PROJEKTI
   

Project
Acronym: PUREWATER 
Name: Natural Zeolites in Water Quality System 
Project status: From: 2008-04-30 To: 2011-04-30 (Completed)
Contract number:  
Action line:  
Type (Programme): Eureka 
Instrument: EUREKA 
Project cost: 149.985,00 EUR
Project funding: 0,00 EUR
Project coordinator
Organisation Name: NATIONAL INSTITUTE OF CHEMISTRY  
Organisation adress: HAJDRIHOVA, 19 
Organisation country: Slovenija 
Contact person name: Prof. Dr. Kaucic Venceslav  
Contact person email: Email 
Croatian partner
Organisation name: Fakultet kemijskog inženjerstva i tehnologije 
Organisation address: Marulićev trg 20 
Contact person name: Prof. Dr. Štefica Cerjan-Stefanović
Contact person tel:
00385 1 45 97 210  Contact person fax: 00385 1 45 97 210 
Contact person e-mail: Email 
Partners
Organisation nameCountry
University of Zagreb / Faculty of Textie Technology Hrvatska 
Belgrade University / Faculty of Technology and Metallurgy Srbija 
Belgrade University / Faculty of Agriculture Srbija 
Silkem d.o.o. Slovenija 
CWG d.o.o. Hrvatska 
GM Water d.o.o. Srbija 
Short description of project
Many toxic heavy metal ions are discharged into the environment with industrial wastes causing serious water and soil contamination. Heavy metal ions such as Cr3+, Cu2+, Zn2+ and Pb2+ are common metal ions, which accumulate in living organisms causing numerous disorders and diseases. They are also common groundwater contaminants at industrial installations. Arsenic is a well known metalloid which causes serious problems in drinking water since it is extremely poisonous. The presence of arsenic in water is due to the dissolution of minerals from subterranean strata or from an anthropogenic origin such as the leaching of arsenic compounds from smelting of metal ores, agricultural pesticides or wood preservatives. Arsenic contamination of groundwater as a source of drinking water has been a health risk for many regions around the world. The WHO (World Health Organisation) established that even a low concentration of arsenic in drinking water produces negative effects on human health, therefore the arsenic reference value for drinking water is 0.010 mg/dm3. Many wells spread all over the world exceed this value. Thus, there is still an urgent need for development of a cost-effective method for arsenic removal from groundwater and wastewater. Numerous methods exist for removing heavy metal and arsenic ions from water. Precipitation, ultra-filtration, reverse osmosis, ion exchange and adsorption are some of the commonly used techniques. As it is easy to remove the sorbent from aqueous media after treatment, sorption is generally considered to be the most suitable method. The use of alternative low-cost materials such as potential sorbents has recently been extensively studied. The processes using activated carbons or alumina as adsorbent are considered to be particularly competitive and effective, however they are not suitable in developing countries due to the high costs associated with the production and regeneration of the spent adsorbent. Accordingly, ion exchange is considered to be cost-effective only when low-cost exchangers such as natural zeolites are used. Zeolites are naturally occurring aluminosilicates. They are well known for their ion exchange, catalytic and sorption properties. The structures of zeolites consist of three-dimensional networks of SiO4 and AlO4 tetrahedra arranged in an alternating manner. This produces negatively charged lattice, where the presence of exchangeable captions such as sodium, potassium or calcium balances the net negative charge. These captions are exchangeable with the captions of heavy metals in water solutions. The arsenic is found as anionic species in water, thus it is not exchangeable by the ions from zeolite. However, the high specific area of zeolites as well as the possibility of a chemical modification of the zeolite surface, allow zeolites to be effective sorbents for anionic species also. Clinoptilolite is the most abundant natural zeolite. Its tabular morphology shows an open reticular structure of easy access exhibited by (eight- and ten-member ring) channels up to 0.7 nm in diameter. The clinoptilolite samples from various regions show different sorption and ion-exchange behaviour, the difference being mainly caused by a different composition of zeolitic tuffs. In this project, two large clinoptilolite deposits from SERBIA (Vranjska Banja and Beocin) and one from CROATIA (Donje Jesenje) will be investigated for use in heavy metal and arsenic ion removal from waste and drinking water. Ion exchange and adsorption methods will be used for the pollutant removal. The performance of natural zeolitic tuffs will be compared with the adsorption characteristics of synthetic zeolite A (4 nm channels) produced in SLOVENIA in order to evaluate their technological and economical advantages and disadvantages. 
Short description of the task performed by Croatian partner
The Faculty of Chemical Engineering and Technology (FCET) and Faculty of Textile Technology (TTF) will conduct experimental work in the sorption of metal ions by the zeolite minerals from Donje Jesenje (CROATIA) and Vranjska Banja and Beocin (SERBIA). The Facultyes will play a crucial role in developing procedures for the removal of heightened arsenic concentration from drinking water, since groundwater in the area of the eastern part of Croatia contains high concentrations of arsenic. The efficiency of As removal by zeolite is greatly affected by the modification zeolite of iron ions. A surfactant-modified sample shows a strong affinity to anionic species. Both methods will be studied for the immobilisation of arsenic species on the CLI samples and the As removal from drinking water. One of the primary objectives of the project is to study the As sorption on the CLI as a function of: 1) the type of As species (arsenate (V) vs. arsenite (III)), 2) the Fe/surfacant surface loading level, and 3) counter-ion desorption, so that the mechanism of As sorption on modified-CLI can be elucidated. The influence of the process variables such as the mass ratio of the (waste or drinking) water to clinoptilolite (CLI), particle size of CLI, pre-treatment of CLI, water pH, presence of other ions in water, will also be investigated. Kinetic and thermodynamic parameters for the ion exchange and sorption processes will be determined. Desorption of the metal-loaded samples will also be performed in laboratory and pilot experiments. The Faculty will also participate in the definition of processing parameters and the design of pilot plants. The contribution of the Faculty of Textile Technology (TTF) will be also in experimental work in the developing procedures for reduction of coloured textile waste waters and eliminating of chromium species and copper ions from textile effluents after treatment by natural zeolites through studying the adsorption mechanism. Spectroscopic methods will be suggested for measuring the content of copper and chromium ions. 


   

 


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