Global Journal of Human-Social Science, B: Geography, Environmental Science and Disaster Management, Volume 22 Issue 3

IV. C onclusion The application of coagulation treatment for raw leachate collected from Saje dumpsite showed the leachate was characterized by low pH and high concentration of pollutants; especially that of organic matter as observed in the COD level and high level of heavy metals which are all above the WHO and the FMEnv limit for waste water. The study showed that the leachate from the dumpsite is polluted and there is need for it to be treated before it is released into environment. The study showed that coagulation treatment is efficient in ameliorating the polluting potential of dumpsite leachates. All the four coagulants; ferric chloride, ferrous sulphate, alum and MOS were able to reduce the heavy metals in the leachate by over 55% and MOS removing as high as 95.6%. MOS was better than the other coagulants in terms of removal efficiency for heavy metal. The coagulants were not as effective against COD, with alum giving the highest removal efficiency of 41.7% and MOS increased the COD concentration. None of the coagulants was able to bring the COD level down to below the FMEnv standard limit. This study also revealed pH as an important factor in coagulation. It was established that each coagulant has the pH at which it works best; to remove contaminants. This pH isreferred to as the optimum pH. In this study the optimum pH for Ferric chloride and ferrous sulphate was 7.0, Alum was 6.0 and MOS was 10.0. This study had determined the optimum dosage of each coagulant to get the best use of them. It was observed that the optimum dosage for ferric chloride, ferrous sulphate, alum and MOS were 3.0g/L, 3.0g/L, 5.0g/L and 5.0g/L respectively. From the results Alum was the best coagulant for treating leachates, closely followed by ferric chloride, MOS and ferrous sulphate in that order. This study has shown little or no seasonal variation in the concentration of leachate. The season did not have significant effect on the efficiency of the coagulants Moringa Oleifera showed good coagulating properties, and has many advantages compared to aluminium sulphate. It did not affect the pH, alkalinity or conductivity of the water, and it can be produced locally at low cost. Moringa oleifera is an environmentally- friendly natural coagulant that can be used to replace alum and other inorganic coagulants particularly in treating drinking water. It is a method that certainly can be considered as a good, sustainable and cheap solution for smaller waterworks, if the supply of Moringa seeds can be guaranteed. R eferences R éférences R eferencias 1. Achankeng, E. 2003. Globalization, Urbanization and Municipal Solid Waste Management in Africa. Conference Proceedings - African on a Global Stage. 2. American Public Health Association (APHA) 1999. Standard Methods for the Examination of Water and Wastewater, 20th ed., APHA, Washington, DC. 3. Amuda, O.S. and Alade, A. (2006). Coagulation/ flocculation process in the treatment of abattoir wastewater. Desalination, 196, pp. 22-31. 4. Arnoldsson E., Bergman M., 2007. Assessment of drinking water treatment using MoringaOleifera natural coagulant. Department of Water Resources Engineering Faculty of Engineering, Lund University. A Master Thesis. 5. Babatola, J.O., 2008. A Study of Hospital Waste Generation and Management Practices in Akure, Nigeria. African Research Review. 2 (3): 292-305 6. Badejo, A.A., A.O. Taiwo, A.A. Adekunle, and B.S. Bada. 2013. Spatio-Temporal Levels of Essential Trace Metals around Municipal Solid Waste Dumpsite in Abeokuta, Nigeria. Pacific Journal of Science and Technology . 14(2): 682-692. 7. Bila, D.M., Montalvão, F., Silva, A.C., & Dezotti, M. (2005). Ozonation of a landfill leachate: evaluation of toxicity removal and biodegradability improvement. Journal of Hazardous Materials, Vol. 117, No. 2-3, (Jan 2005), pp. 235–242, ISSN 0304- 3894. 8. Choi, K.J, Kim, S.G, Kim, C.W. & Park, J.K. (2006). Removal efficiencies of endocrine disrupting chemicals by coagulation/flocculation, ozonation, powdered/granular activated carbon adsorption, and chlorination. Korean J. Chem. Eng, 23(3), pp. 399-408. 9. Donevska, K., Jovanovski, M., Efremov, A. and Papic, J., 2006. Impact Assessment of solid waste landfill in the Municipality of Center Zupa. Faculty of Civil Engineering, Skopje, Rebablic of Macedonia. 10. Ibrahim M. I, Ahmed S. F, Nabil M. A, Mahmoud H. M, and Mohamed A. E, 2012. Combined coagulation flocculation pretreatment unit for municipal wastewater. Journal of Advanced Research (2012) 3, 331–336. 11. Lee, M.R, Zawawi, D. and Abdul, A.A.L. (2012). Treatment of leachate by Coagulation-Flocculation using different coagulants and polymer. International Journal on Advanced Science, Engineering and Information Technology, 2, 2, pp. 1-4. 12. Oh, B.T, Lee, J.Y. & Yoon, J.Y. (2007). Removal of contaminants in leachate from landfill by waste steel scrap and converter slag. Environ Geochem Health, 29, pp. 331-336. Volume XXII Issue III Version I 64 ( ) Global Journal of Human Social Science - Year 2022 © 2022 Global Journals B Abatement of Polluting Effects of Waste Dump Leachates using Different Coagulants