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Pollution Control on River Nile in the White Nile State Sugar Hub of Sudan Mohmmed Alnail,† Martin Kabenge,*,‡ Jianhua Li,‡ Miao Zhu,‡ Ali Abubaker,§ and Aisha Magzoub∥ †
Ministry of Agriculture and Forests, Government of Sudan, P.O. Box 8178, Gadaref, 12217, Sudan UNEP-Tongji Institute of Environment for Sustainable Development, State Key Laboratory of Pollution Control and Resource Reuse Study, Tongji University, Siping Rd 1239, Shanghai, 200092, China § Key Laboratory of Efficient Irrigation-Drainage and Agricultural Soil-Water Environment, College of Water Conservancy and Hydropower, Hohai University, Nanjing, 210098, China ∥ Sudanese Environmental Conservation Society, Khartoum-Arkwit Block No. 68, Khartoum, 44266, Sudan Covering an area of about 39 701 km2, the White Nile State is located in central Sudan, bordering Khartoum State in the north, North Kordofan State in the west, South Kordofan State and the Upper Nile State in the southeast, and Al-Gazira and Sinnar States in the east. In the White Nile State region, the sugar industry is the main pollution source into the River Nile. Sugar cane processing factories are located in close proximity to the banks of the Blue Nile and White Nile where they discharge their effluent directly into the river. According to the Sudan postconflict environmental assessment carried out by UNEP1 the wastewater contains an elevated BOD, which can reach 800−3000 ppm. A prior investigation carried out at Assalaya, one of the sugar cane processors in the region, had revealed that the factory’s discharge into the river had BOD, COD, and TSS of 1200 mg/L, 2160 mg/L, and 2080 mg/L, respectively.2 Furthermore, the runoff from irrigated sugar cane fields that contains high agrochemicals content such as insecticides, herbicides, and fertilizers also finds its way into the river. This all in turn contaminates the water leaving the lives of people and their livestock that depend on the river’s water at risk. In order to improve water quality while promoting water iver Nile is the longest river in the world, shared by 11 conservation in the Nile Basin, prompt and effective measures countries that constitute the Nile Basin countries, namely need to be taken. An efficient and cost-effective wastewater Egypt, Sudan, South Sudan, Ethiopia, Uganda, Kenya, treatment system needs to be adopted and put in place by the Tanzania, Rwanda, Burundi, the Democratic Republic of the sugar cane processors to control the pollution discharge into Congo, and Eritrea. The river stretches a 6695 km length from the river. The Waste Stabilization Ponds (WSP) system is a low its source the Kagera Basin in Rwanda and Burundi to the Nile cost wastewater treatment system that uses bacterial activity to Delta in Egypt that empties into the Mediterranean Sea. The remove organic matter, nutrients, and microbes in sewage. The Nile basin covers about 10% of the African continent and is typical setup of the WSP involves three ponds in series relied upon by over 160 million people for their food, irrigation comprising of anaerobic, facultative, and maturation ponds in water, domestic water supply, hydroelectric power production, that order. In the anaerobic pond, the suspended solids are tourism, transportation,and fishing. Despite its significant removed and some of the soluble elements of organic matter importance, the river Nile is experiencing increasing deterioare digested an-aerobically. In the facultative pond, aerobic ration in water quality. This is due increasing pollution loads degradation occurs. Here most of the remaining organic matter arising from high population and economic growth in the is removed through the coordinated activity of algae and region. The River has been exposed to nonpoint source heterotrophic bacteria. The main function of the third pond, pollution such as chemicals and sedimentations from maturation pond, is the removal of pathogens through agricultural practices and very highly toxic substances from facilitating microbes death and removal of nutrients especially mining activities. In addition, there is severe point source nitrogen by algal activity. The use of WSP has shown up to 95% pollution from domestic and industrial discharge especially in urban areas. The lack of adequate wastewater treatment facilities has seen extensive discharge of untreated effluent Received: October 3, 2013 into the river from domestic, agricultural and industrial sources Accepted: October 11, 2013 Published: October 31, 2013 in riparian states (Figure 1). ‡
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© 2013 American Chemical Society
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dx.doi.org/10.1021/es4044159 | Environ. Sci. Technol. 2013, 47, 12628−12629
Environmental Science & Technology
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Figure 1. Direct discharge of untreated effluent from Assalaya sugar factory into the Blue Nile. Source: UNEP, 2007.1 (4) Damodharan, M. U.; Reddy, V. Impact of sugar industrial treated effluent on the growth factor in sugarcaneCuddalore, India. J. Sustainable Bioenergy Syst. 2012, 2, 43−48.
improvement in water quality due to their high efficiency in removing wastes from water.3 Since Sudan is one of the African countries that suffer from water shortage, water conservation through reuse of treated effluent from the sugar cane factories can be a key step to meet the irrigation demands of the region. The reuse of treated effluent has also been proved to effectively substitute the use of chemical fertilizers while increasing yields of sugar cane plantations.4 Comprehensive waste management policies should be put in place and also be uniformly implemented by all riparian states in order to control pollution and protect the environment and human health, with focus on utilizing available environmentally friendly technology.
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected]. Notes
The authors declare no competing financial interest.
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ACKNOWLEDGMENTS This study is part of the Africa-China Cooperation Program on Environment which is supported by the Ministry of Science and Technology of China (MOST) and coordinated by the United Nations Environment Programme (UNEP). It was supported in part by the Fundamental Research Funds for the Central Universities.
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REFERENCES
(1) UNEP. Sudan Post-Conflict Environmental Assessment; United Nations Environment Programme: Nairobi, Kenya, 2007. (2) Magid, M. A.; El Hassan, B. M. Recycling of agricultural/ industrial waste: The case of wastewater from sugar factories in the Sudan. MEW & S J. 1988, 4, 98−102. (3) Pena, M. R.; Mara, D. D.; Sanchez, A. Dispersion studies in anaerobic ponds: Implications for design and operation. Water Sci. Technol. 2000, 42, 10−11. 12629
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