Abstract
Earlier studies have indicated that variability in size, surface texture and charge greatly influence the contaminant removal process in granular media. Based on surface characteristics of montmorillonite, it is anticipated that small addition of this clay would increase adhesion sites for bacterial growth and extracellular polymer production in the slow sand filter and thereby enhance its contaminant removal ability. Experiments were performed by permeating groundwater contaminated with pathogens (total coliform and E. Coli) and inorganic contaminants through the bentonite amended slow sand filter (BASSF). Surprisingly, the BASSF retained inorganic contaminants besides pathogens. Water-leach tests (pH of water leachate ranged from 2 to 9) with spent BASSF specimen indicated that the inorganic contaminants are irreversibly adsorbed to a large extent. It is considered that the combined effects of enhanced-organic matter mediated adhesion sites and increased hydraulic retention time enables the BASSF specimen to retain inorganic contaminants. It is envisaged that BASSF filters could find use in treating contaminated groundwater for potable needs at household and community level.
Similar content being viewed by others
References
El-Taweel, G. E. and Ali, G.H., Water, Air and Soil, 2000, vol. 120, p. 21.
Huisman, L. and Wood, W.E. Slow Sand Filtration, Geneva: World Health Organisation, 1974, p. 122.
Haarhoff, J. and Cleasby, J. L., Biological and Physical Mechanisms in Slow Sand filtration, in: Slow Sand Filtration, American Society of Civil Engineers, New York, 1991.
Stevik, T. K., Aa, K., Ausland G., and Hanssen, J. F., Water Res., 2004, vol. 38, p. 1355.
Fontes, D.E., Mills A. L., Hornberger G.M., and Herman, J. S., Appl. Environ. Microbiol., 1991, vol. 57, p. 2473.
Tan, Y., Bond, W. J., and Griffen, D.M., Soil Sci. Soc. Am. J., 1992, vol. 56, p. 133.
Huysman, F. and Verstraete, W. Soil Biol. Biochem., 1993, vol. 25, p. 83.
Fletcher, M., and Loeb, G. I., Appl. Environ. Microbiol., 1996, vol. 37, p. 67.
Van Olphen, H., An Introduction to Clay Colloid Chemistry, New York, Wiley, 1963.
Rao, S.M., Kachroo, T.A., Allam, M.M., Joshi, M.R., and Acharya, A., Proc. of 12th Int. Conf. of Int. Assoc. for Computer Methods and Advances in Geomechanics, Goa, India, 2008.
IS 2720. Laboratory Determination of Permeability. Part 17, New Delhi: Bureau of Indian Standards, 2002.
Das, B.M., Principles of Geotechnical Engineering, Fifth Edition, Singapore, Thomson, 2002.
IS 1622. Methods of Sampling and Microbial Examination of Water, New Delhi: Bureau of Indian Standards, 2003.
IS 5401. Microbiology; General Guidance for the Enumeration of Coliforms. Part 2, Most Probable Number Technique, New Delhi: Bureau of Indian Standards, 2002.
APHA. Standard Methods for the Examination of Water and Wastewater: in Eaton A. D., Clesceri, L.S., Rice, E.W., Greenberg, A.E, and Franson M. H. (Eds.), Washington D.C. American Public Health Association, 2005.
ASTM F1647. Standard Test Methods for Organic Matter Content of Putting Green and SP.orts Turf Root Zone Mixes, Philadelphia (USA): ASTM, 2010.
Yong, R.N., and Warkentin, B.P. Soil Properties and Behaviour. New York: Elsevier, 1975.
Campos, L.C., Su, M.F.J., Graham, N.J.D., and Smith, S.R., Water Res., 2002, vol. 36, p. 4543.
Lynch, J.M. and Bragg, E. Adv. in Soil Sci., 1985, vol. 2, p. 133.
Author information
Authors and Affiliations
Additional information
Original English Text © S.M. Rao, R. Malini, A. Lydia, Y. Lee, 2013, published in Khimiya i Tekhnologiya Vody, 2013, Vol. 35, No. 1, pp. 43–53.
About this article
Cite this article
Rao, S.M., Malini, R., Lydia, A. et al. Contaminants removal by bentonite amended slow sand filter. J. Water Chem. Technol. 35, 23–29 (2013). https://doi.org/10.3103/S1063455X13010049
Received:
Published:
Issue Date:
DOI: https://doi.org/10.3103/S1063455X13010049