Nitrate Removal from Drinking Water Using Modified Natural Clays

Document Type : Research Paper

Authors

Abstract

High level of nitrate in the water resources causes some health and environmental problems. The objective of this study was to remove nitrate from drinking water using modified natural clays. Natural clay (bentonite) was modified with HCl (2N), H2SO4 (2N) and H2SO4 (4N).Structure and morphology of bentonite was determined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Adsorption process was accomplished in a batch with emphasis on the effect of various parameters such as contact time, pH, adsorbent dosage and nitrate concentration on adsorption efficiency. In order to understand the adsorption process, equilibrium isotherms were also determined. The results showed that maximum nitrate adsorption achieved for adsorbent modified with H2SO4(4N)and optimum pH  and contact time were found 4 and  60 min respectively. The obtained data showed the most correlation with Freundlich model. Finally, finding of this study suggested that the adsorbent modified with H2SO4 (4N) is a suitable and effective adsorbent to remove nitrate from drinking water.

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1.Nanbakhsh, H. (2003). “Study of nitrate and nitrite in Urmia drinking water wells in years 2001 and 2003.” Urmia Medical Journal , 14(2), 98-103. (In persian)
2. Ghadimi, M., and Eslami, A. (2011). “Study of nitrite and nitrate changes trend in Zanjan groundwater resources using GIS from 2006 to 2010.” 5th National Conference of Environmental Engineering; Tehran, Iran. P. 683. (In persian)
3. Miranzadeh, M.B., Mostafavi, G.R., and Jalali, A. (2006). “Survey of nitrate concentration in water supply wells and water distribution network in Kashan during 2005-2004.” KAUMS Journal, 10(2), 39-45. (In Persian).
4. Izanloo1, H., Rahimi, T., Mahmoodian, M. H., Khazaei, M., Yavari, Z., and Asgari, A.R. (2010). “Nitrate removal from water using granules ferric hydroxide absorbent.” J. Health System Research, 6, 952-959.
(In Persian).
5. Institute of Standards and Industrial Research of Iran. (2009). Drinking water -Physical and chemical specifications, ISIRI 1053 5th revision
6. Bhatnagar, A., and Sillanpaa, M. A. (2011). “Review of emerging adsorbents for nitrate removal from water.” Chemical Engineering, 168, 493-504.
7. Azizi, Sh., Jazayeri, S. H., and Peighambarzadeh, S. M. (2088). “Study of activation parameters on active bentonite adsorption capacity.” Iran Chemistry Engineering Journal, 7 (3), 50-56. (In Persian)
8. Mena-Duran, C.J., Sun Kou, M.R., Lopez, T., Azamar-Barrios, J.A., Aguilar, D.H., and Domı´nguez, M.I. (2007). “Nitrate removal using natural clays.” Applied Surface Science, 253, 5762-5766.
9. Jinamoni, S., and Goswami Archana, S. (2011). “Study of the removal of toxic anions from contaminanted water utilizing natural kaolinite clay of Assam.” International Journal of Research in Chemistry and Environment, 2(1), 92-96.
10. Nese Ozturk, T. (2004). “Ennil bektasnitrate removal from aqueous solution by adsorption onto various materials.” J. of  Hazardous Materials, 112, 155-162.
11. APHA, AWWA,WEF. (1999). Standard methods for the examination of water and wastewater, 20th Ed., USA.
12. Torkian, A. (1993). Water and wastewater examination manual, Isfahan Medical Science University, Isfahan. (In Persian)
13. Tchobanoglous, G. (2003). Wastewater engineerin:Treatment and reuse, 4th Ed., Mc Graw-Hill, New York.
14. Chabani, M., Amrane, A., and Bensmaili, A. (2009). “Equilibrium sorption isotherms for nitrate on resin Amberlite IRA-400.” J. of Hazardous Materials, 165, 27-33.
15. Mousavi, S., Asadi, H., and Esfandbod, M. (2010). “Ion exchange efficeincy in nitrate removal from Water.” Water and Soil Knowledge., 4, 185-200.
16. Ho, Y.S. (2006). “Isotherms for the sorption of lead onto peat: Comparison of linear and non-linear methods.” Polish Journal of Environmental Studies, 15, 81-86.
17. Mahamudur, I. (2008). “Development of adsorption media for removal of lead and nitrate from water [dissertation].” Rourkela: National Institute of Technology, 2008, 118-156.
18. Naddafi, K., Nabizadeh Nodehi, R., and Jahangiri Rad, M. (2011). “Removal of reactive blue 29 dye from water by single-wall carbon nanotubes.” Iran. J. Health & Environ, 3 (4), 359-368. (In Persian)
19. Bhatnagar, A., Kumar, E., and Sillanpaa, M. (2010). “Nitrate removal from water by nano-alumina.” Chemical Engineering, 163, 317-323.
20. Maleki, A., and Eslami, A. (2011). “Isotherm and kinetics of arsenic (V) adsorption from aqueous solution using modified wheat straw.” Iran. J. Health and Environ., 3 (4), 439-450. (In Persian)
21. Shokouh Saljoghi, Z., Malek Pour A., Rafiee, G.R, Imani, A., Bakhtiary, M. (2011). “Removal of nitrite and nitrate from recirculation aquaculture system effluent by modified bentonites.” J. of Water and Wastewater,
2, 46-54. (In Persian)
22. Demiral, H., and Gunduzoglu, G. (2010). “Removal of nitrate from aqueous solutions by activated carbon prepared from sugar beet bagasse.” Bioresource Technology, 101, 1675-1680.