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

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.

2016 ◽  
Vol Volume 112 (Number 11/12) ◽  
Author(s):  
Rabelani Mudzielwana ◽  
Mugera W. Gitari ◽  
Titus A.M. Msagati ◽  
◽  
◽  
...  

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.


2017 ◽  
Vol 61 (3) ◽  
pp. 188 ◽  
Author(s):  
Poornima G. Hiremath ◽  
Thomas Theodore

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.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Temesgen Abeto Amibo ◽  
Surafel Mustafa Beyan ◽  
Tsegaye Markos Damite

The problem extent of the large concentration of fluoride ions in drinking water is still a central health issue. In the present study, lanthanum doped magnetic Teff straw biochar (LDMTSB) was developed as a novel adsorbent for removing fluoride ions in the groundwater in Rift-Valley regions, especially Hawassa city, Ethiopia. The synthesized LDMTBC was characterized via FTIR, XRD, SEM, and BET. And, this analysis proposed that multiadsorption techniques such as ligand exchange, precipitations, and electrostatic interaction could be evinced throughout the fluoride ions adsorption process by LDMTSB. The constraints that influence the adsorption efficacy, namely, a dosage of LDMTSB, contact time, pH of the solution, and rotational speed, were analyzed and optimized using the response surface methodology approach. Under the optimum situations, LDMTSB dosage: 3.97 g, contact time: 56.36 min, rotational speed: 591.19 rpm, and pH: 3.968 demonstrate high efficacy of LDMTSB with 98.89% fluoride removal capacity. Further, the quadratic model (R2 = 0.9841) was designated for governing the mathematical process. The LDMTSB was successful in the removal of fluoride ions in the groundwater. This study provides a valuable economical solution for the application of Teff straw.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Tesfaye Akafu ◽  
Achalu Chimdi ◽  
Kefyalew Gomoro

Exposure to fluoride beyond the recommended level for longer duration causes both dental and skeletal fluorosis. Thus, the development of cost-effective, locally available, and environmentally benign adsorbents for fluoride removal from contaminated water sources is absolutely required. In the present study, diatomaceous earth (diatomite) locally available in Ethiopia, modified by treating it with an aluminum hydroxide solution, was used as an adsorbent for fluoride removal from aqueous solutions. Adsorption experiments were carried out by using batch contact method. The adsorbent was characterized using FT-IR spectroscopy. Effects of different parameters affecting efficiency of fluoride removal such as adsorbent dose, contact time, initial fluoride concentration, and pH were investigated and optimized. The optimum adsorbent dose, contact time, initial fluoride concentration, and pH values were 25 g/L, 180 min, 10 mg/L, and 6.7, respectively. The performance of the adsorbent was also tested under optimum conditions using groundwater samples taken from Hawassa and Ziway. Langmuir and Freundlich isotherm models were applied to describe the equilibrium data. Compared to Langmuir isotherm (R2 = 0.888), the Freundlich isotherm (R2 = 0.985) model was better fitted to describe the adsorption characteristics of fluoride on Al-diatomite. The Langmuir maximum adsorption capacity was 1.67 mg/g. The pseudosecond-order model was found to be more suitable than the pseudofirst-order to describe the adsorption kinetics. The low correlation coefficient value of R2 = 0.596 for the intraparticle diffusion model indicates that the intraparticle diffusion model does not apply to the present studied adsorption system. The maximum fluoride removal was observed to be 89.4% under the optimum conditions which indicated that aluminum hydroxide-modified diatomite can be used as efficient, cheap, and ecofriendly adsorbents for the removal of fluoride from contaminated water.


2011 ◽  
Vol 1 (4) ◽  
pp. 213-223 ◽  
Author(s):  
Sabrina Sorlini ◽  
Daniela Palazzini ◽  
Carlo Collivignarelli

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.


2019 ◽  
Author(s):  
Habtamu Demelash Enyew ◽  
Abebe Hailu Beyene ◽  
Zewdu Abebe ◽  
Addisu Dagnaw Melese

Abstract Background: The concentration of fluoride in ground drinking water greater than the world health organization standard value imposes a serious health, social and economic problem in developing countries. In the Ethiopian Rift Valley where deep wells are the major source of drinking water, high fluoride level is expected. Though many epidemiological studies on fluoride concentration and its adverse effects have been conducted in the region, the result is highly scattered and needs systematically summarized for better utilization. Objective: This research is aimed at estimating the pooled level of fluoride concentration in ground drinking water and the prevalence of dental fluorosis among Ethiopian rift valley residences. Methods: Cochrane library, MEDLINE/PubMed and Google scholar databases were searched for studies reporting the mean concentration of fluoride in ground water and prevalence of dental fluorosis in Ethiopian Rift valley. Search terms were identified by extracting key terms from reviews and selected relevant papers and review medical subject headings for relevant terms. Results: The mean fluoride level in ground water and the prevalence of dental fluorosis were pooled from eleven and nine primary studies conducted in Ethiopian Rift Valley respectively. The pooled mean level of fluoride in ground water therefore was 6.03 mg/l (95% CI; 4.72–7.72, p < 0.001) and the pooled prevalence of dental fluorosis among residents in Ethiopian rift valley was 32% (95% CI: 25, 39%, p<0.001), 29% (95% CI: 22, 36%, p<0.001) and 24% (95% CI: 17, 32%, p<0.001 for mild, moderate and sever dental fluorosis respectively. The overall prevalence of dental fluorosis is 28% (95% CI: 24, 32%, p<0.001). Conclusions: Though, the concentration level varies across different part of the rift valley region, still the level of fluoride in ground drinking water is greater than the WHO standard value (1.5mg/l). Relatively high-level pooled prevalence of dental fluorosis was also seen in Ethiopian rift valley. Therefore, further studies covering the temperature, exposure time and other intake path ways with large sample size is recommended. Interventional projects should be implemented to decrease the concentration of fluoride in the ground drinking water source. Key words: Dental fluorosis, Fluoride, Concentration, Rift Valley, Ethiopia


2021 ◽  
Vol 18 (1) ◽  
pp. 107-112
Author(s):  
Thirumala Mothe ◽  
Patnam Umashankar ◽  
Vishnuvardhan Reddy Sultanpuram

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.


METANA ◽  
2020 ◽  
Vol 16 (2) ◽  
pp. 47-54
Author(s):  
Adhi Setiawan ◽  
Nadya Ayu Arianingtyas ◽  
Novi Eka Mayangsari ◽  
Tanti Utami Dewi

Proses produksi asam fosfat menghasilkan air limbah dengan kandungan fluoride dan Chemical Oxygen Demand (COD) yang berpotensi mencemari lingkungan jika tidak diolah secara tepat. Kandungan ion fluoride di dalam air dapat menjadi ancaman serius bagi kesehatan manusia karena menyebabkan kerusakan pada gigi dan tulang. Kombinasi presipitasi dan elektrokoagulasi merupakan salah satu alternatif yang efektif untuk menurunkan kandungan fluoride dan COD. Penelitian ini bertujuan menganalisis pengaruh pH presipitasi, tegangan, dan waktu kontak terhadap penyisihan fluoride dan COD pada limbah industri fosfat menggunakan metode presipitasi dan elektrokoagulasi. Proses presipitasi dan elektrokoagulasi dilakukan secara batch. Presipitan menggunakan bahan berupa Ca(OH)2 sedangkan proses elektrokoagulasi menggunakan elektroda aluminium yang tersusun secara monopolar. Pengaturan pH presipitasi menggunakan pH 5, 7, dan 9. Elektrokoagulasi menggunakan variasi waktu kontak 40, 50, dan 60 menit. Variasi tegangan listrik 17, 22, dan 27 V. Hasil penelitian menunjukkan bahwa peningkatan pH meningkatkan efisiensi penyisihan pada proses presipitasi. Peningkatan nilai tegangan listrik dan waktu kontak menyebabkan peningkatan efisiensi penyisihan fluoride dan COD. Efisiensi tertinggi pada proses penyisihan fluoride dan COD diperoleh pada kondisi pH 9, waktu kontak 60 menit dan tegangan 27 volt dengan nilai efisiensi penyisihan fluoride sebesar 99,84% dan efisiensi penyisihan COD sebesar 56,35%. The production process of phosphoric acid produces wastewater containing fluoride and COD which has the potential to pollute the environment if not treated properly. The content of fluoride ions in water can be a serious threat to human health because it causes damage to teeth and bones. The combination of precipitation and electrocoagulation is an effective alternative to reduce fluoride and COD content. This study aims to analyze the effect of pH of precipitation, voltage, and contact time on fluoride and COD removal in industrial phosphate waste using precipitation and electrocoagulation methods. The precipitation and electrocoagulation processes are carried out in batches. Precipitant uses a material in the form of Ca (OH) 2, while the electrocoagulation process uses aluminum electrodes that are arranged monopolarly. Setting the pH of the precipitation using pH 5, 7, and 9. Electrocoagulation using a variation of contact time 40, 50, and 60 minutes. Electric voltage variations 17, 22, and 27 V. The results showed that increasing pH increased the removal efficiency in the precipitation process. Increasing the value of the power supply voltage and contact time led to an increase in the efficiency of fluoride and COD removal. The highest efficiency in fluoride and COD removal process was obtained at conditions of pH 9, contact time of 60 minutes and a voltage of 27 volts with a fluoride removal efficiency value of 99.84% and COD removal efficiency of 56.35%.


Author(s):  
Dr. Rekha Tripathi

In the present investigation samples of ground water ( open well, hand pump), wheat and vegetables (spinach, potato and tomato) were collected from different areas of Dausa district of Rajasthan and analyzed to access the adverse effect on human health due to fluoride accumulation. The fluoride concentration varies between 5.1-14.9 mg/l in the collected water samples, where as in wheat samples it was found in the range of 3.42-14.25mg/l and in vegetables from 1.19-22.45mg/l. The fluoride accumulation was found to be much higher in leafy vegetable (spinach) than that of in other vegetables, where seeds or tubers are the main edible part (potato and tomato). Cereal crop ( wheat ) also estimated with more fluoride content then potato and tomato. The maximum concentration of fluoride in water, wheat and vegetables was 14.9mg/l (Bairwa Mohalla/Dausa ), 14.25 µg/g (Seengpura/Dausa) and 22.45 µg/g (Kalyanpura/ Dausa) respectively. It was observed that large number of people from Bairwa Mohalla/Dausa were suffering from Skeletal and Dental fluorosis.


2019 ◽  
Author(s):  
Habtamu Demelash Enyew ◽  
Abebe Hailu Beyene ◽  
Zewdu Abebe ◽  
Addisu Dagnaw Melese

Abstract Background: The concentration of fluoride in ground drinking water greater than the world health organization standard value imposes a serious health, social and economic problem in developing countries. In the Ethiopian Rift Valley where deep wells are the major source of drinking water, high fluoride level is expected. Though many epidemiological studies on fluoride concentration and its adverse effects have been conducted in the region, the result is highly scattered and needs systematically summarized for better utilization. Objective: This research is aimed at estimating the pooled level of fluoride concentration in ground drinking water and the prevalence of dental fluorosis among Ethiopian rift valley residences. Methods: Cochrane library, MEDLINE/PubMed and Google scholar databases were searched for studies reporting the mean concentration of fluoride in ground water and prevalence of dental fluorosis in Ethiopian Rift valley. Search terms were identified by extracting key terms from reviews and selected relevant papers and review medical subject headings for relevant terms. Results: The mean fluoride level in ground water and the prevalence of dental fluorosis were pooled from eleven and nine primary studies conducted in Ethiopian Rift Valley respectively. The pooled mean level of fluoride in ground water therefore was 6.03 mg/l (95% CI; 4.72–7.72, p < 0.001) and the pooled prevalence of dental fluorosis among residents in Ethiopian rift valley was 32% (95% CI: 25, 39%, p<0.001), 29% (95% CI: 22, 36%, p<0.001) and 24% (95% CI: 17, 32%, p<0.001 for mild, moderate and sever dental fluorosis respectively. The overall prevalence of dental fluorosis is 28% (95% CI: 24, 32%, p<0.001). Conclusions: Though, the concentration level varies across different part of the rift valley region, still the level of fluoride in ground drinking water is greater than the WHO standard value (1.5mg/l). Relatively high-level pooled prevalence of dental fluorosis was also seen in Ethiopian rift valley. Therefore, further studies covering the temperature, exposure time and other intake path ways with large sample size is recommended. Interventional projects should be implemented to decrease the concentration of fluoride in the ground drinking water source. Key words: Dental fluorosis, Fluoride, Concentration, Rift Valley, Ethiopia


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