Fluoride removal from drinking water in Senegal: laboratory and pilot experimentation on bone char-based treatment

2011 ◽  
Vol 1 (4) ◽  
pp. 213-223 ◽  
Author(s):  
Sabrina Sorlini ◽  
Daniela Palazzini ◽  
Carlo Collivignarelli
Keyword(s):  
Drinking Water ◽  
Dental Fluorosis ◽  
Low Cost ◽  
Fluoride Concentration ◽  
Pilot Scale ◽  
Appropriate Technology ◽  
World Health ◽  
Fluoride Removal ◽  
Process Conditions ◽  
Bone Char

In Senegal there are four regions where fluoride concentration in drinking water exceeds the World Health Organization guide value of 1.5 mg/L. This generates permanent damages to the teeth (dental fluorosis) and to the skeleton (skeletal fluorosis). A safe, efficient, simple and low-cost effective defluoridation technique is not available yet and needs to be developed in order to prevent the occurrence of fluorosis. This experimental research was carried out in order to define an appropriate technology for fluoride removal from groundwater in Senegal. Batch tests and filtration tests at laboratory and pilot scale were carried out using animal bone char as adsorbent material for fluoride removal. Possible influencing parameters, such as specific ions in Senegalese drinking water, were investigated and the best process conditions were defined for the application in Senegal. The results attest to the efficacy of bone char in removing fluoride from Senegalese water: at pilot scale the mean specific adsorption was 2.7 mg F−/g of bone char, corresponding to a total treated volume of 4,000 L and a filter life of nearly three months.

scholarly journals Characterisation of smectite-rich clay soil: Implication for groundwater defluoridation

2016 ◽  
Vol Volume 112 (Number 11/12) ◽  
Author(s):  
Rabelani Mudzielwana ◽  
Mugera W. Gitari ◽  
Titus A.M. Msagati ◽  
◽  
◽  
...  
Keyword(s):  
South Africa ◽  
Rural Areas ◽  
Contact Time ◽  
Clay Soil ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
Limpopo Province ◽  
World Health ◽  
Fluoride Removal ◽  
X Ray

Abstract Groundwater is a widely used and affordable source of drinking water in most of the rural areas of South Africa. Several studies have indicated that groundwater in some boreholes in South Africa has a fluoride concentration above the level recommended by the World Health Organization (1.5 mg/L). Fluoride concentrations above the permissible limit (>1.5 mg/L) lead to dental fluorosis, with even higher concentrations leading to skeletal fluorosis. In the present work, we evaluate the application of smectite-rich clay soil from Mukondeni (Limpopo Province, South Africa) in defluoridation of groundwater. The clay soil was characterised by mineralogy using X-ray diffraction, by elemental composition using X-ray fluorescence and by morphology using scanning electron microscopy. Surface area and pore volume was determined by the Brunauer–Emmett–Teller surface analysis method. Cation exchange capacity and pHpzc of the soil were also evaluated using standard laboratory methods. Batch experiments were conducted to evaluate and optimise various operational parameters such as contact time, adsorbent dose, pH and initial adsorbate concentration. It was observed that 0.8 g/100 mL of smectite-rich clay soil removed up to 92% of fluoride from the initial concentration of 3 mg/L at a pH of 2 with a contact time of 30 min. The experimental data fitted well to a Langmuir adsorption isotherm and followed pseudo second order reaction kinetics. Smectite-rich clay soil showed 52% fluoride removal from field groundwater with an initial fluoride concentration of 5.4 mg/L at an initial pH of 2 and 44% removal at a natural pH of 7.8. Therefore smectite-rich clay soil from Mukondeni has potential for application in defluoridation of groundwater. Chemical modification is recommended to improve the defluoridation capacity.

Fabrication of metal oxide - biopolymer nanocomposite for water defluoridation

MRS Advances ◽  
2018 ◽  
Vol 3 (36) ◽  
pp. 2109-2118
Author(s):  
Erick Mobegi ◽  
Mildred Nawiri ◽  
Dickson Andala
Keyword(s):  
Drinking Water ◽  
Low Cost ◽  
Fluoride Concentration ◽  
Underground Water ◽  
World Health ◽  
Maximum Adsorption Capacity ◽  
Sorption Behaviour ◽  
Water Ph ◽  
Defluoridation Of Water ◽  
Health Organization

ABSTRACTFluoride levels in drinking water exceeding 1.5 mg/L especially underground water can be detrimental to health. Various defluoridation technologies exist such as reverse osmosis, adsorption and ion exchange. However, adsorption has been preferred over the other due to its low cost and ease of operation. In this study, a novel adsorbent nanomaterial was prepared to remove fluoride from drinking water. The influence of different parameters such as pH, contact time, co-existing ions and dosage were investigated in order to understand the sorption behaviour of the adsorbent under varying conditions. The adsorption process best fitted with the Langmuir model with a maximum adsorption capacity of 62.5 mg/g. The adsorbent can be used under normal water pH=7. Anions and cations had no influence on the sorption capacity except for chlorides, carbonates and bicarbonates. The adsorbent reduced fluoride concentration from 10 ppm to approximately 1.5 ppm per 50 mg nanocomposite loading as recommended by World Health Organization. The synthesized nanocomposite can be used for defluoridation of water with high fluoride concentrations beyond recommended limit.

scholarly journals RELATIONSHIP BETWEEN FLUORIDE CONTENTS IN GROUNDWATER AND PREVALENCE OF FLUOROSIS IN TAY SON DISTRICT, BINH DINH PROVINCE, VIETNAM

2018 ◽  
Vol 54 (4B) ◽  
pp. 240
Author(s):  
Phan Nhu Nguyet
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
World Health ◽  
Well Water ◽  
Drinking Water Standard ◽  
Limit Value ◽  
The Government ◽  
Health Organization

The communities within Binh Dinh province in the Central Vietnam are reliant on groundwater as their primary supply of domestic and potable water. Meanwhile, it is seriously contaminated with fluoride that causing fluorosis problem for people. This study aims to investigate the link between severity of dental fluorosis rate in a population and fluoride concentration in drinking water in Tay Son area. A total of 50 well-water samples were collected and 220 people were surveyed by questionnaire from 50 households at 3 villages: Tay Phu, Binh Tuong, Tay Giang of Tay Son district, Binh Dinh province, Vietnam. The quantitative assessment of severity of dental fluorosis was done by calculating the Community Fluorosis Index (CFI) using Dean’s classification. Result of this study showed that fluoride concentration in well-water varied from 0.31 mg/L to 7.69 mg/L (mean 2.66 mg/L, SD: 2.18 mg/L) with 70 % of well-water samples above the maximum permissible limit of 1.5 mg/L of World Health Organization (WHO) drinking water standard. 100 % people surveyed was suffered from dental fluorosis and Dean scale of dental fluorosis ranged from level 2 to level 5. CFI varied from 3.45 to 4.13 above limit value (0.6). The community seriously suffered from dental fluorosis. The fluoride concentrations and Dean Index have high correlation (r = 0.580, p < 0.0001). Based upon results of this study, it is recommended that the government should supply drinking water with appropriate fluoride content for this community.

scholarly journals Development of a low cost household bone-char defluoridation filter

2020 ◽  
Vol 14 (5) ◽  
pp. 1921-1927
Author(s):  
Boris Merlain Djousse Kanouo ◽  
Mathias Fru Fonteh ◽  
Steve Pindjou Ngambo
Keyword(s):  
Drinking Water ◽  
Low Income ◽  
Low Cost ◽  
Appropriate Technology ◽  
Bone Char ◽  
Water Filter ◽  
Point Of Use ◽  
Dental And Skeletal Fluorosis ◽  
Northern Cameroon ◽  
Low Income Families

Regular intake of drinking water containing fluoride above permissible levels (>1.5 mgl-1) is responsible for dental and skeletal fluorosis. The objective of this study was to develop a low cost and efficient water defluoridation filter using local materials. The filter frame was made from Polyvinyl chloride pipe of 125 mm diameter and 1 m height, with a useful filtration volume of 9.55 l. The filtration layer consisted of a sequence of three strata: gravel, bone-char and sand, giving a total weight of 15 kg. Based on the concentration of fluoride in drinking water in parts of northern Cameroon, three different fluoride ion concentrations (10 mgl-1, 20 mgl-1 and 30 mgl-1) were prepared in the laboratory using distilled water and allowed to flow through the filter at the rate of 3.33 lh-1. High fluoride uptake capacity was observed (94.8% to 99.1%), depicting the suitability of the filter in defluoridation. The constructed filter costed about 17 US$. Based on these results, the filter can be recommended as an appropriate technology to mitigate fluoride health hazards problems in low income families. Although the estimated replacement frequency of biochar was three months, further research is required to optimize the point of use system performances.Keywords: Bone-char, water filter, fluoride.

scholarly journals Dental caries and its association with increasing water fluoride concentration in district Rudraprayag, Uttarakhand

2021 ◽  
Vol 8 (8) ◽  
pp. 4005
Author(s):  
Nidhi Sharma ◽  
Vartika Saxena ◽  
Manisha Naithani
Keyword(s):  
Drinking Water ◽  
Dental Caries ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
World Health ◽  
Therapeutic Window ◽  
Caries Experience ◽  
Fluoride Level ◽  
Cross Sectional ◽  
Water Fluoride

Background: Evidence from scientific literature confirms both beneficial and detrimental effects of fluoride on human health with only a narrow range between intakes associated with these effects. The limits of this range have been controversial among researchers since the 1930s. Considering this, the World Health Organization (WHO) permissible limit of fluoride in India has been reduced from 1.5 to 1.0 mg/l in 1998. This study aimed to evaluate the association between increasing water fluoride levels and dental caries prevention on permanent teeth.Methods: This cross-sectional study involved 1400 children (aged 6–19 years). Caries experience and dental fluorosis were recorded using DMFT/deft and Dean's index respectively. Also, fluoride concentration in drinking water was analyzed. Around 14.4% of children had dental caries with maximum frequency among 9-10 years of age. A significant negative correlation between caries experience and water fluoride level was found (p<0.05), with the lowest DMFT scores at the fluoride level of 0.61–2 mg/l and the highest at 0.0–0.3 mg/l. Whereas, high prevalence of dental fluorosis was observed above 0.7 mg/l.Results: The study revealed that the presence of 0.3-0.7 mg/l fluoride in drinking water reduces dental caries, without an objectionable rise in dental fluorosis.Conclusions: It can be suggested that fluoride has anticaries property but due to a ‘narrow therapeutic window’ of 0.3-0.7 mg/l, in a country like India where endemic fluorosis is prevalent, its topical application should be encouraged which is almost equally effective with less systemic adverse effects.

scholarly journals Drinking Water Fluoride Levels for a City in Northern Mexico (Durango) Determined Using a Direct Electrochemical Method and Their Potential Effects on Oral Health

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Nelly Molina Frechero ◽  
Leonor Sánchez Pérez ◽  
Enrique Castañeda Castaneira ◽  
Anastasio Oropeza Oropeza ◽  
Enrique Gaona ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
Mean Value ◽  
National Standard ◽  
Preventative Measures ◽  
The Government ◽  
The City

Fluoride is ingested primarily through consuming drinking water. When drinking water contains fluoride concentrations >0.7 parts per million (ppm), consuming such water can be toxic to the human body; this toxicity is called “fluorosis.” Therefore, it is critical to determine the fluoride concentrations in drinking water. The objective of this study was to determine the fluoride concentration in the drinking water of the city of Durango. The wells that supply the drinking water distribution system for the city of Durango were studied. One hundred eighty-nine (189) water samples were analyzed, and the fluoride concentration in each sample was quantified as established by the law NMX-AA-077-SCFI-2001. The fluoride concentrations in such samples varied between 2.22 and 7.23 ppm with a 4.313 ± 1.318 ppm mean concentration. The highest values were observed in the northern area of the city, with a 5.001 ± 2.669 ppm mean value. The samples produced values that exceeded the national standard for fluoride in drinking water. Chronic exposure to fluoride at such concentrations produces harmful health effects, the first sign of which is dental fluorosis. Therefore, it is essential that the government authorities implement water defluoridation programs and take preventative measures to reduce the ingestion of this toxic halogen.

scholarly journals Impact of pretreatment on defluoridation of drinking water by bone char adsorption

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Adam Teusner ◽  
Rhett Butler ◽  
Pierre Le Clech
Keyword(s):  
Drinking Water ◽  
Low Cost ◽  
Feed Solution ◽  
Hollow Fibre ◽  
Human Consumption ◽  
Bone Char ◽  
Subsequent Removal ◽  
Filter Performance ◽  
Point Of Use ◽  
Gravity Driven

Fluoride concentrations in drinking water in excess of 1.5 mg L-1 are unsafe for human consumption. To reduce excess fluoride intake, developing countries must use low-cost, point-of-use defluoridation techniques. Although previous work has extensively assessed defluoridation using bone char (BC), most of the advanced studies have been based on the use of fluoridated distilled water as a feed solution. In the present study, BC columns were challenged with a range of model solutions, mimicking various pretreatment options. As a result, the relative impact of dissolved organic carbon (DOC) and suspended solids (SS) on the performance of BC filters was assessed. In addition, the performance of a gravity-driven, hollow fibre ultrafiltration (UF) module was examined with regards to the potential for use as a pretreatment option. SS were observed to severely clog the columns and cause the complete cessation of flow. The subsequent removal of SS by UF improved the general filter performance as well as increasing the BC lifetime by 50 %. The UF module achieved a reduction in DOC of 34 ± 6 %, resulting in an additional 30 % increase in the lifetime of the BC column.

scholarly journals Evaluation of Physicochemical Characteristics in Drinking Water Sources Emphasized on Fluoride: A Case Study of Yancheng, China

2019 ◽  
Vol 16 (6) ◽  
pp. 1030 ◽  
Author(s):  
Yumin Wang ◽  
Ran Yu ◽  
Guangcan Zhu
Keyword(s):  
Cluster Analysis ◽  
Factor Analysis ◽  
Drinking Water ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
Water Sources ◽  
Total Alkalinity ◽  
Drinking Water Sources ◽  
Fluoride Exposure ◽  
Exposure Levels

In this study, the concentration of fluoride and the associated health risks for infants, children, and adults were analyzed and compared for three drinking water sources in Yancheng City, Jiangsu Province, China. To analyze the relationship between the water quality parameters of pH, fluoride (F−), sulfate (SO42−), chloride (Cl−), total dissolved solids (TDS), total alkalinity (TAlk), sodium (Na+), and potassium (K+), statistical analyses including correlation analysis, R-mode cluster analysis and factor analysis were performed based on monthly data from the year 2010 to 2015. The results indicated: (1) Fluoride concentrations in the drinking water sources ranged from 0.38 to 1.00 mg L−1 (mean = 0.57 mg L−1) following the order of Tongyu River > Yanlong Lake > Mangshe River; (2) fluoride concentrations in 22.93% of the collected samples were lower than 0.5 mg L−1, which has the risk of tooth cavities, especially for the Mangshe River; (3) the fluoride exposure levels of infants were higher than children and adults, and 3.2% of the fluoride exposure levels of infants were higher than the recommended toxicity reference value of 122 μg kg−1 d−1 as referenced by Health Canada, which might cause dental fluorosis issues; (4) the physico-chemical characteristics are classified the into four groups reflecting F−- TAlk, Na+-K+, SO42−-Cl−, and pH-TDS, respectively, indicating that fluoride solubility in drinking water is TAlk dependent, which is also verified by R-mode cluster analysis and factor analysis. The results obtained supply useful information for the health department in Yancheng City, encouraging them to pay more attention to fluoride concentration and TAlk in drinking water sources.

Adsorption of fluoride from aqueous solution using low cost adsorbent

2013 ◽  
Vol 13 (2) ◽  
pp. 238-248 ◽  
Author(s):  
R. Buamah ◽  
R. Asare Mensah ◽  
A. Salifu
Keyword(s):  
Drinking Water ◽  
Low Cost ◽  
Northern Ghana ◽  
Fluoride Removal ◽  
Order Kinetic ◽  
X Ray ◽  
Removal Capacity ◽  
Removal Technologies ◽  
High Aluminium ◽  
Model Water

High fluoride levels beyond the recommended value of 1.5 mg/L have been detected in several groundwater wells in Northern Ghana. This occurrence has led to the capping of many high yielding wells that hitherto have been major sources of drinking water for the populace in these arid areas. Most of the fluoride removal technologies applied in the area has not been versatile in effectively removing fluoride because of the varying water qualities. This study focused on screening adsorbents including high aluminium or iron containing bauxite ores, fabricated zeolite and activated Neem seeds for removal of fluoride from drinking water. The model water used was prepared by simulating the prevailing groundwater quality in Northern Ghana. The high aluminium bauxite ore (HABO) had the highest fluoride removal capacity. Within the pH range tested (5–7), the fluoride removal decreased with increasing pH. Occurrence of sulfate, chloride and nitrate in the model water reduced the fluoride removal capacity by 57, 24 and 38% respectively. The combined effect of these anions showed a 60% reduction in the fluoride removal capacity. The Freundlich and Langmuir isotherms gave an adsorption capacity (K) of 0.90 mg/g for the HABO. The adsorption kinetics fitted well the pseudo second-order kinetic model. The HABO is thermally stable and has kaolinite [Al2Si2O5(OH)5] and gibbsite [Al(OH)3] as its major components. X-ray fluorescence (XRF) and energy dispersive X-ray (EDX) results showed Al, Fe, Ti, O, C and Si as the predominant elements in the HABO.

scholarly journals Natural fluoride levels from public water supplies in Piauí State, Brazil

2009 ◽  
Vol 14 (6) ◽  
pp. 2215-2220 ◽  
Author(s):  
Josiene Saibrosa da Silva ◽  
Wallesk Gomes Moreno ◽  
Franklin Delano Soares Forte ◽  
Fábio Correia Sampaio
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Urban Areas ◽  
Urban Population ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
Public Water Supply ◽  
Water Supplies ◽  
Two Samples ◽  
High Prevalence

The aim of this work was to determine the natural fluoride concentrations in public water supplies in Piauí State, Brazil, in order to identify cities in risk for high prevalence of dental fluorosis. For each city, two samples of drinking water were collected in the urban area: one from the main public water supply and another from a public or residential tap from the same source. Fluoride analyses were carried out in duplicate using a specific ion electrode and TISAB II. From a total of 222 cities in Piauí, 164 (73.8%) samples were analyzed. Urban population in these towns corresponds to 92.5% of the whole state with an estimated population of 1,654,563 inhabitants from the total urban population (1,788,590 inhabitants). A total of 151 cities showed low fluoride levels (<0.30 mg/L) and 13 were just below optimum fluoride concentration in the drinking water (0.31-0.59 mg/L). High natural fluoride concentration above 0.81 mg/L was not observed in any of the surveyed cities. As a conclusion, most of the cities in Piauí have low fluoride concentration in the drinking water. The risk for a high prevalence of dental fluorosis in these urban areas due to natural fluoride in the water supplies is very unlikely. Thus, surveys about the dental fluorosis prevalence in Piauí should be related with data about the consumption of fluoridated dentifrices and other fluoride sources.

Sign in / Sign up

Export Citation Format

Share Document