A review of fluoride in african groundwater and local remediation methods

Kut, Kwai Malak Kwai; Sarswat, Ankur; Srivastava, Ashwini K.; Pittman, Charles U.; Mohan, Dinesh

doi:10.1016/j.gsd.2016.09.001

Cited by 131 publications

(48 citation statements)

References 136 publications

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“…Water temperature (T), pH and EC were measured in situ using a portable Multi-functional water quality analyzer (Multi 3430) (WTW a xylem brand, Weilheim, Germany) that was calibrated before use. Major ions (Ca 2+ , Mg 2+ , Na + , K + , SO 4 . Water samples were equilibrated with CO 2 for oxygen isotopic analysis and the Cd-reduction method was used to produce hydrogen gas for deuterium analysis.…”

Section: Sample Collection and Analysismentioning

confidence: 99%

“…Fluoride in groundwater is a concern for health worldwide and attracts a lot of attention, since high fluoride (>WHO limit of 1.5 mg/L) in drinking water can often cause dental (F − > 1.5 mg/L), skeletal (F − > 4 mg/L) and crippling (F − > 10 mg/L) fluorosis [1]. More than eight million people are subjected to high fluoride groundwater in the Ethiopian rift valley [2], about 200 million in other places in the world [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

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Geochemical Evolution of Fluoride and Implication for F− Enrichment in Groundwater: Example from the Bilate River Basin of Southern Main Ethiopian Rift

Haji

Wang

et al. 2018

Water

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Groundwater is the most important source of drinking water. Fluoride was found in high concentrations in the groundwater from deep wells of the water supply in the southern main Ethiopian rift. The high concentration of fluoride is dominantly geogenic rather than anthropogenic in origin, as the agricultural area was not found to be contaminated with NO 3 − . Knowledge of fluoride enrichment will help to provide management plans for developing deep groundwater and minimizing the health risks of exposure to fluoride. The chemical processes of fluoride were investigated in the waters in the Bilate River basin using hydrochemical and isotopic tools. The F − concentration ranged from 0.5 to 1.29 mg/L in water from shallow wells and from 0.48 to 5.61 mg/L in water from deep wells. Seventy percent of deep well samples had F − > 1.5 mg/L higher than the World Health Organization potable guideline. The high fluoride concentration in the groundwater was mainly situated in the rift valley of the Bilate River basin, in contrast with low F − groundwater in the highland. The concentration of fluoride was lowest in Ca-Mg-HCO 3 type groundwater and highest in Na-HCO 3 type groundwater. Moreover, F − was positively correlated with HCO 3 − , Na + , Na + /Ca 2+ and pH in groundwater and Na + /Ca 2+ ratios were increased along the flow path. Hydrogeological, hydrodynamic and hydrochemical conditions are responsible for fluoride accumulation in the deep aquifers. Strong dynamic flow in highland areas flush away weathered chemical components (e.g., F − ). Thus, surficial weathering is not a major controlling factor for high concentrations of Fluoride in deep groundwater but the combination of silicate hydrolysis and ion exchange mainly control fluoride enrichment in stagnant flow environments.In past decades, researchers have studied the geographical distribution of fluoride concentration [6-8] and its relationship with dental caries, dental fluorosis and skeletal fluorosis [9][10][11] in the Ethiopian rift valley. Water quality and fluoride sources were investigated in the central Ethiopian rift [12]. The occurrence of health problems related to fluoride are well documented in the Central Ethiopian rift valley, whereas hydrogeochemistry and F − enrichment mechanism in the southern Ethiopian rift valley have not yet been investigated and are poorly understood.Fluoride in groundwater is related to various rock types, that is, sedimentary rocks [13,14], igneous rock [12,15], or metamorphic rock [16,17], influenced by geochemical and climatological conditions [18]. Volcanic emissions and geothermal water are also sources of fluoride in groundwater [19][20][21]. Fluorine-bearing minerals like topaz, fluorite, tourmaline, muscovite, biotite, hornblende and villianmite, release F − through weathering and water-rock interaction [22][23][24]. Besides natural sources, fluoride can be derived from anthropogenic activity including mining activities, industrial emissions and agricultural fertilizers [25][26][27].The south Ethiopian rift is locate...

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Section: Sample Collection and Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Geochemical Evolution of Fluoride and Implication for F− Enrichment in Groundwater: Example from the Bilate River Basin of Southern Main Ethiopian Rift

Haji

Wang

et al. 2018

Water

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“…However, the baseline water quality of HPBs sources in Africa remains understudied compared to other continents globally. Africa wide meta-analyses of groundwater quality have been undertaken for selected water quality parameters, including nitrate (Ouedraogo and Vanclooster 2016), fluoride (Kut et al 2016), arsenic (Ahoulé et al 2015) and faecal contamination (Bain et al 2014). These meta-studies have highlighted that the majority of published studies on groundwater quality in Africa have (i) limited geographical and geological scope, (ii) studies rarely consider paired observations of microbiological and chemical water quality, and (iii) results are often reported from a mixture of different groundwater source types (e.g.…”

Section: Introductionmentioning

confidence: 99%

Drinking water quality from rural handpump-boreholes in Africa

Lapworth

MacDonald

Kebede

et al. 2020

Environ. Res. Lett.

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Groundwater provides a vital source of drinking water for rural communities in many parts of Africa, particularly in the dry season when there are few safe alternative sources. This paper summarises results from a study (n = 428) assessing dry season water quality, both microbiological and inorganic chemistry, in handpump equipped boreholes (HPBs) across the Ethiopia Highlands (n = 142), Malawi (n = 162) and Uganda (n = 124) using a stratified, randomised sampling design. This study seeks to examine general water quality by randomly sampling rural groundwater supplies across larger areas with different geology and climate. The majority, 72%, of HPBs surveyed provide good quality dry season drinking water as defined by WHO drinking water quality criteria. Within this overall picture, the most notable constraints were from thermotolerant coliforms (TTCs), which exceeded the WHO drinking water guideline of zero colony forming units (cfu/100 ml) in 21% of sites (range 0-626 cfu/100 ml). TTC contamination was found to have a significant and positive correlation with annual average rainfall (ρ = 0.2, p = 0.00003). Across all three countries, WHO health based chemical drinking water quality values were exceeded at 9% of sites and were found for manganese (4%), fluoride (2.6%) and nitrate (2.5%); arsenic concentrations were below the guideline value of 10 µg l −1 (range < 0.5-7 µg l −1 ). The high percentage of Mn exceedances (14% ± 5.2% >400 µg l −1 ) found in drinking water sources in Uganda challenges the decision by WHO not to formalise a health-based guideline for Mn. While the overall level of microbiological contamination from HPBs is low, results from this study strongly suggest that at a national and regional level, microbiological contamination rather than chemical contamination will provide a greater barrier to achieving targets set for improved drinking water quality under the UN-SDG 6. Efforts should be made to ensure that boreholes are properly sited and constructed effectively to reduce pathogen contamination.

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“…3 Fluorosis is an incurable disease and it is now regarded as a global health problem with countries such as India, China, Mexico, Pakistan, Ethiopia and Egypt largely affected. 4,5 Defluoridation is the viable option for areas that have groundwater containing fluoride concentration greater than World Health Organization standard of 1.5 mg L -1 . 3 Several authors have identified adsorption as suitable method for defluoridation in rural areas because it uses materials that are available at little or no cost and it is easy to operate.…”

Section: Introductionmentioning

confidence: 99%