Document Type : علمی - پژوهشی
Department of Environmental Science, Faculty of Natural Resources and Environmental Science, Malayer University, Malayer, Iran
Department of Research and Technology, Ministry of Science, Research and Technology, Tehran, Iran
Introduction: Absorptive wells are one of the most common forms of onsite sanitation facilities in many developing countries. These latrines are suitable as a means of isolating human waste; however, conditions within pits often lead to nitrification of the contained waste. In areas with a near-surface aquifer, the potential for nitrate pollution arising from Absorptive wells cannot be ignored.Material and methods: In this study, Hypothetical aquifer was made, to gather relevant information about the Absorptive wells in use and the soil and groundwater underneath the Hypothetical aquifer. Modeling was then conducted to demonstrate the potential for nitrate pollution of the groundwater from the latrines in such settings. The depth from the bottom of the pits to the water table was considered as 5, 10 or 30 m, to represent the range of aquifer depths at the study sites. Nitrate half-lives ranging from 500 to 1500 days were considered, and time scales from 6 months to several years were modeled.Results and discussion: The results highlighted the high likelihood of nitrate pollution of groundwater reaching levels exceeding the World Health Organization guideline value for nitrate in drinking water of 50 mg/L after as short a period as two years for the aquifer situated 5 m below the pits, when considering moderate to long nitrate half-lives in the subsurface. Careful siting of latrines away from high water table areas, more frequent pit emptying, or switching to urine diversion toilets may be effective solutions to reduce nitrate passage from Absorptive wells into groundwater, although these solutions may not always be applicable, because of social, technical and economic constraints.Conclusion: The study highlights the need for more reliable data on the typical nitrate concentrations in Absorptive wells and the nitrate half-life in different subsurface conditions.
- Adadzi, P.C., 2012. Deep Row Trenching of Pit Latrine and Waste Water Treatment Works Sludge: Water and Nutrient Fluxes in Forest Plantations. MSc Dissertation. School of Agricultural, Earth and Environmental Sciences, University of KwaZulu-Natal.
- Ahmed, K.M., Khandkar, Z.Z., Lawrence, A.R., Macdonald, D.M.J. and Islam, M.S., 2002. Appendix A: an investigation of the impact of on-site sanitation on the quality of groundwater supplies in two peri-urban areas of Dhaka, Bangladesh. In: Assessing Risk to Groundwater from On-site Sanitation: Scientific Review and Case Studies. Keyworth, UK: British Geological Survey, pp. 37-67.
- Aillery, M., Gollehon., N. andJohanson, R., 2005. Managing Manure to Improve Air and Water Quality,Economic Research report 9, United States Department of Agriculture, Vol. 6, pp. 65.
- Almasri, M.N. and Kaluarachchi, J.J., 2007. Modeling nitrate contamination of groundwater in agriculturalwatersheds. Journal of Hydrology. 343, 211-229.
- Amini, M., Abbaspour, K.C., Berg, M., Winkel, L., Hug, S.J., Hoehn, E., Yang, H. and Johnson, C.A., 2008. Statistical modeling of global geogenic arsenic contamination in groundwater. Environmental science & technology. 42, 3669-3675.
- ARGOSS, 2001. Guidelines for assessing the risk to groundwater from on-site sanitation. BritishGeological Survey Commissioned Report, CR/01/142.97.
- ARGOSS., 2002. Assessing Risk to Groundwater from On-site Sanitation: Scientific Review andCase Studies British Geological Survey Commissioned Report, CR/01/079N. 105.
- Banerjee, G., 2011. Underground pollution travel from leach pits of on-site sanitation facilities: a case study. Clean Technol Environ Policy. 13, 489-497.
- Banks, D., Karnachuk, O.V., Parnachev, V.P., Holden, W. and Frengstad, B., 2002. Groundwater contamination from rural pit latrines: examples from Siberia and Kosova. J Chartered Inst Water Environ Manage. 16, 147-152.
- Butler, A.P., Brook, C. and Godley, A., 2003. Attenuation of landfill leachate in unsaturatedsandstone. Proceedings of the Ninth International Waste Management and Landfill Symposium,Sardinia.
- Chidavaenzi. M., Bradley, M., Jere, M. and Nhandara, C., 2000. Pit latrine effluent infiltration into groundwater: the Epworth case study. SchriftenrVerWasser Boden Lufthyg. 105, 171-177.
- Cruz, M.C., Cacciabiu, D.G., and Gil, J.F., 2012. The impact of point source pollution on shallowgroundwater used for human consumption in a threshold country. Journal of Environmental Monitoring. 14, 2338-2349.
- Del Porto, D. and Steinfeld, C., 1999. The Composting Toilet System Book, a Practical Guide toChoosing, Planning and Maintaining composting Toilet Systems, A Water-Saving, PollutionPreventing Alternative, Concord, Massachussetts, The Center for Ecological Pollution Prevention.
- Dovonou, F.E., 2012. DiagonosticQualitatifetEnvironnemental de l’AquifereSuperficiel du Champ de CaptageIntensif de Godomey au Benin (Afrique de l’Ouest): Elements Pour un Plan d’ActionsStrategiques de Protection des Resource en Eau SouterraineExploitees, PhD thesis, Universited’Abomey-Calavi.
- Dzwairo, B., Hoko, Z., Love, D. and Guzha, E., 2006. Assessment of the impacts of pit latrines on groundwater quality in rural areas: a case study from Marondera district, Zimbabwe. Physics and Chemistry of the Earth. 31, 779-788.
- Environment Agency, 2005. Attenuation of nitrate in the subsurface environment. Science Report SC030155/SR2, pp. 108
- Geissen, V., Mol, H., Klumpp, E., Umlauf, G., Nadal, M., van der Ploeg, M., van de Zee, S.E. and Ritsema, C.J., 2015. Emerging pollutants in the environment: a challenge for water resource management. International soil and water conservation research. 3, 57-65.
- Herbert, M. and Kovar, K., 2009. Groundwater Quality: Remediation and Protection. Wallingford, International Association Hydrological Sciences. No. 250.
- Heatwole, K.K. and McCray, J.E., 2007. Modeling potential vadose-zone transport of nitrogen from onsite wastewater systems at the development scale. Journal of Contaminant Hydrology. 91, 184-201.
- Howard, G., Pedley, S., Barrett, M., Nalubega, M. and Johal, K., 2003. Risk factors contributing to microbiological contamination of shallow groundwater in Kampala, Uganda. Water Resources. 37, 3421-3429.
- Kouame, K.J., 2007. Contribution a la GestionIntegree des RessourcesenEaux (GIRE) du District d’Abidjan (Sud de la Cote d’Ivoire): Outilsd’aide a la decision pour la prevention et la protection des eauxsouterrainescontre la pollution, PhD thesis, Universite Felix Houphouët-Boigny.
- Lee, M.J., Hwang, S. and Ro, H.M., 2014. Interpreting the effect of soil texture on transport and removal ofnitrate-N in saline coastal tidal flats under steady-state flow condition. Continental Shelf Research. 84, 35-42.
- Liu, G.D., Wu, W.L. and Zhang, J., 2005. Regional differentiation of non-point source pollution of agriculture-derived nitrate nitrogen in groundwater in northern China. Agriculture, ecosystems & environment. 107, 211-220.
- Mafa, B., 2003. Environmental hydrogeology of Francistown.BundesanstaltfürGeowissenschaften and Rohstoffe and Department of Geological Survey Botswana.
- Mondal, N.C., Saxena, V.K. and Singh, V.S., 2005. Assessment of groundwater pollution due to tannery industries in and around Dindigul, Tamilnadu, India. Environmental Geology. 48, 149-157.
- Oroji, B. and Solgi, I., 2016. Vulnerability Assessment of Asadabad (Hamadan) Plain Groundwater by GIS. Journal of Environmental Sciences. 14, 91-104
- Pujari. P.R., Padmakar, C., Labhasetwar, P.K., Mahore, P. and Ganguly, A.K., 2012. Assessment of the impact of on-site sanitation systemson groundwater pollution in two diverse geologicalsettings—a case study from India. Environmental Monitoring and Assessment. 184, 251-263.
- Schouw, N.L., Danteravanich, S. and Mosbaek, H., 2002. Composition of human excreta – a casestudy from Southern Thailand. Science of the Total Environment. 286, 155-166.
- Shaw, E.M., 1994. Hydrology in practice. Formerly of the Department of Civil Engineering Imperial College of Science, Technology and Medicine. London, Chapman & Hall, pp. 628.
- Shamrukh, M., Corapcioglu, M. and Hassona, F., 2001. Modelling the effect of chemical fertilizers onground water quality in the Nile Valley Aquifer, Egypt. Ground Water. 39, 59-67.
- Simunek, J., van Genuchten, M.T. and Sejna, M., 2006. The HYDRUS Software Package for SimulatingTwo- and Three- Dimensional Movement of Water, Heat, and Multiple Solutes in VariablySaturated Media, Technical Manual, Version 1.0, PC Progress, Prague, Czech Republic, pp. 241.
- Solgi, I. and Oroji, B., 2017. A Survey of Nitrate and Nitrite Concentrations in Groundwater of Urban and Agricultural Areas of the Asadabad Plain. Iran – Water Resources Research (Article in press).
- Still, D.A. and Nash, S.R., 2002. Groundwater contamination due to pit latrines located in a sandy aquifer: a case study fromMaputaland. In: Water Institute of Southern Africa Biennial Conference. Durban, South Africa:Water Institute of Southern Africa, pp. 1–6.
- Thye, Y.P., Templeton, M.R. and Ali, M., 2011. A critical review of technologies for pit latrine emptying indeveloping countries. Critical Reviews in Environmental Science and Technology. 41, 1793-1819.
- Van Genuchten, M.T. and Alves, W.J., 1982. Analytical solution of the one-dimensional convectivedispersive solute transport equation, Technical Bulletin. U.S. Department Agricultural Research Service.
- Verheyen, J., Timmen-Wego, M., Laudien, R., Boussaad, I., Sen, S. and Koc, A., 2009. Detection of adenoviruses and rotaviruses in drinking water sources used in rural areas of Benin, West Africa. Applied and Environmental Microbiology. 75, 2798-2801.
- Vinger, B., Hlophe, M. and Selvaratnam, M., 2012. Relationshipbetween nitrogenous pollution of borehole waters anddistances separating them from pit latrines and fertilizedfields. Life Science Journal. 9, 402-407.
- World Health Organization, 2011. Nitrate and Nitrite in Drinking-water. Background document for development of WHO Guidelines for Drinking-water Quality,pp. 31.
- Zingoni, E., Love, D., Magadza, C., Moyce, W. and Musiwa, K., 2005. Effects of a semi-formal urban settlement on groundwater quality Epworth (Zimbabwe): case study and groundwater quality zoning. Physics and Chemistry of the Earth. 30, 680-688.