Advanced search
1 file | 1.01 MB Add to list

Identification of low fluoride areas using conceptual groundwater flow model and hydrogeochemical system analysis in the aquifer system on the flanks of an active volcano : Mount Meru, northern Tanzania

Author
Organization
Abstract
This study investigates the localities of low and high F⁻ groundwaters in the aquifer system on the flanks of Mount Meru to come up with guidelines to provide groundwater that can be used for drinking water supply without health impacts on the population. Our study focuses on parts of the flanks which were only partially or not at all covered by previous research. Results show that the groundwater chemistry of F⁻-rich NaHCO3 alkaline groundwater in the area is controlled by dissolution of weathering aluminosilicate minerals (especially Na-K-feldspars), dissolution of F⁻-bearing minerals, the precipitation of carbonate minerals as secondary products and the dissolution of magmatic gases. Evaporative concentration of solutes, precipitation and redissolution of evaporitic salts may locally play a role, especially on the north-eastern flank of Mount Meru. The low F⁻ groundwaters which can be used for drinking water supply without health impacts under the WHO limit (1.5 mg/L) are the low-fluoride springs from the high-altitude recharge areas on the eastern and north-western flanks of Mount Meru inside Arusha National Park, whereas on the western flank the groundwater meets the Tanzanian limit (4.0 mg/L). On the south-western flank, the shallow aquifer composed of alluvium deposits at lower elevations, shows F⁻ values that meet the Tanzanian limit. One of the three investigated deep boreholes on this flank also meets the Tanzanian limit, this suggests a possibility of finding more localities of relatively low F⁻ groundwaters in the deep aquifer. Yet, in general, the deposits at lower elevations (the debris avalanche deposits, mantling ash, alluvial fan deposits and lake deposits) are found to contain high to very high F⁻ values, whereas the deposits at high elevations (pyroclastics and lavas) contain groundwater of low F⁻ values. Thus, the internal texture and grain size of geological formations (causing variable weatherability), the burial depth of these formations (less weathering at depth) and the water residence times are the factors determining the groundwater mineralisation and F⁻ concentrations in the area. The study identified that the deep hydrothermal system (volcanic emissions) has influence on the high F⁻ groundwaters on the eastern and north-eastern flanks of Mount Meru.
Keywords
Hydrogeochemistry, Alkaline Groundwater, Magmatic Degassing, East African Rift System, WATERS

Downloads

  • (...).pdf
    • full text (Published version)
    • |
    • UGent only
    • |
    • PDF
    • |
    • 1.01 MB

Citation

Please use this url to cite or link to this publication:

MLA
Bennett, George, et al. “Identification of Low Fluoride Areas Using Conceptual Groundwater Flow Model and Hydrogeochemical System Analysis in the Aquifer System on the Flanks of an Active Volcano : Mount Meru, Northern Tanzania.” SCIENCE OF THE TOTAL ENVIRONMENT, vol. 814, no. C, 2022, doi:10.1016/j.scitotenv.2021.152682.
APA
Bennett, G., Van Reybrouck, J., Shemsanga, C., Kisaka, M., Tomašek, I., Fontijn, K., … Walraevens, K. (2022). Identification of low fluoride areas using conceptual groundwater flow model and hydrogeochemical system analysis in the aquifer system on the flanks of an active volcano : Mount Meru, northern Tanzania. SCIENCE OF THE TOTAL ENVIRONMENT, 814(C). https://doi.org/10.1016/j.scitotenv.2021.152682
Chicago author-date
Bennett, George, Jill Van Reybrouck, Ceven Shemsanga, Mary Kisaka, Ines Tomašek, Karen Fontijn, Matthieu Kervyn, and Kristine Walraevens. 2022. “Identification of Low Fluoride Areas Using Conceptual Groundwater Flow Model and Hydrogeochemical System Analysis in the Aquifer System on the Flanks of an Active Volcano : Mount Meru, Northern Tanzania.” SCIENCE OF THE TOTAL ENVIRONMENT 814 (C). https://doi.org/10.1016/j.scitotenv.2021.152682.
Chicago author-date (all authors)
Bennett, George, Jill Van Reybrouck, Ceven Shemsanga, Mary Kisaka, Ines Tomašek, Karen Fontijn, Matthieu Kervyn, and Kristine Walraevens. 2022. “Identification of Low Fluoride Areas Using Conceptual Groundwater Flow Model and Hydrogeochemical System Analysis in the Aquifer System on the Flanks of an Active Volcano : Mount Meru, Northern Tanzania.” SCIENCE OF THE TOTAL ENVIRONMENT 814 (C). doi:10.1016/j.scitotenv.2021.152682.
Vancouver
1.
Bennett G, Van Reybrouck J, Shemsanga C, Kisaka M, Tomašek I, Fontijn K, et al. Identification of low fluoride areas using conceptual groundwater flow model and hydrogeochemical system analysis in the aquifer system on the flanks of an active volcano : Mount Meru, northern Tanzania. SCIENCE OF THE TOTAL ENVIRONMENT. 2022;814(C).
IEEE
[1]
G. Bennett et al., “Identification of low fluoride areas using conceptual groundwater flow model and hydrogeochemical system analysis in the aquifer system on the flanks of an active volcano : Mount Meru, northern Tanzania,” SCIENCE OF THE TOTAL ENVIRONMENT, vol. 814, no. C, 2022.
@article{8732927,
  abstract     = {{This study investigates the localities of low and high F⁻ groundwaters in the aquifer system on the flanks of Mount Meru to come up with guidelines to provide groundwater that can be used for drinking water supply without health impacts on the population. Our study focuses on parts of the flanks which were only partially or not at all covered by previous research. Results show that the groundwater chemistry of F⁻-rich NaHCO3 alkaline groundwater in the area is controlled by dissolution of weathering aluminosilicate minerals (especially Na-K-feldspars), dissolution of F⁻-bearing minerals, the precipitation of carbonate minerals as secondary products and the dissolution of magmatic gases. Evaporative concentration of solutes, precipitation and redissolution of evaporitic salts may locally play a role, especially on the north-eastern flank of Mount Meru. The low F⁻ groundwaters which can be used for drinking water supply without health impacts under the WHO limit (1.5 mg/L) are the low-fluoride springs from the high-altitude recharge areas on the eastern and north-western flanks of Mount Meru inside Arusha National Park, whereas on the western flank the groundwater meets the Tanzanian limit (4.0 mg/L). On the south-western flank, the shallow aquifer composed of alluvium deposits at lower elevations, shows F⁻ values that meet the Tanzanian limit. One of the three investigated deep boreholes on this flank also meets the Tanzanian limit, this suggests a possibility of finding more localities of relatively low F⁻ groundwaters in the deep aquifer. Yet, in general, the deposits at lower elevations (the debris avalanche deposits, mantling ash, alluvial fan deposits and lake deposits) are found to contain high to very high F⁻ values, whereas the deposits at high elevations (pyroclastics and lavas) contain groundwater of low F⁻ values. Thus, the internal texture and grain size of geological formations (causing variable weatherability), the burial depth of these formations (less weathering at depth)  and the water residence times are the factors determining the groundwater mineralisation and F⁻ concentrations in the area. The study identified that the deep hydrothermal system (volcanic emissions) has influence on the high F⁻ groundwaters on the eastern and north-eastern flanks of Mount Meru.}},
  articleno    = {{152682}},
  author       = {{Bennett, George and Van Reybrouck, Jill and Shemsanga, Ceven and Kisaka, Mary and Tomašek, Ines and Fontijn, Karen and Kervyn, Matthieu and Walraevens, Kristine}},
  issn         = {{0048-9697}},
  journal      = {{SCIENCE OF THE TOTAL ENVIRONMENT}},
  keywords     = {{Hydrogeochemistry,Alkaline Groundwater,Magmatic Degassing,East African Rift System,WATERS}},
  language     = {{eng}},
  number       = {{C}},
  pages        = {{17}},
  title        = {{Identification of low fluoride areas using conceptual groundwater flow model and hydrogeochemical system analysis in the aquifer system on the flanks of an active volcano : Mount Meru, northern Tanzania}},
  url          = {{http://dx.doi.org/10.1016/j.scitotenv.2021.152682}},
  volume       = {{814}},
  year         = {{2022}},
}

Altmetric
View in Altmetric
Web of Science
Times cited: