scholarly journals Use of CaO Loaded Mesoporous Alumina for Defluoridation of Potable Groundwater Containing Elevated Calcium Levels

Environments ◽  
2019 ◽  
Vol 6 (6) ◽  
pp. 66
Author(s):  
Mahesh Jayaweera ◽  
Madhusha Sudasinghe ◽  
Buddhika Gunawardana ◽  
Achini Peiris ◽  
Jagath Manatunge
Keyword(s):  
Potable Water ◽  
Fluoride Concentration ◽  
Langmuir Model ◽  
Mesoporous Alumina ◽  
Unknown Etiology ◽  
Order Model ◽  
Fluoride Adsorption ◽  
High Calcium ◽  
High Fluoride ◽  
Strong Covalent Bonding

Defluoridation in the presence of high calcium levels in potable groundwater is paramount, as the consumption of groundwater enriched with fluoride, and calcium has been implicated in causing chronic kidney disease of unknown etiology (CKDu) in Sri Lanka. CaO loaded mesoporous alumina (COMA) offers a great potential for defluoridation of potable water, but the effectiveness of COMA in the presence of calcium has not been investigated. This study, therefore, focuses on the investigation of the suitability of COMA for the defluoridation of potable water with high calcium levels. Mesoporous alumina was successfully functionalized with CaO to synthesize nano-level COMA with an optimum dosage for defluoridation being 2 g L−1. The amount of fluoride adsorbed increased (2.4–19.5 mg g−1) with the increase of the initial fluoride concentration (5–40 mg L−1), and the residual fluoride levels (0.8–1.47 mg L−1) were within the range specified by the WHO for drinking water. The amount of fluoride adsorbed by COMA varied between 6.50 and 7.97 mg g−1 with initial calcium levels between 0 and 1500 mg L−1, indicating that defluoridation was effective in the presence of high calcium levels. The fluoride adsorption was best fitted with the Langmuir model with a maximum monolayer capacity of COMA being 17.83 mg g−1, and adsorption kinetics fitted with the pseudo-2nd order model indicating strong covalent bonding by way of chemisorption. Thus, COMA can be effectively utilized as an adsorbent material in defluoridation efforts in areas prevalent with CKDu in the presence of high fluoride (15 mg L−1) and calcium (1500 mg L−1) levels.

scholarly journals The Extremely High Adsorption Capacity of Fluoride by Chicken Bone Char (CBC) in Defluoridation of Drinking Water in Relation to Its Finer Particle Size for Better Human Health

Healthcare ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 123 ◽  
Author(s):  
H. Herath ◽  
Tomonori Kawakami ◽  
Masamoto Tafu
Keyword(s):  
Drinking Water ◽  
Adsorption Capacity ◽  
Fluoride Concentration ◽  
Contaminated Water ◽  
Bone Char ◽  
Health Issues ◽  
High Adsorption ◽  
Fluoride Adsorption ◽  
Chicken Bone ◽  
High Fluoride

The ingestion of fluoride-contaminated water causes serious health issues in people all over the world. In the current study, the adsorption of fluoride onto chicken bone char (CBC) was investigated as a defluoridation technique. Finer-sized CBC with a diameter of 106–212 µm was used to investigate the fluoride adsorption capacity onto CBC. Results revealed that finer-sized CBC yielded an unusually high fluoride adsorption capacity of 11.2 mg/g at the equilibrium fluoride concentration of 10 mg/L. The study shows that CBC can be utilized in the defluoridation of drinking water and that finer-sized CBC enhances ion exchange to perform a higher adsorption capacity.

Synthesis, Characterization and Adsorption Studies of a Graphene Oxide/Polyacrylic Acid Nanocomposite Hydrogel

2021 ◽  
Vol 19 (9) ◽  
pp. 46-54
Author(s):  
Makarim A. Mahdi ◽  
Aymen A.R. Jawad ◽  
Aseel M. Aljeboree ◽  
Layth S. Jasim ◽  
Ayad F. Alkaim
Keyword(s):  
Industrial Effluents ◽  
Langmuir Model ◽  
Isotherm Models ◽  
Nanocomposite Hydrogel ◽  
Adsorption System ◽  
Order Model ◽  
Solution Ph ◽  
Freundlich Model ◽  
Dye Sorption ◽  
Pseudo Second Order

The AAc/GO nanocomposite hydrogel was successfully employed as a polymeric Nano sorbent of the removal efficiency of M G dye from the model. The complication of the mechanism of the adsorption system was completely exposed by examining how solution pH affects adsorption, Ionic strength isotherm models, kinetic models, and thermodynamics. The adsorption of the MG dye was greatly dependent on the solution pH. The Freundlich model has been demonstrated to be the most accurate in describing the MG dye sorption, whilst the Langmuir model was shown to be the least accurate. Additionally, these integrated mechanisms fit nicely within the framework of a pseudo-second-order model. Additionally, the contact time at equilibrium short (ten minutes) required to MG removes demonstrates the AAc/GO nanocomposite hydrogel can be considered an efficient and potentially useful adsorbent for MG removal from industrial effluents.

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.

Fluoride Concentration in Groundwater of Khapa Town, Saoner Tehsil, Nagpur District – A Case Study

Agropedology ◽  
2019 ◽  
Vol 29 (2) ◽  
Author(s):  
Ruchir Gupta ◽  
◽  
Rashmi Gupta ◽  
Keyword(s):  
Tamil Nadu ◽  
Andhra Pradesh ◽  
Fluoride Concentration ◽  
High Ambient Temperature ◽  
Irreversible Damage ◽  
Aquifer System ◽  
Nagpur District ◽  
High Fluoride ◽  
High Level

Fluoride is known to contaminate groundwater in many countries notably India, Sri Lanka, China, rift valley countries in East Africa, Turkey and parts of South Africa. Sporadic incidence of high fluoride content in groundwater has been reported in 19 states and union territories across the country (CGWB 2010; Pol 2012). The fluoride occurrences in top aquifer system are endemic in many parts of Andhra Pradesh, Tamil Nadu, Karnataka, Gujarat, Rajasthan, Punjab, Haryana, Bihar and Kerala (Agarwal et al. 1997; Latha et al. (1999); Gopalakrishnan et al. (2012). The toxicity of fluoride is generally influenced by high ambient temperature, alkalinity, calcium and magnesium contents in drinking water (BIS 1991). High level of fluoride posses serious health hazards to humans and irreversible damage to plants. The present study was carried out to assess the fluoride concentration of groundwater in the selected villages around Khapa town of Nagpur district.

Fluorosis Mitigation Programmes and its Impact on Health - The Indian Scenario

2021 ◽  
Vol 13 (2) ◽  
pp. 48-55
Author(s):  
Mukherjee Avisek ◽  
R Yashoda ◽  
Puranik Manjunath
Keyword(s):  
Indian Population ◽  
Potable Water ◽  
Effective Solution ◽  
Governmental Agencies ◽  
Rural Settings ◽  
High Fluoride ◽  
Alternative Water ◽  
Defluoridation Of Water ◽  
Alternative Water Sources ◽  
Indian Scenario

In India, the availability of safe potable water remains a challenge in rural settings, where 72% of Indian population reside with high reliance on alternative water sources. In our country, the states having some circumscribed areas of high fluoride levels (endemic fluoride belts with F content in ground water above 4 ppm). Fluorosis mitigation is therefore necessary. Thus, the objective of this narrative review is to discuss various fluorosis mitigation programmes in India.Medline was the primary database used in the literature search. Other databases were also searched for relevant publications. Since the late 1980s, government and non-governmental agencies launched efforts to control fluorosis. However, most of attempts were mainly on defluoridation of water, so it cannot be proposed as the only or most effective solution to mitigate fluorosis.

scholarly journals Development of an Experimental Dentifrice with Hydroxyapatite Nanoparticles and High Fluoride Concentration to Manage Root Dentin Demineralization

2020 ◽  
Vol Volume 15 ◽  
pp. 7469-7479
Author(s):  
Aila Maria Cipriano Leal ◽  
Marcus Vinícius Beserra dos Santos ◽  
Edson Cavalcanti da Silva Filho ◽  
André Luis Menezes Carvalho ◽  
Cinthia Pereira Machado Tabchoury ◽  
...  
Keyword(s):  
Fluoride Concentration ◽  
Hydroxyapatite Nanoparticles ◽  
High Fluoride Concentration ◽  
High Fluoride ◽  
Root Dentin

scholarly journals Fluoride ion adsorption from wastewater using magnesium(II), aluminum(III) and titanium(IV) modified natural zeolite: kinetics, thermodynamics, and mechanistic aspects of adsorption

2017 ◽  
Vol 8 (4) ◽  
pp. 479-489 ◽  
Author(s):  
Zhijun Ma ◽  
Qi Zhang ◽  
Xingyuan Weng ◽  
Changye Mang ◽  
Liwei Si ◽  
...  
Keyword(s):  
Natural Zeolite ◽  
Adsorption Process ◽  
Fluoride Ion ◽  
Ion Adsorption ◽  
Order Model ◽  
Fluoride Ions ◽  
Modified Zeolite ◽  
Fluoride Adsorption ◽  
Pseudo Second Order ◽  
Modified Zeolites

Abstract Natural zeolite was modified using metal ions, including magnesium(II), aluminum(III) and titanium(IV). The modified zeolite was then used as an adsorbent for the investigation of the adsorption kinetics, isotherms, and thermodynamic parameters of fluoride ions in wastewater at various pHs and temperatures. The kinetics and thermodynamics for the removal of the fluoride ions onto the modified zeolite have also been investigated. The fluoride ion adsorption capacity of the three types of modified zeolites exhibited an increase, then decrease, with rising pH. The fluoride adsorption capacity of the modified zeolites decreased with an increase in temperature. The pseudo-second-order model is more suitable for describing the adsorption kinetic data than the pseudo-first-order model for modified zeolite and the adsorption process of the fluoride ions reveals pseudo-second-order kinetic behavior, respectively. It was found that the adsorption equilibrium data fit the Freundlich isothermal equation better than that of the Langmuir isothermal and Dubinin–Radushkevich (D–R) isothermal equations. Thermodynamic analysis suggests that the negative values of ΔG0 and ΔH0 further indicate that the fluoride adsorption process is both spontaneous and exothermic. The results of competitive adsorption tests suggest that the modified metal zeolite materials adsorb fluoride ions with high selectivity.

scholarly journals Biomarkers for the Assessment of Fluoride Exposure in Children

2020 ◽  
Vol 54 (2) ◽  
pp. 134-143
Author(s):  
Oladipo S. Idowu ◽  
Ralph M. Duckworth ◽  
Ruth A. Valentine ◽  
Fatemeh Vida Zohoori
Keyword(s):  
Significant Positive Correlation ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
Strong Correlations ◽  
Positive Correlation ◽  
Validated Questionnaires ◽  
Fluoride Exposure ◽  
Fluoride Intake ◽  
Whole Saliva ◽  
High Fluoride

Due to practical difficulties in quantifying fluoride exposure, the ability of various biomarkers to predict exposure has been investigated previously. However, the results are inadequate for validation of their application and usefulness. This study aimed to investigate the association between contemporary/recent biomarkers of fluoride exposure and total daily fluoride intake (TDFI) of children with large differences in fluoride exposure through drinking water. TDFI was assessed in 61 healthy 4- to 5-year-old children who provided at least 1 biomarker sample; 32 lived in a low-fluoride area (0.04 mg F/L) and 29 lived in a high-fluoride area (3.05 mg F/L). Validated questionnaires were administered to evaluate fluoride intake from diets (including water) and toothpaste ingestion. Daily urinary fluoride excretion (UFE) and fluoride concentrations in plasma, fasting whole saliva, hair, and nails (toenails/fingernails) were evaluated and related to total fluoride exposure. TDFI, UFE, and fluoride concentrations of biomarkers were statistically significantly higher in the high-fluoride area than in the low-fluoride area. There was a strong statistically significant positive correlation between TDFI and UFE (ρ = 0.756, p < 0.001); plasma fluoride concentration (ρ = 0.770, p < 0.001); and toenail fluoride concentration (ρ = 0.604, p < 0.001). The statistically significant positive correlation between TDFI and fingernail fluoride concentration (ρ = 470, p < 0.001) as well as between TDFI and fasting whole saliva fluoride concentration (ρ = 0.453, p = 0.001) was moderate, whereas it was weak between TDFI and hair fluoride concentration (ρ = 0.306, p = 0.027). In conclusion, the current study confirmed the suitability of 24-h urine samples for estimating fluoride exposure in children. The strong correlations between TDFI and fluoride in plasma and toenails also suggest these biomarkers may be considered for health risk assessments of fluoride in children who are susceptible to development of dental fluorosis.

Sign in / Sign up

Export Citation Format

Share Document