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Distribution and removal efficiency of heavy metals by a conventional activated sludge at a municipal wastewater treatment plant in Kisumu City, Kenya

Author Affiliations

  • 1Maseno University, P.O. Box 333-40105, Maseno, Kenya
  • 2Maseno University, P.O. Box 333-40105, Maseno, Kenya
  • 3Masinde Muliro University of Science and Technology, P.O. Box 190-50100, Kakamega, Kenya
  • 4Kenyatta University, P.O. Box 43844-00100, Nairobi, Kenya
  • 5Egerton University, P.O Box 536-20115, Egerton, Kenya
  • 6The Technical University of Kenya, P.O. Box 52428-00200, Nairobi, Kenya

Res.J.chem.sci., Volume 7, Issue (8), Pages 19-25, August,18 (2017)


The aim of this study was to evaluate the occurrence and the instantaneous overall efficiency of the municipal wastewater treatment facility in Kisumu City-Kenya, a highly populated City, and compare the effluent quality parameters to the National Environmental Management Authority (NEMA) regulations. The heavy metals concentrations (Cu, Pb, Zn, Fe, Mg and Mn) were determined from the inflow and at each stage of the water treatment process including sludge to the effluent discharged to the recipient river. Sample preparation and analysis were done according to the recommended methods. The findings on site characteristics show that pH and chemical oxygen demand (COD) in the treated effluent exceeded the allowable limits. All the selected metal ions (Cu, Pb, Zn, Fe, Mg and Mn) were detected with 100% frequency in the influent water except for Pb which was below the instrumental detection limit (0.001 mg/L). The levels of the heavy metals recorded in the sediment samples were significantly higher than those in the corresponding water samples. The ascending order of the metal percentage removal efficiency (%R) from the treatment plant was: Zn (-127.77%) < Fe (3.66%) < Mn (16.64%) < Cu (24.26%) < Mg (46.97%) indicating that the removal efficiency was directly proportional to the initial metal ion levels in the influent. It is concluded that the plant is a point source for Zn loading into the recipient waters and biosorption and dissolution of the metal ions in the liquid fraction of the sludge were the key modes of metal elimination from the wastewater.


  1. Karvelas M., Katsoyiannis A. and Samara C. (2003)., Occurrence and fate of heavy metals in the wastewater treatment process., Chemosphere, 53(10), 1201-1210.
  2. Barakat M.A. (2011)., New trends in removing heavy metals from industrial wastewater., Arabian J. Chem., 4(4), 361-377.
  3. Achieng G.O., Ongeri D.M.K. and Omwoyo W.N. (2013)., Impact of anthropogenic activities on copper and lead levels in Kisumu city soils., Sky J. Soil Sci. Environ. Manage., 2(5), 47-52.
  4. Gulyas G., Fazekas B., Varga R. and Karpati A. (2010)., Biological purification of chemically pre-treated dairy industry., Current World Environ., 5(2), 373-378.
  5. Verma R. and Suthar S. (2015)., Impact of density loads on performance of duckweed bioreactor: A potential system for synchronized wastewater treatment and energy biomass production., Am. Inst. Chem. Eng. Environ. Program., 34, 1596-1604.
  6. Kimosop S.J., Getenga Z.M., Orata F.O., Okello V.A. and Cheruiyot J.K. (2016)., Residue levels and discharge loads of antibiotics in wastewater treatment plants and hospital lagoons within Lake Victoria Basin, Kenya., J. Environ. Monit. Assess., 188, 532. DOI: 10.1007/s10661-016-5534-6
  7. Musungu C.P., Jondiko I.O., Lalah J., Ongeri D., Chepkui R. and Kiema F. (2013)., The extent of nutrient removal by wastewater treatment plants along the Nyalenda Wigwa Stream and the River Kisat (Kenya)., Ecohydrol. Hydrobiol., 13(4), 236-240.
  8. Environmental Management and Coordination (Water Quality) Regulations (2006)., Legal Notice 120, Third Schedule, Standards for Discharge of Effluent into the Environment.,
  9. Eaton A.D., Clesceri L.S. and Greenberg A.E. (1995)., Standard Methods for the Examination of Water and Wastewater., American Public Health Association, Washington, DC, 8-11.
  10. APHA-AWWA-WPCF (1998)., Standard methods for the Examination of Water and Wasewater., American Public Health Association, Washingtion, DC. Part 3000, 3-8.
  11. Taha A.W., Dakroury A.M., Sayed G.E. and El-Salam S.A. (2007)., Assessment removal of heavy metals ions from wastewater by cement kiln dust (CKD)., Eleventh International Water Technology Conference, Sharm El-Sheikh, Egypt, 879-893.
  12. Oliveira A., Bocio A., Trevilato T., Takayanagui A., Domingo J. and Segura-munoz S. (2007)., Heavy metals in untreated/treated urban effluent and sludge from a biological wastewater treatment plant., Environ. Sci. Pollut. Res., 14(7), 483-489.
  13. Bazrafshan E., Moein H., Kord Mostafapour F. and Nakhaie S. (2013)., Application of electrocoagulation process for dairy wastewater treatment., J. Chem., 1-8.
  14. Pathak U., Das P., Banerjee P. and Datta S. (2016)., Treatment of wastewater from a dairy industry using rice husk as adsorbent: treatment efficiency, isotherm, thermodynamics, and kinetics modelling., J. Thermodyn., 1-7.
  15. Mostafa A.A. (2013)., Treatment of cheese processing wastewater by physicochemical and biological methods., Inter. J. Microbiol. Res., 4(3), 321-332.
  16. Ravva S.V. and Sarreal C.Z. (2014)., Survival of Salmonella enterica in aerated and non-aerated wastewaters from dairy lagoons., Inter. J. Environ. Res. Public Health., 11(11), 11249-11260.
  17. Mohebi-Fard E., Reyahi-Khoram M. and Sobhan-Ardakani S. (2015)., Performance evaluation of the wastewater treatment plant of Pelareh Dairy Industry, Iran., J. Adv. Environ.Health Res., 3(4), 250-257.
  18. Penradee C., Kyoung-Woong K. and Suthipong S. (2008)., Metal Contents and Its Variation in Wastewater and Sewage Sludge: A Case Study of Bangkok Central Wastewater Treatment Plants., Proceedings of the International Symposia on Geoscience Resources and Environments of Asian Terranes (GREAT 2008), 4th IGCP 516, and 5th APSEG; 489-492.
  19. Council Directive (1986)., Council Directive on the protection of the environment, and in particular of the soil, when sewage sludge is used in agriculture., Offic. J. Eur. Comm., 181, 6-12.
  20. EPA (1994)., Land application of sewage sludge., A guide for land applies on the requirement of the Federal standards for the use or disposal of sewage sludge, 40 CFR 503.
  21. Lazzari L., Sperni L., Bertin P. and Pavoni B. (2000)., Correlation between inorganic (heavy metals) and organic (PCBs and PAHs)., micropollutant concentrations during sewage sludge composting processes.
  22. Abdel-Shafy H. (1996)., Fate of heavy metals via chemical–biological upgrading of sewage sludge treatment plants., Environ. Manage. Health, 7(3), 28-36.
  23. Planquart P., Bonin G., Prone A. and Massiani C. (1999)., Distribution, movement, and plant availability of trace metals in soils amended with sewage sludge composts: application to low Metal loadings., Sci. Total Environ., 241(1-3), 161-179.
  24. Voutsa D., Zaxariadis G., Gantidis N., Samara C. and Kouimtzis T. (1996)., Evaluation of municipal and industrial wastewater sludges for agricultural purposes., Fresenious Environ. Bull., 5, 1-6.
  25. Chipasa K.B. (2003)., Accumulation and fate of selected heavy metals in a biological wastewater treatment system., Waste Manage., 23, 135-143.