Sustainable Tertiary Wastewater Treatment Is Required for Water Resources Pollution Control in Africa

Abstract

T here is a significant lack of proper wastewater treatment in most African countries, especially in sub-Saharan Africa. Untreated sewage effluent is one of the most common types of pollution found around urban rivers and in groundwater sources in many African cities. By 2020, 75−250 million people in Africa may be exposed to increased water stress due to climate change and pollution will only exacerbate the situation. 1 In Kenya, for example, most municipal wastewater treatment plants (WWTPs) discharge partially treated or untreated wastewater containing high levels of organic matter with mean effluent TSS, COD cr , and BOD 5 being 246 mg/L, 253 mg/L and 98 mg/L, respectively, (as of 2004) against a discharge requirement of 30, 50, and 30 mg/L, respectively. This situation replicates itself across most cities in the developing world. Dar es Salaam, Accra, Khartoum, Harare, Maputo, and Kampala, to name but a few, discharge treated and untreated sewage into their water bodies. In 2004, only about 14% of sewage was collected and treated in Dakar, and the rest was discharged into the sea without treatment. 2 The story is the same in Latin America, where less than 15% of the wastewaters collected in sewered cities and towns is treated prior to discharge. 3 The inadequacy in treatment stems from a number of reasons that include poor operation and maintenance of existing systems or complete breakdown of the same, overloading, and lack of tertiary systems for extended

Municipal wastewater can result in a dramatic decline in freshwater fishes: a lesson from a developing country

“…Dudgeon, 2000). This is primarily because the majority of the industries do not have a proper treatment plant or plants have been kept idle to reduce operating costs (Omosa et al, 2012;Haque, 2017). Thus similar results can also be expected in other developing countries where wastewaters are being drained into the nearby water bodies without any prior treatment.…”

“…The current management practice for wastes or industrial effluents in Bangladesh, as well as in other developing countries, is similar (e.g. Girija et al, 2007;Omosa et al, 2012;Haque, 2017) À draining them out into the nearby waters, usually rivers, usually without any prior treatment (e.g. Dudgeon, 2000).…”

“…While the impacts and remediation of freshwater pollution, especially organic pollution, have a long and well-recorded history in the developed world (Hynes, 1963;Mason, 2001), wastewater is a serious and emerging problem in the majority of developing countries (e.g. Girija et al, 2007;Omosa et al, 2012;Haque, 2017). This is primarily because industrial, agricultural, municipal and sewage discharge cause deterioration of receiving water quality (Dudgeon, 1992;Vaseem and Banerjee, 2013;Paul, 2017) and make freshwater habitats unfavourable for natural communities of micro and macroorganisms living in the system (Karaouzas et al, 2018).…”

Water and Wastewater Treatment in Africa – Current Practices and Challenges

“…Stabilization ponds are widely used by industries including sugar, textile, dairy, and paper factories . Due to limited capability of stabilization ponds, the pollutant concentration in the effluent of pond system is still very high . For example, we found that the typical influent chemical oxygen demand of municipal WWTPs is often higher than 2000 mg/L in many pond systems in Africa, while it is approximately 400 mg/L in other countries .…”

Effects of coaxial dielectric barrier discharge on water treatment at different sites of Kathmandu Valley, Nepal

“…This causes increase in water crisis and environmental deterioration (Bhatta R. et al, 2015 The increasing pace of urbanization and population growth continues to affect the quality of drinking water. The increasing consumption of water and discharge of wastewater has been resulted with the growing population and rising economy, which causes huge pollution (Omosa I. B. et al, 2012).…”