", meaning to boil, and "Lithos", meaning stone, the name refers to the conspicuous loss of water when zeolite minerals are heated.

Natural zeolites were discovered as major constituents of volcanic tuffs in saline lake deposits of the western Turkey and of marine deposits in Japan and Italy. Since that time, occurrences have been reported in sedimentary rocks of volcanic origin in several countries of the world. The flat-lying nature and high purity of the natural deposits in Turkey have aroused considerable commercial interest here and abroad.

Zeolites have unusual crystalline structures that give them unique chemical properties. They consist of a tetrahedral network of oxygen and silicon atoms where aluminum replaces some of the silicon to form aluminosilicates, comprised of hydrogen, oxygen, aluminum and silicon. The result is an extended honeycomb of channels and cavities varying in size from 2.5 to 5.0 angstroms, depending on the type of zeolite mineral. This unique structure makes zeolites different from other aluminosilicates such as kaolin and bentonite. Aluminum atoms have fewer electrons than silicon available for bonding with the oxygen atoms (three instead of four), thus causing an imbalance of electrical charge. Positively charged metal ions and cations, such as those of sodium, potassium magnesium and calcium can neutralize the charge. They sit within the network, surrounded by loosely bound molecules of water. Neither the cations nor the water molecules completely fill the channels so they can move about and be replaced by other ions and molecules without disrupting the crystal structure.

In one gram of zeolite, the channels provide up to several hundred square meters of surface area on which chemical reactions can take place. Zeolites can adsorb or absorb huge amounts of materials, for instance, ions or gas molecules. The result is that you can use zeolites to exchange, say, sodium ions with calcium ions in water which makes these minerals extremely efficient water softeners. Furthermore, the cavities and channels within the crystal may occupy up to 50% of its volume. These crystals readily take in large quantities of water so they are usually hydrated, but heat will drive the water out leaving spaces into which other molecules can slip. The channels and cavities in the sponge-like structure are all the same shape and size in a particular type of zeolite. This means that zeolites can act as sieves, catching only molecules small enough to fit into the cavities, while excluding larger molecules. You can use this property to separate complex mixtures of compounds. Zeolites also act as "shape selective catalysts" by sucking in molecules of a selected shape and size and brining them close enough to react in a particular way.

One potentially important application employs the great absorbing power of zeolites. The natural minerals can absorb up to 30% of their dry weight of gases such as nitrogen or ammonia. This means you can use them to remove gases that are toxic or smelly and to separate gases. For instance, the natural zeolite clinoptilolite can reduce potentially harmful levels of ammonia and hydrogen sulfide given off by the urine and feces of farm animals when confined indoors, i.e. horse stalls, livestock shows, dairy barns and poultry houses. Household pets can receive similar treatment. Zeolites may absorb over 70% of their dry weight in water and 90%+ of their dry weight in hydrocarbons and other petrochemicals.

GAS ADSORPTION: the ability to selectively adsorb specific gas molecules.

• * Odor Control

* Industrial Gas Separation

• * Desiccation

* Heat Storage and Solar Refrigeration

• * Water Treatment

* Agriculture and Horticulture
* Aquaculture

ODOR CONTROL

INDUSTRIAL GAS SEPARATION

The ability of zeolites to adsorb many gases on a selective basis is in part determined by the size of the channels ranging from 2.5 to 5.0°A 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, steam, oxygen, nitrogen, formaldehyde, and others.

• Odor Control

GNTT AB´s' Clinoptilolites are naturally occurring earth minerals which are uniquely effective in the control of ammonia and its resultant malodor. These Clinoptilolite minerals also appear to be beneficial in the containment of hydrogen sulfide, another olfactory irritant.
Ammonia and hydrogen sulfide are two gaseous by-products from the breakdown of organic matter whether it be food or waste products in the home environment or in animal rearing areas. Both of these gases, when released into the atmosphere, are irritating and according to health officials, damaging when prolonged exposure occurs at relatively high levels.
Ammonia is an offensive odor for both man and animal and its potential for aggravation of both eye and respiratory systems becomes acute as accumulations increase in confined areas. Concentrations of ammonia in enclosed chicken areas have been severe enough to cause blindness and inhibit growth. A reduction in swine feed conversion has been noted where levels of ammonia are elevated. Horses are prone to bronchial infections which are believed to be caused, in part, by irritation to the respiratory system from the inhalation of ammonia.
Hydrogen sulfide, a typical gaseous by-product from waste decomposition, is also believed to be a cause of some respiratory ailments in both animals and humans.
Unpleasant odors can also result from the breakdown of foods and other organic products in storage areas as well as the decomposition of wastes and unwanted by-products in various industrial processes, disposal sites, garbage bins, and pet litter boxes.
Natural Clinoptilolites, such as those available through GNTT AB´s, have been found to be particularly helpful in the control of ammonia and hydrogen sulfide in confined livestock rearing areas, zoos, kennels, pet shops, and pet litter trays, all of which release offensive ammonia fumes causing distress to the animals as well as human beings. These problems can be arrested by Clinoptilolite application. These natural minerals have also been used very effectively in the control of malodors emanating from waste disposal areas, public toilets, garbage bins, diaper pails, refrigerators, pantries, and some industrial processes.
Clinoptilolites are able to perform this function due to their ability to adsorb certain cations and gases. Natural Clinoptilolites can selectively adsorb the ammonium ion present as wastes breakdown, as well as impact ammonia as it begins to volatilize. The capture of ammonium removes the basis of odor generation.
Due to its unique properties, Clinoptilolite once loaded with ammonium from odor control applications, makes a remarkable soil amendment and may be added to potted plants, lawns, gardens, and agricultural fields. The Clinoptilolite then makes nitrogen (from the ammonium) available to the plants over an extended period of time. This acts as a slow release mechanism in the soil, making fertilizers more effective by increasing their efficiency. Therefore, use of GNTT AB´s' Clinoptilolites for odor control can result in an useful or saleable by-product.
Homeowners with pets often have pet litter trays which can lead to unpleasant and offensive odors. Clinoptilolite placed in the litter tray with the normal litter can eliminate these odors by adsorbing ammonia and ammonium (primary odor sources).

• Industrial Gas Separation

The potential use of GNTT AB´s' Clinoptilolites in many industries for select removal of gases from composite gaseous mixtures is seemingly endless.
Zeolites have the potential of providing precise and specific separation of gases when applied in conjunction with properly engineered systems. The following list depicts those gases on which natural Clinoptilolites are currently known to effect:
CO, CO2, SO2, H2S, NH3, HCHO, Ar, O2, N2, H2O, He, H2, Kr, Xe, CH3, OH, Freon, Formaldehyde
The type of zeolites used in combination with different kinds of gas separation equipment will vary the efficiency of gas removal. The potential importance of such systems to eliminate certain gases such as SO2 will greatly impact industry and the environment.
Operations are already in existence which utilize natural zeolites in the upgrading of natural gas and methane. In this case zeolites can be used to remove H2O, CO2, and SO2 thereby producing a higher value natural gas which might otherwise be useless due to unsuitable quality caused by high concentrations of impurities.
The possibilities for the use of zeolites in the elimination and containment of the aforementioned gases and gaseous compounds appears endless at present. In most cases, the true potential for natural zeolites to improve the handling of such gases requires further scientific study.

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DESICCATION

HEAT STORAGE & SOLAR REFRIGERATION

Natural zeolites possess a high affinity for water and have the capability of absorbing 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.

• Desiccation

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.

• Heat Storage and Solar Refrigeration

GNTT AB´s' Clinoptilolites high rate of absorption and ability to hydrate and dehydrate while maintaining structural stability have been found to be useful in various heat storage and solar refrigeration systems. This hygroscopic property coupled with an inherent exothermic reaction when taken from a dehydrated to hydrated form (rate of absorption), makes natural zeolites effective in the storage of solar and waste heat energy.
Low energy density and time of availability have been key problems in the use of solar and waste heat energy. Commercial storage systems have been developed incorporating zeolites which overcome these problems.
These systems are capable of operating from solar or industrial waste heat and other turmoil polluters, thereby converting underutilized resources into useful energy.
The capacity of natural Clinoptilolites to store heat energy and absorb water vapor used in that exchange of energy comes from their honeycomb structure and resultant high internal surface area.
When "charged" with heat, Clinoptilolites can store latent heat energy indefinitely if maintained in a controlled environment and not exposed to water vapor. This stored energy can be liberated as needed by simple addition of controlled amounts of water vapor which initiates the exothermic reaction. Most other storage media lack this basic property.
Heat storage units using natural Clinoptilolites reduce dependence on secondary / backup heating systems and allow for efficient and safe use of waste heat.
The principle of absorption-desorption can be utilized as a key component in the refrigeration cycle as well. In this case, natural Clinoptilolites are used as a transfer mechanism moving water as a refrigerant through the condensers and evaporators. The efficiency of the system is based on the nonlinearity of the natural Clinoptilolites absorption isotherms as compared to pressure. Clinoptilolites will absorb water vapor at low partial pressure and desorb a majority of it at high partial pressure. This difference in partial pressure may be achieved through temperature changes which would be experienced in a solar panel going from high day temperatures to low night temperature.

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WATER TREATMENT
AGRICULTURE & HORTICULTURE
AQUACULTURE 

The highly selective cation exchange capacity makes Clinoptilolites especially beneficial in controlling specific cationic levels in water systems, agriculture and many other areas.

• Water Treatment

The high Cation Exchange Capacity (C.E.C.) of GNTT AB s' Clinoptilolites combined with their selective affinity for specific cations make them uniquely suited to various applications in water treatment. These natural Clinoptilolites have been shown to be effective in industrial and municipal waste water systems. The following is a listing of those cations which can be removed from various effluents by Clinoptilolites under the proper conditions:
Rb+, Li+, K+, Cs+, NH+4, Na+, Ag+, Cd+2, Pb+2, Zn+2, Ba+2, Sr+2, Cu+2, Ca+2, Hg+2, Mg+2, Fe+3, Co+3, Al+3, Cr+3
One of the first full scale projects to incorporate natural American zeolites in a municipal tertiary water treatment system was built for the Tahoe Truckee Sanitation Agency. This system utilizes zeolite as an ion exchange medium for the removal of ammonium (NH+4). The municipal effluent containing ammonium is passed through the natural zeolite which adsorbs the ammonium ion. The efficiency of ammonium removal is dependent upon temperature, water quality, and rate of flow. Regeneration of the natural zeolite bed for reuse is achieved by passing a brine solution through it. The regenerant then is passed through a stripping unit and the ammonium is concentrated as ammonium sulfate.
A pilot project near Denver, Colorado, is now using natural American zeolites for the removal of ammonium in a potable water system. Similar systems are now in production which remove various pollutants including heavy metals and radioactive ions from industrial effluents.
An alternative method to a typical tertiary water treatment plant is to apply effluents over natural soils. The soil filters the pollutants from the water as it gradually percolates to the natural ground-water table which may be eventually recovered from wells for reuse. The soil, as an ion exchange medium, is regenerated by way of crop production capable of removing many of the pollutants. A major limitation of such systems is the requirement for percolation which typically necessitates the use of sandy soil types not ideal for ion exchange. The low cation exchange capacity of these sandy soils can then be enhanced through the addition of zeolites which will not impede percolation. Tests of just such a system were carried out by Dr. Ian Pepper of the University of Arizona. In these tests, a turf grass was used to regenerate the system and adequate efficiencies of pollutant removal were found to be attainable. Additions of natural zeolites in these systems may be found to favorably improve the holding of heavy metals. Further testing is required to fully demonstrate this possibility.
Systems for the specific removal of cations from industrial wastes utilizing natural zeolites as a component of the filter medium have been commercialized. These systems have successfully recovered precious metals from plating operations as well as basic industrial pollutants from effluents.

• Agriculture and Horticulture

GNTT AB ´s Clinoptilolites are natural earth minerals possessing unique properties beneficial to the professional and amateur growers. GNTT AB ´s Clinoptilolites improve your soils structure by coupling high Cation Exchange Capacity (C.E.C.) with selective affinity for ammonium and potassium.
By way of these properties, Clinoptilolites can reduce nutrient loss due to leaching by increasing the retention of these nutrients and slowly releasing them as needed by the soil and plants. Increasing the C.E.C. of the growing media and, in particular, the selective form of the C.E.C. has a direct bearing upon nutrient retention. This effect is most evident in sandy soils where it can provide the plant population with a more efficient and uniform supply of these nutrients.
The selectivity of GNTT AB`s Clinoptilolites for ammonium can help buffer the soil and in part can prevent toxicity which might otherwise occur when excess ammonium is applied. This property may allow the grower to use this less costly form of nitrogen in larger, less frequent applications during the growing season.
Growers of agronomic as well as horticultural crops often use an ammonium based fertilizer to supply nitrogen as an essential nutrient. Too much ammonium supplied to emerging crops can be toxic and can lead to burning of the root system. 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 may help solve this problem.
The correct type of Clinoptilolite application to soils may be expected to do the following:
• Act as a slow release mechanism of potassium and ammonium in a soil system
• Reduce the chance of ammonium toxicity by way of its cation exchange capacity, avoiding root burning
• Improve the retention of ammonium, thus reducing the loss of nitrogen contained in fertilizers; such losses often occur by leaching and subsequent runoff resulting from heavy rainfall or excessive irrigation
• The retention and timely release of needed nutrients by these natural zeolites can create improvements in foliage and blossom count, which may relate directly to overall crop yield.

GNTT AB's  Clinoptilolites can improve some of the characteristics of the growing media. The initial quality and texture of the growing media, the fertilization, and the amount of Clinoptilolite determine the degree of this improvement.
Clinoptilolites properly applied to field 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 rivers, streams, and ponds reduce the waters ability to adsorb oxygen. Adequate oxygen levels are imperative to fish and aquatic life. Water authorities are concerned about the increasing levels of undesirable pollutants in water, and the expensive outlays necessary to reduce these pollutants to acceptable levels.
Likewise, chemical effluents from various chemical waste dumps are further sources of water pollution where Clinoptilolites can be of benefit by capturing the problematic substance prior to migration into the water system.

• Aquaculture

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 this ammonium in fish farming, fish aquaria and fish transport.
The unique properties of these naturally occurring minerals make GNTT AB´s Clinoptilolites beneficial in a variety of end uses in aquaculture. Their high Cation Exchange Capacity (C.E.C.) allows them to be an excellent medium for the removal of toxic ammonia by way of ion exchange as a physical / chemical filter, or for bacterial breakdown as a substrate in a biological filter. Plus, the affinity of some zeolites for nitrogen makes them capable of producing oxygen enriched air for water system aeration.
The ability of Clinoptilolites to chemically reduce ammonia is accomplished by the adsorption of ammonium on the natural Clinoptilolite thereby shifting the NH4--NH3 equilibrium in the aqueous solution and reducing the potential for NH3 toxicity. When the optimum quantity of Clinoptilolites is used, the NH4 level is reduced at a rate highly dependent upon the rate of water movement.
The actual quantity of natural Clinoptilolites required depends upon water pH, water temperature, water volume, fish species, concentration of fish population, water quality and the rate of water flow through the Clinoptilolite bed.
A variety of systems have been designed and engineered utilizing GNTT AB´s Clinoptilolites in the reduction of ammonia in fish rearing environments.
Variations of this basic use are available for home and commercial aquariums as well as fish transportation systems. In the trans-shipment of fish, Clinoptilolites allow the safe transportation of more fish over a longer period of time.
As a substrate in biological filters, Clinoptilolites are remarkably effective as well. They provide a suitable habitat for the growth of the bacterial populations required in the breakdown of NH4 to NO3 and remain effective as chemical filters capable of modifying fluctuations in the systems NH4 levels. This property actually enhances the biological functions making the NH4 available to bacteria at a more stable level, thus enabling this population to remain abundant during periods of low NH4 contamination. The bacterial population may then better respond to dramatic changes in concentration.
The removal of nitrogen by one species of Clinoptilolites provides a means of generating oxygen enriched air. Here the nitrogen is adsorbed by the Clinoptilolite which may then be regenerated through a pressure swing to allow the continuation of this cycle. As the oxygen content is concentrated sufficiently, it may then be introduced into the system. Such a process allows for the increase of dissolved oxygen and relative reduction of dissolved nitrogen normally present when applying standard aeration.

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GNTT AB´s' products, the naturally occurring Clinoptilolite mineral, has the ability to capture cesium 134, 137, and strontium 90 isotopes and are ideally suited for the treatment of liquid radioactive waste effluents and in the design of sorbent barriers. The inherent properties of these minerals include a high Cation Exchange Capacity (C.E.C.), appropriate cation exchange kinetics, resistance to attrition and ionizing radiation.

Users of zeolite products include the British Nuclear Fuels Ltd. Site Ion Exchange Effluent Plant (SIXEP), West Valley Nuclear, and the Oak Ridge National Laboratory Process Waste Treatment Plant. Low - and intermediate-level liquid wastes generated at these plants are cycled through highly-selective ion exchange columns packed with natural zeolites. The Clinoptilolites significantly reduce concentrations of cesium and strontium to levels below mandated discharge limits. In addition to achieving decontamination objectives, the immobilized ions in the spent Clinoptilolite can be easily handled and be economically encapsulated in cement.

Zeolites have been utilized for over a decade in other radioactive waste management programs at Hanford, Washington; Savannah River, South Carolina; the Idaho National Engineering Laboratory; and the General Electric Laboratory in Morris, Illinois.

Applications include the removal of cesium from high-level waste water, decontamination of low and intermediate-level waste water and fixation of radioactive waste for long-term storage. An important consideration in favor of natural zeolites is their low cost relative to the synthetic analogues.

In addition to treating radioactive process waste water, natural zeolites are being utilized in the construction and design of sorbent barriers. These permeable barriers employ sorbent materials including natural zeolites and activated carbon to selectively contain low level contaminants percolating from shallow land burial sites. The zeolites are combined with clays and other materials that retard the migration of the leachate long enough to allow exchange or decay of the radioactive ions. Water passes through these systems at rates that will allow uptake of soluble radionuclides but prevent ponding or the so-called bathtub effect.

Sorbent barrier systems designed at Battelles Pacific Northwest Laboratory eliminate the need for, and the expense of, long-term maintenance of shallow radioactive waste burial trenches.

Additional application of Clinoptilolites in sorbent barriers include:
1) a top cover to prevent contaminant uptake by vegetation;
2) an inner layer within a leachate/liner trench designed to produce a cleaner leachate;
3) backfill surrounding above- or below-ground storage vaults, to prevent contaminant release should a breach occur in the primary storage container.

For More Information Contact GNTT AB´s, Inc.

The previous description of natural zeolites begins to outline the tremendous potential of this unique mineral. There are other uses not listed here which further utilize the benefits of this minerals unusual mix of properties. The cost effectiveness of natural zeolites in retrofit designs and newly developed systems will push them to the forefront of state of the art technologies. For just pennies per pound, this product can be applied in a variety of uses ranging from single low tech systems to intricate functions in high tech designs. 

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