scholarly journals Isolation of Fluoride Resistant Microorganisms from Fluoride Contaminated Ground Water Samples of Nalgonda District and their role in Bioremediation

2021 ◽  
Vol 18 (1) ◽  
pp. 107-112
Author(s):  
Thirumala Mothe ◽  
Patnam Umashankar ◽  
Vishnuvardhan Reddy Sultanpuram
Keyword(s):  
Ground Water ◽  
Fluoride Concentration ◽  
Luria Bertani ◽  
Resistant Bacteria ◽  
Fluoride Removal ◽  
Batch Mode ◽  
Two Samples ◽  
High Fluoride Concentration ◽  
High Fluoride ◽  
Nalgonda District

Consuming of water contaminated with high fluoride concentration for a very long time causes health problems such as, dental and skeletal fluorosis. Hence, defluoridation of water is essentially required before consumption, when water is contaminated with high fluoride concentration. In this present study, research was focussed on to isolate bacteria which are showing fluoride resistantance from samples of ground water from high fluoride affected regions of Nalgonda. After analysis of 10 samples from different areas of Nalgonda district, two samples of ground water from Narketpally and Nampally showed the high fluoride concentrations of 9.18 ppm and 7.55 ppm respectively. Hence, in the present study, Narketpally ground water sample with highest ppm was considered to isolate fluoride resistant bacteria. A total of eight fluoride resistant organisms were purified from this sample with varying fluoride resistance on Luria Bertani agar with varying fluoride concentraion from 25mg/L to 600mg/L at pH 7. Among the eight strains isolated, three strains MB1, F and G were showing high fluoride resistance (up to 500mg/L), which were further explored for their role in bioremediation of fluoride. In batch mode study, MB1 strain showed high fluoride degradation of 68%, whereas, F and G strains showed 57% and 44%fluoride removal, respectively, when fluoride concentration was present at 20 mgL-1 at 30 °C temperature and pH 7, with dextrose (10 g) utilised as source of carbon per 100 mL media after incubation of 8 days. Results indicate that, MB1 possibly a potential fluoride resistant bacterium with high fluoride bioremediation capacity.

scholarly journals Defluoridation of South Tunisian Brackish Water by Alum Coagulation/Flocculation: A Preliminary Work

2017 ◽  
Vol 5 (3) ◽  
pp. 727-740
Author(s):  
Khaoula Missaoui ◽  
Wided Bouguerra ◽  
Chiraz Hannachi
Keyword(s):  
Brackish Water ◽  
Fluoride Concentration ◽  
Settling Time ◽  
Experimental Results ◽  
Fluoride Removal ◽  
Operating Parameters ◽  
High Fluoride Concentration ◽  
Initial Ph ◽  
High Fluoride ◽  
Alum Coagulation

Fluoride removal from aqueous solution was investigated using the chemical coagulation-flocculation by alum in reason of the efficiency and the simplicity of the process. Preliminary experiments were carried out to study the effect of some operating parameters such as: pH, initial fluoride concentration, coagulant dose, adjuvant coagulation dose, flocculent dose and settling time. Obtained experimental results showed that the treatment of fluoride by alum coagulation causes acidification of the solution. The effect of the initial pH solution on fluoride removal is negligible. Experimental results proved that coagulation process is effective in waters with low or medium levels of fluoride. Defluoridation rate was seen to increase with increasing coagulant and adjuvant coagulation doses. Optimal flocculent dose and optimal settling time were found 4.2 mg L-1 of FABI and 60 min respectively. Subsequently, experimental design methodology using two-level full factorial design was applied to optimize the defluoridation by coagulation-flocculation. Therefore, four operating parameters which are supposed to affect the removal efficiency were chosen: initial fluoride concentration, coagulant dose, coagulation adjuvant dose and settling time. From the statistical analysis, it is inferred that the four studied parameters have an influence on the fluoride removal. In fact, initial fluoride concentration has a positive effect unlike coagulant dose, coagulation adjuvant dose and settling time. Experiment tests were performed to evaluate the efficiency of coagulation-flocculation process for south Tunisian brackish water with high fluoride concentration. The obtained results showed that fluoride removal reached 59%.

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 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

Ultrastructure and Composition of Enamel in Human Dental Fluorosis

1989 ◽  
Vol 3 (2) ◽  
pp. 203-210 ◽  
Author(s):  
T. Yanagisawa ◽  
S. Takuma ◽  
O. Fejerskov
Keyword(s):  
Surface Layer ◽  
Dental Fluorosis ◽  
Fluoride Concentration ◽  
Occlusal Caries ◽  
Electron Microscopic ◽  
High Fluoride Concentration ◽  
High Fluoride ◽  
Materials Used ◽  
High Degree ◽  
Hexagonal Crystals

Materials used in this work were 13 permanent molars exhibiting dental fluorosis (between 5 and 9 on the Thylstrup-Fejerskov scale, 1978) obtained from adults (aged 20-40 years) living in regions with 3.5 ppm fluoride in the water supplies. Small but deep occlusal caries lesions necessitated extraction. Light and polarized microscopic, microradiographic, electron microscopic, and electron-probe- and ion-micro-analytical studies were made. Enamel surfaces were generally cloudy to opaque, with several pits or defects of various sizes and degrees of brown-staining. An extensively hypomineralized area extended from the inner enamel to the surface layer, which was mineralized to a high degree. The hypomineralized area contained sparsely arranged, flattened, hexagonal crystals with either perforated centers or defects extending from the perimeter and indicating either no or low fluoride content. The highly mineralized surface layer, however, was composed of many large, flattened, hexagonal crystals and extremely small, irregularly shaped crystals. Both types were free of central perforations and defects. A high fluoride concentration was determined in the highly mineralized surface layer. These findings suggest that the hypomineralized area undergoes caries-like changes in terms of crystal dissolution and that the highly mineralized surface layer contains hydroxyapatite and fluoridated-hydroxyapatite, or fluorapatite, or both.

Prevention of Erosion and Abrasion by a High Fluoride Concentration Gel Applied at High Frequencies

2006 ◽  
Vol 40 (2) ◽  
pp. 148-153 ◽  
Author(s):  
M.D. Lagerweij ◽  
W. Buchalla ◽  
S. Kohnke ◽  
K. Becker ◽  
Á.M. Lennon ◽  
...  
Keyword(s):  
Fluoride Concentration ◽  
High Frequencies ◽  
High Fluoride Concentration ◽  
High Fluoride

Preparation and Characterization of Biogenic Chitosan-Hydroxyapatite Composite: Application in Defluoridation

MRS Advances ◽  
2018 ◽  
Vol 3 (36) ◽  
pp. 2089-2098 ◽  
Author(s):  
Agatha W. Wagutu ◽  
Revocatus L. Machunda ◽  
Yusufu Abeid Chande Jande
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Fluoride Concentration ◽  
Health Concern ◽  
Coliform Bacteria ◽  
Fluoride Removal ◽  
Biomass Waste ◽  
Batch Mode ◽  
Treated Water ◽  
Hydroxyapatite Composite

ABSTRACTIn Northern Tanzania, high levels of fluoride in community drinking water supply is recognized as one of the major public health concern, the problem is further ameliorated by presence Escherichia coli and fecal coliform bacteria in surface water and shallow wells. Efforts to decontaminate the water involve mostly the use of low efficient bone char for fluoride removal without disinfecting the pathogens. To address this problem, a robust adsorbent which is capable of removing fluoride and microbes simultaneously with minimal diverse impact on the treated water is necessary. Here we highlight development of composite material developed from recycling of crustacean biomass waste from sea food industry. Chitosan polymer, isolated from prawns shell was composited with crab shell derived brushite (CaHPO4.2H2O) to form chitosan-hydroxyapatite composite. XRD and FT-IR analysis confirmed transformation of brushite phases into hydroxyapatite and formation hybrid composite. Fluoride adsorption tests were performed in batch mode to evaluate effectiveness. Defluoridation capacity of up to 6.4 mg/g in field water containing fluoride concentration of 5-70 mg/L was achieved. The best performance was observed with fluoride concentration of 10 mg/L and below. Apart from fluoride removal, the composite also reduced color tint and microbes from surface water samples. The pH of the treated water in most samples remained around 6.5-8.5, which is acceptable for drinking water.

scholarly journals Using High Fluoride Concentration Products in Public Policy: A Rapid Review of Current Guidelines for High Fluoride Concentration Products

2016 ◽  
Vol 50 (Suppl. 1) ◽  
pp. 50-60 ◽  
Author(s):  
Gail V.A. Douglas ◽  
Martin P. Ramsdale ◽  
Karen Vinall-Collier ◽  
Julia I. Csikar
Keyword(s):  
Oral Health ◽  
Fluoride Concentration ◽  
Third Party ◽  
Rapid Review ◽  
Fluoride Varnish ◽  
Health Improvement ◽  
Evidence Based ◽  
The World ◽  
High Fluoride Concentration ◽  
High Fluoride

Despite improvements in dental caries levels since the widespread introduction of fluoride toothpastes, it is still a disease which is considered to be a priority in many countries around the world. Individuals at higher risk of caries can be targeted with products with a high fluoride concentration to help reduce the amount and severity of the disease. This paper compares guidance from around the world on the use of products with a high fluoride concentration and gives examples of how guidance has been translated into activity in primary care dental practice. A rapid review of electronic databases was conducted to identify the volume and variation of guidance from national or professional bodies on the use of products with a high fluoride concentration. Fifteen guidelines published within the past 10 years and in English were identified and compared. The majority of these guidelines included recommendations for fluoride varnish use as well as for fluoride gels, while a smaller number offered guidance on high fluoride strength toothpaste and other vehicles. Whilst there was good consistency in recommendations for fluoride varnish in particular, there was sometimes a lack of detail in other areas of recommendation for other vehicles with a high fluoride concentration. There are good examples within the UK, such as the Childsmile project and Delivering Better Oral Health, which highlight that the provision of evidence-based guidance can be influential in directing scarce resources towards oral health improvements. Policy can be influenced by evidence-based national recommendations and used to help encourage dental professionals and commissioners and third-party payers to adopt higher levels of practices aimed at oral health improvement.

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