Geogenic contaminants and groundwater quality around Lake Victoria goldfields in northwestern Tanzania

Fanuel Ligate; Enrico Lucca; Julian Ijumulana; Regina Irunde; Vivian Kimambo; Joseph Mtamba; Arslan Ahmad; Rajabu Hamisi; Jyoti Prakash Maity; Felix Mtalo; Prosun Bhattacharya

doi:10.1016/j.chemosphere.2022.135732

Geogenic contaminants and groundwater quality around Lake Victoria goldfields in northwestern Tanzania

Chemosphere. 2022 Nov;307(Pt 2):135732. doi: 10.1016/j.chemosphere.2022.135732. Epub 2022 Jul 21.

Authors

Affiliations

¹ KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTHRoyal Institute of Technology, Teknikringen 10B, Stockholm, SE-100 44, Sweden; DAFWAT Research Group, Department of Water Resources Engineering, College of Engineering and Technology, University of Dar Es Salaam, Dar Es Salaam, Tanzania; Department of Chemistry, Mkwawa University College of Education, University of Dar Es Salaam, 2513, Iringa, Tanzania. Electronic address: ligate@kth.se.
² Department of Agricultural, Food, Environmental and Forestry Sciences and Technologies, The University of Florence, Cascine, Florence, 18 50144, Italy.
³ KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTHRoyal Institute of Technology, Teknikringen 10B, Stockholm, SE-100 44, Sweden; DAFWAT Research Group, Department of Water Resources Engineering, College of Engineering and Technology, University of Dar Es Salaam, Dar Es Salaam, Tanzania.
⁴ KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTHRoyal Institute of Technology, Teknikringen 10B, Stockholm, SE-100 44, Sweden; DAFWAT Research Group, Department of Water Resources Engineering, College of Engineering and Technology, University of Dar Es Salaam, Dar Es Salaam, Tanzania; Department of Chemistry, College of Natural and Mathematical Sciences, The University of Dodoma, Tanzania.
⁵ DAFWAT Research Group, Department of Water Resources Engineering, College of Engineering and Technology, University of Dar Es Salaam, Dar Es Salaam, Tanzania.
⁶ KWR Water Cycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, the Netherlands; SIBELCO Ankerpoort NV, Op de Bos 300, 6223 EP Maastricht, the Netherlands; Department of Environmental Technology, Wageningen University and Research (WUR), Droevendaalsesteeg 4, 6708, PB Wageningen, the Netherlands.
⁷ KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTHRoyal Institute of Technology, Teknikringen 10B, Stockholm, SE-100 44, Sweden.
⁸ Department of Chemistry, School of Applied Sciences, KIIT Deemed to Be University, Bhubaneswar, Odisha, 751024, India.
⁹ KTH-International Groundwater Arsenic Research Group, Department of Sustainable Development, Environmental Science and Engineering, KTHRoyal Institute of Technology, Teknikringen 10B, Stockholm, SE-100 44, Sweden; KWR Water Cycle Research Institute, Groningenhaven 7, 3433 PE Nieuwegein, the Netherlands.

PMID: 35872057
DOI: 10.1016/j.chemosphere.2022.135732

Abstract

Geogenic contamination of groundwater is frequently associated with gold mining activities and related to drinking water quality problems worldwide. In Tanzania, elevated levels of trace elements (TEs) have been reported in drinking water sources within the Lake Victoria Basin, posing a serious health risk to communities. The present study aims to assess the groundwater quality with a focus on the concentration levels of geogenic contaminants in groundwater around the Lake Victoria goldfields in Geita and Mara districts. The water samples were collected from community drinking water sources and were analysed for physiochemical parameters (pH, EC, Eh), major ions, and trace elements. The analysed major ions included Na⁺, K⁺, Ca²⁺, Mg²⁺, SO₄^2-, HCO₃^- and Cl^- whereas the trace elements were As, Al, Li, Ba, B, Ti, V, U, Zr, Sr, Si, Mn Mo, Fe, Ni, Zn, Cr, Pb, Cd, and V. The present study revealed that the concentration levels of the major ions were mostly within the World Health Organization (WHO) drinking water standards in the following order of their relative abundance; for cations, Ca²⁺∼Na⁺>Mg²⁺>K⁺ and for anions was HCO₃^- > SO₄^2- > NO₃^-, Cl^- > PO₄^3-. Statistical and geochemical modelling software such as 'R Studio', IBM SPSS, geochemical workbench, visual MINTEQ were used to understand the groundwater chemistry and evaluate its suitability for drinking purpose. The concentration of As in groundwater sources varies between below detection limit (bdl) and 300 μg/L, with highest levels in streams followed by shallow wells and boreholes. In approximately 48% of the analysed samples, As concentration exceeded the WHO drinking water guideline and Tanzania Bureau of Standards (TBS) guideline for drinking water value of 10 μg/L. The concentration of the analyzed TEs and mean values of physicochemical parameters were below the guideline limits based on WHO and TBS standards. The Canadian Council of Ministries of the Environment Water Quality Index (CCME WQI) shows that the overall water quality is acceptable with minimum threats of deviation from natural conditions. We recommend further geochemical exploration and the periodic risk assessment of groundwater in mining areas where high levels of As were recorded.

Keywords: Arsenic; Drinking water quality; Geogenic contamination; Lake victoria goldfields; Visual MINTEQ.

MeSH terms

Cadmium / analysis
Canada
Drinking Water* / analysis
Environmental Monitoring
Gold / analysis
Groundwater* / analysis
Lakes / analysis
Lead / analysis
Tanzania
Trace Elements* / analysis
Water Pollutants, Chemical* / analysis
Water Quality

Substances

Drinking Water
Trace Elements
Water Pollutants, Chemical
Cadmium
Lead
Gold