Paper No. 148-18
Presentation Time: 4:35 PM
ARSENIC OCCURRENCE IN AFRICAN WATER SYSTEMS AND LOW-COST TREATMENT TECHNOLOGIES
IRUNDE, Regina Filemon1, IJUMULANA, Julian2, LIGATE, Fanuel J.3, BHATTACHARYA, Prosun4, AHMAD, Arslan5, MTAMBA, Joseph O.6 and MTALO, Felix W.6, (1)KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, Stockholm, 100 44, Sweden; Department of Water Resources Engineering, College of Engineering and Technology, University of Dar es Salaam, Dar es Salaam, Tanzania, United Republic of; Department of Chemistry, College of Natural and Applied Sciences, University of Dar es Salaam, P.O.Box 35061 Dar es Salaam, Dar es Salaam, P.O.Box 35061, Tanzania, United Republic of, (2)KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, Stockholm, 100 44, Sweden; Department of Transportation and Geotechnical Engineering, College of Engineering and Technology, University of Dar es Salaam, Dar es Salaam, P.O.Box 35091, Tanzania, United Republic of; Department of Water Resources Engineering, College of Engineering and Technology, University of Dar es Salaam, Dar es Salaam, Tanzania, United Republic of, (3)KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, Stockholm, 100 44, Sweden; Department of Water Resources Engineering, College of Engineering and Technology, University of Dar es Salaam, Dar es Salaam, Tanzania, United Republic of; Department of Chemistry, Mkwawa College of Education, University of Dar es Salaam, Dar es Salaam, P.O.Box 35091, Tanzania, United Republic of, (4)KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 10B, Stockholm, 100 44, Sweden, (5)SIBELCO Ankerpoort NV, Op de Bos 300, Maastricht, 6223 EP, Netherlands; Department of Environmental Technology, Wageningen University and Research (WUR), Wageningen, 6708 PB, Netherlands, (6)Department of Water Resources Engineering, College of Engineering and Technology, University of Dar es Salaam, Dar es Salaam, Tanzania, United Republic of
For the past two decades, few sporadic studies on arsenic occurrence in the environment particularly in surface and groundwater systems have reported high levels of arsenic (As) concentrations in several countries in the African continent. Arsenic concentrations up to 10000 µg/L have been reported in surface water systems caused by human activities such as mining, industrial effluents, municipal solid waste disposals, etc. Similarly, concentrations between 0.02 and 1760 µg/L have been reported in many groundwater systems which account for approximately 60 – 70 % of drinking water demand particularly in rural areas. Under natural conditions, As is mobilized in groundwater systems through weathering processes and dissolution of Arsenic bearing minerals such as sulfides (pyrite, arsenopyrite, chalcopyrite), iron oxides, and other mineralized granitic and gneissic rocks. Recently, public health studies in some African countries such as Tanzania and Ethiopia have reported high levels of arsenic in human tissues such as toenails as well as in urine among pregnant women exposed to As contaminated groundwater, respectively. Despite the levels of As in toenails for young and adult people differed significantly, they correlated positively with As levels in community boreholes (r = 0.72; R2 = 0.52; P <0.001). In urine, concentrations between 0 and 150 µg/L were reported among pregnant women depending on arsenic contaminated drinking water within Geita gold mining areas in the north-western part of Tanzania. Lack of awareness on health issues related to arsenic in groundwater systems has limited the detailed studies, both on understanding the occurrence and mobilization of arsenic as well on potential mitigation measures. The few reviewed removal studies were at laboratory scale. Availability of local materials in African areas such as soils, sands, magnesite, bauxite, iron ore, gypsum, wood char, bone char and activated carbon from agricultural wastes call attention among researchers to develop low cost, affordable and sustainable removal technologies for community use particularly in rural African countries.