Comparison of Water Defluoridation Using Different Techniques

Fluoride pollution in subsurface water is a significant problem for different nations across the world because of the intake of excessive fluoride caused by the drinking of the contaminated subsurface. Water pollution by flouride can be attributed to the natural and human-made agents. Increased levels of fluoride in drinking water may result in the irretrievable demineralization of bone and tooth tissues, a situation called fluorosis, and other disorders. There has long been a need for fluoride removal from drinking water to make it safe for human use. Among the various fluoride removal methods, adsorption is the method most popularly used due to its cheap cost, ease of utilization, and being a scalable and simple physical technique. According to the findings of this study, the highest concentration of fluoride (0.1–15.0 mg/L) was found in Sweden and the lowest (0.03–1.14 mg/L) in Italy. We collected the values of adsorption capacities and fluoride removal efficiencies of various types of adsorbents from valuable released data accessible in the literature and exhibited tables. There is still a need to find the actual possibility of using biosorbents and adsorbents on a commercial scale and to define the reusability of adsorbents to decrease price and the waste generated from the adsorption method. This article reviews the currently available methods and approaches to fluoride removal of water.

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Removal of Fluoride from Drinking Water by Gel Composite of Metal Ion and Humic Acid Adsorbent

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.726-731.695 ◽

2013 ◽

Vol 726-731 ◽

pp. 695-699

Author(s):

Li Hong ◽

Si Xiang Wang ◽

Yong Liu ◽

Yue Chun Zhang

Keyword(s):

Drinking Water ◽

Humic Acid ◽

Contact Time ◽

Metal Ion ◽

Fluoride Removal ◽

Batch Adsorption ◽

Solution Ph ◽

Adsorption Method ◽

Sem Images ◽

Fluoride Adsorption

Humic acid adsorbent modified with metal ions was prepared by gel polymerization and named gel composite of metal ion and humic acid, which abbreviated GCMH to uptake fluoride from drinking water. The samples were measured by X-ray diffraction (XRD) patterns and scanning electron microscope (SEM) images. Fluoride adsorption onto the synthesized samples was investigated by batch adsorption method. In previous works, detailed studies were carried out to investigate the effect of contact time, adsorbent dose, initial solution pH, temperatures and co-existing anions. The maximum fluoride removal was obtained at pH7. Presence of HCO3− adversely affected the adsorption of fluoride. The optimum absorption conditions were at the dose of 10g/L, temperature of water of 55°Cand contact time of 6hs.

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Comparison of Electrocoagulation Process and Other Treatment Technologies in Fluoride Removal from Groundwater

Academic Perspective Procedia ◽

10.33793/acperpro.02.03.142 ◽

2019 ◽

Vol 2 (3) ◽

pp. 1275-1282

Author(s):

Benan Yazici Karabulut ◽

Ayse Dilek Atasoy

Keyword(s):

Drinking Water ◽

Ion Exchange ◽

Fluoride Removal ◽

The World ◽

Effective Technology ◽

Electrocoagulation Process ◽

Treatment Technologies ◽

As Adsorption ◽

Removal Technologies ◽

Water Fluoride

Groundwater is one of the most important natural resources in the world and plays a very important role in the supply of drinking water. Fluoride is probably one of the most common groundwater pollutants in the world for various reasons (structure of soil and rocks, etc.). The concentration of fluoride in groundwater above 1.5 mg/L begins to pose some risks to human health. Various conventional techniques such as adsorption, ion exchange, reverse osmosis, nanofiltration, precipitation have been developed for the removal of fluoride from water. However, they have several limitations, such as post-treatment re-treatment, less efficiency and higher installation costs. The electrocoagulation process is an effective technology for fluoride removal within conventional techniques. In this study, fluoride removal technologies are emphasized, and the studies done in this field are examined. The aim of this study is to investigate the advantages of electrocoagulation method in fluoride removal and to compare electrocoagulation process with other treatment technologies.

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Optimization of regenerated bone char for fluoride removal in drinking water: a case study in Tanzania

Journal of Water and Health ◽

10.2166/wh.2006.0011 ◽

2006 ◽

Vol 4 (1) ◽

pp. 139-147 ◽

Cited By ~ 44

Author(s):

M. E. Kaseva

Keyword(s):

Particle Size ◽

Grain Size ◽

Drinking Water ◽

Contact Time ◽

Fluoride Removal ◽

Bone Char ◽

Removal Capacity ◽

Maximum Value ◽

The World

This paper presents findings of a study on optimization and application of the regenerated bone char media for the defluoridation of drinking water in Tanzania where more than 30% of all water sources have fluoride concentrations above the 1.50 mg/l which is recommended by the World Heath Organization (WHO). In this study, regeneration temperature, regeneration duration, contact time, regenerated bone char dosage and particle size were investigated. Results indicate that the highest fluoride removal and adsorption capacity were 70.64% and 0.75 mg-F/g-bc, respectively, for a sample with bone char material that was regenerated at 500°C. In this study the optimum burning duration was found to be 120 min, which resulted in residual fluoride that varied from a maximum value of 17.43 mg/l for a 2 min contact time to a minimum value of 8.53 mg/l for a contact time of 180 min. This study further indicated that the smallest size of regenerated bone char media (0.5–1.0 mm diameter) had the highest defluoridation capacity, with residual fluoride which varied from 17.82 mg/l at 2 min contact time to 11.26 mg/l at 120 min contact time. In terms of dosage of the regenerated bone char media it was established that the optimum dosage was 25 g of bone char media with a grain size of 0.50–1.0 mm. This had a fluoride removal capacity of 0.55 mg-F/g-BC. Column filter experiments indicated that regenerated bone media is capable of removing fluoride from dinking water to meet both WHO and Tanzania recommended values.

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The Effect of The Electrode in Fluoride Removal from Drinking Water by Electro Coagulation Process

International Conference on Chemical, Environmental and Biological Sciences (CEBS-2015) March 18-19, 2015 Dubai (UAE) ◽

10.15242/iicbe.c0315073 ◽

2015 ◽

Cited By ~ 1

Keyword(s):

Drinking Water ◽

Fluoride Removal ◽

Coagulation Process ◽

Electro Coagulation

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Diseases Prevention by Water Defluoridation Using Hydrotalcites as Decontaminant Materials

Revista de Chimie ◽

10.37358/rc.17.1.5412 ◽

2017 ◽

Vol 68 (1) ◽

pp. 168-171 ◽

Cited By ~ 2

Author(s):

Letitia Doina Duceac ◽

Cristina Elena Dobre ◽

Ioana Pavaleanu ◽

Gabriela Calin ◽

Simona Nichitus ◽

...

Keyword(s):

Dental Fluorosis ◽

Precipitation Method ◽

Original Structure ◽

Fluoride Removal ◽

Major Goal ◽

Bone Stiffness ◽

Morphological Aspects ◽

Adsorption Capacities ◽

Interlayer Structure ◽

Co Precipitation

Preventing diseases is deemed to be the major goal of our century especially when an excessive fluoride in drinking water can cause dental fluorosis, bone stiffness, rheumatism and skeletal fluorosis. Fluoride uptake from groundwater implies a worldwide multidisciplinary effort in order to develop renewable, cheap, human friendly materials. Among other materials, hydrotalcites could be good candidates for an efficient fluoride removal from water due to their adsorption, anion exchange and reconstruction properties. These nanostructured materials were synthesized using co-precipitation method in controlled conditions. Presence of anions in the interlayer structure and morphological aspects were performed by FTIR and SEM techniques. Thermal treatment of hydrotalcites showed good adsorption capacities for water defluoridation mostly due to their tendency to restore the original structure.

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PTSA (pressure and thermal swing adsorption) method to remove trihalomethanes from drinking water

Water Science & Technology ◽

10.2166/wst.1997.0283 ◽

1997 ◽

Vol 35 (7) ◽

pp. 243-250 ◽

Cited By ~ 1

Author(s):

Shigekazu Nakano ◽

Tomoko Fukuhara ◽

Masami Hiasa

Keyword(s):

Drinking Water ◽

Residual Chlorine ◽

Remarkable Difference ◽

Adsorption Method ◽

Heating And Cooling ◽

Point Of Use ◽

Thermal Swing Adsorption ◽

Long Time ◽

Musty Odor ◽

Vacuum Heating

It has been widely recognized that trihalomethanes (THMs) in drinking water pose a risk to human health. THMs can be removed to a certain extent by the conventional point-of-use (POU) unit which is composed of activated carbon (AC) and microfilter. But it's life on THMs is relatively shorter than on residual chlorine or musty odor. To extent the life of AC adsorber, pressure and thermal swing adsorption (PTSA) was applied by preferential regeneration of chloroform. PTSA was effective to remove THMs, especially chloroform. Adsorption isotherms of chloroform at 25 and 70°C showed a remarkable difference so that thermal swing was considered effective. Chloroform was also desorbed by reducing pressure. By vacuum heating at 70°C, chloroform was almost desorbed from AC and reversible adsorption was considered possible. A prototype of POU unit with PTSA was proposed. Regeneration mode would consist of dewatering, vacuum heating and cooling (backwashing). The unit was maintained in bacteriostatic condition and could be used for a long time without changing an AC cartridge.

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Assessment of drinking water contamination in food stalls of Jashore Municipality, Bangladesh

Applied Water Science ◽

10.1007/s13201-021-01470-w ◽

2021 ◽

Vol 11 (8) ◽

Author(s):

Molla Rahman Shaibur ◽

Mohammed Sadid Hossain ◽

Shirina Khatun ◽

F. K. Sayema Tanzia

Keyword(s):

Water Quality ◽

Drinking Water ◽

World Health Organization ◽

Fast Food ◽

Pathogenic Bacteria ◽

Permissible Limit ◽

World Health ◽

Drinking Water Contamination ◽

The World ◽

Health Organization

AbstractThis study aimed to determine the quality of drinking water supplied in different types of food stalls in Jashore Municipality, Bangladesh. A total of 35 water samples were collected from different tea stalls, street side fast food stalls, normal restaurants and well-furnished restaurants. The water quality was evaluated by determining the distinct physical, chemical and biological parameters. The results revealed that the water used in the food stalls and restaurants for drinking purpose was in desired quality in terms of turbidity, electrical conductivity, pH, total dissolved solids, nitrate (NO3−), sulfate (SO42−), phosphate (PO43−), chloride (Cl−), sodium (Na) and potassium (K) concentrations. The values were within the permissible limit proposed by the Bangladesh Bureau of Statistics and the World Health Organization. Concentrations of calcium (Ca) and magnesium (Mg) found in several samples were higher than the World Health Organization standard. Iron (Fe) concentrations were higher than the permissible limit of the World Health Organization. Only 46% exceeded the permissible limit of Bangladesh Bureau Statistics. The threatening result was that the samples were contaminated by fecal coliform, indicating that the people of Jashore Municipality may have a greater chance of being affected by pathogenic bacteria. The drinking water provided in the street side fast food stalls was biologically contaminated. The findings demonstrate that the drinking water used in food stalls and restaurants of Jashore Municipality did not meet up the potable drinking water quality standards and therefore was detrimental to public health.

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Efficiency of Arsenic and Iron Removal Plants (AIRPs) for Groundwater Treatment in Rural Areas of Southwest Bangladesh

Water ◽

10.3390/w13030354 ◽

2021 ◽

Vol 13 (3) ◽

pp. 354

Author(s):

Md. Aminur Rahman ◽

Sazal Kumar ◽

A. S. M. Fazle Bari ◽

Abhishek Sharma ◽

Mohammad Mahmudur Rahman

Keyword(s):

Drinking Water ◽

Cancer Risk ◽

Monsoon Season ◽

Cancer Risk Assessment ◽

Future Research ◽

Treated Water ◽

Post Monsoon ◽

Drinking Water Standard ◽

Guideline Value ◽

Removal Efficiencies

Arsenic (As) removal plants were installed in As-endemic areas of Bangladesh to remove As from well water. In many cases, these removal plants did not perform satisfactorily. This study evaluated the efficiency of 20 As and iron (Fe) removal plants (AIRPs) during pre- and post-monsoon conditions in rural Bangladesh. Results revealed that As removal efficiencies ranged from 67% to 98% and 74 to 93% during the pre- and post-monsoons periods, respectively. In the post-monsoon season As removal at individual AIRP sites was on average (4.01%) greater than in the pre-monsoon season. However, two removal plants were unable to remove As below 50 µg L−1 (Bangladesh drinking water standard) during pre-monsoon, while 11 samples out of 20 were unable to remove As below the WHO provisional guideline value of 10 µg L−1. During post-monsoon, none of the samples exceeded 50 µg L−1, but eight of them exceeded 10 µg L−1. The Fe removal efficiencies of AIRPs were evident in more than 80% samples. Although As removal efficiency was found to be substantial, a cancer risk assessment indicates that hazard quotient (HQ) and carcinogenic risk (CR) of As in treated water for adults and children are above the threshold limits. Thus, additional reductions of As concentrations in treated water are needed to further reduce the excess cancer risk due to As in drinking water. Since 55% and 40% of the AIRPs were unable to remove As < 10 µg L−1 during pre-monsoon and post-monsoon, further improvement including changes in AIRP design, regular cleaning of sludge, and periodic monitoring of water quality are suggested. Future research is needed to determine whether these modifications improve the performance of AIRPs.

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Minimization of the Disinfection by-Product Precursors in Treated Waters Exposed to Ozone and Chlorine

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.884-885.91 ◽

2014 ◽

Vol 884-885 ◽

pp. 91-95

Author(s):

Shang Chao Yue ◽

Le Jun Zhao ◽

Xiu Duo Wang ◽

Qi Shan Wang ◽

Feng Hua He

Keyword(s):

Drinking Water ◽

Organic Carbon ◽

Dissolved Organic Carbon ◽

Water Supply ◽

River Water ◽

Water Samples ◽

Full Scale ◽

Ultraviolet Absorbance ◽

Treatment Processes ◽

Removal Efficiencies

The objectives of this study were to investigate impact of preoxidation on disinfection by-product (DBP) precursors in drinking water via two different preoxidation methods. The full-scale study was conducted on surface river water in a water supply plant in Tianjin, China. Two treatment trains were performed, with prechlorination and preozonation as preoxidation methods, respectively. The water samples were collected on different stages along the treatment processes and analyzed by following organic parameters: dissolved organic carbon (DOC), UV254 and specific ultraviolet absorbance (SUVA). The results indicated that Train 2 with preozonation was more effective to reduce DBP precursors. Preozonation possessed an excellent ability in the removal of UV254 and SUVA, the removal efficiencies were 25.14% and 18.77%, respectively, comparing to the removal rates of 6.66% and 5.64% during prechlorination, separately.

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