REVIEW OF THE RELATED LITERATURE. drinking water are essential as well as toxic depending on their levels. For

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1 REVIEW OF THE RELATED LITERATURE This paper discussed on Fluoride and iodide, the most imp. constituents of drinking water are essential as well as toxic depending on their levels. For their analysis in water mostly ion selective electrodes, spectrophotometry, titrimetry and colourimetry etc. have been used. During this work Ion Selctive electrodes offer an efficient method for the measurement of the two halides were mostly used. This paper focuses on ion selective electrodes are being used extensively for the analysis of different anions and cations in general fluoride and iodide in particular.[2] These researchers studied on fluoride contamination in drinking water due to natural & anthropogenic activities has been recognised as one of the major problems world wide imposing a serious threat to human health. For research work here adsorption process is used. For this Alumina and aluminium-based adsorbents are used for defluoridation of water. [3] In this study it was found that groundwater of Tonk dist. is contaminated with fluoride by naturally fluoride rich rock salt system. Physiochemical analysis has main consideration to asses the quality of water for it best utilization like drinking, irrigation. The result of this study helps in enhancing awareness of health hazards of contaminated water.[4] This paper discussed on fast spcetrometric determination of fluoride in ground waters by flow injection using partial least- squares calibration.fluoride plays a central role in the prevention of dental caries, and is regularly employed for this purpose in drinking water.

2 By these researchers, a series of real ground water samples was analysed by means of the proposed method and observed that, these natural water samples not only contain fluoride and sulphate but also the other components. This paper focuses on how injection analysis combined with multivariate calibration of absorption spectra appears to be an excellent analytical resource for determination of fluoride in water samples.[5] This paper discussed on the defluoridation of drinking water using burnt bricks. Fluoride is an essertial trace element in the formation of bone and teeth animals. Fluoride in excess amount lead to dental and skeletal fluorosis. Defluoridation is the removal of excess fluoride for this burnt brick powder is used as an adsorbent. The advantage of using brick powder are it is porous material & hence the adsorption process increases. It is economical and efficient burnt brick powder is easily available.[6] This paper discussed on evaluation of fluoride bottled water and its incidence in fluoride endemic and non endemic areas. Many developed countries have chosen fluoride as one of priority substance to be assesed in order to evaluate its impact on the environment and human health. The purpose of this study is to quantify fluorides present in bottled waters sold in Algerian market to establish a checkup of daily fluoride in take via water and to control if the labeling mention the fluoride content according to the regulation.[7] Fluoride contamination in drinking water is a burning enviornmental issue of the world today. The paper focuses on in order to migrate the rising problem of fluorosis one has to ensure fluoride free safe drinking water to the

3 rural communication of Purulia. This involve selection of area specific appropriating technology for safe water supply and sustaitanably of the programme through active participation of the user community. [8] This paper discussed on determination of fluoride contents in drinking water in vicinity areas of Shirpur Taluka. The researcher collected 21 water samples from different villages and concentration of Fluoride was done by using potentiometer. They use Fluoride ion selective electrode for determination of concentration of Fluoride.[9] These papers discussed on ground water, ground water is ultimate and most suitable fresh water resource for human consumption in both urban as well as rural areas. Ground water is also frequently using as the alternative source for agricultural and industrial sector. [10, 11] In this article, the removal of fluoride from diluted solution with Neosepta AHA anion exchange membrane has been studied by Donnan dialysis. The amount of fluoride ion in groundwater for some places in the world exceeds the acceptable values. Therefore various methods for removal of fluoride ions from groundwater have been investigated.[12] The present study calculate the Water Quality Index (W.Q.I.). for this physico-chemical parameters were monitored for the calculation of W.Q.I. for the rainy, winter and summer seasons. The water quality index values in the present investigation are reported to be less than 75 (67.20, and 70.37) for different season indicating that the water quality is poor and totally safe for human comsumption.[13]

4 In this study, The authors investigated the fluoride levels in urine and drinking water. Urinary samples were collected form 130 healthy saudi adults aged years old. Fluoride concentrations in urine and water samples were measured with the fluoride specific electrode using an Orion Research ph meter after dilution of each sample (1:1) with total ionic strength adjustment buffer. The mean ( ± SD) value of urinary fluoride was ugm L with range of ugm L. The levels of fluoride in water was ugm L with range of ugm L. [14] In this article it is stated that, Dibrugarh district of Assam is famous for tea production. Major area of the district is covered by large number of small and big tea gardens. Tea gardens use huge amount of fertilizers and pesticides, which are potential sources of fluoride. In this study, monitored the fluoride level and some other parameters of groundwater of a large area occupied by different types of small and big tea gardens. Fluoride level in the groundwater of tea garden area is found slightly greater than another area.[15] This study was carried out to analyse developments in the analysis of fluoride- ( ). A fluoride electrode assembly was examined in terms of potential- concentration curves and potential- time response. The behaviour of the F- ion - selective electrode ( FISE ) with the studied internal contact based on a copper (II) ion - selective electrode was in good agreement with the commercial fluoride electrode. In this paper a new chemical method for the determination of fluoride in samples with high fluoride content such as tooth paste has been reported. The method is fast and relatively free from interference.[16]

5 This paper focuses on the defluoridation of drinking water using multiwalled carbon nano tubes. In this study, the potential sorption capacity of multi walled carbon nano tubes ( MWCNT s) was investigated as a means of removing fluoride from drinking water. The important thing in this paper is (MWCNTs) were used to remove fluoride from both experimental solutions and natural drinking water for the 1st time.[17] Present investigation aims to remove fluoride by polycinnamamide thorium (IV) phosphate. Fluoride toxicity is characterized by variety of signs and symptoms. Fluoride related health hazards (fluorosis) are a major environmental problem in many regions of the world. Polycinnamamide thorium (IV) phosphate, a fibrous ion exchanger have synthesized from cinnamamide thorium nitrate and phosphoric acid by co-precipitation method. This technique of removal may be suitably employed to treat potable water where conc. of fluoride is not high.[18] In this paper water samples were collected from various water types (ground water from tube well, and dug wells and hot spring water) in polythene bottles. In this article it can be concluded that, high conc. of fluoride in groundwater in the area is mainly due to the presence the hot spring and its interaction with surrounding groundwater and surface water and the topography aerial extent of fluoride contamination.[19] This paper discussed on the value of ph. range among 6.8 to 8.3. It is in the prescribed limit of ICMR ( Indian Council of Medical Research ). A little bit increase in ph level may depress the effectiveness of the disinfectants like chlorination there by requiring the additional chlorines, Dissolved oxygen ranges from mg / L. D.O. indicating the nearly pure symptoms[20]

6 This paper focuses on when fluoride is ingested, some is take up by body tissues, with long term deposition in teeth and bones. The major sources of ingested fluoride are water and other dietary sources including tea, food and drinks prepared with fluoridated water. [21] This study was carried out to analyze groundwater quality. Fluoride concentration was recorded in the range of mg/l. As per the desirable and maximum permissible limits for fluoride in drinking water recommended by WHO and by Bureau of Indian Standards (BIS), which is 1.5 mg/l. [22] In this article an attempt was made to investigate the removal of fluoride, arsenic and coliform bacteria from drinking water using modified homemade filter media. The physico-chemical and biological analysis is of water samples had been done before and after the treatment. The objective of this study is to make a modified homemade slow sand filter media to determine its efficiency for removal of impurities from drinking water to make it potable.[23] A new water-soluble fluorescent fluoride ion signaling system has been developed based on the ligand exchange mechanism in aqueous medium. This procedure is based on the exchnge of two Alizarin Red S (ARS) molecules coordinated to A1 (III) by fluride ion without interference from other common anions.[24] In this paper the results of the work show that most of the physicochemical parameters like ph, TDS, TH, TA, F and NO 3 are more than desirable limit of BIS.[25] This paper discussed on fluoride in water is an essential for human beings and its deficiency as well as higher concentration both is injurious to human

7 health. Flouride occurs in almost all natural water supplies. Fluorides in high concentrations are not a common constituent of surface water, but they may occur in detrimental concentrations in ground waters. Such studies will help to solve the fluoride problem in ground water by hydrogeological and geochemical information.[26] In this present research work, biopolymer chitosan has been modified by impregnation of lanthanum to enhance the fluoride removal capacity of chitosan. The adsorbent has been characterized with XRD, SEM and FTIR studies. From present investigation it can be inferred that LCF can be used for removal of fluoride from drinking water. [27] The results of this article reveal that low cost, locally available industrial waste material generated from aluminium sulphate manufacturing process promissing material to remove excess fluoride from water. The ability of waste residue, generated from alum manufacturing process, to remove fluoride ion from water has been investigated. The overall results of this article show that the waste residue is efficient defluoridating material from water. [28] In the present paper an attempt has been made to understand hydrochemical composition of groundwater as well as fluoride concentration in shallow and deeper aquifers. The origin of fluoride content in water and the remedial measures for control of fluorosis are discussed.[29] In this paper new simple and sensitive Spectrophotometric determination of fluoride in drinking ground water has been developed using aluminiumresorcin blue complex. This method is base on the reaction of fluoride with the coloured complex to produce colourless aluminium fluoride complex and releasing of the free ligand. This study aimed to develop spectrophotometric

8 method for determination of fluoride in drinking water using aluminium resorcin blue complex with fluoride ions. [30]