Tinospora cordifolia – AS BIOADSORBENT FOR REMOVAL OF FLUORIDE FROM WATER

International Research Journal of Engineering and Technology (IRJET) e ISSN: 2395 0056

Volume: 09 Issue: 07 | July 2022 www.irjet.net p ISSN: 2395 0072

Tinospora cordifolia – AS BIOADSORBENT FOR REMOVAL OF FLUORIDE FROM WATER

1M.Tech Scholar in Environmental Engineering, Department of Civil Engineering, M.Dasan Institute of Technology, Kozhikode, Kerala, India

2Associate Professor, Department of Mechanical Engineering, M.Dasan Institute of Technology, Kozhikode, Kerala, India ***

Abstract An adsorption study in a batch and column was carried out by using Tinospora cordifolia as a bio adsorbent for the removal of fluoride from water. In the batch study the adsorbent size, adsorbent dosage, initial fluoride concentration and the time of contact are considered. The adsorbent is dried using the sunlight and powdered using grinder and sieved through the 300 μm, 150 μm, 75 μm sieves to obtain the corresponding particle size. Here we applied the adsorbent dosage as 1 g/l, 2.5 g/l and 3 g/l and the initial fluoride concentration as 3 mg/l, 5 mg/l and 7 mg/l. The contact time considered are 5 minutes,10 minutes,15 minutes,30 minutes and 45 minutes. The batch study shows that 150 μm sized adsorbent removed fluoride efficiently with a adsorbent dosage of 2.5 g/l and initial fluoride concentration of 3 mg/l with contact time of 30 minutes. On the basis of this the column study was conducted with adsorbent size 150 μm and initial fluoride concentration 3 mg/l. A column with diameter 50 mm and height 60 cm are used. The experiment conducted by varying the adsorbent bed depth as 15 cm, 25 cm and 35 cm and also varying the flow rate as 14 ml/min and 22 ml/min. The first cycle completed with this three bed depth and find out the best column. The column with bed depth 15 cm and flow rate 14 ml/min shows 87.97% fluoride removal. Then the second cycle repeated with this same parameter and find the saturation point for the column, after the saturation of the column the adsorbent required regeneration, here we used Sodium Hydroxide (NaOH) solution for this. After completing the second cycle the column is washed with NaOH solution and repeat the experiment as third cycle. About 90% of regeneration is achieved near to the saturation point.

Fluoride enters into the human body through a variety of sources like water, food, air, medicine, and cosmetics. Among these, drinking water is the most common source which makes fluoride available to human beings. Fluoride isknowntohavebothbeneficialanddetrimentaleffectson health, depending on the dose and duration of exposure. The desirable concentration of fluoride as F in drinking water is 1.0 mg/l. Low F content (< 0.60 mg/l) causes dental caries, whereas high (>1.20 mg/l) fluoride levels resultinfluorosis.Hence,itisessentialtohaveasafelimit of F concentration of between 0.60 and 1.20 mg/l in drinking water. The Bureau of Indian Standards (BIS) prescribed desirable limit as 1.0 mg/l and maximum permissible limit in the absence of alternate source as 1.5 mg/l. In India, about 62 million people are at risk of developing fluorosis from drinking high F water [6]. Low amount of fluoride is necessary in the prevention of tooth decay and the development of proper bone structure in humansandanimals.Itisconsideredtobeamicronutrient for humans since it prevents dental caries by decreasing the rate of demineralisation of the dental enamel or reverses the progression of existing decay by promoting the rate of remineralisation.High doses of fluoride leadto the development of dental and skeletal fluorosis, depending on the concentration of fluoride in drinking water[12].

Key

Words: Adsorption, Fluoride, Bio adsorbent, Regeneration,Removal

1. INTRODUCTION

The quality of water resources has been declining and deteriorating in recent years [8]. Fluoride is naturally found in many of the ground water sources. Consumption of water having excess fluoride over a prolonged period leadstoachronicailmentknownasfluorosis.Fluorosisisa cripplingdiseaseaffectingbones,teethandsofttissues[5].

Adsorption is the preferred technique for fluoride removalatcommunityandhouseholdlevelsinruralareas because of its low cost and ease of operation, high efficiency, easy accessibility, environmental benignity, and needlessofoperationalskillandelectricpowertorun,and since adsorbents can in principle be reused and recycled makingitidealforuseinlessdevelopedruralareas.Ithas the added advantage that it can be applied to a decentralized water supply system. The availability of different adsorbents inlarge amounts andlow costs make them potential candidates for the fluoride removal in remoteareas[16].

The main objectives of this study are to evaluate the performanceof Tinospora cordifolia as a bio adsorbentfor the fluoride removal of water, using batch study and columnperformance.Inthebatchstudyweareconsidering

International Research Journal of Engineering and Technology (IRJET) e ISSN: 2395 0056

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the parameters like Adsorbent dosage, Initial concentration,Sizeofadsorbentandcontacttime.Similarly in column performance we are considering Initial concentration, Bed depth and Flow rate. And to check the possibility of regeneration study using NaOH as regenerant.

2. MATERIALS AND METHODOLOGY

2.1 Adsorbent Used

Tinospora cordifolia commonly known as “Chittamrit” in Kerala state, India belongs to Menispermaceae family of kingdomPlantaeusedasadsorbentmaterialforthestudy. It is a genetically diverse, large, deciduous climbing shrub mainly found at higher altitude. Some variety of active componentsderivedfromtheplantlikesteroids,aliphatics, diterpenoidlactones,alkaloids,andglycosidesareisolated fromthedifferentpartsoftheplant,likeroot,stem,leaves etc

2.2 Adsorbent Preparation

Inthisstudyweareusingtheplantstemforconducting theexperiment.Thestemoftheplantiscollectedand itis washed with distilled water to remove the dust and other impurities. Then the stem is shredded into small size to ensure fast drying. The shredded stem is allowed to dry undersunlighttillcompletemoistureisremovedandthen itispowderedwiththehelpofgrinderandsievedthrough 300 micron, 150 micron and 75 micron to obtain the respectedparticlesizeofadsorbent.

2.3 Preparation of Fluoride Solution

The required sample solution is made up by diluting the Fluoride standard solution traceable to SRM (Standard Reference Material) from NIST (National Institute of StandardsandTechnology)NaF inH2O,MadeinGermany, EMDMilliporeCorporation.

2.4 Batch Study

To study the effect of various controlling parameters like adsorbent size, adsorbent dosage, initial fluoride concentration,andtimeofcontactonthefluorideremoval capacity of Tinospora cordifolia. The batch experiments were conducted using a total sample volume of 1000 ml foreachadsorptionrun,andthesampleswereagitatedin a reciprocating shaker. The adsorbent size used for the experiment are 300 micron, 150 micron and 75 micron. The adsorbent dosage is taken as 1 g/l, 2.5 g/l and 3 g/l. The initial fluoride concentration of 3 mg/l. 5 mg/l and 7 mg/lareconsidered.5min,10min,15min,30minand45 min are considered as the contact time for this experiment.

2.5 Column Study

The column experiment for the removal of fluoride from the water by Tinospora cordifolia was performed using a 50 mm diameter and 60 cm length P.V.C pipe, and it is attached to a flow control valve for adjusting the flow throughthecolumn.

The adsorbent is sandwiched between the layers of glassbeadstopreventtheloss ofadsorbent.Thedepth of adsorbent is considered as 15 cm, 25 cm, and 35 cm and considering the flow rate as 14 ml/min and 22 ml/min. The prepared fluoridesolutionisallowedto passthrough the adsorbent in the column and the samples were collectedin5min,10min,15min.30minand45min for eachadsorptionrun.

(i) Breakthrough Study

Intheadsorptiontheadsorbentgetscompletelysaturated at some point due to the unavailability of adsorption site on adsorbent, and the adsorption starts decreasing. Thereafter the adsorbent become completely lifeless. To find this saturation point we continued second cycle with thebestcolumnselectedfromthecycle1columnstudy.

2.6 Regeneration of Bio-Adsorbent

In the environmental and economic aspects, the regeneration of adsorbent is very important. After every adsorptionrunthechancefortheadsorbentgetexhausted is possibly very high, to avoid this we need to regenerate the adsorption capacity of the adsorbent. Here we are using 0.1 M NaOH solution for this purpose. After the saturation of the adsorbent the NaOH solution is passed through the adsorbent bed, and fluoride removal is checkedagain.

3. RESULTS AND DISCUSSION

3.1 Batch Study

In the Batch study we are mainly considering the parameters such as adsorbent size, adsorbent dosage, initial fluoride concentration and time of contact, the detailed result of this parameters are included in the followingsections.

(i) Effect of Adsorbent Size

The study of the effect of adsorbent size on the fluoride removal efficiency was carried out by using 75 μm, 150 μmand300μmsizedadsorbent.

International Research Journal of Engineering and Technology (IRJET) e ISSN: 2395 0056

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88.47 89.27 80.53

2.5 g/l, 3 mg/l 2.5 g/l, 5 mg/l 2.5 g/l, 7 mg/l 1 g/l, 3 mg/l 1 g/l, 5 mg/l 1g/l, 7 mg/l 83.2

Fluoride Removal

Fig 1:EffectofAdsorbentsizeontheremovalefficiency ofFluoride.

Amaximumof89.27%removalisobtainedforthe150μm sized adsorbent and 88.47 % removal is obtained for 75μm sized adsorbent, but considering the 300 μm sized adsorbent the removal declines to 80.53%. Fig 1 shows the effect of adsorbent size on the fluoride removal capacityoftheadsorbents.

(ii) Effect of Adsorbent Dosage

Thestudyoftheeffectofadsorbentdosageonthefluoride removal efficiency was carried out with a dosage of 1 g/l, 2.5 g/l and 3 g/l. The study is done by keeping the adsorbent size as 150 μm and varying the initial fluoride concentrationas3mg/l,5mg/land7mg/l.

With initial fluoride concentration 3 mg/l and adsorbent dosage 2.5 g/l and 3 g/l shows a removal of 89.27% and 89.20% respectively, and 83.20% fluoride removal for 1 g/l adsorbent dosage. Similarly for 5 mg/l initialfluorideconcentration82.58%removalachievedfor both 2.5 g/l and 3 g/l adsorbent dosage and 82.30% obtainedfor1g/l adsorbentdosage.Inthecaseof7mg/l initial concentration, 80.89% and 80.87% fluoride removal achieved for 2.5 g/l and 3 g/l and 78.80% removalfor1g/ladsorbentdosage.Fromthisanalysisitis clear that 2.5 g/l adsorbent dosage shows better removal thantheotherdosagesconsidered.

89.27 89.2 82.3 82.58 82.58 78.8 80.89 80.87 72 74 76 78 80 82 84 86 88 90 92 1 2.5 3

Adssorbent Dosage (g/l)

Fig 2: EffectofAdsorbentDosageontheremoval efficiencyofFluoride.

Fig 2 shows the effect of adsorbent dosage on the fluorideremovalcapacityoftheadsorbents.

(iii) Effect of Initial Fluoride Concentration

Theeffectofinitialconcentrationontheextentofremoval of the fluoride was studied by varying the concentrations from 3 mg/l, 5 mg/l and 7 mg/l. While keeping the adsorbentsizeas150μmandadsorbentdosageas2.5g/l.

Forthisstudytwocontacttimeareconsidered15minutes and 30 minutes, the initial concentration with 3 mg/l shows89.27%fluoridein30minutesand86.87%fluoride removal in 15 minutes. For 5 mg/l initial fluoride concentration shows 82.92% removal in 30 minutes and 82.58% in 15 minutes. And 80.89% and 82.04% fluoride removal for 7 mg/l initial fluoride concentration at 30 minutesand15minutesrespectively

2.5 g/l, 15 min 2.5 g/l, 30 min

88

86

3 mg/l 5 mg/l 7 mg/l 89.27 82.92 80.89 80

90 2 3 4 5 6 7 8

84

82

Fluoride Removal (%) Initial Fluoride Concentration (mg/l)

Fig 3: EffectofInitialFluorideConcntrationonthe removalefficiencyofFluoride.

The results obtained were plotted as percentage removal of fluoride versus initial concentration of the fluoride ion in the solution as shown in Fig.3. We can see

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that the percentage removal of the fluoride ion has decreased with an increase in initial concentration of the fluorideion.

(iv) Effect of Contact Time

The study of the effect of contact time on the fluoride removal efficiency wascarriedout byvaryingitfrom 5 to 45 minutes, keeping the adsorbent size as 150 μm, adsorbent dosage as 2.5 g/l and with an initial concentrationof3mg/l.

adsorbent gets fully saturated and hence further increase inadsorptionwillnotoccur.

3.2 Column Study

From the batch study we noted that the adsorbent Tinospora cordifolia shows better performance with adsorbent size 150 μm and for an initial fluoride concentration of 3 mg/l for 30 minutes at an adsorbent dosage of 2.5 g/l. In the column study we are mainly considering the parameters such as depth of adsorbent bedandtheflowrate.

(i) Effect of Adsorbent Bed Depth

Fig 4: EffectofTimeonFluorideRemoval

Fig.4 shows the effect of contact time on the fluoride removal capacity of the adsorbents. As contact time increases percent removal also increases initially and gradually attains almost an equilibrium condition in nearly 30 minutes. A maximum of 89.27% removal could beaccomplishedbytheadsorbent Tinospora cordifolia.

Forthissetofexperimentthebeddepthistakenas15cm, 25 cm and 35 cm, we have passed the 3 mg/l fluoride solution through the column and collected the samples at an interval of 5 min, 10 min, 15 min, 30 min and 45 min with flow rate of 14 ml/min and 22 ml/min. A fluoride removalof87.97%isobtainedfor15cmbeddepth,87.30 %and85.97%offluorideremovalareachievedbycolumn withadsorbentbeddepth25cmand35cmrespectivelyat the flow rate of 14 ml/min. From this analysis it is clear thatfor14ml/minflowrate,effectofadsorbentbeddepth on fluoride removal is negligible, but in 22 ml/min flow rate the fluoride removal increases with increase in adsorbent bed depth. That is if flow rate increases the depthrequiredarealsomoreformoreadsorbentsites.

(ii) Effect of Flow Rate

In the column study 14 ml/min and 22 ml/min discharge is considered. The 14 ml/min flow rate shows better removal in all adsorbent bed depth considered. The 22 ml/min shows less removal, this is due to the time of holding the fluoride solution in the adsorbent column is less in higher flow rate and which is higher in low flow rate. For 14 ml/min the final fluoride concentration at 5 minutesis0.638mg/landitdecreasedto0.361mg/lin45 minutes. In 22 ml/min flow rate final fluoride concentration observed as 0.652 mg/l at 5 minutes and decreased to 0.495 mg/l at 30 minutes. From this it is clearthatifflowrateincreasestheadsorptiondecreases.

(iii) Effect of Time on Final Fluoride Concentration

Fig 5: FinalFluorideConcentrationversesTime(Batch Study)

The final fluoride concentration verses time graph is shown in the Fig.5, the gradual decrease in final fluoride level is observed after 30 minutes there is no further decreaseobserved.Aftershowingthehighestremovalthe

The

fluoride concentration verses time graph is shown in Fig.6, for 5 minutes all bed depth and flow rate showalmostsameremoval.

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0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 0 5 10 15 20

15 cm, 14 ml/min 15 cm, 22 ml/min 25 cm, 14 ml/min 25 cm, 22 ml/min 35 cm, 14 ml/min 35 cm, 22 ml/min

3.3 Regeneration Study

Before throwing the adsorbent after its saturation we need to check the possibility of regeneration. Sodium Hydroxidesolutionwasusedasregenerant

Fig 6: FinalFluorideConcentrationversesTime(Column Study)

The bestremoval observed forthecolumnwith15cm beddepthand14ml/minflowratefor5minutesthefinal fluoride concentration is 0.683 mg/l and the minimum fluoride concentration observed at 45 minutes as 0.361 mg/l.

(iv) Break through Study

Breakthrough analysis shows, the fluoride removal increases gradually in the initial phase and after some pointitbecomestablewhichmeansthereisnoincreasein adsorptiontakesplace.

A fluoride removal of 78.20% obtained at 5 minutes and increases gradually increased to 87.27% removal at 75 minutes. After 75 minutes there is no further increase in adsorption occurs, and at 105 minutes a small drop in fluoride removal occurs. The graph represents stable line from75minutesto90minutesandthenitdeclineswhich meanstheremovalefficiencydecreases.

Removal (%) Time (Min)

Fig 7: BreakthroughCurve.

The highest fluoride removal achieved at 75 minutes andat105minutesasmalldropinfluorideoccurs.

Fig 8: EffectofNaOHonRegenerationofAdsorbent.

After saturation of the adsorbent column in cycle 2 is washedwithNaOHsolution.Initiallyafluorideremovalof 74.03% occurs at 5 minutes and it gradually increases to 75.87% in 10 minutes, 76.87% in 15 minutes, 77.47% in 30minutes,78.80%in45minutes,79.30%in60minutes, 79.67% in 75 minutes, 80.03% in 90 minutes and the highest removal of 80.10% in 105 minutes and 120 minutes, which shows that the regenerated adsorbent get saturated and no further increase in adsorption occurs. After 135 minutes the removal gets a slight decline to 79.90%.

This study shows that the regeneration of adsorbent is possible for the adsorbent used in this experiment. 90% regeneration of adsorbent is achieved near to the saturationpoint.

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The Fig 9 shows the comparison between cycle 2 and cycle3.Incycle2,amaximumof87.27%fluorideremoval occursandincycle3itdeclinesto80.10%.

4. CONCLUSIONS

The fluoride contamination in the water is very serious issue faced in many places in the world. The plant Tinospora cordifolia as a bio adsorbent used for the removaloffluoridefromthewaterisanaturallyoccurring material with great availablity, it possesses some medicinalvaluesandmoreoverwithhighfluorideremoval efficiency.

Inthisstudyweconductedabatchstudyandacolumn study, in the batch study we are mainly considered four parameters namely Adsorbent size, adsorbent dosage, Initial fluoride concentration and time of contact. The adsorbent size used for this experiment are 75 μm, 150 μm,and300μm.Theadsorbentdosage1g/l,2.5g/land3 g/l.Theinitialfluorideconcentrationof3mg/l,5mg/land 7mg/larechosen.Thetimevaryingfrom5minutesto45 minutes as time of contact. After the batch experiments withthisparameter,weobtainedbestfluorideremovalfor adsorbentsize150μmandaninitialconcentration3mg/l withadsorbentdosage2.5g/lat30minutestime.

Onthebasisoftheresultobtainedfromthebatchstudy we are conducted the column study using 150 μm sized adsorbent and with an initial fluoride concentration of 3 mg/l. In the column study we are mainly focusing on the adsorbent bed depth and flow rate through the column. For this study we are chosen three adsorbent bed depths 15 cm, 25 cm and 35 cm. And two flow rates 14 ml/min and 22 ml/min. As the first cycle of the column study has completed, we noticed that column of 15 cm bed depth with14ml/minflowrateshows87.97%fluorideremoval. After this we need to find out the saturation point of the column for breakthrough analysis of adsorbent. In the second cycle with bed depth 15 cm and flow rate 14ml/min,theexperimentcontinuesassimilartothefirst cycle the fluoride removal increases gradually to 87.27 % and after 75 minutes it become stable which means that the adsorbent gets saturated, no further increase in removalispossibleusingthesameadsorbentbed.

Asthecolumngetsaturatedinthesecondcycle,before throwing it we need to try a regeneration study on it. UsingNaOHsolutionthecolumniswashedandcontinued thethirdcycle.The74.03%fluorideremovalin5minutes and gradually increases to 80.03% in 90 minutes and 80.10% 105 minutes, after 105 minutes no further increaseinremovalseeninthecolumn.Bycomparingthe cycle 2 and cycle 3 around 90% of regeneration achieved neartothesaturationpoint.

Fromthissetsofexperiments,wecanconcludethatthe plant Tinospora cordifolia can be used for adsorbent for removing fluoride from water, as it shows high removal efficiencyandregenerationcharacteristics.

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