Zeolite mean? This article in agriculture and in the process of the filtration of water in abundance, is used. To be familiar with a variety of the substance and application of the text to read.
Properties and features
Zeolite, natural resources, abundant, and cheap cost, and are the crystals of alumina silicate hydrated are made. This compounds the physical properties of the chemical value, such as cation exchange, etc., sieve, molecular, etc., catalyst and adsorbent are. The structure they form porous is, that this تخلخلها contains water and cations of alkali and alkaline earth industry. Since the discovery of the minerals in a sedimentary rock and volcanic., the Caspian Sea millennia ago tuff (a rock firefighting) zeolites in many regions of the world has been discovered.
In recent decades, this natural material applications, a wide variety of absorption. catalyze., the building industry, agriculture, soil remediation, and energy have found. Zeolite natural in all over the world. the capacity of the ion exchange different for cations such as ammonium and heavy metals from your show. In addition to this, some of which are the ability to attract anions and organic compounds as well. Modified zeolites in different ways, such as acid washing and Ion Exchange is performed. With this, the capacity to absorb the material for the absorption of anions and organic compounds increased.
Application in water treatment:
Nowadays the world due to a lack of clean drinking water , clean with the water crisis facing is. With the rapid advancement of various industries, a lot of sewage from industrial processes produced in soils and in water, drain it. Element usually contains contaminants such as ions, cationic and anionic., the pigments and organic compounds, are, that the negative effects on the ecosystem have.
The removal of these contaminants to the technology complex and expensive needs. Recently, it is believed that we can attract as a technology for simple and effective for the purification of water and wastewater used. This technology has been widely applied to the effectiveness of the adsorbent depends on. Activated carbon, soil clay minerals. بایومواد, etc. zeolites and some wastes, solid industrial are widely used as adsorbents in water treatment and effluent and the removal of ions and organic compounds are used. In recent years, research and many reports based on the use of zeolite, a natural water filtration is provided.
One of the types of contaminants that are dangerous in recent decades, with the increase of population and the progress of the industry caused severe pollution in industrial wastewater has been heavy metals are. These pollutants, the health of humans, animals and plants strongly about the threat puts. The majority of this pollution include Hg, etc., Pb, etc., Ag., the Cu, Cd, etc., Cr, etc., Zn, etc., Ni, etc., Co and Mn can be. In the table below is a summary of the studies on the uptake of heavy metals by the use of zeolite different is brought.
|Zeolite||Ion metal||Absorption (meq/gr)|
زئولیتهای different across the world are known. Clinoptilolite, etc. موردنیت, etc. فیلیپسیت, etc. چابازیت, etc. انالسیم and lomontit common forms of zeolite are, while arfrit, etc. palingate, etc. barririt And Mazit are very rare. In the meantime, clinoptilolite is the most abundant type this material for natural and is the most widely used there. In the table below are the chemical formula and the spatial structure of the different types of it have been brought.
|Type||Chemical formula||The structure of space|
|چابازیت||(Ca,Na2,K2)2Al4Si8O24.12H2O||Three tilt or لوزوجه|
The following is a sample of clinoptilolite to accompany the SEM image, it can see.
In the table below, the values of chemical compounds, zeolites different is brought.
|فیلیپسیت and چاپازیت Italy||56.42||15.8||4.08||2.42||0.86||2.35||0.004||8.14|
|Clinoptilolite and موردنیت Chilean||67||13||2||3.2||0.69||2.6||0.2||0.45|
|Clinoptilolite and موردنیت sex||66.5||11.81||1.3||3.11||0.72||2.01||0.21||3.12|
Modified zeolite, natural
Technical attract each zeolite-dependent physical and chemical properties of adsorbent. The ratio of Si/Al and the type of Cation, the greatest impact on attracting converts. This specification can be used with several chemical methods to improve the efficiency of the separation of zeolite natural improve. Methods modified by acid washing and dipped in storage with the surfactant by Ion Exchange two common approaches for the correction.
Generally acid shower these compounds cause of removing the impurities that the pores of the reason has to be. Of course, aciding might, over time, the structure of it destroy. The two main methods of correction there that can be done with its use of zeolite exchange protein production. One exchange of ammonium and follow it calcination and the two exchange a direct ion with a solution of acid haze. In the method of exchange of ammonium structure can be maintained while acidwash generally cause the destruction and reduction of thermal stability can be.
Zeolites are materials, chemical, and mineral آلومینوسیلیکات hydrated, which are four-dimensional, interlocking alumina (AlO4 ) and silica (SiO4 ) have been made . In simpler terms, they جامداتی are with the crystal structure, relatively open and three-dimensional that of the elements, aluminium, oxygen and Silicon have been made, with the alkali metal or alkaline earth (such as sodium, potassium, and magnesium) and water molecules have been trapped. In the gap between them zeolites with crystal structures very different are formed that have open pores (because sometimes it is the cavity is said to be) in the Make-Up is very regular and almost to the size of the molecules is small.
A variety of zeolites
Zeolites are naturally or are formed, or they can be synthesized, or for industrial production. Today, 50 different types of zeolite is available.
1. N a 2 K 2 C a M g ( A , l, O 2 ) 2 ( S i O 2 ) 2 . 6 H 2 O ( اریونیت )
2. N a 2 C a ( A , l, O 2 ) 2 ( S i O 2 ) 4 .6 H 2 O ( Gemelinite)
3. H x [ ( Al O 2 ) x ( S i O 2 ) 96 – x ] .16 H 2 O ( ZSM-5 )
They are more in volcanic rocks and sediment are found.
1. Zeolite clinoptilolite (Clino) and the ratio of silica to alumina 5 to 1.
Zeolite کلینو in the middle of an acidic environment does not break down, and is widely used in the agricultural industry as feed additive and modifier of soil used.
2. N a 56 ( Al O 2 ) 56 ( S i O 2 ) 136 .250 H 2 O ( Faujasite )
Zeolite synthesis has been
Zeolite , synthetic, usually with the process of crystallization is slow, gel, silica-alumina in the presence of قلیاها and lockers organic synthesis are. Interesting to note is that using this process بایوساید can be different structures to build. Apart from changes in the structure, zeolites can be from a variety of atoms other production or construction that make them chemically interesting and activates. For example, the so-called هترواتم include germanium, iron, gallium, etc., blonde, tap, etc., tin, and titanium.
The process is another important that is to perform the synthesis of zeolite can be used. the processing of Sol-Gel is. Here, the properties of the product greatly depends on different factors such as pH of the system, operating temperature, etc. composition of the reaction mixture, time of seed before the reaction, time of reaction, and formats used depend on. In this process, a few other element (metals, metal oxides) can be easily imported. Generally, Sol سیلیکالیت produced to the method of hydrothermal very stable. The process for the synthesis of زئو usually by many to be preferred because it can be easily increased.
Several zeolite for a particular purpose, the synthesis of which there have been a well-known example زئو A is usually in the detergent washing can be used. Zeolite synthesis has the ratio of silica to alumina 1 to 1 would be.
Properties and features of zeolites
Zeolites are solid very stability that are against a variety of environmental conditions that many other materials, challenges etc. of resistance can work. High temperature annoy them and not give up because the melting point is relatively have high (over 1000 degrees Celsius) and do not combust. They are also against the pressures of high resistance are, in water or other solvents, Mineral Solution and not in the air, the oxide are not.
It is believed not that they go through, for example, contact with skin or inhalation, etc., causing health problems are, although to form fibrous possible effects of carcinogens (cancer-causing) have .
Since they are non-reactive and are based on the natural minerals are. it is believed that any environmental effects harmful whatsoever. Although zeolites may be very frustrating to comment, agree, etc., nature, stable and non-reactive, they are not something that they do useful work.
- Zeolites in environmental conditions different solids, the very sustainability are. Melting point zeolites are very high, namely, 1000 degrees Celsius.
- They are in water or other solvents, inorganic insoluble are.
- They are in the presence of air under the oxidation of fasting.
- Obvious feature of zeolite structure of cage-like open it is to the zeolite helps water and ions, potassium, and calcium into the trap without any permission.
- The Shape of the natural zeolite randomly occurs and the size of the pores is not uniform, while the zeolite synthetic method is very accurate with the size of the pores of uniform, can be synthesized.
- Zeolite – rich alumina to the molecule polar, like water are attracted, while the zeolite, a silica-rich side of the molecule non-polar are attracted.
- Since that زئولیتها واکنشپذیر are not from natural minerals into the hands of tourists. any the detrimental effects of Environmental Respect. although there is skin to skin contact or inhalation may be the effect of carcinogenicity have.
The most interesting thing in the case of zeolites , the open structure and cage-like, and the “framework” of them and the way they can other molecules inside the trap set.
That is, the water molecules and ions, alkali metal or alkaline earth (atoms with a positive charge with electrons is very low, which sometimes کاتیونها also called) is part of the crystals of the zeolite are – though not necessarily always, there remains do. زئولیتها can ions with a positive charge, the other with metal ions, which are initially trapped inside them to swap their (technically this as cation exchange is known) and, as کرونستد more than 250 years ago, discovered, etc. can easily water molecules themselves also to earn or lose (to this mode, the reversible say, dehydration).
Zeolites have pores neatly with a fixed size that are to small molecules allow straight through it, but larger molecules into a trap.
That’s why, sometimes, as they sift molecular remembered .
Unlike زئو that natural forms of random sizes and combination are found, etc. زئولیتهای artificial sizes are very accurate and uniform (usually from about 1 micrometer to 1 mm) are made to fit a particular application requirements. In other words, they are a certain size to molecules of a given size (smaller) within your trap in Perth.
Although all zeolites are آلومینوسیلیکات are, some containing alumina are more, while some others contain silica are more. زئو-rich Poly aluminium chloride to the molecule polar, like water are attracted, while the zeolite, a silica-rich with molecules غیرقطبی work better.
Some زئولیتها like زئولیتهای natural fibrous (Erionite), when inhaled, can cause cancer are.
Zeolites have high porosity and surface are vast.
That’s why it’s for biological filtration, water can be used.
Also زئو upload cation, undesirable, etc., the radioactive elements and heavy metals from the water, remove it.
Zeolites in water, insoluble are, so they can be with the filtration of the aqueous solution separated.
Cases, the use of zeolites
Photo: NASA are experimenting with the use of zeolites to store hydrogen that can be used in fuel cells to be used . The photo above zeolite grown on the land show. The lower part of the crystals, a similar show that the effect of gravity in space have grown. Photo by Flight Facility Marshall Space NASA by the Internet Archive .
The cage structures, such as zeolites them in all kinds of different useful lives. One of the biggest uses of everyday zeolites in conditioner, water and filters the water . For example, in conditioners water, ion exchange, etc. hard water (rich in calcium and magnesium ions) through a column filled with زئولیتهای contains sodium directed. زئولیتها calcium and magnesium ions into the trap opened fire, and the ions of sodium in their place, releasing them. so the water softer, but in terms of sodium richer it is. Many of detergent washing machine and dishwasher daily, containing zeolites are made up of calcium and magnesium, dynamic and water to make soft, their performance will have more.
Two application is very common and everyday other zeolites in the control of odors and litter pets. In both, the structure of crystalline porous zeolites by trapping fluids, unwanted molecules smell can help. This simple idea that our houses are very effective., the applications is very important on the outside, they are: زئولیتها in the removal of radioactive fallout from the waste and nuclear and cleanup of contaminated soils to heavy metals-toxic, highly effective, respectively . (Looking for the nuclear disaster of Fukushima in Japan in 2011, the rice farmers zeolites in their farms scattered up any pollutants, radioactive lasting into the trap of pocket.) Many other uses of zeolites, including the production of concrete, air, soil, and food animals.
The chemical composition and structure of zeolites
All zeolites are Framework آلومینوسیلیکات have formed, in which the silicon and aluminum for the tetrahedron are synchronized. Cation of silicone and Cation aluminum by four anion oxygen (O2-) have enclosed. The structure of the tetrahedron Si0 4 and Al0 4 building blocks zeolites will form.
The formula of zeolites often for the following to be provided:
However, zeolites tend chemical elements have different have in their composition. The formula of zeolite :
M = any metal that can be magnesium, sodium, potassium, etc., lithium, or calcium to be.
n = the capacity of the cation of the metal.
y = The number of water molecules in the structure of the zeolite.
y/x = ratio of Si/Al atomic
The structure of the crystalline zeolite in comparison with other solids, crystalline, very different. Zeolites can be used as a solid crystalline particular structure clear framework with cavities occupied by ions and water molecules, which release significant movement are considered.
Occurrence and production of zeolite
As above said. zeolites are naturally in places can be found that the volcanic rock and layers of ash with groundwater alkaline reaction can make. According to reports, about 245 the framework of the unique zeolite, discover, and around 40 the framework of the zeolite naturally. Every time that a new structure of zeolite found by the commission of the structure of the international zeolite carefully reviewed. After identification, the matter is a mark of something receives. Generally, the techniques of open-pit mine for the extraction of زئو natural used.
On the other hand zeolite that in terms of industrial importance have to be artificially produced. Some of the most common methods that are used include heating aqueous solutions of alumina and silica with sodium hydroxide. Reagent equivalents also include aluminate, sodium silicate sodium. Some other changes include changes in the cations to add a cation, a quaternary ammonium is. To date, more than 200 zeolites, synthetic synthesis. This is by using the process of crystallization is slow, includes gel, silica-alumina, and also the addition of alkali and templates Organics do.
There is zeolite production, and the synthetic form has several advantages compared to zeolite, a natural. زئو artificial in a state of uniform and pure phase are produced. In addition, the structures of unique زئو can be used for as well as industrial production. For example, zeolite A. In addition, since the silica and alumina is the most abundant mineral components on Earth. زئو can be used for unlimited produced and shipped.
The application of zeolites
Some of the most common applications زئو are as follows.
The cage structures, such as zeolites them in the exchange of ions is very useful works. For example, hard water through a column filled with زئو containing sodium passes. In this process, calcium and magnesium by زئو, the fall into the trap, and the ions of sodium, can that result in soft water is water rich in sodium is. Nowadays زئو in detergent to remove magnesium and calcium are also used, resulting in a softening of the water and increasing the efficiency of detergent used.
As the catalyst
Zeolites as catalysts in several reactions is important, such as cracking, ایزومریزاسیون and the synthesis of hydrocarbons are used. The porous structure of زئو it to a catalyst is very effective become available. In addition, the pores in a زئو particular has the shape and size of the flat that are زئو on the molecules of certain selected works. Thus, zeolites as catalyzed selective form will also be reincarnated.
کاتالیزورهای zeolite mean?
Zeolites by Max Pskov from the University of Stockholm. An excellent introduction and much more accurate than زئو of the website ASDN. This explains how the structure of the زئو different to them, and helps catalyze in. adsorption and Ion Exchange in different applications everyday, and industrial work.
Another of the important uses of zeolites as catalysts in the production of medicines (pharmaceuticals) and in the petrochemical industry, which is کراکرهای a catalyst to break down the molecules of hydrocarbons to gasoline, diesel, oil, white wax, and a variety of other petroleum byproducts can be . Again, this porous structure زئو is important. Pores numerous in the open structure, a زئو like millions of test tube is small, in which the atoms and molecules into the trap of unfolding and chemical reactions can be done easily.
Since the pores in a زئو particular size and shape, the fixed ones. کاتالیزورهای زئو can selectively on the molecules of a certain work, which is why sometimes they کاتالیزورهای choose a shape to say.
Like all catalysts, etc. زئو are repeatedly are reusable.
Zeolite , the adsorption capacity is very high and they have to absorb a variety of materials are used. They have a wide range of applications in the field of filtration, etc., drying and separation have.
Isolation of harmful substances
Zeolite can be effectively of radioactive fallout from nuclear waste eliminated. Also it can be use for cleaning water or dirt smeared to toxic metals, heavy work.
Commercial and domestic
- Zeolites , as molecular sieve, etc., often in the vacuum pump style absorption cooling are used.
- Bed shorthair غیرمجموعه often زئو are.
- زئو artificial as an additive in the process of concrete production, asphalt heating can be used.
One of the minerals, rare zeolite, etc., known as تامسونیت, as the gems collected.
- Systems oxygen concentrator-based زئو is widely used for the production of oxygen medical grade can be used.
- In agriculture, clinoptilolite for the purification of soil used.
Store and use solar energy
Zeolite to store thermal solar heat from کلکتورهای solar thermal are used. Also for refrigeration, absorption can be used. In such cases, the heat of the top of the absorption of zeolites, and the ability to become hydrated and dewatering at the same time maintain the stability of the structural widely used. This property moisture surveys, etc., when an exothermic reaction inherent in during the transition from one form of low water to form a hydrated matching can be. زئو natural in harvesting solar heat, and the heat energy Heather gives.
The term zeolite for the first time in 1756 by Excel Frederick , etc. Connie Swedish botanist was used. During the process of rapid heating, the material that was observed is a large amount of steam it produces. This is because Blue was the material previously attracted were. After viewing such a development., the so-called invented. The word comes from the Greek words زέω (zéō) means “to boil” and λίθος (líthos), meaning “stone”.
Zeolites are hydrated alkali metal and alkaline earth are.
During the past 200 years, about 40 زئو natural identification. They are the most common
More than 150 زئو synthesis. They are the most common زئو A, X, Y, and ZMS-5 are. ; زئو natural and artificial, because of, property, recruitment, ion exchange, etc. molecular sieve, and the properties of the catalytic unique فردشان for commercial used. Main markets زئو natural include litter, pets, board, animals, etc. applications gardening (تهویهکننده soil and environments, growth), and wastewater treatment., the prominent categories, the main use for زئو synthetic absorbents, etc. detergents, etc. sieve molecular are.