JWARP  Vol.11 No.6 , June 2019
Assessment of Cadmium and Lead in Dried Sewage Sludge from Lubigi Feacal Sludge and Wastewater Treatment Plant in Uganda
Abstract: Sludge contains organic and inorganic compounds including traces of heavy metals such as lead (Pb), cadmium (Cd), copper (Cu), nickel (Ni), chromium (Cr) and others. These metals restrict the use of sludge in agriculture because their accumulation is harmful to the environment and particularly the food chain. Cadmium and lead are among the most common heavy metals found in municipal wastewater treatment plant sludge. They are capable of bioaccumulation in plant tissues like roots and leaves and are non-biodegradable and therefore they remain in the sludge which is disposed on land or used as fertilizers on farms. The presence of heavy metal pollutants serves as a great threat to soils and also makes plants grown on such soils unfit for animal and human consumption as they may have detrimental effects to animal and human life. For instance, Pb and Cd are known to be human carcinogens. This study therefore aimed to investigate the levels of Cd and Pb in the treated dry sludge from Lubigi Feacal Sludge and Wastewater treatment plant located in Kawempe division, Kampala city, Uganda so as to ascertain its safety for use on agricultural lands. Two batches of samples were collected and analyzed at Government Analytical laboratory in Wandegeya, Uganda. The acid digested sludge samples were analyzed using Atomic Absorption Spectroscopy (AAS) method. The average concentrations of Pb found in collected sludge samples, batch 1 (11.912 mg/kg dm) and batch 2 (5.304 mg/kg dm) were far below the Environment Protection Agency (EPA) maximum permissible concentration (840 mg/kg) for any land application. Cadmium was not detected in all the sludge samples collected; there is an implication that it is either completely absent in the sludge generated by the plant or present but far below detectable levels. The sludge generated from Lubigi fecal sludge and wastewater treatment plant is therefore safe for application on agricultural lands as far as Pb and Cd concentrations are concerned.
Cite this paper: Kyayesimira, J. , Ssemaganda, A. , Muhwezi, G. and Andama, M. (2019) Assessment of Cadmium and Lead in Dried Sewage Sludge from Lubigi Feacal Sludge and Wastewater Treatment Plant in Uganda. Journal of Water Resource and Protection, 11, 690-699. doi: 10.4236/jwarp.2019.116040.

[1]   KCCA-KFSM (2017) Kampala Feacal Sludge Management; Improving Feacal Sludge Management for On-Site Sanitation. Kampala.

[2]   Schoebitz, L., Bischoff, F., Lohri, C.R., Niwagaba, C.B., Siber, R. and Strande, L. (2017) GIS Analysis and Optimisation of Faecal Sludge Logistics at City-Wide Scale in Kampala, Uganda. Sustainability, 9, 194.

[3]   Strande, L., Ronteltap, M. and Brdjanovic, D. (2014) Faecal Sludge Management; Systems Approach for Implementation and Operation. IWA Publishing, London.

[4]   Lazdina, D., Lazdins, A., Bebre, I. and Gusarevs, I. (2017) Technological Process of Sewage Sludge De-Watering by Impulse Method and Assessment of Options to Use Dried Material. Engineering for Rural Development, 16, 217-221.

[5]   Mwakaboko, A.S., Lugwisha, E.H.J. and Kayogolo, C.W. (2014) The Performance of the Selected Waste Stabilization Ponds in Dar es salaam, Tanzania in Removing Heavy Metals. International Journal of Science, Environment and Technology, 3, 2024-2037.

[6]   Bonfiglioli, C.S., Bianchini, L. and Pellegrini, M. (2014) Sewage Sludge: Characteristics and Recovery Options.

[7]   Akpor, O.B., Ohiobor, G.O. and Olaolu, T.D. (2014) Heavy Metal Pollutants in Wastewater Effluents: Sources, Effects and Remediation. Advances in Bioscience and Bioengineering, 2, 37-43.

[8]   Khan, A., Khan, S., Khan, M.A. and Qamar, Z. (2015) The Uptake and Bioaccumulation of Heavy Metals by Food Plants, Their Effects on Plants Nutrients, and Associated Health Risk: A Review. Environmental Science and Pollution Research, 22, 13772-13799.

[9]   NWSC (2014) The Water Herald: Frontiers for Business Opportunities. Water Herald, Kampala, 1-36.

[10]   Lindberg, E. and Rost, A. (2018) Treatment of Faecal Sludge from Pit Latrines and Septic Tanks Using Lime and Urea.

[11]   Omagor, J. and Barasa, B. (2018) Effects of Human Wetland Encroachment on the Degradation of Lubigi Wetland System, Kampala City Uganda. Environment and Ecology Research, 6, 562-570.

[12]   Christensen, T.H., Pedersen, L.R. and Tjell, J.C.H.R. (2007) Comparison of Four Methods for Digestion of Sewage Sludge Samples for Analysis of Metals by Atomic Absorption Spectrophotometry. International Journal of Environmental Analytical Chemistry, 12, 41-50.

[13]   Urben, P. (2007) Bretherick’s Handbook of Reactive Chemical Hazards. 7th Edition, Elsevier Ltd., Oxford.

[14]   Bettinellia, M., Baffi, C., Beone, G. and Spezia, S. (2000) Soil and Sediment Analysis by Spectroscopic Techniques Part I: Determination of Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn. Atomic Spectroscopy, 21, 37-76.

[15]   Katz, S.A., Jenniss, S.W., Chatt, A., Tout, R.E. and Mount, T. (2007) Comparison of Sample Preparation Methods for the Determination of Metals in Sewage Sludges by Flame Atomic Absorption Spectrometry. International Journal of Environmental Analytical Chemistry, 9, 209-220.

[16]   Mghweno, L.R., Makokha, A.O., Magoha, H.S. and Wekesa, J.M. (2008) Environmental Lead Pollution and Food Safety around Kampala City in Uganda. Journal of Applied Biosciences, 12, 642-649.

[17]   Islam, R., Al Foisal, J., Rahman, M., Lisa, L.A. and Paul, D.K. (2016) Pollution Assessment and Heavy Metal Determination by AAS in Wastewater Collected from Kushtia Industrial Zone in Bangladesh. African Journal of Environmental Science and Technology, 10, 9-17.

[18]   Radulescu, et al. (2014) Determination of Heavy Metal Levels in Water and Therapeutic Mud by Atomic Absorption Spectrometry. Romanian Journal of Physics, 59, 1057-1066.

[19]   Baysal, A., Ozbek, N. and Akman, S. (2013) Determination of Trace Metals in Wastewater and Their Removal Processes. INTECH, London.

[20]   Barin, J.S., Bartz, F.R., Dressler, V.L., Paniz, J.N.G. and Flores, é.M.M. (2008) Microwave-Induced Combustion Coupled to Flame Furnace Atomic Absorption Spectrometry for Determination of Cadmium and Lead in Botanical Samples. Analytical Chemistry, 80, 9369-9374.

[21]   US EPA (2000) Environmental Assessment for the Final Effluent Limitations Guidelines, Pretreatment Standards for New and Existing Sources and New Source Performance Standards for the Centralized Waste Treatment Point Source Category. 1-86.

[22]   Morrison, G., Fatoki, O.S., Linder, S. and Lundehn, C. (2004) Determination of Heavy Metal Concentrations and Metal Fingerprints of Sewage Sludge from Eastern Cape Province, South Africa by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP). Water, Air, & Soil Pollution, 152, 111-112.

[23]   Shamuyarira, K.K. and Gumbo, J.R. (2014) Assessment of Heavy Metals in Municipal Sewage Sludge: A Case Study of Limpopo Province, South Africa. International Journal of Environmental Research and Public Health, 11, 2569-2579.

[24]   Snyman, H. and Herselman, J. (2006) Guidelines for the Utilisation and Disposal of Wastewater Sludge: Volume 2: Requirements for the Agricultural Use of Wastewater Sludge.

[25]   UNEP (2011) Partnership for Clean Fuels and Vehicles; Outcome and Influence Evaluation of the UNEP Based Partnership for Clean Fuels and Vehicles (PCFV). Nairobi.

[26]   Mann, R.M., Vijver, M.G. and Peijnenburg, W.J.G.M. (2011) Metals and Metalloids in Terrestrial Systems: Biomagnification and Subsequent Adverse Effects. In: Ecological Impacts of Toxic Chemicals, Bentham Science Publishers Ltd., Sharjah, 43-62.