scholarly journals Remediation of Fluoride Laden Water by Complexation with Triethylamine Modified Maize Tassels

2016 ◽  
Vol 6 (1) ◽  
pp. 44
Author(s):  
Charles Kamathi Mwangi ◽  
Isaac W. Mwangi ◽  
Ruth N. Wanjau ◽  
Sauda Swaleh ◽  
Manohar Ram ◽  
...  
Keyword(s):  
Water Samples ◽  
Agricultural Waste ◽  
Fluoride Concentration ◽  
Water Remediation ◽  
Fluoride Removal ◽  
Fluoride Ions ◽  
Freundlich Isotherms ◽  
Real Water Samples ◽  
Model Solutions ◽  
Point Of Use

<p class="1Body">Several methods for the removal of fluorides in water have been proposed, most of which rely on the use of biomaterials and bone char. In such processes, the adsorbent become loaded with the pre-concentrated pollutant leading to a disposal problem. This study reports on the modification of the maize tassels with triethylamine followed by its subsequent application on the removal of fluoride ions from water. The theory underlying the removal method is based on the interaction of the permanently charged quaternized material with the highly electronegative fluoride ion. This is a regeneratable, affordable, eco-friendly, solution to the problem of secondary pollution and sustainable water remediation method of this toxic water pollutant. The resulting biomaterial derived from agricultural waste was used in the removal experiments on both model solutions and real water samples. The effect of pH, contact time, initial fluoride concentration and biomaterial resin dosage were investigated. It was observed that the amount complexed fluoride ions per unit mass of biomaterial increased with increase in concentration up to a point of saturation. The optimum removal pH was found to be 4.0. The biomaterial was very effective in fluoride removal as 86% of the fluoride was removed within the first 20 min. However, the uptake of fluoride ions in real water samples was found to be slightly lower compared to the model solutions. The experimental data was analysed using Langmuir and Freundlich isotherms. It fitted best in the Langmuir isotherm implying a chemisorption process. The adsorption capacity was found to be 0.19 mg/g and it was also observed that the sorbent when packed in a SPE column could be regenerated by stripping the attached fluoride ions with a dilute hydrochloric acid solution. These findings show that the modified material is suitable for application in the removal of fluorides in water at a point of use. This is intended to offer a solution to the drinking water for the children born by the population living in areas that are naturally fluoridated. Such parents are mean with their smile due to the problem of their permanently brown stained teeth.</p>

scholarly journals Biosorption of Fluoride from Synthetic and Ground Water Using Chlorella vulgaris Immobilized in Calcium Alginate Beads in an Upflow Packed Bed Column

2017 ◽  
Vol 61 (3) ◽  
pp. 188 ◽  
Author(s):  
Poornima G. Hiremath ◽  
Thomas Theodore
Keyword(s):  
Experimental Data ◽  
Ground Water ◽  
Chlorella Vulgaris ◽  
Water Samples ◽  
Packed Column ◽  
Fluoride Concentration ◽  
Fixed Bed ◽  
Fluoride Removal ◽  
Fluoride Ions ◽  
Fluoride Adsorption

The potential of immobilized Chlorella vulgaris to remove fluoride from synthetic and real ground water samples in a fixed bed was investigated. The effect of important kinetic parameters including column bed height, feed flow rate and influent fluoride concentration of solution on fluoride removal was studied. Thomas, Yoon-Nelson, and BDST models were used to analyze the experimental data and understand the influence on biosorption performance. The models’ predictions were in good agreement with the experimental data for all the process parameters studied, indicating that the models were suitable for fixed-bed column design. Fluoride adsorption was reversible. Desorption of fluoride ions was accomplished by pumping 0.1 N HCl solution. The reusability of adsorbent was studied by subjecting column to repeated cycles of fluoride adsorption and desorption. The suitability of immobilized C. vulgaris adsorbent for fluoride removal from ground water samples of Pavagada taluk, Tumakuru district was studied in the packed column.

scholarly journals Fluoride Variations in Rivers on the Slopes of Mount Meru in Tanzania

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Aldo J. Kitalika ◽  
Revocatus L. Machunda ◽  
Hans C. Komakech ◽  
Karoli N. Njau
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Laboratory Experiments ◽  
Fluoride Concentration ◽  
Ion Selective Electrode ◽  
World Health ◽  
Wet Season ◽  
Selective Electrode ◽  
Fluoride Ions ◽  
The World

This study reports the variations of fluoride ions in rivers on the slopes of Mount Meru in the northern part of Tanzania. More than 318 water samples were collected from Temi, Nduruma, Tengeru, and Maji ya Chai Rivers in both wet (mid-March and April) and dry (August) seasons. The samples were analyzed for fluoride levels using Ion Selective Electrode (ISE). The minimum and maximum average fluoride levels in the wet season were 0.24±0.03 mg/l and 65.20±0.03 mg/l, respectively, whereas the average lowest and highest levels in the dry season were 1.02±0.02 mg/l and 69.01±0.03 mg/l, respectively. Tengeru River had the lowest fluoride levels in both seasons, whereas Maji ya Chai recorded the highest fluoride levels in both seasons. The headwater of all rivers with the exception of Maji ya Chai met the World Health Organization’s (WHO) maximum acceptable fluoride levels of 1.50 mg/l and the downstream environment qualified for Tanzania Bureau of Standards (TBS) maximum permissible fluoride concentration in drinking water of 4.00 mg/l. Also, the laboratory experiments showed that fluoride containing rocks exposed to pH above 7.6 display high leaching of F− in solution which gradually increased with the increase in pH, indicating that dissolution of fluoride in water is a function of pH.

Adsorption of fluoride from aqueous solution by enhanced chitosan/bentonite composite

2013 ◽  
Vol 68 (9) ◽  
pp. 2074-2081 ◽  
Author(s):  
Qian Liu ◽  
Ruihua Huang ◽  
Bingchao Yang ◽  
Yanping Liu
Keyword(s):  
Aqueous Solution ◽  
Ph Value ◽  
Fluoride Concentration ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Fluoride Removal ◽  
Fluoride Ions ◽  
Adsorbent Dosage ◽  
Batch System ◽  
Monolayer Adsorption

In this work, enhanced chitosan/bentonite composite was prepared by treating chitosan/bentonite composite with concentrated hydrochloric acid (HCl). The adsorption of fluoride ions from aqueous solution onto the enhanced chitosan/bentonite composite was investigated. Adsorption studies were performed in a batch system, and the effects of various parameters, such as the pH value of the solution, adsorbent dosage and initial fluoride concentration, were evaluated. The optimum operating conditions for fluoride removal by the enhanced chitosan/bentonite composite were pH = 7 or so, and adsorbent dosage =1.2 g. Increasing initial fluoride concentration reduced the adsorption of fluoride onto the enhanced chitosan/bentonite composite. Furthermore, the presence of other co-anions weakened the adsorption of fluoride onto this adsorbent. The equilibrium adsorption isotherms were well described by both the Freundlich and Langmuir models. The maximum monolayer adsorption capacity was 2.95 mg/g at 293 K.

scholarly journals Adsorption Efficiency of Cement Impregnated Magnesium Oxide on the Removal of Fluoride

2020 ◽  
Vol 5 (2) ◽  
pp. 109-117
Author(s):  
Iohborlang M. Umlong ◽  
Bodhaditya Das ◽  
Rashmi Rekha Devi
Keyword(s):  
Drinking Water ◽  
Magnesium Oxide ◽  
Fluoride Concentration ◽  
Sorption Process ◽  
Fluoride Removal ◽  
Cement Slurry ◽  
Freundlich Isotherms ◽  
Removal Capacity ◽  
Complex Process ◽  
Pseudo Second Order

Presence of fluoride in drinking water above the prescribed limit may lead to a severe health complication. We present in this paper the fluoride removal capacity of cement impregnated MgO (MgO-cement) from drinking water. MgO-cement was prepared by adding magnesium oxide (MgO) into the cement slurry solution in the ratio of 1:10. Batch experiments were performed as a function of adsorbent dose, contact time, effect of pH and effect of co-ions. The percentage removal decreases with increasing initial fluoride concentration. Co-ions effect revealed that hydroxide ion was found to interfere more with fluoride removal followed by bicarbonate and least effect with sulphate. Reaction mechanism follows Freundlich isotherms. From the kinetic study we observed that uptake of fluoride ion is fast in the first sixty minutes and equilibrium time found to be independent of the initial fluoride concentration. Adsorption kinetics followed the pseudo second order model showing that the sorption of fluoride is a complex process. Surface as well as intraparticle diffusion contribute in the sorption process. No leaching of magnesium in the treated water was detected.

scholarly journals A novel fluorescent off–on probe for the sensitive and selective detection of fluoride ions

RSC Advances ◽  
2019 ◽  
Vol 9 (55) ◽  
pp. 32308-32312 ◽  
Author(s):  
Lihong Li ◽  
Min Zhang ◽  
Kaijing Chang ◽  
Yu Kang ◽  
Guodong Ren ◽  
...  
Keyword(s):  
Water Samples ◽  
Fluoride Ion ◽  
Selective Detection ◽  
Ion Detection ◽  
Fluoride Ions ◽  
Real Water Samples

A sensitive and selective fluorescent off–on probe is developed for fluoride ion detection, and its applicability has been demonstrated by determining fluoride ions in real-water samples and toothpaste samples.

scholarly journals Zn–Al Layered Double Hydroxides Synthesized on Aluminum Foams for Fluoride Removal from Water

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2109
Author(s):  
Yuliu Li ◽  
Riccardo Narducci ◽  
Alessandra Varone ◽  
Saulius Kaciulis ◽  
Eleonora Bolli ◽  
...  
Keyword(s):  
Layered Double Hydroxides ◽  
Fluoride Concentration ◽  
Threshold Value ◽  
Absorption Efficiency ◽  
Polluted Water ◽  
Fluoride Removal ◽  
Synthesis Methods ◽  
Aluminum Foams ◽  
Fluoride Ions ◽  
Double Hydroxides

Fluoride excess in water represents an environmental issue and a risk for human health since it can cause several diseases, such as fluorosis, osteoporosis, and damage of the nervous system. Layered double hydroxides (LDHs) can be exploited to remove this contaminant from water by taking advantage of their high ion-exchange capability. LDHs are generally mixed with polluted water in the form of powders, which then cause the problem of uneasy separation of the contaminated LDH sludge from the purified liquid. In this work, Zn–Al LDH films were directly grown in situ on aluminum foams that acted both as the reactant and substrate. This method enabled the removal of fluoride ions by simple immersion, with ensuing withdrawal of the foam from the de-contaminated water. Different LDH synthesis methods and aluminum foam types were investigated to improve the adsorption process. The contact time, initial fluoride concentration, adsorbent dosage, and pH were studied as the parameters that affect the fluoride adsorption capacity and efficiency. The highest absorption efficiency of approximately 70% was obtained by using two separate growth methods after four hours, and it effectively reduced the fluoride concentration from 3 mg/L to 1.1 mg/L, which is below the threshold value set by WHO for drinking water.

Development and Comparative Analysis of Aluminosilicate Based Ceramic Filters for Ground Water Defluoridation

2014 ◽  
Vol 936 ◽  
pp. 822-828 ◽  
Author(s):  
Johnson Kwame Efavi ◽  
Abu Yaya ◽  
Solomon Adeborna ◽  
Julius Fobil
Keyword(s):  
Ground Water ◽  
Contact Time ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
Fluoride Removal ◽  
Fluoride Ions ◽  
Ceramic Filters ◽  
Low Levels ◽  
Filter Thickness ◽  
Time Required

Low levels of fluoride in drinking water is healthy for the teeth enamel, however, higher concentrations result in dental fluorosis with prolonged exposures leading to skeletal fluorosis. Fluoride removal capacities of ceramic filters using aluminosilicates (Anfoega clay, Kibi kaolin, Laterite soil and Termitaria earth) samples from Ghana Geological Survey Department have been investigated and analysed for possible application in the Bongo District of Ghana noted forhavinghigh fluoride concentration in its ground water. Batch sorption studies conducted revealed that the amount of fluoride ions removed increased proportionally with increasing filter thickness, temperature and contact time to an optimum value. Using particle size ranges of <355μm and 1cm filter thickness at room temperature, the percentage of fluoride removed by the samples reached an optimum value after 70mins. Increases in filter thickness, contact time or temperatureincreased the amount of fluoride ions removedand the time required to reach the optimum value reduced significantly.

scholarly journals Diarrhea prevalence in a randomized, controlled prospective trial of point-of-use water filters in homes and schools in the Dominican Republic

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Nathan Tintle ◽  
Kristin Van De Griend ◽  
Rachel Ulrich ◽  
Randall D. Wade ◽  
Tena M. Baar ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Samples ◽  
Controlled Trial ◽  
World Health ◽  
Dissolved Metals ◽  
Randomized Controlled ◽  
Point Of Use ◽  
Diarrhea Prevalence ◽  
Clean Drinking Water ◽  
Post Filter

Abstract Background Lack of sustainable access to clean drinking water continues to be an issue of paramount global importance, leading to millions of preventable deaths annually. Best practices for providing sustainable access to clean drinking water, however, remain unclear. Widespread installation of low-cost, in-home, point of use water filtration systems is a promising strategy. Methods We conducted a prospective, randomized, controlled trial whereby 16 villages were selected and randomly assigned to one of four treatment arms based on the installation location of Sawyer® PointONE™ filters (filter in both home and school; filter in home only; filter in school only; control group). Water samples and self-reported information on diarrhea were collected at multiple times throughout the study. Results Self-reported household prevalence of diarrhea decreased from 25.6 to 9.76% from installation to follow-up (at least 7 days, and up to 200 days post-filter installation). These declines were also observed in diarrhea with economic or educational consequences (diarrhea which led to medical treatment and/or missing school or work) with baseline prevalence of 9.64% declining to 1.57%. Decreases in diarrhea prevalence were observed across age groups. There was no evidence of a loss of efficacy of filters up to 200 days post-filter installation. Installation of filters in schools was not associated with decreases in diarrhea prevalence in school-aged children or family members. Unfiltered water samples both at schools and homes contained potential waterborne bacterial pathogens, dissolved heavy metals and metals associated with particulates. All dissolved metals were detected at levels below World Health Organization action guidelines. Conclusions This controlled trial provides strong evidence of the effectiveness of point-of-use, hollow fiber membrane filters at reducing diarrhea from bacterial sources up to 200 days post-installation when installed in homes. No statistically significant reduction in diarrhea was found when filters were installed in schools. Further research is needed in order to explore filter efficacy and utilization after 200 days post-installation. Trial registration ClinicalTrials.gov, NCT03972618. Registered 3 June 2019—retrospectively registered.

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