How variations in concentrations of metal ions and suspended solids downstream river Rwabakazi in Uganda can be used to study pollution


  • Mukasa-Tebandeke, I. Z. Makerere University
  • Karume, I. Makerere University
  • Ssebuwufu, J. University of Kisubi
  • Wasajja , H. Z. Wesleyan University
  • Nankinga, R Wesleyan University, Connecticut USA.
  • Habimana, M Kabale University



Dissolved oxygen, turbidity, Total suspended solids, Electrical conductivity, Concentration of metal ions, Erosion


Pollution is affecting river Rwabakazi in the Nile basin. Its effects are reflected by high turbidity, pH, total suspended solids, (T.S.S.), electrical conductivity, metal ions concentrations, and low concentration of dissolved oxygen (DO5). In this study, we report the variations in selected physicochemical parameters of waters of the Rwabakazi river.  Turbidity, pH, concentrations of selected metal ions, T.S.S., and DO5 of water sampled from three selected sites on the river in Kabale were very high. Mean DO5 fell from 96 ± 2 mg/L to 86± 1.5 mg/L downstream. The mean pH fell from 7.8 ± 0.03 to 7.6 ± 0.04, showing the removal of basic components. The turbidity dropped from370 ± 3 NTU to 305 ± 2 NTU, showing that the haziness of water decreased. The concentration of iron(II) fell from 320 ± 0.3 mg/L to 291 ± 0.2 mgL-1 indicating the fair extent of heavy metal ions downstream. The T.S.S. decreased from 330 ± 5 mg/L to 300± 5 mg/L, and concentrations of calcium and magnesium ions also decreased, providing evidence for self-purification. The available data suggests that river Rwabakazi is polluted as a result of poor agricultural practices, erosion, and flash flooding.  Further studies on nutrient and pesticide pollution of this river need to be carried out, and trees should be planted on steep open surfaces to minimize erosion. 


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Author Biographies

Mukasa-Tebandeke, I. Z., Makerere University

College of Natural Sciences, School of Physical Sciences, Department of Chemistry, Box 7062, Kampala.

Karume, I., Makerere University

Chemistry Department, School of Physical Sciences, College of Natural Sciences

Wasajja , H. Z., Wesleyan University

Departments of Earth Sciences

Nankinga, R, Wesleyan University, Connecticut USA.

Departments of Earth Sciences

Habimana, M, Kabale University

Department of Chemistry, Faculty of Science 


Al-Busaidi M, Yesudhason P, Al-Mughairi S, Al-Rahbi WA, Al-Harthy KS, Al-Mazrooei NA. (2011) Toxic metals in commercial marine fish in Oman with reference to national and international standards. Chemosphere 85 : 67– 73.

American Public Health Association (2003). Standard Methods for the Examination of water and Waste Water, 20th ed. Method 4500 E.

American Public Health Association (APHA), 1995. Standard Methods for Analysis of Water and Wastewater, 18th edition. Port City Press, Baltimore,MD.

Bacchin, P;. A. Marty; P. Duru; M. Meireles ; P. Aimar (2011). Colloidal surface interactions and membrane fouling: Investigations at pore scale Advances in Colloid and Interface Science 164, 2–11

Bilotta, G. S., & Brazier, R. E. (2008). Understanding the influence of suspended solids on water quality and aquatic biota. Water research, 42(12), 2849-2861.

Bracchini, L., Loiselle, S.A., Tognazzi, A., Dattilo, A.M., Focardi, S.,Cózar, A., (2007). The optical qualities of shallow wetland lined bays in Lake Victoria. Wetl. Ecol. Manag., 15, 509-510

Castro-Gonz´alez MI, M´endez-Armenta M.(2008) Heavy metals: implications associated to fish consumption. Environ Toxicol Pharmacol, 26: 263–271.

Chapman, D, (1996) Water Quality Assessments - A Guide to Use of Biota, Sediments and Water in Environmental Monitoring - Second Edition, University Press, Cambridge

Cózar, A., Bergamino, N., Mazzuoli, S., Azza, N., Bracchini, L., Dattilo, A., (2007). Relationships between wetland ecotones and inshore water quality in the Ugandan coast of Lake Victoria. Wetlands Ecology and Management, 15, 499– 507. doi:10.1007/s11273-007-9046-6.

de Zwart, A. H., de Boer, J., Vafei, A., Schotting R.J., Hassanizadeh, S.M. (2006). Experimental investigation of clogging processes in sandy aquifers near water supply wells, using X-ray chromatography. In preparation.

EPA, U. (2017). Secondary drinking water standards: Guidance for nuisance chemicals. Drinking Water Contaminants-Standards and Regulations.

Etale A, Drake DC. (2013):Industrial Pollution and Food Safety in Kigali, Rwanda. Int J Environ Res., 7 :403-406.

Grinning Planet. (2019) Polluted Seas: Major Bodies of Water/Areas with Serious Water Pollution Problems. Accessed 20 Aug 2019.

Grochowska J. and Tandyrak, R. (2009). The influence of the use of land on the content of calcium, magnesium, iron and manganese in water exemplified in three lakes in Olsztyn vincinity. Limnol. Rev., 9(1): 9-16.

Hakizimana P, Maniragaba A, Nshimiyimana FX. (2019): Assessment of Heavy Metals in Amaranthus Spinosus, Kigali, Rwanda. Int J Advanced Res Publ,, 3 : 7-12.

Inglezakis, V.J., Stylianou, M.A., Gkantzou, D., and Loizidou, M.D., (2007): Removal of Pb (II) from aqueous solutions by using clinoptilolite and bentonite as adsorbents. Desalination, 210, pp 248-256

Kaaya, L. T., Day, J., & Dallas, H. F. (2015). Tanzania River Scoring System (TARISS): a macro-invertebrate- based biotic index for rapid bio-assessment of rivers. African Journal of Aquatic Science, 40, 109–117.

Kasangaki, A., Babaasa, D., Efitre, J., McNeilage, A., & Bitariho, R. (2006). Links between anthropogenic perturbations and benthic macroinvertebrate assemblages in Afro-montane forest streams in Uganda. Hydrobiologia, 563, 231–245.

Kasangaki, A., Capman, L. J., & Balirw, J. (2008). Land use and the ecology of benthic macroinvertebrate assemblages of high altitude rainforest streams in Uganda. Freshwater Biology, 53, 681–697.

Kennedy, K.K., Maseka, K.J. and Mbulo, M. (2018): Selected adsorbents for removal of contaminants from wastewater: Towards engineering clay minearls. Open journal of applied sciences 8, 355-369

Lange, G-M, R. Hassan, K. Hamilton., 2003. Environmental Accounting in Action case studies from South Africa. Edward Elgor. UK.)

Liess, M., Schäfer, R., & Schriever, C. (2008). The footprint of pesticide stress in communities—species traits reveal community effects of toxicants. Science of the Total Environment, 406, 484–490.

McDowell‐Boyer, L.M.; R. Hunt, J.R.; Sitar, N. (1986) :Particle transport through porous media Water resources research 22(13) 1901-1921

Ministry of Infrastructure, Republic of Rwanda, (MISR) . (2010). Rwanda National Policy and Strategy for Water Supply and Sanitation Services. Kigali: Ministry of Infrastructure.

Ministry of Natural Resources, Republic of Rwanda, MINIRENA. (2011). Water resources management sub-sector strategic plan (2011–2015). Kigali: MINIRENA.

Musinguzi, M. Ejiri, A.H. (2016) Trends in degradation of freshwater urban wetlands in Kampala Uganda a case study of Lubigi wetland. International journal of research in earth and environmental sciences4(3)

National Institute of Statistics of Rwanda, NISR. (2014). Fourth Population and Housing Census, Rwanda 2012. Kigali: Ministry of Finance and Economic Planning, National Institute of Statistics of Rwanda.

National Institute of Statistics of Rwanda, NISR. (2015). Rwanda poverty profile, 2013/2014. Results of Integrated Household Living Conditions Survey. Kigali: National Institute of Statistics of Rwanda.

Ndayisaba, L., & Mihale, M. J. (2015). Seasonal impacts of land use practices on water quality in Ngoma District, Rwanda. The African Resources Development Journal, 2, 1–20.

Nhapi I (2011) Assessment of Water Pollution Levels in the Nyabugogo Catchment, Rwanda The Open Environmental Engineering Journal 4(1):40-53 DOI: 10.2174/1874829501104010040

Nhapi I, Wali UG, Uwonkunda BK, Nsengimana H, Banadda N, Kimwaga R. (2011): Assessment of Water Pollution Levels in the Nyabugogo Catchment, Rwanda. Open Environ Eng J., 4: 40-53.

Nshimiyimana, F.; I. Nhapi, U. G. Wali, H. Nsengimana, N. Banadda, I. Nansubuga, F. Kansiime (2010) Assessment of Heavy Metal Pollution in a Trans-Boundary River: The Case of the Akagera River International journal of mathematics and computation 9 (D10) ISSN 0974-570X

Ogwok P, Muyonga JH, Sserunjogi ML.(2009): Pesticide residues and heavy metals in Nile perch (Lates niloticus) belly flap oil. Bull Environ Contam Toxicol., 82 : 529-933.

Omara, T.;Nteziyaremye, P.; Akaganyira, S.; Waswa, D. O., Nyambura,L. K.; Moraa D. N.; Jematia, B.K.; Ogwang, R.; Epiaka, S.M.; Jepchirchir, A,; and Maiyo, A. (2020) Physicochemical Quality of Water and Health Risks Associated with the Consumption of the Extant African Lung Fish, Protopterus annectens from Nyabarongo and Nyabugogo Rivers, Rwanda: BMC research notes 2020 13

Pearson, J., & McPhedran, K. (2008). A literature review of the non-health impacts of sanitation. Waterlines, 27, 48–61.

Potasznik, A., & Szymczyk, S. (2015). Magnesium and calcium concentrations in the surface water and bottom deposits of a river-lake system. Journal of Elementology, 20(3).

Rahman MS, Molla AH, Saha N, Rahman A.(2012) Study on heavy metals levels and its risk assessment in some edible fishes from Bangshi River, Savar, Dhaka, Bangladesh. Food Chem., 134 : 1847–1854.

Ramachandran V, Fogler HS. (1999). Plugging by hydrodynamic bridging during flow of stable colloidal particles within cylindrical pores J Fluid Mech 385. , 129–156.

Rwanda Natural Resources Authority, RNRA. (2014). Consultancy services for the development of Rwanda’s national water resources master plan, master plan report. Kigali: RNRA.

Sekomo, B. C., Uwamariya, V., Birori, M., Nkundimana, E., & Nkuranga, J. B. (2012). Water quality monitoring in Rwanda. Kigali: National University of Rwanda.

Sekomo, C.B., Rousseau, D.P.L., & Lens, P.N.L., (2012a). Use of Gisenyi Volcanic Rock for Adsorptive Removal of Cd(II), Cu(II), Pb(II), and Zn(II) from Wastewater. Water Air and Soil Pollution

Sen Gupta, P. (2013). Potential health impacts of hard water. International journal of preventive medicine, 4(8), 866.

Sen, T. K., and Khilar, K. C. (2006). Review on subsurface colloids and colloid-associated contaminant transport in saturated porous media. Advances in Colloid and Interface Science, 119(2-3), 71-96.

Singh, N., Nagpal, G., Agrawal, S. and Rachina (2018). Water purification by using various adsorbents: A review. Environmental technology and innovation 11, 187-240.

Sutherland, B. A., Meyer, J. L., & Gardiner, E. P. (2002). Effects of land cover on sediment regime and fish assemblage structure in four southern Appalachian streams. Freshwater Biology, 47, 1791–1805.

Syafalni, Rohana Abdullah, Ismail Abustan, Aimi Nadiah Mohd Ibrahim (2013). Wastewater treatment using bentonite, the combinations of bentonite-zeolite, bentonite-alum, and bentonitelimestone as adsorbent and coagulant International Journal of Environmental Sciences Volume 4 No.3, 2013 391

UNEP (2008) Vita Water graphics, 2nd edition. An Overview of the State of the World‘s Fresh and Marine Waters. URL: (Accessed 16 May 2020)

U.S. Environmental Protection Agency, Eutrophication:

U.S. Environmental Protection Agency, National Nutrient Guidance:

van Olphen, H. (1977), An Introduction to Clay Colloid Chemistry,Wiley Interscience, New York, NY, USA, 2nd edition, 1977.

Verma, A., Wei, X., & Kusiak, A. (2013). Predicting the total suspended solids in wastewater: a data-mining approach. Engineering Applications of Artificial Intelligence, 26(4), 1366-1372.

Water Aid Rwanda. (2016). WaterAid Rwanda Country Programme Strategy: 2016–2021. Kigali: WaterAid Accessed January 20, 2018.

Water for Growth Rwanda, WFGR. (2017). Muvumba Catchment Plan Summary—integrating land and water resources management through joint performance contracts. Kigali: MINIRENA Accessed April 2, 2020.

Water Resources Information Bulletin No 06 for December 2012"

World Health Organization, WHO (2004). Guidelines for Drinking Water Quality, vol. 1, 3 rd ed. World Health Organization, Geneva, Switzerland.

World Health Organization, WHO (2008). Guidelines for Drinking Water Quality, Incorporating the first and second Addenda. vol. 1, 3rd ed. World Health Organization, Geneva, Switzerland. 20. Oeteman, B.C.J (1980).

World Health Organization, WHO. (2017). Drinking-water fact sheet. Geneva: WHO Accessed January 20, 2018.

World Water Assessment Programme. The United Nations World Water Development Report: Water for People, Water for Life; UNESCO: Paris, France, 2003.

Wronski, T., Dusabe, M. C., Apio, A., Hausdorf, B., & Albrecht, C. (2015b). Biological assessment of water quality and biodiversity in Rwandan rivers draining into Lake Kivu. Aquatic Ecology, 49, 309–320.



How to Cite

Mukasa-Tebandeke, I. Z., Karume, I., Ssebuwufu, J., Wasajja , H. Z., Nankinga, R, & Habimana, M. (2020). How variations in concentrations of metal ions and suspended solids downstream river Rwabakazi in Uganda can be used to study pollution. JOURNAL OF ADVANCES IN CHEMISTRY, 17, 44-63.




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