Fluoride Concentration Research Articles

The association between fluoride concentrations and spontaneous humeral fracture in first-lactation dairy cows: results from two New Zealand studies

The association between fluoride concentrations and spontaneous humeral fracture in first-lactation dairy cows: results from two New Zealand studies

Seasonal Variation of Physicochemical Properties in the Lower River Benue, Nigeria

The study investigates the impact of seasonal changes on water quality in the River Benue, Nigeria. Conducted over eighteen months from January 2020 to June 2021, the research focuses on three locations: Ibi, Lau, and Mayo-Ranewo. Key physicochemical parameters such as temperature, pH, turbidity, conductivity, Biochemical Oxygen Demand (BOD), hardness, dissolved oxygen (DO), fluoride, and nitrate were measured to assess water quality. The findings reveal significant seasonal variations in these parameters, influenced by rainfall patterns, land use, and anthropogenic activities. Temperature ranged from 25.56°C to 30.70°C, remaining within acceptable limits for tropical waters, supporting stable biological processes. However, turbidity levels exceeded recommended values, indicating the presence of suspended solids that could impair water quality and harm aquatic life. Total dissolved solids (TDS) and conductivity showed potential contamination risks, likely due to agricultural runoff and urban discharges. Dissolved oxygen (DO) levels were generally adequate, especially during the wet season, enhancing oxygen content through increased photosynthetic activity and water inflows. However, BOD spiked with rainfall, signalling organic pollution and potential eutrophication risks. Seasonal shifts in pH and water hardness reflected changes in runoff and photosynthesis, with values largely within acceptable ranges for aquatic life. Fluoride and nitrate concentrations increased in the wet season, primarily due to agricultural runoff, highlighting the influence of land-based activities on water quality.

Comparative assessment of enamel surface remineralisation with three different dentifrices: An energy dispersion x-ray spectroscopy analysis

Comparative assessment of remineralisation of enamel surface when treated with three different dentifrices. Sixty-six extracted upper right first premolars were demineralized to form artificial white spot lesions. The samples were divided into 3 groups: Group 1-Biomin F, Group 2- Clinpro ToothCreme, Group 3- Amflor. They were treated with three different dentifrices (22/ group) for 14 days in simulated oral conditions. Energy dispersion X-Ray Spectroscopy was done pre and post remineralistaion. The primary evaluation parameter for this study was the Ca/P ratio. As per the results, the maximum increase in Ca/P ratio was seen in Group1, followed by Group 3 and 2 respectively. The results were found to be statistically significant. (p=0.045 i.e. p<0.05) The secondary evaluation parameter for this study was the change in Fluoride content. As per the results, the maximum increase in Fluoride content was seen in Group 2 which was followed by Group 3 which is equivalent to Group 1. However, the results were found to be statistically non-significant. (p=0.219 i.e. p>0.05) Biomin F has the highest remineralisation efficiency when compared to the other 2 dentifrices. Biomin F contains an optimum combination of fluoride (600 ppm), phosphate and calcium ions, incorporated within the structure of the glass itself. The glass gradually dissolves over up to 12 hours neutralizing acids in the mouth and deposit fluorapatite. Thus, it can be used in patients undergoing orthodontic treatment to prevent or reduce the formation of white spot lesions.

INFLUENCE OF FLUORIDE ON PUBLIC HEALTH AND WORKER’S HEALTH – LITERATURE REVIEW

Dental caries is a multifactorial disease that affects a large part of the world's population. Can be prevented by various means and methods, including the use of fluoridated mouthwashes, topical fluoride, fluoridated toothpaste and fluoridation of public water supplies for human consumption. Fluoride has been shown to be a therapeutic agent that modulates dental caries. Frequent contact between patients and small concentrations of fluoride hinders demineralization and activates remineralization, in addition to inhibiting cariogenic microorganisms. The oral health of workers is directly related to the health of the population, since they are part of this context and suffer from the same problems that occur in the environment in which they live. Since workers are the agents who convert work activity into profits for the employer, a detailed and complete vision addressing prevention is extremely important, as this is a way to reduce absenteeism and keep workers in their jobs, achieving better performance of their activities. This bibliographic review aims to analyze fluoride in its various forms and evaluate its anti-cariogenic power for workers, with the aim of preventing cavities and providing well-being, quality of life and greater productivity to them. Based on the data analyzed, it is concluded that fluoride is an effective and inexpensive measure to prevent the appearance of cavities and that due to the large size of Brazil and its socioeconomic difficulties, fluoridated toothpaste associated with assisted brushing, with topical fluoride applications, prove to be the best measures to prevent cavities and absenteeism, consequently improving public health indices. This is one of the most relevant public policies, which is in fact underestimated and which can change the reality of Brazil, reducing high government costs and promoting the quality of life of the population, which suffers from oral problems, which can affect the entire organism, causing a series of other ailments, which should be avoided by adopting preventive measures on a permanent basis.

Concentration and Stability of Fluoride Chemically Available in Charcoal-Containing Toothpastes.

Among the wide variety of commercially oral hygiene products, activated-charcoal-based toothpastes have irrupted the market, claiming multiple benefits. Although most are fluoride-free, others incorporate fluoride into their formulations, yet the chemical availability and stability of fluoride in these products remain unclear. Our study aimed to assess the chemical availability and stability of fluoride in commercially fluoridated toothpastes formulated with activated charcoal. We purchased duplicate samples with different lot numbers of different brands containing fluoride (F) and activated charcoal (n=20) in the US and Chile. Three toothpastes, one non-fluoridated, one containing sodium fluoride (NaF) and another with sodium monofluorophosphate (Na2FPO3), were used as controls. All toothpastes were evaluated at the time of purchase (fresh) and after their expiration date (aged). We determined total-F and available total soluble-F (TSF), using a F specific ion electrode. Values were expressed in mg F/kg (ppm F, w/w). Most evaluated toothpaste contained NaF (70%) or Na2FPO3 (30%) as the F salt, and all declared to contain silica. The TSF concentration ranged from 952.6 to 1438.1 and from 925.7 to 1493.7 ppm F for fresh and aged toothpaste, respectively. TSF remained close to total-F and in agreement with the F concentration reported by the manufacturer. After expiring, the commercial toothpastes did not form insoluble F, except the Na2FPO3/CaCO3-based control. The silica-based toothpastes formulated with activated charcoal present fluoride potentially bioavailable and chemically stable to control caries. However, concerns regarding abrasiveness, as raised by other researchers, cast doubt on the suitability of these toothpastes for widespread use.

Synthesis of bagasse-derived magnetic biochar for the removal of fluoride from water solution

ABSTRACT Fluoride levels in drinking water pose a significant environmental threat, and adsorption is a common technique. However, many adsorbent materials have drawbacks such as poor adsorption capabilities, extended contact times, high pH levels, and large dosages. A biochar-based magnetic composite adsorbent has been developed for water defluoridation using a chemical co-precipitation process to immobilize iron particles on the biochar surface. X-ray diffraction analysis, Fourier transformed infrared spectroscopy, Brunauer–Emmett–Teller, and scanning electron microscopy were used to analyse the composite. The central composite design was used to design laboratory tests, which included four input variables: solution pH, dosage, contact time, and initial concentration. The adsorbent dosage was 5.92 g/L, the aqueous pH was 5.79, the contact time was 66.48 min, and the initial fluoride concentration was 12.38 mg/L. The removal efficiency was predicted to be 98.61%, with a 98.55% removal efficiency at optimum conditions. The study concluded that the composite adsorbent can be a reliable and sustainable solution for fluoride removal from water.

Feed Monocalcium Phosphate Derived from Wet-process Phosphoric Acid and Calcium-based Raw Materials

In this study, granulated feed-grade monocalcium phosphate was produced using highly purified wet-process phosphoric acid (WPA) and finely milled limestone (99.5% CaCO3). The WPA was desulfated to 0.09–0.14% SO₃, defluorinated to 0.18–0.20% F, and concentrated to 50.55% P₂O₅. Under controlled conditions—achieving a 95% reaction rate and a 15-minute decomposition time—a high-quality product was obtained. The final composition included 50.45% digestible P₂O₅, 38.02% water-soluble P₂O₅, 21.14% total CaO, and 14.39% water-soluble CaO, with a fluoride content of 0.16%. The granules achieved 2.13 MPa in strength, with over 85% in the optimal 2-3 mm size range, meeting GOST 23999-80 standards. This phosphate supplement offers high bioavailability for livestock, poultry, and aquaculture.

Effect of Chronic Consumption of Fluoridated Water on Sciatic Nerve Conduction Velocity in Male Wistar Rats.

The long-term effect of fluoridated water consumption during development on the velocity of nerve impulse conduction in the sciatic nerve of rats was assessed. Thirty male Wistar rats, 21 days old, were randomly assigned to five groups. Three groups were given fluoridated water ad libitum (as the only source) at different concentrations (10, 100, and 150 ppm), designated as groups F10, F100, and F150, respectively. The study included a control group (C) that received fluoridated water at the maximum level established by the World Health Organization (1.5 ppm of fluorides) and another group that received deionized water (DW). The animals were treated until they reached 90 days of age. Electrophysiological recordings were performed on the rats' sciatic nerves to determine nerve conduction velocity, and blood plasma was extracted for fluoride concentration analysis. The study found that the F150 group had a lower nerve impulse conduction velocity in the sciatic nerve compared to the C group (P = 0.0015). Additionally, there was a negative correlation between the concentration of fluorides in plasma and the nerve conduction velocity (r = -0.5132, P = 0.0037). These findings indicate that chronic consumption of high concentrations of fluoride leads to a decrease in nerve conduction velocity. This, in conjunction with potential alterations in the central nervous system, may explain the deficits in learning and memory tests that have been documented in numerous studies evaluating individuals exposed to fluoride consumption. These results provide valuable information for understanding the effects and action mechanisms of fluoride in exposed individuals.

Defluoridation of Groundwater Using Low-cost Adsorbents

Excessive fluoride in groundwater poses significant health risks to millions of people worldwide, necessitating effective and accessible defluoridation methods. This study investigates the use of column filtration for removing fluoride from groundwater. The study employs a systematic approach to evaluate the performance of different adsorbent materials in a fixed-bed column setup. Various materials were tested as adsorbents in column, including Brick powder, Neem leaf powder, Lime, Sawdust, and Vetiver. The research examines the effects of key operational parameters such as bed depth, flow rate, and initial fluoride concentration on the overall removal efficiency. Experiments were conducted using groundwater to assess the method's effectiveness. Results indicated that column filtration can effectively reduce fluoride concentrations to below the World Health Organization's recommended limit of 1.5 mg/L. This report contributes to the development of efficient, cost-effective, and sustainable solutions for groundwater defluoridation. All adsorbents used were inexpensive materials, available easily in nature and locally at village or rural level. Some of the adsorbents were very effective in removal of fluoride ion and can be used as defluoridating agents but they impart color and turbidity to the groundwater. Among all the adsorbents used, Vetiver demonstrated higher removal efficiency of 78% followed up by limestone 77% removal but hindered by its precipitation. Sawdust and brick powder were also efficient up to a certain extent of 72% and 69% respectively in adsorbing fluoride ions. Neem leaves powder was found to be least effective in adsorbing showing about 50% removal efficiency.

The effect of water filter pitchers on the mineral concentration of tap water.

To investigate the effect of water filter pitchers on the concentration of different minerals in tap water. Nine water filter pitchers (A-I) were chosen based on consumer preferences and Amazon reviews. Each filter was tested for its ability to modify the concentrations of fluoride, calcium, magnesium, potassium, and sodium in tap water. Tap water samples were collected before and after filtration, at various intervals (1, 5, 10, 30, 50, 75, and 100 L) during filtration, and analyzed using an ion-specific electrode (fluoride) and atomic absorption spectrometry (other minerals). Statistical analyses were conducted to compare filtered and unfiltered water mineral concentrations. Water filter pitcher effect: Filters F (p < 0.001) and G (p = 0.030) decreased fluoride concentrations. All filters except I (p = 0.235) and H (p = 0.717) decreased calcium concentrations (p < 0.01). Filters E (p = 0.018), D (p = 0.014), and G (p = 0.010) decreased magnesium concentrations. Filters I (p = 0.028) and D (p = 0.009) increased potassium concentrations. Filter A (p = 0.002) increased sodium concentrations, while C (p = 0.034) decreased sodium concentrations. Effect of filter aging: All filters affected mineral concentrations over time but to varying extents. Filter G had the most pronounced effect on reducing mineral concentrations compared to all others. No filter was able to completely remove fluoride from tap water, contrary to the claims made by three manufacturers. The present study highlighted that water filter pitchers vary greatly in their ability to affect mineral concentrations in tap water during their use. Further research is needed to develop more effective water treatment solutions.

Study on dissociation mechanism and process of regenerated cryolite

Solid waste produced in the process of aluminum electrolysis is a substantial secondary source of fluorine, the fluoride electrolyte in aluminum electrolysis carbon slag accounts for about 75%. Regenerative cryolite, extracted from anode carbon residue through flotation or calcination, possesses a significant potential for fluorine recovery. The fluoride in regenerated cryolite is mainly insoluble, making its efficient dissociation crucial for utilizing the solid waste from aluminum electrolysis. This study uses regenerative cryolite and sodium carbonate to examine how roasting temperature, time, and the reagent-to-cryolite ratio (R/C) affect cryolite dissociation. Dissociation efficiency is measured using indices like baking loss, leaching loss, fluoride ion concentration in the leachate, and fluoride ion conversion rate. Optimal dissociation is achieved at 780-820°, 2.0-2.5 hours roasting time, and an R/C ratio of 1.0-1.2. Orthogonal experimental results highlight the predominant influence of R/C, with roasting temperature being the secondary factor and roasting time having the least impact. Notably, at 780°, 2.0 hours, and an R/C ratio of 1.2:1, the fluoride ion conversion rate reaches a peak of 94.23%. This allows for recycling and production of high-value fluoride products, benefiting both the environment and the economy.

Exposure and probable ingestion of fluoride through non-dietary edible items from Panipat (NCR), India.

The present study revealed that various non-dietary items like pan masala, chewing tobacco, betel nuts, and toothpaste may contribute to the fluoride burden of the human body. In this line, an attempt was made to analyze the fluoride content of non-dietary items collected from Panipat City of Haryana. The study depicts that intake of pan masala, chewing tobacco, betel nuts, and toothpaste expose the consumers to 21.0 to 56.80, 18.00 to 36.20, 7.45 to 77.40, and 21.10 to 1118.20µg fluoride/g respectively. The demand for these non-essential edible items is increasing daily, and people are unaware of the detrimental health effects of these products. The people of the study area are advised to prohibit these products as they contain an appreciable amount of fluoride.

Analysis of a survey of the adult population on oral hygiene products

Aim – to assess the use of oral hygiene products by consumers as a method of primary prevention of the development of dental diseases, as well as to study their motivation when choosing personal oral hygiene products. Materials and methods. The study was carried out using an individually developed and validated questionnaire. The questionnaire included 21 questions. Respondents were selected by random selection. Results. Established a low level of hygiene education of respondents (34% of respondents to the questionnaire visit a dentist twice a year or more, the main criterion for choosing toothpaste for 36% of respondents is the possibility of using the whole family, 53.5% of respondents do not matter the content of fluoride in the toothpaste, 89.1 do not use other sources of fluoride, less than 50% of those surveyed use additional means of oral hygiene. The results of the questionnaire showed that about 40% of respondents acquire oral hygiene products in a pharmacy and need professional consultations of specialists on the composition of toothpaste and its effectiveness, the right choice of toothbrush, which determines the area of knowledge, that a pharmaceutical worker should own. Conclusion. Have been identified the information needs on oral hygiene products. The need for training in proper oral care and orientation to timely treatment of the dentist for preventive purposes and at the first symptoms, as well as information on primary prevention measures to preserve the dental health of the population. It is important to raise public awareness of the role of fluoride in the prevention of the development of caries, as well as to use additional means of oral hygiene products and fluoride sources. One way to improve public hygiene awareness is for a pharmacist to provide competent advice to pharmacists and to increase the level of completeness in the use of oral hygiene products by the consumer.

Label-Free Electrochemical Sensor Sensitivity Enhancement Using Field Effect Transistors: Fluoride Ions for Fuel Cell Degradation Analysis

In the context of proton exchange membrane fuel cells, precise monitoring of fluoride ions in the effluent water is crucial. Associated with the fluoride ion accumulation, membrane degradation and reduction of fuel cell efficiency arise. This study focuses on developing extended gate field-effect transistors (EGFET) sensors for real-time monitoring of fluoride ion concentrations. High sensitivity and specificity in detecting the concentration of fluoride ions using both N-type (TN0702) and P-type (LP0701) metal-oxide-semiconductor field-effect transistors (MOSFET) were achieved. The transfer characteristics (Id vs Vgs) owere thoroughly examined across a range of fluoride concentrations from parts per million (ppm) to parts per billion (ppb). N-type MOSFET-based sensors showed a distinct decrease in drain current (Id) with increasing fluoride concentration. With fluoride concentrations changed, the P-type MOSFET exhibited a notable shift in the threshold voltage (Vgs). A robust linear relationship was observed on calibration curves with R2 values exceeding 0.90 between the natural logarithm of fluoride concentration (lnC) and gate-source voltage (Vgs). This work demonstrates that MOSFET can significantly enhance the sensitivity of electrochemical sensors without complex labeling processes. The improvement has a future in the miniaturization of cost-effective sensor systems for fuel cell applications, facilitating real-time performance and degradation monitoring.

Hydrochemical processes and fluoride enrichment patterns in high-fluoride geothermal water in the Weihe Basin, China.

The enrichment of fluoride in the deep geothermal water of the Lantian - Bahe Formation in parts of the Weihe Basin in China is a potential health hazard for the millions of inhabitants of this region. We conducted hydrochemical and hydrogeological analyses of water samples from 31 geothermal wells in the Weihe Basin, with the aims of determining the distribution characteristics, enrichment patterns, hydrochemical processes, and the factors influencing the geochemistry of deep geothermal fluids. We also evaluated the potential health hazards of fluoride ions in these fluids. Our results show that geothermal fluids with high fluoride content are widely distributed in the deep aquifers of the Weihe Basin. The principal hydrochemical types are: HCO3-Na and SO4⋅HCO3⋅Cl-Na. We used hydrodynamic simulation and regression analysis to show that the high proportion of HCO3- in the geothermal water facilitates the precipitation of Ca2+ and the dissolution of fluorine-bearing minerals. The high temperature, alkaline environment, cation exchange reactions, and dissolution and precipitation processes lead to Ca2+ depletion, which facilitates the release of fluoride ions from the surrounding rocks into the geothermal fluids. A human health risk assessment shows that the hazard quotient (HQ) values of geothermal water for adult males, adult females, children, and infants are: 3.96 - 14.41 (median 6.55), 3.32 - 12.08 (median 4.50), 4.63 - 16.84 (median 5.50), and 7.48 - 27.22 (median 9.00), respectively. Infants are the most susceptible to the effects of high fluoride in groundwater due to their physiological characteristics. while the potential health risks of F- for children and adult women/men are relatively low. Therefore, in the process of developing deep geothermal water, it is necessary to prevent it from mixing into shallow drinking water as much as possible. If the fluoride ion content in the shallow water exceeds the standard, it may have an impact on the local environment and residents' health. These findings provide a scientific foundation for the effective management of high fluoride groundwater in the Weihe Basin and analogous regions elsewhere.

Synthesis of 2D Mo1.33CTz i-MXene with ordered vacancies by hydrothermal etching of (Mo2/3Y1/3)2AlC i-MAX phase

Two-dimensional Mo1.33YxCTz i-MXene carbides with ordered vacancies have great potential for applications in various fields of science. However, their synthesis requires the use of complex technological procedures. In this work, Mo1.33YxCTz i-MXene was synthesized by hydrothermal etching method using hydrochloric acid and lithium fluoride for the first time. Based on the structure and morphology, the conversion of i-MAX phase to i-MXene was successfully achieved. Using EDS and XPS analysis, it was shown that reaction temperature, etching time and fluoride concentration are effective tools for controlling the ordered vacancies formed at the yttrium site. In particular, Mo1.33YxCTz compounds with Y contents in the range x = 0–0.24 were obtained. This research opens up new possibilities for the targeted control of i-MXene properties at the atomic scale by simple hydrothermal treatment.

The effect of photo-thermo-induced crystallization on the properties and microstructure of transmission volume Bragg gratings

Volume Bragg gratings (VBGs) recored on photo-thermo-refractive (PTR) glass are extensively utilized in high power lasers, optical communication, holographic display fields, etc. In the majority of application fields, high refractive index modulation (RIM) value and high transmittance are the required parameters for transmission Volume Bragg gratings (TVBGs) devices. This study indicates that the RIM values and transmittance of TVBGs strongly depend on the size and concentration of sodium fluoride (NaF) crystals within the grating periodic structure. Increasing the UV exposure dose causes a reduction in the size of NaF crystals, leading to a finitely rise in the RIM value of TVBGs. Prolonging the crystallization heat treatment time and elevating the temperature effectively enhance the RIM value of TVBGs, which also significantly enlarge the size of NaF crystals in the grating periodic structure. By fine-tuning the process parameters of photothermal induced crystallization, a RIM value of 20–320 ppm is freely controlled. For 1.5 mm thick TVBGs, the above RIM value range can meet the application requirements of achieving high diffraction efficiency in the visible to near-infrared range. Following UV exposure at a dose of 5 J/cm2 and nucleation at 480 °C for 120 min, crystallization treatments at 550 °C for 30–60 min and at 570 °C for 60–120 min are determined as optimal for fabricating TVBGs with high diffraction efficiency and transmittance in the visible (532 nm) and near-infrared (1053 nm) bands, respectively.

Mineral pollutants and coliform contamination in groundwater pose health risks to consumers: a spatiotemporal study in a mining-impacted area

The presence of mineral pollutants, combined with bacterial contamination, has significantly impacted groundwater quality and led to various health-related issues in mining-impacted areas. Therefore, we measured the concentration of fluoride (F-), phosphate (PO43-), sulphate (SO42-), ammonium (NH4+), nitrate (NO3-), the total coliforms (TCs), and physiochemical characteristics in groundwater samples of South Khorasan, Eastern Iran. For this, we collected water samples from 100 wells in spring and autumn across this mining-impacted area. We then measured the concentrations of mineral pollutants and assessed their associated health risks to children and adults using the Environmental Protection Agency (EPA) models and spatiotemporal zoning maps in ArcGIS. The concentrations of PO43-, NH4+, SO42-, NO3-, and F- were 0.70 ± 0.34, 0.82 ± 0.9, 175.45 ± 123, 15.26 ± 9.41, and 0.53 ± 0.68 mg/L in spring, and 0.71 ± 3.18, 4.68 ± 31, 306.72 ± 615.80, 19.30 ± 15.61, and 0.72 ± 0.65 mg/L in autumn, respectively. PO43-, NH4+, and SO42- exceeded both the World Health Organization (WHO) and EPA, but NO3- exceeded only EPA standards. TCs in both seasons exceeded the standards set by the EPA and WHO. The hazard quotient (HQ) values indicated non-carcinogenic risks for F⁻ and NO3⁻, while posing no risks NH4⁺ and PO43⁻ in both adults and children during autumn and spring.Hazard index (HI) was greater than 1 for all minerals in both children and adults in autumn and spring. No correlation was observed between mineral compounds and TCs in the study area, yet the water samples were highly contaminated by coliform with a significant risk to adults and children. In essence, both mineral pollutants and TCs potentially pose serious risks to human, and more efforts are required to improve the quality of water in this area.

Substantiation of safety and quality indicators of natural mineral and spring waters in Ukraine for the preparation of food for infants

The object of the research is regulatory support for the use of natural mineral waters and spring waters for the preparation of food for infants. Along with drinking water, natural mineral water is used for the preparation of food for infants, which is more protected from contamination. Currently, there are no approved safety parameters for natural mineral waters and spring waters in Ukraine, as well as requirements for markings on packaging or labeling that relate to the suitability of these waters for feeding infants. In this work, based on the results of the analysis of the current legal documents of European countries (Poland, Bulgaria, the Czech Republic, France, Germany) on the use of natural mineral waters in the preparation of food for infants, the indicators of the safety and quality of natural mineral and spring waters in Ukraine in the preparation of food are substantiated food for infants. Because of the specific physiological needs of children at an early age, water for cooking is an important factor in their normal psychophysical development. Water for preparing infant food must meet stricter criteria for total mineralization (suggested: ≤500 mg/l), the content of certain macro-components, nitrites (suggested: ≤0.1 mg/l), nitrates (suggested: ≤10 mg/l), ammonium (suggested: ≤0.1 mg/l), fluorides (suggested: ≤0.7 mg/l), sanitary and microbiological indicators (suggested normalization of the indicator of the total microbial number in the finished product). The peculiarities of the technology of industrial packaging of natural mineral waters and spring waters for the preparation of infant food are outlined. These waters are packaged only non-carbonated, without the addition of any preservatives or disinfectants. Packaging of these waters should take place near water points, which should be reliably protected from biological and chemical contamination. The obtained results can be used for the development and approval of a normative legal act in Ukraine on the regulation of the use of natural mineral waters and spring waters for the preparation of infant food.

Adsorption Isotherm, Kinetic and Thermodynamic Studies for Removal of Fluoride Ions from Drinking Water Using Modified Natural Pumice

This study aimed to modify pumice using aluminum chloride as an adsorbent for defluoridation. Batch and column experiments were carried out to evaluate the effects of pH, initial fluoride concentration, contact time, dose, and temperatur. The modified pumice adsorbent showed good fluoride removal in both batch and column studies. Fluoride up-take was observed to be effective &gt;7%, at pH 6.5-7.5, and adsorption equilibrium time was observed at 60 min. the adsorption results were modelled using kinetic and isotherm models. Experimental data indicated that fluoride adsorption follows the second pseudo-order kinetics model (R2 &gt; 0.99) and fits well with both the Freundlich and Langmuir isotherm models, which showed favorability for the adsorption of fluoride with a maximum capacity of 0.083 mg/g. The negative values of ∆Ho and ∆Go indicate that the adsorption process was feasible, exothermic, and spontaneous. The column performance showed the best fluoride uptake efficiency, with a breakthrough capacity of 0.48 mg/g. The %R was approximately %100 using0.1M NaOH. Fluoride levels in real wells water decreased dramatically (e.g. 4.1-0.88, 7.1-1.54, and 6.2-1.46 mg/L). The results revealed that modified pumice has the potential for fluoride removal from drinking water.