Zeolita

ORCHARD MANAGEMENT IN SUSTAINABLE FRUIT PRODUCTION Journal of Fruit and Ornamental Plant Research vol. 12, 2004 Special ed.

USE OF NATURAL ZEOLITE (CLINOPTILOLITE) IN AGRICULTURE
Ersin Polat1, Mehmet Karaca2, Halil Demir1 and A. Naci Onus1
1

Akdeniz University, Faculty of Agriculture, Department of Horticulture 07059 Antalya, TURKEY 2 Akdeniz University, Faculty of Agriculture, Departmentof Field Crops 07059 Antalya, TURKEY (Received May 6, 2004/Accepted August 26, 2004)

A B S T R A C T Zeolites have been increasingly used in various application areas such as industry, agriculture, environmental protection, and even medicine. Although, there are no certain figures on the total amount of these minerals the world, some countries e.g. Cuba, USA, Russia, Japan, Italy, SouthAfrica, Hungary and Bulgaria, have important reserves and production potentials. According to reports of 2001, the total consumption of zeolites was 3.5 million tons of which 18% came from their natural resources and the rest from synthetics. More than forty naturally occurring zeolites were reported by different research groups, and clinoptilolite, erionite, chabazite, heulandite, mordenite, stilbitand philipsite are the most well-known. The most common for agricultural applications is clinoptilolite since it has high absorption, cation exchange, catalysis and dehydration capacities. Zeolites are, therefore, used as a promoter for better plant growth by improving the value of fertilizers;retaining valuable nitrogen and improving the quality of resulting manures and sludge. They can also beused as a molecular sieve or filter medium. Key words: zeolites, clinoptilolite, application areas, plant growing, agriculture

INTRODUCTION Identification of zeolite as a mineral goes back to 1756, when a Swedish mineralogist, Fredrich Cronstet, began collecting some well-formed crystals from a copper mine in Sweden. They were named “ Zeolite”from the Greek words meaning “ boiling stones” that is,because of ability to froth when , heated to about 200°C. After their discovery, zeolites were considered as

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minerals found in volcanic rocks for a period of two hundred years. Fortunately in 1950s, they were rediscovered and reported to exist on all the continents (Anonymous, 2004a). In the world, their commercial production and use started in 1960s, but in Turkey theywere first discovered in 1971. To date, more than forty types of zeolites have been reported by different research groups. Among these minerals, analcime (sometimes known as analcite), clinoptilolite, erionit, chabazite, mordenite, and philipsite are well known  (Doğan,  2003).  Also,  more  than  150 zeolites have been synthesized. Some of the common synthetics are zeolites A, X, Y, and ZMS-5. Thosenaturally occurring and synthetic minerals are used commercially because of their unique adsorption, ion-exchange, molecular sieve, and catalytic properties. Extensive research is very important to assure that the source of natural zeolites can provide their sufficient quantity with uniform characters and unique properties (cation exchange capacity, pH and B content) for application andcommercial processing. Research is under progress to enhance the use of zeolites (Kütük et al., 1996). There are many minerals that show similar cage-like framework structures or have similar properties and/or are associated with zeolites, but actually are not them. Therefore, zeolites without well defined chemical characteristics may cause severe problems in their application (Kocakuşak et al., 2001).Zeolites have many important tasks such as ion exchange, filtering, odour removal, chemical sieve, water softener and gas absorption. Therefore, apart of agriculture, numerous examples of their application are cement and brick production, stabilization of soil, building materials, paint components with anti-corrosive property, defluorination of industrial wastes, desulphurization of flue gas,...