TOWARDS A SAFER ENVIRONMENT: ZEOLITIZATION OF BENTONITE AND ITS POTENTIALITIES FOR REMOVING HEAVY METALS FROM WASTEWATER | ||||
| Journal of Soil Sciences and Agricultural Engineering | ||||
| Article 8, Volume 1, Issue 6, June 2010, Page 533-553 PDF (877.05 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/jssae.2010.74887 | ||||
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| Author | ||||
| S. M. Abdallah | ||||
| Department of Soils, Faculty of Agriculture, Ain Shams University | ||||
| Abstract | ||||
| Zeolites have several applications in many fields related to pollution control, radioactive waste management, petroleum refining, purification of gases, agriculture and others. The production of zeolites using clay minerals as a resource constitutes one important issue of waste management. To convert bentonite clay to zeolitic materials, sodium hydroxide at different concentrations with two different treatments (magnetic stirring and autoclave treatments) were used. Obtained results indicated that alteration was carried out and zeolitic materials appeared. X-ray diffraction analysis, Infra-red spectroscopy, chemical composition, cation exchange capacity and accessibility of internal sites were used to characterize the produced zeolitic materials. Natures of obtained zeolitic materials depend on the method of contact between clay and alkaline agent. Autoclave treatment showed the conversion of montomorillonite and kaolinite in the bentonite clay sediment to sodalite and analcime zeolitic materials, while magnetic stirring converted the same mineral to sodalite only at 3M of NaOH. The C.E.C values of produced zeolitic materials increased with the rise in NaOH concentration until 2M only and decreased when increasing NaOH concentration in both clay sediments by both treatments (stirring and autoclave). Obtained results indicated that although ammonium is widely used to measure C.E.C, it seems inappropriate to apply to materials having smaller pores than the diameter of ammonium ion such as sodalite. Produced zeolitic materials have internal sites accessible to exchange with different ions and suitable to utilize in removing heavy metals or other ion toxicants from wastewater. Potentialities of produced zeolititc materials to remove heavy metals from industrial wastewater were studied as a function of contact time. The maximum percentage of metals removed was increased more than two to more than three times than initial bentonite with different arrangement of metals removed. The current study indicated that zeolitic materials not only had highly percentage of metals removed but also had highly selectivity for certain ions. | ||||
| Keywords | ||||
| Zeolitization – bentonite sediments – sodalite – analcime – wastewater treatment – heavy metals – X-ray diffraction analysis – Iinfra-red spectroscopy | ||||
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