research article infrared spectroscopic study on the...

Research ArticleInfrared Spectroscopic Study on the Modified Mechanism ofAluminum-Impregnated Bone Charcoal

Hao Li1 Yufan Yang2 Shuangjun Yang3 Anpu Chen1 and Dazuo Yang4

1 College of Chemistry Sichuan University Chengdu Sichuan 610064 China2West China School of Public Health Sichuan University Sichuan 610064 China3 College of Light Industry Sichuan University Chengdu Sichuan 610064 China4College of Life Science and Technology Dalian University of Technology Dalian 116021 China

Correspondence should be addressed to Hao Li lihao chem 92hotmailcom

Received 16 May 2014 Accepted 2 June 2014 Published 22 June 2014

Academic Editor Qingrui Zhang

Copyright copy 2014 Hao Li et al This is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Fluoride contamination in drinking water is a prominent and widespread problem in many parts of the world Excessive ingestionof fluoride through water can lead to the high risk of fluorosis in human body Bone charcoal with the principal active componentof hydroxyapatite is a frequently used adsorbent for fluoride removal Many laboratory experiments suggest that the aluminum-impregnated bone charcoal is an effective adsorbent in defluoridation However the mechanisms underlying this modificationprocess are still not well understood which in turn greatly impedes the further studies on other different modified adsorbents Toaddress this issue we used the infrared spectroscopy to examine the bone charcoal and the aluminum-impregnated bone charcoalrespectively The comparative results show that the minusOH peak of infrared spectroscopy has been intensified after modificationThis significant change helped speculate the modified mechanism of the aluminum-impregnated bone charcoal In additionit is found that the hydroxide ion dissociates from hydroxyapatite in the modification process Such finding implies that thetetrahydroxoaluminate can be combined with the hydroxyapatite and the aluminum ion can be impregnated onto the bone charsurface

1 Introduction

Fluoride is widely distributed in nature which mainly existsin lithosphere hydrosphere biosphere and atmosphere [12] Most fluorides are soluble even the lowest solubility ofcalcium fluoride can reach 40mgL in normal condition [3]The soluble fluorides in rocks can dissolve in water which arethe main sources of the fluorides in fresh water Thereforehumans obtain fluorides largely from drinking water [4]There exists about 2 to 3 g (commonly 26 g) fluorine in ahealthy adult body 90 of which distributes in bones andteeth [5 6] A trace of fluorine is useful to prevent saprodontiabut excessive amount tends to be harmful [7 8] It is supposedto be poisonous if the intake of fluorine is higher than 4mgdtherefore people are more likely to develop fluorosis of bonewhen the amount of fluorine in drinking water is more than4 ppm [9]

As the fluorine-containing substances are increasinglyapplied in industry the amount of the fluorine-containing

wasted water tends to become higher Purification anddefluoridation of high-fluorinated drinkingwater have drawnmore andmore attention Conventional methods of defluori-dation are precipitation and adsorption [10ndash13] Adsorptionmethod is mainly used in the deep disposal of low fluorine-containing waste water and natural water Because theadsorption method of disposing fluorine-containing wastewater has the advantages of lower cost and higher removalrate [14] the modification of traditional fluorine removalagent and the research of new fluorine removal materialsare popular topic in relative area [15ndash17] Traditional fluorineremoval agents include alumina natural zeolite and rareearth while the new adsorbent with good adsorption effects iscalcium aluminate slag aluminum sulfate modified bamboocharcoal and bone charcoal [18ndash23] In the midst of theseadsorbents bone charcoal is now considered to be oneof the most recommendatory adsorbents in defluoridationsince World Health Organization regarded bone charcoal as

Hindawi Publishing CorporationJournal of SpectroscopyVolume 2014 Article ID 671956 7 pageshttpdxdoiorg1011552014671956

2 Journal of Spectroscopy

40mL saturatedsolution of AlCl3

Modified bonecharcoal

Ultrasonicimmersion

20 g bone charcoalparticle size

48 hoursmm08sim12

+

Figure 1 Manufacturing approach of aluminum-impregnated bone charcoal

the high-performance absorbent of fluorion in undevelopedregions [24] Based on this reason we aimed at studying thedefluoridation effect of bone charcoal and finding out themechanism of the modification and adsorption

Bone charcoal is a porous black granular materialproduced by charring animal bones [25] It is made up ofhydroxyapatite (57ndash80) calcium carbonate (6ndash10) andactivated carbon (7ndash10) In the development of purificationbone charcoal was primarily used for filtration and decolouri-sation which can also adsorb a large quantity of pollutantslike pigments as well as fluorinion from water [26] Based onthe absorption theory the hydroxylapatite in bone chars canbe used to remove fluoride andmetal ions fromwatermakingit useful for the treatment of drinking supplies

Adsorption is a separation method with the equilibriumprincipleThemain components of bone charcoal are hydrox-yapatite The mechanism of the removal of fluorine is mainlythe adsorption and ion exchange reaction which is shown asfollows

Ca10(PO4)

6(OH)2+ 2Fminus 997888rarr Ca

10(PO4)

6F2+ 2OHminus (1)

Previous research [27] reported that being immersed inaluminum solution for certain temporal bone charcoal canbe modified The aluminum can impregnate onto the surfaceof bone charcoal improving the effect of the defluoridationwhich is the main core of our work However although thisnovel modified approach to optimize the performance ofaluminum-impregnated bone charcoal in defluoridation hasbeen discovered the mechanism of the modification is stillundefined It is undoubtedly a huge impediment for us toexplore the further studies of modified adsorbent Thereforewe paid our attention to construct a probable reaction duringthe modified process in order to resolve this crucial problem

Infrared spectroscopy is one of the most common ana-lytic techniques in material characterization [28] It is thespectroscopy that deals with the infrared region of theelectromagnetic spectrum with longer wavelength and lowerfrequency compared to the visible light It covers a rangeof techniques mostly based on absorption spectroscopyAs with all spectroscopic techniques it can be used tostudy chemicals and relative substances [29] In recent yearsthere are more and more explorations of reaction mech-anism detected by spectroscopic methods [30ndash37] Greenand his coworkers [30] obtained the information of dualcatalytic sites during oxidation of CO on AuTiO

2catalyst

by spectroscopic observation Roithova [31] concluded thecharacterization approaches of reaction intermediates by ionspectroscopy Acik and his coworkers [32] have detectedthe role of oxygen during thermal reduction of grapheneoxide using infrared absorption spectroscopy Black andhis coworkers [33] used spectroscopic method to screen

for superoxide reactivity in LindashO2batteries Chen and his

coworkers [34] used FT-IR spectroscopy as a part of theinstruments to determine mechanisms in water-gas-shiftreaction on AuCeO

2 Huang and his coworkers [35] uti-

lized surface-enhanced Raman spectroscopy to study p-aminothiophenol Costa and his coworkers [36] used relativespectroscopic methods to determine the clues to the internalbarrier layer capacitance mechanism Xu and his coworkers[37] clarified the thermal deterioration mechanism of bio-oilpyrolyzed from rice husk using Fourier transform infraredspectroscopyThe common point of the studies listed above isthat all of them utilized the relative spectroscopic approachesto determine or infer themechanism of the chemical reactionand process proving that the spectroscopy is an availableapproach to estimate the mechanism of chemical reactionsWhat is worthmentioning is that all of these listed researcheswere published in the recent three years showing that usingspectroscopic approaches to establish the conjecture of chem-ical reactions is becoming a popular method among relativeacademic fields Since detecting the modified mechanism ofaluminum-impregnated bone charcoal and calculating themain reaction process by themodeling approach are difficultin our study we innovatively used infrared spectroscopy toobtain the infrared spectrums of the modified bone charcoaland the unmodified one so that the mechanism can beinferred during the change of the modification

2 Materials and Methods

21 Material Source and Treatment Raw materials of bonecharcoal in our experiments were supplied by LangfangHuaya Water Treatment Ltd Hebei Province China All thebone charcoals were sieved by screens of which the gran-ularity is approximately from 08 to 12mm Because of theadsorptionmechanism shown in (1) alkaline environment ofsolution can provide a better effect of defluoridation thus toensure the good adsorbabilitymaterials were firstly immersedin saturated solution of sodium hydrate for 12 hours and thenimmersed in deionized water for 12 hours After repetitivescrubbing these raw bone charcoals were stoved by electricthermostatic drying oven under the temperature of 120∘CAfterwards the bone charcoals were sealed in the desiccator

The manufacturing approach of aluminum-impregnatedbone charcoal in our study met the standards of modifiedapproaches created by previous studies 20 g bone charcoalwas immersed in 40mL saturated solution of AlCl

3 and

the modification system was immersed in the ultrasonicoscillator so that aluminum ion can impregnate onto thebone charcoal better The modification procedure is shownin Figure 1

Journal of Spectroscopy 3

Figure 2 Aluminum-impregnated bone charcoal

To guarantee the modification we chose the saturatedsolution so the aluminum ion can impregnate onto the bonecharcoal during the process of ultrasonic immersion Thedried aluminum-impregnated bone charcoal is shown asFigure 2

The aluminum-impregnated bone charcoal takes on acolor of silvery white and grey while the unmodified bonecharcoal is atrousThe change of macroscopic features can beobserved obviously from this characteristic

For comparison we also designed a series of othermodified bone charcoals After the testing results ferri-impregnated bone charcoal and magnesium-impregnatedbone charcoal are also considered to be good modifiedadsorbents with high removal rates of fluorinion Thereforewe used these two modified bone charcoals together withthe blank control group (those ultrasonic immersed inthe saturated solution of sodium hydroxide) as the controlgroups in the analysis of adsorption isotherm (see Section 31Adsorption Isotherm)

22 Preparation of Fluoride Solution The sodium fluoride(NaF AR) with deionized water configured to stock fluorin-ion solution of 10 gL Then it was diluted to be 50mgLas to be used for the follow-up test This actual initial massconcentrationwas determined by fluoride selective electrode

23 Adsorption Isotherms To test the rationality of choos-ing aluminum-impregnated bone char as the object ofstudy we chose ferri-impregnated bone charcoal aluminum-impregnated bone charcoal and magnesium-impregnatedbone charcoal as the main objects of studying the adsorp-tion isotherms All the metal-modified bone charcoals weremodified under the same conditions and procedures Inaddition those raw bone charcoals immersed in the saturatedsolution of sodium hydroxide ultrasonically were taken asthe blank control group In the midst of these four typesof bone charcoal each kind of bone charcoals was dividedinto 6 groups respectively 02 04 08 12 16 and 20 gAfter three-hour defluoridation adsorption isotherms weredeveloped during sample analysis

3 Results and Discussion

31 Adsorption Isotherm Previous studies show that theadsorption process of bone charcoal is corresponded with

055

050

045

040

035

030

025

020

015

010

005

Adso

rbed

amou

nt (m

gg)

Equilibrium concentration (mgL)0 2 4

NaOHAl

MgFe

Figure 3 Adsorption isotherms of different modified bone char-coals in defluoridation

Langmuir isotherm [38ndash41] which is an ordinary adsorptionprocess of general adsorbents For a better comparisonseveral modification experiments with different immersedions were done and we obtained the adsorption isothermsfor different ion-modified bone charcoal in defluoridationwhich is shown in Figure 3 (blank control group bonecharcoal immersed in saturated solution of sodium hydrate)

Results shown in Figure 3 indicate the descending orderof the corresponding defluoridation efficiency as followsferri-impregnated bone charcoal aluminum-impregnatedbone charcoal magnesium-impregnated bone charcoal andsodium hydrate immersed bone charcoal Nevertheless ourexperimental results are quite different from Shenrsquos previ-ous study [42] In Shenrsquos study the defluoridation effectof aluminum bone charcoal is higher than those of ferri-impregnated bone charcoal However due to the differentsource of raw bone charcoals and the precise procedure ofour modification experiments we considered our results areaccurate and reliable

Although ferri-impregnated bone charcoal had the bestdefluoridation effect in our experiments however ferri ionis toxic and harmful to human body which means that itcannot be applied to the practical applications [43]Thereforealuminum-impregnated bone charcoal is still the most ratio-nal option for defluoridation Besides results also prove thatthe aluminum-impregnated bone charcoal of our research iseffective and can be used for further studies of the modifiedmechanism

32 Infrared Spectroscopic Study on Aluminum-ImpregnatedBone Charcoal In order to study the modified mechanismof aluminum-impregnated bone charcoal two samples fromthe same raw bone charcoal were determined by infraredspectrum Figure 4 shows the infrared spectrum of raw bonecharcoal without modification while Figure 5 shows theinfrared spectrum of aluminum-impregnated bone charcoal

4 Journal of SpectroscopyTr

ansm

ittan

ce (

)

Without modification

Wavenumber

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

20

4000 3500 3000 2500 2000 1500 1000

(cmminus1)

Figure 4 Infrared spectrumof bone charcoal withoutmodification

Tran

smitt

ance

()

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

4000 3500 3000 2500 2000 1500 1000

Aluminum-impregnated modification

Wavenumber (cmminus1)

Figure 5 Infrared spectrum of aluminum-impregnated bone char-coal

Figures 4 and 5 show the infrared spectrums of the twosamples of bone charcoal respectively It is obvious that thereare some differences of the peaks between the two infraredspectrumsThe arrow heads in Figures 4 and 5 are the indexesof thesemain differences In order to present these differencesin a more evident way Figures 4 and 5 were overlapped intothe one picture which is shown in Figure 6

Figure 6 depicts an interesting phenomenon after mod-ification in the stretching vibration area of hydrogen bondheld together with ndashOH intensity of the typical absorptionband of hydroxyapatite (3400 cmminus1 nearby) [44 45] hasrisen obviously In contrast other peaks have tiny significantchange This strange phenomenon attracted our attentionunder the theoretically dry condition how to explain thisbizarre change of the peak

To explain the interesting phenomenon presented inFigure 6 we should consider the possible reaction betweenaluminum ion and bone charcoal at first One of themost striking explanations of this phenomenon is thatanion exchange has happened during the modified processHydroxide ion is dissociated from CandashOH during the anionexchange elevating the PH value Under this circumstancealuminum ion can combine with hydroxyl ion formingtetrahydroxoaluminate ion Based on this conjecture the

Tran

smitt

ance

()

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

20

4000 3500 3000 2500 2000 1500 1000




Figure 6 The overlapped infrared spectrum of Figures 4 and 5

modified mechanism is constructed as the reaction shown asfollows

Ca10(PO4)

6(OH)2+ Al (OH)minus

4

997888rarr Ca10(PO4)

6OH sdot Al (OH)

4+OHminus

(2)

In previous study Chen and her coworkers [46] offeredan explanation for the mechanism of removal of arsenic (V)using bone charcoal as the adsorbent

Ca10(PO4)

6(OH)2+HAsO

4

2minus


6(HAsO

4) + 2OHminus

(3)

Compared to our conjecture of the modified mechanismChenrsquos research indicates that bone charcoal can arise fromthe ion exchange reaction during the adsorption fromwhich we can infer that the mechanism of adsorption andmodification is extremely similar In other words duringthe modification process aluminum ion can be ldquoadsorbedrdquoonto the surface of bone charcoal and we deduce that thiscombination is stable and thus the aluminum can impregnatefirmly

As for the adsorption mechanism of aluminum-impregnated bone charcoal Dong [47] offered an explanationfor the high performance of the modified bone charcoalThis explanation discusses that because the aluminum ionhas the unoccupied orbital there exists the complex reactionbetween aluminum ion and fluorinion and the maximumcoordination number is considered to be six

Al3+ + Fminus larrrarr AlF2+

darr

Al3+ + 2Fminus larrrarr AlF+2

darr

Al3+ + 3Fminus larrrarr AlF03

darr


minus


darr


2minus

darr


3minus

(4)Dongrsquos explanation of aluminum-impregnated bone

charcoal seems reasonable However according to our studysome of the unoccupied orbitals of the aluminum impreg-nated onto the bone charcoal had actually been occupiedduring the modified process Therefore the average maxi-mum coordination number of aluminum in the aluminum-impregnated bone charcoal may be less than six Basedon our opinion the adsorption mechanism explained byDong [47] is not totally perfect which may overestimate theadsorption effects of aluminum-impregnated bone charcoalOur research indicates that in the process of defluoridationaluminum-impregnated bone charcoal is undergoing twokinds of adsorption process On the one hand hydroxyapatitein bone charcoal is undergoing the adsorption process as(1) presents on the other hand aluminum which has beenimpregnated onto the bone charcoalrsquos surface is undergoingthe process of coordination reaction aluminum combineswith fluorinion in a stable way

According to previous studies [48ndash51] some similarresearches on determining the mechanisms of differentadsorbents were used to make comparison Namasivayamand Kavitha [48] detected the adsorption interactions of dyephenol and chlorophenol onto coir pith carbon from aque-ous solution using various detection techniques Nadeem andhis coworkers [49] detected the modified carbon adsorbentsby SEM In addition Ahmad andKumar [50] also utilize SEMto detect the adsorption information of amaranth dye ontoalumina reinforced polystyrene Gupta and his coworkers[51] detected the details about banana pseudostem fiber inthe removal of harmful malachite green dye using Fouriertransform infrared spectroscopy scanning electron micro-scope and X-ray diffractometer These studies are advancedin detecting the properties of adsorbents which can seemas the excellent references Nevertheless these researchesdid not detect the adsorption processes of the modificationmechanisms of the studied adsorbents by infrared spectro-scopic methods Hence our research has successfully madeup the blank of this area According to the comparison usinginfrared spectroscopy to detect and infer the modificationmechanism of bone charcoal is proved to be effective andavailable

4 Conclusion

Fluoride contamination is a prominent and widespreadproblem in many parts of the world Such contaminationin drinking water is mostly natural and unpreventablethat affects the health for human beings There is a com-mon agreement that drinking fluoridated water can leadto a high risk of fluorosis in human body To reduce therisk metal-impregnated bone charcoal has been frequentlyused as an ideal material for fluoride removal In this

study the defluoridation efficiency of the bone charcoalsmodified by different metal ions was investigated Theiradsorption isotherms help highlighting the descending orderof the corresponding defluoridation efficiency as followsferri-impregnated bone charcoal aluminum-impregnatedbone charcoal magnesium-impregnated bone charcoal andsodium hydrate immersed bone charcoal Considering thepotential toxicity of ferri-impregnated bone charcoal thealuminum-impregnated bone charcoal was adapted as themost rational adsorbent for defluoridation in our exper-iments Its modified mechanism was further successfullyexplored using the infrared spectroscopy The strengtheningof the hydroxyl peak intensified in infrared spectrum wasexamined The results imply that the probable modifiedreaction is ion exchange and tetrahydroxoaluminate cancombine with hydroxyapatite which in turn suggests thataluminum ion can be impregnated onto the surface of thebone charcoal In future study more attention deserves to bepaid to the adsorption of lead and arsenic as some advancedresearches provide great inspirations on the topic [46 52ndash55]

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

Authorsrsquo Contribution

Hao Li and Yufan Yang contributed equally to this paper

Acknowledgment

This work was supported by the Fund for Fostering Talentsin Basic Science of the National Natural Science (Grant noJ1103315)

References

[1] P J Riordan ldquoFluoride supplements for young children ananalysis of the literature focusing on benefits and risksrdquo Com-munityDentistry andOral Epidemiology vol 27 no 1 pp 72ndash831999

[2] R CMaheshwari ldquoFluoride in drinking water and its removalrdquoJournal of Hazardous Materials vol 137 no 1 pp 456ndash4632006

[3] G Rolla and E Saxegaard ldquoCritical evaluation of the com-position and use of topical fluorides with emphasis on therole of calcium fluoride in caries inhibitionrdquo Journal of DentalResearch vol 69 pp 780ndash785 1990

[4] M N Anjum M T Shah F Ali et al ldquoGeochemical studiesof fluoride in drinking water of union council ganderi districtnowshera Khyber Pakhtunkhwa Pakistanrdquo World AppliedSciences Journal vol 27 no 5 pp 632ndash636 2013

[5] D Taylor J G Hazenberg and T C Lee ldquoLiving with cracksdamage and repair in human bonerdquoNatureMaterials vol 6 no4 pp 263ndash268 2007

[6] H Yamamoto Y Iwami TUnezaki Y Tomii and S Ebisu ldquoFlu-oride uptake in human teeth from fluoride-releasing restorative


material in vivo and in vitro two-dimensional mapping byEPMA-WDXrdquo Caries Research vol 35 no 2 pp 111ndash115 2001

[7] K K Cheng I Chalmers and T A Sheldon ldquoAdding fluorideto water suppliesrdquo BritishMedical Journal vol 335 no 7622 pp699ndash702 2007

[8] X Zhan H Xu and G Li ldquoThe toxicity of sodium fluoride onpulmonary arterial smooth muscle cell proliferationrdquo ChineseJournal of Control of Endemic Disease vol 6 p 11 2003

[9] Y Kim and F P Gabbai ldquoCationic boranes for the complexationof fluoride ions in water below the 4 ppm maximum contami-nant levelrdquo Journal of the American Chemical Society vol 131no 9 pp 3363ndash3369 2009

[10] N Parthasarathy J Buffle and W Haerdi ldquoCombined use ofcalcium salts and polymeric aluminium hydroxide for defluori-dation of waste watersrdquoWater Research vol 20 no 4 pp 443ndash448 1986

[11] A K Yadav C P Kaushik A K Haritash A Kansal and NRani ldquoDefluoridation of groundwater using brick powder as anadsorbentrdquo Journal of HazardousMaterials vol 128 no 2-3 pp289ndash293 2006

[12] S JagtapM K N Yenkie N Labhsetwar and S Rayalu ldquoDeflu-oridation of drinking water using chitosan based mesoporousaluminardquo Microporous and Mesoporous Materials vol 142 no2-3 pp 454ndash463 2011

[13] P Loganathan S Vigneswaran J Kandasamy and R NaiduldquoDefluoridation of drinking water using adsorption processesrdquoJournal of Hazardous Materials vol 248-249 no 1 pp 1ndash192013

[14] A Bhatnagar E Kumar and M Sillanpaa ldquoFluoride removalfrom water by adsorptionmdasha reviewrdquo Chemical EngineeringJournal vol 171 no 3 pp 811ndash840 2011

[15] Y Sun Q Fang J Dong X Cheng and J Xu ldquoRemoval offluoride from drinking water by natural stilbite zeolite modifiedwith Fe(III)rdquo Desalination vol 277 no 1-3 pp 121ndash127 2011

[16] Y Nie C Hu and C Kong ldquoEnhanced fluoride adsorptionusing Al (III) modified calcium hydroxyapatiterdquo Journal ofHazardous Materials vol 233-234 pp 194ndash199 2012

[17] Q Zhang Q Du T Jiao et al ldquoRationally designed porouspolystyrene encapsulated zirconium phosphate nanocompositefor highly efficient fluoride uptake in watersrdquo Scientific Reportsvol 3 pp 1ndash9 2013

[18] E Kumar A Bhatnagar U Kumar andM Sillanpaa ldquoDefluori-dation from aqueous solutions by nano-alumina characteriza-tion and sorption studiesrdquo Journal of Hazardous Materials vol186 no 2-3 pp 1042ndash1049 2011

[19] L Gomez-Hortiguela A B Pinar J Perez-Pariente et alldquoIon-exchange in natural zeolite stilbite and significance indefluoridation abilityrdquo Microporous and Mesoporous Materialsvol 193 pp 93ndash102 2014

[20] A M Raichur and M Jyoti Basu ldquoAdsorption of fluorideonto mixed rare earth oxidesrdquo Separation and PurificationTechnology vol 24 no 1-2 pp 121ndash127 2001

[21] M-J Bai andY-Y Chu ldquoRemoval of fluorine ions fromwastew-ater using calcium aluminate slagrdquo Environmental Science ampTechnology vol 9 no 34 pp 117ndash120 2008

[22] Q Zhang and G Wang ldquoResearch on removing effects ofthe bamboo-carbon for fluoride from drink waterrdquo GuangdongWeiliang Yuansu Kexue vol 12 no 3 p 63 2005

[23] C K Rojas-Mayorga A Bonilla-Petriciolet I A Aguayo-Villarreal et al ldquoOptimization of pyrolysis conditions andadsorption properties of bone char for fluoride removal from

waterrdquo Journal of Analytical and Applied Pyrolysis vol 104 pp10ndash18 2013

[24] J K Fawell Fluoride in Drinking-Water World Health Organi-zation 2006

[25] M E Kaseva ldquoOptimization of regenerated bone char forfluoride removal in drinking water a case study in TanzaniardquoJournal of Water and Health vol 4 no 1 pp 139ndash147 2006

[26] F Ospitali D C Smith and M Lorblanchet ldquoPreliminaryinvestigations by Raman microscopy of prehistoric pigments inthe wall-painted cave at Roucadour Quercy Francerdquo Journal ofRaman Spectroscopy vol 37 no 10 pp 1063ndash1071 2006

[27] N A Medellin-Castillo R Leyva-Ramos R Ocampo-Perez etal ldquoAdsorption of fluoride from water solution on bone charrdquoIndustrial and Engineering Chemistry Research vol 46 no 26pp 9205ndash9212 2007

[28] B C Smith Fundamentals of Fourier Transform Infrared Spec-troscopy CRC Press Boca Raton Fla USA 2011

[29] C Krafft and V Sergo ldquoBiomedical applications of Raman andinfrared spectroscopy to diagnose tissuesrdquo Spectroscopy vol 20no 5-6 pp 195ndash218 2006

[30] I X Green W Tang M Neurock and J T Yates Jr ldquoSpectro-scopic observation of dual catalytic sites during oxidation of COon a AuTiO

2catalystrdquo Science vol 333 no 6043 pp 736ndash739

2011[31] J Roithova ldquoCharacterization of reaction intermediates by ion

spectroscopyrdquo Chemical Society Reviews vol 41 no 2 pp 547ndash559 2012

[32] M Acik G Lee C Mattevi et al ldquoThe role of oxygenduring thermal reduction of graphene oxide studied by infraredabsorption spectroscopyrdquo The Journal of Physical Chemistry Cvol 115 no 40 pp 19761ndash19781 2011

[33] R Black S H Oh J-H Lee T Yim B Adams and L F NazarldquoScreening for superoxide reactivity in Li-O

2batteries effect on

Li2O2LiOH crystallizationrdquo Journal of the American Chemical

Society vol 134 no 6 pp 2902ndash2905 2012[34] Y Chen H Wang R Burch C Hardacre and P Hu

ldquoNew insight into mechanisms in water-gas-shift reaction onAuCeO

2(111) a density functional theory and kinetic studyrdquo

Faraday Discussions vol 152 pp 121ndash133 2011[35] Y-F Huang D-Y Wu H-P Zhu et al ldquoSurface-enhanced

Raman spectroscopic study of p-aminothiophenolrdquo PhysicalChemistry Chemical Physics vol 14 no 24 pp 8485ndash8497 2012

[36] S I R Costa M Li J R Frade and D C Sinclair ldquoModulusspectroscopy of CaCu

3Ti4O12

ceramics clues to the internalbarrier layer capacitance mechanismrdquo RSC Advances vol 3 no19 pp 7030ndash7036 2013

[37] F Xu Y Xu R Lu G-P Sheng and H-Q Yu ldquoElucidationof the thermal deterioration mechanism of bio-oil pyrolyzedfrom rice husk using fourier transform infrared spectroscopyrdquoJournal of Agricultural and Food Chemistry vol 59 no 17 pp9243ndash9249 2011

[38] G Ghanizadeh and G Asgari ldquoAdsorption kinetics andisotherm of methylene blue and its removal from aqueoussolution using bone charcoalrdquo Reaction Kinetics Mechanismsand Catalysis vol 102 no 1 pp 127ndash142 2011

[39] J A Wilson I D Pulford and S Thomas ldquoSorption of Cu andZn by bone charcoalrdquo Environmental Geochemistry and Healthvol 25 no 1 pp 51ndash56 2003

[40] M T Ghaneian G Ghanizadeh M T H Alizadeh et al ldquoEqui-librium and kinetics of phosphorous adsorption onto bonecharcoal from aqueous solutionrdquo Environmental Technologyvol 35 no 7 pp 882ndash890 2014


[41] C W Cheung C K Chan J F Porter and G Mckay ldquoCom-bined diffusionmodel for the sorption of cadmium copper andzinc ions onto bone charrdquo Environmental Science amp Technologyvol 35 no 7 pp 1511ndash1522 2001

[42] X W Shen Research on the Defluoridation of Bone Charcoal inLow Concentration Wastewater Jiangxi University of Technol-ogy 2011

[43] B Halliwell ldquoAntioxidants in human health and diseaserdquoAnnual Review of Nutrition vol 16 pp 33ndash50 1996

[44] J G Wu Modern FTIR Technology and Application vol 35Science and Technology Literature Press Beijing China 1stedition 1994

[45] Y Mikhaylova G Adam L Haussler K-J Eichhorn and BVoit ldquoTemperature-dependent FTIR spectroscopic and ther-moanalytic studies of hydrogen bonding of hydroxyl (phenolicgroup) terminated hyperbranched aromatic polyestersrdquo Journalof Molecular Structure vol 788 no 1ndash3 pp 80ndash88 2006

[46] Y-N Chen L-Y Chai and Y-D Shu ldquoArsenic(V) removalfrom drinking water by bone charrdquo Journal of Central SouthUniversity (Science and Technology) vol 39 no 2 pp 279ndash2832008 (Chinese)

[47] SMDongResearch onDefluoridation inWater and Soil Systemthe Removal Mechanism Changan University 2004

[48] C Namasivayam and D Kavitha ldquoIR XRD and SEM studies onthe mechanism of adsorption of dyes and phenols by coir pithcarbon from aqueous phaserdquoMicrochemical Journal vol 82 no1 pp 43ndash48 2006

[49] M Nadeem A Mahmood S A Shahid S S Shah AM Khalid and G McKay ldquoSorption of lead from aqueoussolution by chemically modified carbon adsorbentsrdquo Journal ofHazardous Materials vol 138 no 3 pp 604ndash613 2006

[50] R Ahmad and R Kumar ldquoAdsorption of amaranth dye ontoalumina reinforced polystyrenerdquo CleanmdashSoil Air Water vol39 no 1 pp 74ndash82 2011

[51] N Gupta A K Kushwaha and M C ChattopadhyayaldquoAdsorption of brilliant green dye from aqueous solution bybanana pseudo-stem fibersrdquo Journal of the Indian ChemicalSociety vol 89 no 7 pp 891ndash902 2012

[52] Q Zhang Q Du M Hua T Jiao F Gao and B PanldquoSorption enhancement of lead ions from water by surfacecharged polystyrene-supported nano-zirconiumoxide compos-itesrdquo Environmental Science amp Technology vol 47 no 12 pp6536ndash6544 2013

[53] Q Peng J Guo Q Zhang et al ldquoUnique lead adsorption behav-ior of activated hydroxyl group in two-dimensional titaniumcarbiderdquo Journal of the American Chemical Society vol 136 no11 pp 4113ndash4116 2014

[54] M B Baskan and A Pala ldquoBatch and fixed-bed columnstudies of arsenic adsorption on the natural and modifiedclinoptiloliterdquo Water Air amp Soil Pollution vol 225 no 1 pp1ndash10 2014

[55] K Kwok L F Koong G Chen et al ldquoMechanism of arsenicremoval using chitosan and nanochitosanrdquo Journal of Colloidand Interface Science vol 416 pp 1ndash10 2014

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


40mL saturatedsolution of AlCl3

Modified bonecharcoal

Ultrasonicimmersion

20 g bone charcoalparticle size

48 hoursmm08sim12

+

Figure 1 Manufacturing approach of aluminum-impregnated bone charcoal

the high-performance absorbent of fluorion in undevelopedregions [24] Based on this reason we aimed at studying thedefluoridation effect of bone charcoal and finding out themechanism of the modification and adsorption

Bone charcoal is a porous black granular materialproduced by charring animal bones [25] It is made up ofhydroxyapatite (57ndash80) calcium carbonate (6ndash10) andactivated carbon (7ndash10) In the development of purificationbone charcoal was primarily used for filtration and decolouri-sation which can also adsorb a large quantity of pollutantslike pigments as well as fluorinion from water [26] Based onthe absorption theory the hydroxylapatite in bone chars canbe used to remove fluoride andmetal ions fromwatermakingit useful for the treatment of drinking supplies

Adsorption is a separation method with the equilibriumprincipleThemain components of bone charcoal are hydrox-yapatite The mechanism of the removal of fluorine is mainlythe adsorption and ion exchange reaction which is shown asfollows

Ca10(PO4)

6(OH)2+ 2Fminus 997888rarr Ca

10(PO4)

6F2+ 2OHminus (1)

Previous research [27] reported that being immersed inaluminum solution for certain temporal bone charcoal canbe modified The aluminum can impregnate onto the surfaceof bone charcoal improving the effect of the defluoridationwhich is the main core of our work However although thisnovel modified approach to optimize the performance ofaluminum-impregnated bone charcoal in defluoridation hasbeen discovered the mechanism of the modification is stillundefined It is undoubtedly a huge impediment for us toexplore the further studies of modified adsorbent Thereforewe paid our attention to construct a probable reaction duringthe modified process in order to resolve this crucial problem

Infrared spectroscopy is one of the most common ana-lytic techniques in material characterization [28] It is thespectroscopy that deals with the infrared region of theelectromagnetic spectrum with longer wavelength and lowerfrequency compared to the visible light It covers a rangeof techniques mostly based on absorption spectroscopyAs with all spectroscopic techniques it can be used tostudy chemicals and relative substances [29] In recent yearsthere are more and more explorations of reaction mech-anism detected by spectroscopic methods [30ndash37] Greenand his coworkers [30] obtained the information of dualcatalytic sites during oxidation of CO on AuTiO

2catalyst

by spectroscopic observation Roithova [31] concluded thecharacterization approaches of reaction intermediates by ionspectroscopy Acik and his coworkers [32] have detectedthe role of oxygen during thermal reduction of grapheneoxide using infrared absorption spectroscopy Black andhis coworkers [33] used spectroscopic method to screen

for superoxide reactivity in LindashO2batteries Chen and his

coworkers [34] used FT-IR spectroscopy as a part of theinstruments to determine mechanisms in water-gas-shiftreaction on AuCeO

2 Huang and his coworkers [35] uti-

lized surface-enhanced Raman spectroscopy to study p-aminothiophenol Costa and his coworkers [36] used relativespectroscopic methods to determine the clues to the internalbarrier layer capacitance mechanism Xu and his coworkers[37] clarified the thermal deterioration mechanism of bio-oilpyrolyzed from rice husk using Fourier transform infraredspectroscopyThe common point of the studies listed above isthat all of them utilized the relative spectroscopic approachesto determine or infer themechanism of the chemical reactionand process proving that the spectroscopy is an availableapproach to estimate the mechanism of chemical reactionsWhat is worthmentioning is that all of these listed researcheswere published in the recent three years showing that usingspectroscopic approaches to establish the conjecture of chem-ical reactions is becoming a popular method among relativeacademic fields Since detecting the modified mechanism ofaluminum-impregnated bone charcoal and calculating themain reaction process by themodeling approach are difficultin our study we innovatively used infrared spectroscopy toobtain the infrared spectrums of the modified bone charcoaland the unmodified one so that the mechanism can beinferred during the change of the modification

2 Materials and Methods

21 Material Source and Treatment Raw materials of bonecharcoal in our experiments were supplied by LangfangHuaya Water Treatment Ltd Hebei Province China All thebone charcoals were sieved by screens of which the gran-ularity is approximately from 08 to 12mm Because of theadsorptionmechanism shown in (1) alkaline environment ofsolution can provide a better effect of defluoridation thus toensure the good adsorbabilitymaterials were firstly immersedin saturated solution of sodium hydrate for 12 hours and thenimmersed in deionized water for 12 hours After repetitivescrubbing these raw bone charcoals were stoved by electricthermostatic drying oven under the temperature of 120∘CAfterwards the bone charcoals were sealed in the desiccator

The manufacturing approach of aluminum-impregnatedbone charcoal in our study met the standards of modifiedapproaches created by previous studies 20 g bone charcoalwas immersed in 40mL saturated solution of AlCl

3 and

the modification system was immersed in the ultrasonicoscillator so that aluminum ion can impregnate onto thebone charcoal better The modification procedure is shownin Figure 1










055

050

045

040

035

030

025

020

015

010

005

Adso

rbed

amou

nt (m

gg)


NaOHAl

MgFe







ansm

ittan

ce (

)


Wavenumber

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

20

4000 3500 3000 2500 2000 1500 1000

(cmminus1)


Tran

smitt

ance

()

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

4000 3500 3000 2500 2000 1500 1000







Tran

smitt

ance

()

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

20

4000 3500 3000 2500 2000 1500 1000






Ca10(PO4)


4


6OH sdot Al (OH)

4+OHminus

(2)


Ca10(PO4)

6(OH)2+HAsO

4

2minus


6(HAsO

4) + 2OHminus

(3)




darr


darr


darr


minus


darr


2minus

darr


3minus




4 Conclusion







Acknowledgment


References















































3Ti4O12































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of










055

050

045

040

035

030

025

020

015

010

005

Adso

rbed

amou

nt (m

gg)


NaOHAl

MgFe







ansm

ittan

ce (

)


Wavenumber

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

20

4000 3500 3000 2500 2000 1500 1000

(cmminus1)


Tran

smitt

ance

()

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

4000 3500 3000 2500 2000 1500 1000







Tran

smitt

ance

()

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

20

4000 3500 3000 2500 2000 1500 1000






Ca10(PO4)


4


6OH sdot Al (OH)

4+OHminus

(2)


Ca10(PO4)

6(OH)2+HAsO

4

2minus


6(HAsO

4) + 2OHminus

(3)




darr


darr


darr


minus


darr


2minus

darr


3minus




4 Conclusion







Acknowledgment


References















































3Ti4O12































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


ansm

ittan

ce (

)


Wavenumber

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

20

4000 3500 3000 2500 2000 1500 1000

(cmminus1)


Tran

smitt

ance

()

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

4000 3500 3000 2500 2000 1500 1000







Tran

smitt

ance

()

95

90

85

80

75

70

65

60

55

50

45

40

35

30

25

20

4000 3500 3000 2500 2000 1500 1000






Ca10(PO4)


4


6OH sdot Al (OH)

4+OHminus

(2)


Ca10(PO4)

6(OH)2+HAsO

4

2minus


6(HAsO

4) + 2OHminus

(3)




darr


darr


darr


minus


darr


2minus

darr


3minus




4 Conclusion







Acknowledgment


References















































3Ti4O12































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


darr


2minus

darr


3minus




4 Conclusion







Acknowledgment


References















































3Ti4O12































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of









































3Ti4O12































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


























Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

research article infrared spectroscopic study on the...

Documents