Research Article Adsorption of Arsenite by Six Submerged ...downloads.hindawi.com/journals/jchem/2014/450790.pdf · Research Article Adsorption of Arsenite by Six Submerged Plants

Research ArticleAdsorption of Arsenite by Six Submerged Plants fromNansi Lake China

Zhibin Zhang12 Yulin Sun1 Cuizhen Sun1 Ning Wang1 and Yanhao Zhang1

1 School of Municipal and Environmental Engineering Shandong Jianzhu University Jinan Shandong 250101 China2 Center for Sustainable Development amp Global Competitiveness Stanford University Stanford CA 94305 USA

Correspondence should be addressed to Cuizhen Sun sczh2901126com

Received 24 April 2014 Revised 15 September 2014 Accepted 27 October 2014 Published 13 November 2014

Academic Editor Davide Vione

Copyright copy 2014 Zhibin Zhang et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Nansi Lake is the largest and the most important freshwater lake in north China for the South-North Water Transfer Project Dueto long-time and large-scale fish farming of history the excess fish food and excretion usually release pentavalent arsenic whichis converted into trivalent arsenic (As (III)) in the lake sediment and released into lake water Adsorption of arsenite using sixsubmerged plants (Mimulicalyx rosulatus Potamogeton maackianusHydrillaWatermifoil Pteris vittata and Potamogeton crispus)as adsorbing materials was investigated The experimental data obtained have been analyzed using Langmuir Freundlich andDubinin-Radushkevich isotherm models and the pseudo-first-order pseudo-second-order and intraparticle diffusion kineticsmodels According to the results the As (III) equilibrium data agreed well with the Freundlich isotherm model The adsorptioncapacity of the plants was in the following order Potamogeton crispus gt Pteris vittata gt Potamogeton maackianus gt MimulicalyxrosulatusgtHydrillagtWatermifoilThe sorption systemwith the six submerged plants was better described by pseudo-second-orderthan by first-order kinetics Moreover the adsorption with Potamogeton crispus could follow intraparticle diffusion (IPD) modelThe initial adsorption and rate of IPDusingPotamogeton crispus andPteris vittatawere higher than those using other plants studied

1 Introduction

Arsenic (As) is a naturally occurring element in the earthIt is found in soils surface and ground waters in theatmosphere and organisms (including the human body) [1ndash3] Elevated arsenic levels have been found in freshwaterecosystems such as lakes and rivers around the world dueto anthropogenic inputs such as combustion of fossil fuelsmining and smelting and the application of pesticide andpreservatives and additives to livestock feed The occurrenceof high levels of naturally occurring arsenic in groundwaterhas also weakened the success of supplying safe water andabout 35ndash77 million people are at risk of being exposedin Bangladesh [4] Via the food-chain As can eventuallybioaccumulate to higher level that could pose a serious threatto human health The uptake of arsenic can lead to healthproblems such as lung kidney bladder and skin cancer aswell as neurological disorders [5ndash8] Due to the high toxicityand carcinogenicity of arsenic its maximum concentration

in drinking water was limited to 10 120583gL by the WorldHealth Organization (WHO) and the Ministry of Health ofthe Peoplersquos Republic of China [9] Therefore developingeconomical efficient and reliable As removal technologiesfor water treatment is pressing

The conventional technologies such as coagulation pre-cipitation ion exchange and adsorption are available toremove As Adsorption is by far the most widely usedand activated carbon is the most commonly used sorbentHowever its use is costly to be implemented so therehas been considerable interest in the use of other adsorb-ing materials particularly biosorbents [10 11] Plant-basedremediation technology called phytoremediation has beencited as a promising approach to arsenic removal in waterscontaminated with toxic heavy metals [12 13] This approachtakes advantage of the natural ability of plants to removetransform or accumulate elements and compounds fromthe water and to metabolize various molecules in theirtissues and it is an emerging cost-effective and ecofriendly

Hindawi Publishing CorporationJournal of ChemistryVolume 2014 Article ID 450790 7 pageshttpdxdoiorg1011552014450790

2 Journal of Chemistry

technology [12 14 15] However the incorporation of heavymetals produces phytotoxic effects on plants resulting inreduction of biomass which was the consequence of theinhibition of chlorophyll synthesis [16] Adsorption of deadaquatic plants as a simple adsorbent which is used tobind heavy metals from solutions has advantages of highefficiency low cost and no nutrient requirements Also itis possible to recover heavy metals [17ndash19] Macrophytesbiomass including Spirodela intermedia Lemna minor andPistia stratiotes was reported in the literature and the mecha-nism of simultaneousmetal removal (Cd2+ Ni2+ Cu2+ Zn2+and Pb2+) by themwas investigated [20] Nansi Lake (34∘271015840-35∘201015840N 116∘341015840-117∘211015840 E) is located in Shandong provincewith an area of 1266 km2 and a mean depth of 15mThe lakeis the largest and the most important freshwater lake in northChina for the South-North Water Transfer Project [21] Dueto the large-scale fish farming for a long time in this areaconsiderable amounts of excess feeding and fish excretionwere deposited and accumulated in sediment of Nansi LakeThe fish food of history containing large amount of arsanilicacid or roxarsone usually releases pentavalent arsenic (As(V)) through the excess feeding and fish excretion whichis easily converted into trivalent arsenic (As (III)) in thelake sediment and released into lake water [22] As (III)and As (V) are most responsible for water contaminationamong the various forms of arsenic [23] Inorganic As (III) ismore toxic and more mobile than As (V) due to the higherbinding affinity to the sulfhydryl (ndashSH) groups of protein[24]

Therefore it is necessary to systematically determine theadsorption potential of the abundant submerged plants in theNansi Lake because of the low cost as adsorbing materialespecially for developing countries that could provide sup-port to emergency treatment of water pollution accidents Inthis work Pteris vittataMimulicalyx rosulatus Potamogetonmaackianus Hydrilla Watermifoil and Potamogeton cris-pus were used in the removal of As (III) The adsorptionisotherms and kinetics of the six submerged plants for As (III)at low concentration were investigated and compared

2 Methods and Materials

21 Materials Six submerged plants (Mimulicalyx rosulatusPotamogeton maackianus Hydrilla Watermifoil Pteris vit-tata and Potamogeton crispus) were collected from NansiLake and thoroughly rinsed with tap water to remove debrisand sediments Then the washed plants were trimmed tosimilar shape size and leave density

All the chemicals used in the experiments were ofanalytical grade The As (III) stock solution was preparedby dissolving sodium arsenite (NaAsO

2 AR) in deionized

water The As (III) solutions were prepared by dilution of thestock solution of 1000mgL with deionized water pH wascontrolled to 70 by 10molL HCl and 01molL NaOH

In order to evaluate the possibility of the release of Asfrom above these submerged plants a control experimentwas also set up with deionized water Only minute quantity(negligible ppb level) of arsenic was found

22 Measurement of Adsorption Isotherm studies were car-ried out by adding dead submerged plants of 10 g in a 100mLof 0025 0050 0100 0500 and 1000mgL arsenite solutionat pH 70The solution was shaken at 120 rpm at 13∘C for 24 hAfter equilibrium was reached the solutions were filteredthrough 022120583m polytetrafluoroethylene (PTFE) film andthe filtrates were analyzed to determine the concentrationof residual As (III) with atom fluorescence spectroscopy(AFS) The instrument involves using a beam of light froman excitation source of lamps The light excites the electronsin molecules of certain compounds and causes them to emitlight Absorption spectroscopy is measured by recordingthe emission spectra resulting from a range of excitationwavelengths The adsorption capacity of plants could becalculated using the following equation [29]

119902119890=

(1198620minus 119862119890) 119881

119898

(1)

where 119902119890(mgg) is As (III) uptake 119862

0and 119862

119890(mgL) are the

initial and equilibrium As (III) concentration respectively119881(L) is the volume of solution and 119898 (g) is the dry weight ofplant used Triplicate experiments were performed

Kinetic studies were carried out by adding dead sub-merged plants of 10 g into a 100mL of 1000mgL arsenitesolution at pH 70The solution was shaken at 120 rpm at 13∘Cfor up to 24 h At 15min 30min 60min 180min 300min600min and 1440min a small aliquot of the solution wastaken and filtered and the concentration of residual As (III)was determined byAFSTheadsorbedAs (III) amount at time119905 (min) 119902

119905(mgmg) was calculated by the following equation

[29]

119902119905=

(1198620minus 119862119905) 119881

119898

(2)

where 1198620and 119862

119905(mgL) are the concentrations of As (III) at

initial time and time 119905(min) respectively119881 (L) is the volumeof solution and119898 (g) is the weight of plants used

23 Adsorption Isotherm The relationship between the equi-librium adsorption capacity of the plants and the equilibriumconcentration of As (III) at constant temperature can beexpressed by isothermal models In order to establish thebest-fit isotherm equation for adsorption data interpretationand prediction the experimental equilibrium data werefitted into three isotherm models namely the FreundlichLangmuir and Dubinin-Radushkevich equations

The Freundlich adsorption isotherm model describesthe adsorption equilibrium on heterogeneous surfaces TheFreundlich equation can be expressed as follows [30]

119902119890= 119870F sdot 119862119890

1119899 (3)

where 119902119890(mgkg) represents the amount of As (III) adsorbed

at equilibrium by unit weight of plant 119862119890(mgL) is the

equilibriumconcentration ofAs (III) in the bulk solution andthe Freundlich constant119870F ((mgkg)(Lmg)1n) indicates theadsorption capacity of the plants A high value of 119870F implieshigh adsorptive capacities of plants 1119899 is the heterogeneity

Journal of Chemistry 3

factor When 0 lt 1119899 lt 1 the adsorption is favorablewhen 1119899 = 1 the adsorption is irreversible and when 1119899 gt1 the adsorption is unfavorable [31]

A line form of (3) can be obtained by taking logarithms

log 119902119890= log119870F +

1

119899

log119862119890 (4)

The Langmuir adsorption isotherm describes monolayeradsorption onto homogeneous surfaces when assuming thatall the adsorption sites possess equal affinity for the sorbateand that adsorption at one site does not affect adsorption atan adjacent one The Langmuir equation can be written asfollows [32]

119902119890=

119902119898sdot 119870119886sdot 119862119890

1 + 119870119886sdot 119862119890

(5)

where 119902119898

(mgkg) is the maximum As (III) uptake and119870119886(Lmg) is the Langmuir constant related to the affinity

between the sorbent and sorbate Equation (5) can be trans-formed into the following linear form

1

119902119890

=

1

119902119898sdot 119870119886sdot 119862119890

+

1

119902119898

(6)

The Dubinin-Radushkevich (D-R) isotherm model isapplied more generally than Langmuir isotherm because itdoes not assume a homogeneous surface or constant sorptionpotential [33] Dubinin-Radushkevich (D-R) isotherm hascommonly been applied in the following form [34]

log 119902119890= log 119902

119898minus 119870DRsdot120576

2 (7)

where 119870DR (mol2KJ2) is a constant related to the meanadsorption energy and 120576 is the Polanyi potential which canbe calculated from the equation

120576 = 119877119879 log(1 + 1119862119890

) (7)

where 119879 is the absolute temperature in 119870 and 119877 is theuniversal gas constant (8314 KJmol)

The mean energy of sorption 119864 is useful for estimatingthe type of sorption reaction and it is as follows

119864 =

1

radic2 sdot 119870DR (8)

24 Adsorption Kinetics Models The adsorption kinetics canpredict the rate of adsorption of As (III) by plants andprovides valuable data for understanding the adsorptionmechanism The pseudo-first-order pseudo-second-orderand the Weber and Morris intraparticle diffusion kineticsmodels were used to evaluate the adsorption kinetics

With boundary conditions of 119902 = 0 at 119905 = 0 and 119902119905= 119902119890at

119905 = 119905119890 the linear form of pseudo-first-order kinetic equation

is given as follows [35]

log (119902119890minus 119902119905) = log 119902

119890minus

1198961

2303

119905 (9)

0 2 4 6 8 10

Mimulicalyx rosulatusPotamogeton maackianusHydrilla

WatermifoilPteris vittataPotamogeton crispus

t (h)

minus15

minus10

minus05

00

05

10

15

log(qeminusqt)

Figure 1 The linearized Langmuir adsorption isotherms of As (III)by the submerged plants

where 119902119905(mgkg) is the amount of As (III) adsorbed at time

119905 (h) and 1198961(1h) is the adsorption rate constant which can

be determined from the slope and intercept of the linear plotof log(119902

119890minus 119902119905) versus 119905 (h)

With boundary conditions of 119902 = 0 at 119905 = 0 and 119902119905=

119902119890at 119905 = 119905

119890 the linear form of pseudo-second-order kinetic

equation is represented as follows [36 37]

119905

119902119905

=

1

1198962(119902119890)2+

119905

119902119890

(11)

where 1198962(kg(hsdotmg)) is the adsorption rate constant which

can be calculated from the linear plot of 119905119902119905against time (h)

The intraparticle diffusion (IPD) was explored by usingthe intraparticle diffusion model which defines that in theadsorption process uptake varies almost proportionally with11990512 rather than with the contact time The intraparticlediffusion model is expressed as follows [38]

119902119905= 119896119894sdot 11990512+ 119862 (10)

where 119896119894(mg(kgsdoth12)) is the rate constant obtained from

the slope of the straight line from a plot of 119902119905versus 11990512

while 119862 (mgkg) is the intercept that gives an idea about thethickness of the boundary layer The larger the intercept thegreater the boundary layer effect

3 Results and Discussion

31 Adsorption Isotherm Figures 1 2 and 3 report the plotsof log 119902

119890versus log 119862

119890 1119902119890versus 1119902max and log 119902

119890versus

1205762corresponding to Freundlich Langmuir and Dubinin-Radushkevich isotherm equations respectively The con-stants and correlation coefficients for the different isothermmodels are presented in Table 1 the equilibrium adsorption


Table 1 Isotherm parameters for Langmuir Freundlich and Dubinin-Radushkevich models for As (III) adsorption at 13∘C

PlantsFreundlich model Langmuir model Dubinin-Radushkevich model119870F

1119899 1198772 119902

1198981198701198861198772 119870DR 119902

119898119864

1198772

(mgkg) (Lmg)1119899 mgkg Lmg mol2kJ2 mgkg kJmolMimulicalyx rosulatus 760 070 097 309 1092 082 0029 552 412 085Potamogeton maackianus 1041 058 099 693 895 098 0024 818 453 095Hydrilla 878 059 092 1808 191 089 0028 797 423 093Watermifoil 412 115 098 minus083 minus235 092 0058 338 295 093Pteris vittata 2499 088 095 664 minus349 091 0044 2268 337 093Potamogeton crispus 3988 099 099 minus365 minus359 095 0055 2339 302 098

0

1

2

3

4



ln Ce (mgL)minus5 minus4 minus3 minus2 minus1

minus1

0

ln Qe

(mg

kg)

Figure 2The linearized Freundlich adsorption isotherms ofAs (III)by the submerged plants

data was better fitted to Freundlich isotherm model thanLangmuir adsorption model for the adsorption process ofthe six submerged plants The Freundlich isotherm describesmultilayer adsorption Higher correlation coefficient (1198772 gt092) for the Freundlich isotherm was found confirmingthat the adsorption is multilayer under the experimentalconditions used The values of 119899 and 119870F were determinedfrom the slopes 1119899 and intercepts log119870F of the straight linesin Figure 2 and are listed in Table 1 The values of 1119899 were inthe range of 058ndash088 for Potamogeton crispus Pteris vittataMimulicalyx rosulatus and Hydrilla indicating that As (III)was favorably adsorbed by these plantsThe values of 1119899were115 and 123 for Potamogeton maackianus and Watermifoilindicating that As (III) was unfavorably adsorbed by theseplants in this study The 119870F values show that the order of As(III) adsorption potential of the plants was Potamogeton cris-pus gt Pteris vittata gt Potamogetonmaackianus gtMimulicalyxrosulatus gt Hydrilla gtWatermifoil

The Dubinin-Radushkevich isotherm model was alsoapplied to estimate the type of adsorption process If the valueof 119864 is in the range of 8ndash16 kJmol the adsorption processfollows by chemical ion-exchange 119864 lt 8 kJmol indicatesthat the adsorption process is of physical nature However



0

1

2

3

minus1

minus2

ln Qe

(mg

kg)

minus100 minus80 minus60 minus40 minus20 0

minus12057620

Figure 3The linearizedD-R adsorption isotherms of As (III) by thesubmerged plants

if the value is more than 16 kJmol the biological sorptionprevails [22] From Table 1 the 119864 values were lower than8 kJmol This supports the fact that the physical adsorptionof As (III) played a significant role for the As (III) adsorptionbyMimulicalyx rosulatus Potamogetonmaackianus HydrillaWatermifoil Pteris vittata and Potamogeton crispus

32 Adsorption Kinetics Figures 4 5 and 6 show the plotsof log(119902

119890minus 119902119905) versus 119905 119905119902

119905versus 119905 and 119902

119905versus 11990512

corresponding to pseudo-first-order pseudo-second-orderand intraparticle diffusion (IPD) model respectively Theregression coefficient 1198772 was calculated from these plots andused as the fitting criterion to determine the applicability ofthe three models

As shown in Figure 4 and Table 2 the estimated 119902119890

values from the linear plot of the pseudo-first-order modelwere much lower than the experimental values Thereforethe kinetic process was not pseudo-first-order In contrastthe pseudo-second-order model obtained high 119902

119890values

which were approximately equal to the experimental valuesMoreover it had 1198772 values higher than 098 for differentplants reflecting the most likely adsorption mechanism Theresults suggest that the interfacial resistance was not the rate


Table 2 Kinetic parameters for pseudo-first-order pseudo-second-order and intraparticle diffusion model models for As (III) adsorptionat 13∘C

Plants 119902119890exp mgkg

Pseudo-first-order model Pseudo-second-order model Intraparticle diffusion model119902119890cal 1198701

1198772 119902

119890cal 1198702

1198772 119870

119894119862

1198772

mgkg 1h mgkg kg(hsdotmg) mg(kgsdoth12) mgkgMimulicalyx rosulatus 854 400 042 089 880 020 010 017 383 053Potamogeton maackianus 985 715 056 099 1017 016 100 020 396 065Hydrilla 968 634 057 098 996 018 100 019 410 064Watermifoil 578 272 048 080 607 0075 099 013 195 058Pteris vittata 2450 915 046 067 2500 0098 100 044 1199 057Potamogeton crispus 2349 1795 015 092 2512 0017 098 050 523 094

0 2 4 6 8 10t (h)

minus15

minus10

minus05

00

05

10

15

log(qeminusqt)



Figure 4 The linearized pseudo-first-order kinetics model for theremoval of As (III) (119879 = 13∘C initial As (III) concentration =1000mgL)

limiting step because the adsorption of As (III) fitted pseudo-second-order kinetics [33]

The correlation coefficient (1198772) values obtained by IPDmodelwere lower than 07 for all of the tested plants except forPotamogeton crispus (ie 1198772 = 094) IPD model is suitablefor the description of the adsorption kinetics of As (III) intoPotamogeton crispus because the correlation coefficient (1198772)was 094 None of the plots pass through the origin Thisshows that the intraparticle diffusion is not the only rate-limiting step and the boundary layer affects the adsorptionprocess [39] Thus other processes make a contribution tothe removal of As (III) with these submerged plants in thisstudy Figure 6 and Table 2 show that intercept (119862 value)with Potamogeton crispus and Pteris vittata is much higherthan for the other plants indicating that Potamogeton crispusand Pteris vittata have a large initial amount of adsorptionThe higher slope with Potamogeton crispus and Pteris vittatameans that the rate of IPD was higher compared to the otherplants

Table 3 Comparison of adsorption capacities of various plants forarsenic removal from aqueous solutions

Plant species Adsorption capacity Reference(mgkg)

Ranunculus flammula 521 [25]Salvinia natans L 2250 [26]Sparganium natans 1137 [25]Spirodela polyrhiza L 2647 [27]Cardamine flexuosa 878 [25]Vaccinium oxycoccos 367 [25]Scenedesmus quadricauda 2520 [28]Pteris vittata 2450 This studyPotamogeton crispus 2349 This study

For lower concentration values of arsenic other plantswere found to be used in several publications The 119902

119898

values of different plants have great differences Potamogetoncrispus and Pteris vittata which had the largest arsenic (III)adsorption capacity in this experiment were compared withthe adsorption capacities of other plants from the literatureThe results are listed in Table 3 From the table we canconclude that Potamogeton crispus and Pteris vittata havelarge adsorption capacity and are well suited to removearsenic from Nansi Lake

4 Conclusions

Results showed that adsorption isotherm favored Freundlichmodels and the adoption process could be fitted by thepseudo-second-order kinetics The intraparticle diffusionwas not the only rate-limiting step in the adsorption process

Potamogeton crispus and Pteris vittata have large adsorp-tion capacity and quick adsorption rate to equilibrium Thearsenic can be lowered to 005mgL in the case of initial con-centration 01mgL [40] The sorption of As by Potamogetoncrispus and Pteris vittata can be a low cost and efficient basisfor removal of low concentration As The research findingsmerit further research to evaluate the practicality of their usein the field


0 5 10 15 20 250

1

2

3

4

5

6

7

8

t (h)



tqt

(kgmiddot

hm

g)

Figure 5 The linearized pseudo-second-order kinetics model forthe removal of As (III) (119879 = 13∘C initial As (III) concentration =1000mgL)

5 10 15 20 25 30 35 400

5

10

15

20

25

30

35

40

t12 (h12)

Qt

(mg

kg)



Figure 6 The linearized intraparticle diffusion model for theremoval of As (III) (119879 = 13∘C initial As (III) concentration =1000mgL)

Conflict of Interests

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

Acknowledgments

This work was financially supported by Shandong ProvinceFinancial Department and Environmental Protection Bureau(no SDZS-2012-SHBT01) Shandong Natural Science Foun-dation (no ZR2012EEQ024) and Doctor Foundation of

Shandong Jianzhu University (no XNBS1228) The adviceand kind suggestions from the anonymous reviewers arehighly acknowledged

References

[1] B K Mandal and K T Suzuki ldquoArsenic round the world areviewrdquo Talanta vol 58 no 1 pp 201ndash235 2002

[2] B Dhir S A Nasim P Sharmila and P Pardha SaradhildquoHeavy metal removal potential of dried Salvinia biomassrdquoInternational Journal of Phytoremediation vol 12 no 2 pp 133ndash141 2010

[3] Z Xie Y Luo Y Wang X Xie and C Su ldquoArsenic resistanceand bioaccumulation of an indigenous bacterium isolatedfrom aquifer sediments of Datong Basin Northern ChinardquoGeomicrobiology Journal vol 30 no 6 pp 549ndash556 2013

[4] M Bromssen L Markussen P Bhattacharya et al ldquoHydrogeo-logical investigation for assessment of the sustainability of low-arsenic aquifers as a safe drinking water source in regions withhigh-arsenic groundwater inMatlab southeastern BangladeshrdquoJournal of Hydrology vol 518 part C pp 373ndash392 2014

[5] H H dos Santos C A Demarchi C A Rodrigues J MGreneche N Nedelko and A Slawska-Waniewska ldquoAdsorp-tion of As(III) on chitosan-Fe-crosslinked complex (Ch-Fe)rdquoChemosphere vol 82 no 2 pp 278ndash283 2011

[6] V C Silva S M Almeida C Resgalla J-F Masfaraud SCotelle and C M Radetski ldquoArsenate (As V) in water quan-titative sensitivity relationships among biomarker ecotoxicityand genotoxicity endpointsrdquo Ecotoxicology and EnvironmentalSafety vol 92 pp 174ndash179 2013

[7] S Bhattacharya K Gupta S Debnath U C Ghosh D Chat-topadhyay and A Mukhopadhyay ldquoArsenic bioaccumulationin rice and edible plants and subsequent transmission throughfood chain in Bengal basin a review of the perspectives for envi-ronmental healthrdquo Toxicological and Environmental Chemistryvol 94 no 3 pp 429ndash441 2012

[8] S Kar J P Maity J-S Jean et al ldquoHealth risks for humanintake of aquacultural fish arsenic bioaccumulation and con-taminationrdquo Journal of Environmental Science and Health PartA ToxicHazardous Substances and Environmental Engineeringvol 46 no 11 pp 1266ndash1273 2011

[9] Y Wang S D Lu X Li and Y J Wu ldquoResearch advancesand prospects in arsenic removal from waterrdquo EnvironmentalScience amp Technology vol 33 no 9 pp 102ndash107 2010

[10] JNgWHCheung andGMcKay ldquoEquilibrium studies for thesorption of lead from effluents using chitosanrdquo Chemospherevol 52 no 6 pp 1021ndash1030 2003

[11] D Mohan and C U Pittman Jr ldquoArsenic removal fromwaterwastewater using adsorbentsmdasha critical reviewrdquo Journalof Hazardous Materials vol 142 no 1-2 pp 1ndash53 2007

[12] M A Rahman H Hasegawa K Ueda T Maki and MM Rahman ldquoInfluence of EDTA and chemical species onarsenic accumulation in Spirodela polyrhiza L (duckweed)rdquoEcotoxicology and Environmental Safety vol 70 no 2 pp 311ndash318 2008

[13] N-X Wang Y Li X-H Deng A-J Miao R Ji and L-YYang ldquoToxicity and bioaccumulation kinetics of arsenate intwo freshwater green algae under different phosphate regimesrdquoWater Research vol 47 no 7 pp 2497ndash2506 2013

[14] S Sauge-Merle C Lecomte-Pradines P Carrier S Cuineand M DuBow ldquoHeavy metal accumulation by recombinant


mammalian metallothionein within Escherichia coli protectsagainst elevated metal exposurerdquo Chemosphere vol 88 no 8pp 918ndash924 2012

[15] R Larios R Fernandez-Martınez I LeHecho and I RucandioldquoA methodological approach to evaluate arsenic speciation andbioaccumulation in different plant species from two highlypolluted mining areasrdquo Science of the Total Environment vol414 pp 600ndash607 2012

[16] M Delgado M Bigeriego and E Guarniola ldquoUptake of Zn Crand Cd by water hyacinthsrdquo Water Research vol 27 no 2 pp269ndash272 1993

[17] F Veglio and F Beolchini ldquoRemoval of metals by biosorption areviewrdquo Hydrometallurgy vol 44 no 3 pp 301ndash316 1997

[18] I A H Schneider and J Rubio ldquoSorption of heavy metalions by the nonliving biomass of freshwater macrophytesrdquoEnvironmental Science and Technology vol 33 no 13 pp 2213ndash2217 1999

[19] I A H Schneider J Rubio and R W Smith ldquoBiosorptionof metals onto plant biomass exchange adsorption or surfaceprecipitationrdquo International Journal of Mineral Processing vol62 no 1ndash4 pp 111ndash120 2001

[20] P Miretzky A Saralegui and A Fernandez Cirelli ldquoSimulta-neous heavy metal removal mechanism by dead macrophytesrdquoChemosphere vol 62 no 2 pp 247ndash254 2006

[21] S LWang C Y Lin X Z Cao and X Zhong ldquoArsenic contentfractionation and ecological risk in the surface sedimentsof lakerdquo International Journal of Environmental Science andTechnology vol 9 no 1 pp 31ndash40 2012

[22] K Angkanaporn and K D C Kiratisehwe ldquoEffects of thedietary inclusion of fishmeal rock phosphate and roxarsone onarsenic residues in tissues of broilersrdquoThai Journal of VeterinaryMedicine vol 38 no 4 pp 57ndash64 2008

[23] S K Maji Y-H Kao C-J Wang G-S Lu J-J Wu and C-W Liu ldquoFixed bed adsorption of As(III) on iron-oxide-coatednatural rock (IOCNR) and application to real arsenic-bearinggroundwaterrdquo Chemical Engineering Journal vol 203 pp 285ndash293 2012

[24] P E Burns S Hyun L S Lee and I Murarka ldquoCharacterizingAs(III V) adsorption by soils surrounding ash disposal facili-tiesrdquo Chemosphere vol 63 no 11 pp 1879ndash1891 2006

[25] C Bergqvist and M Greger ldquoArsenic accumulation and speci-ation in plants from different habitatsrdquo Applied Geochemistryvol 27 no 3 pp 615ndash622 2012

[26] M A Rahman H Hasegawa K Ueda T Maki and M MRahman ldquoInfluence of phosphate and iron ions in selectiveuptake of arsenic species by water fern (Salvinia natans L)rdquoChemical Engineering Journal vol 145 no 2 pp 179ndash184 2008

[27] M A Rahman H Hasegawa K Ueda T Maki C Okumuraand M M Rahman ldquoArsenic accumulation in duckweed(Spirodela polyrhiza L) a good option for phytoremediationrdquoChemosphere vol 69 no 3 pp 493ndash499 2007

[28] J Y Zhang T D Ding andC L Zhang ldquoBiosorption and toxic-ity responses to arsenite (As[III]) in Scenedesmus quadricaudardquoChemosphere vol 92 no 9 pp 1077ndash1084 2013

[29] Y Tang L Chen X Wei Q Yao and T Li ldquoRemoval of leadions from aqueous solution by the dried aquatic plant Lemnaperpusilla Torrrdquo Journal of Hazardous Materials vol 244-245pp 603ndash612 2013

[30] O Moradi A Fakhri S Adami and S Adami ldquoIsothermthermodynamic kinetics and adsorptionmechanism studies ofEthidium bromide by single-walled carbon nanotube and car-boxylate group functionalized single-walled carbon nanotuberdquo

Journal of Colloid and Interface Science vol 395 no 1 pp 224ndash229 2013

[31] D Feller M Vasiliu D J Grant and D A Dixon ldquoTher-modynamic properties of arsenic compounds and the heat offormation of the as atom from high level electronic structurecalculationsrdquo The Journal of Physical Chemistry A vol 115 no51 pp 14667ndash14676 2011

[32] Z A ALOthmanMNaushad andR Ali ldquoKinetic equilibriumisotherm and thermodynamic studies of Cr(VI) adsorptiononto low-cost adsorbent developed from peanut shell activatedwith phosphoric acidrdquo Environmental Science and PollutionResearch vol 20 no 5 pp 3351ndash3365 2013

[33] X-J Xiong X-J Meng and T-L Zheng ldquoBiosorption of CIDirect Blue 199 from aqueous solution by nonviable Aspergillusnigerrdquo Journal of Hazardous Materials vol 175 no 1ndash3 pp 241ndash246 2010

[34] M Jain V K Garg andK Kadirvelu ldquoAdsorption of hexavalentchromium from aqueous medium onto carbonaceous adsor-bents prepared from waste biomassrdquo Journal of EnvironmentalManagement vol 91 no 4 pp 949ndash957 2010

[35] J X Zhang and L L Ou ldquoKinetic isotherm and thermody-namic studies of the adsorption of crystal violet by activatedcarbon from peanut shellsrdquo Water Science and Technology vol67 no 4 pp 737ndash744 2013

[36] F Yu Y Wu J Ma and C Zhang ldquoAdsorption of lead onmulti-walled carbon nanotubes with different outer diametersand oxygen contents kinetics isotherms and thermodynamicsrdquoJournal of Environmental Sciences vol 25 no 1 pp 195ndash2032013

[37] Y S Ho and G McKay ldquoSorption of dye from aqueous solutionby peatrdquo Chemical Engineering Journal vol 70 no 2 pp 115ndash124 1998

[38] B Das R R Devi I M Umlong K Borah S Banerjee andA K Talukdar ldquoArsenic (III) adsorption on iron acetate coatedactivated alumina thermodynamic kinetics and equilibriumapproachrdquo Journal of Environmental Health Science amp Engineer-ing vol 11 no 1 pp 42ndash47 2013

[39] W Zhang Z Xu B Pan L Lv Q Zhang and W Du ldquoAssess-ment on the removal of dimethyl phthalate from aqueous phaseusing a hydrophilic hyper-cross-linked polymer resin NDA-702rdquo Journal of Colloid and Interface Science vol 311 no 2 pp382ndash390 2007

[40] S Yu Research on Arsenic Removal by Biological Technologyfrom Natural Water Shandong Jianzhu University 2012

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

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Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

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technology [12 14 15] However the incorporation of heavymetals produces phytotoxic effects on plants resulting inreduction of biomass which was the consequence of theinhibition of chlorophyll synthesis [16] Adsorption of deadaquatic plants as a simple adsorbent which is used tobind heavy metals from solutions has advantages of highefficiency low cost and no nutrient requirements Also itis possible to recover heavy metals [17ndash19] Macrophytesbiomass including Spirodela intermedia Lemna minor andPistia stratiotes was reported in the literature and the mecha-nism of simultaneousmetal removal (Cd2+ Ni2+ Cu2+ Zn2+and Pb2+) by themwas investigated [20] Nansi Lake (34∘271015840-35∘201015840N 116∘341015840-117∘211015840 E) is located in Shandong provincewith an area of 1266 km2 and a mean depth of 15mThe lakeis the largest and the most important freshwater lake in northChina for the South-North Water Transfer Project [21] Dueto the large-scale fish farming for a long time in this areaconsiderable amounts of excess feeding and fish excretionwere deposited and accumulated in sediment of Nansi LakeThe fish food of history containing large amount of arsanilicacid or roxarsone usually releases pentavalent arsenic (As(V)) through the excess feeding and fish excretion whichis easily converted into trivalent arsenic (As (III)) in thelake sediment and released into lake water [22] As (III)and As (V) are most responsible for water contaminationamong the various forms of arsenic [23] Inorganic As (III) ismore toxic and more mobile than As (V) due to the higherbinding affinity to the sulfhydryl (ndashSH) groups of protein[24]

Therefore it is necessary to systematically determine theadsorption potential of the abundant submerged plants in theNansi Lake because of the low cost as adsorbing materialespecially for developing countries that could provide sup-port to emergency treatment of water pollution accidents Inthis work Pteris vittataMimulicalyx rosulatus Potamogetonmaackianus Hydrilla Watermifoil and Potamogeton cris-pus were used in the removal of As (III) The adsorptionisotherms and kinetics of the six submerged plants for As (III)at low concentration were investigated and compared

2 Methods and Materials

21 Materials Six submerged plants (Mimulicalyx rosulatusPotamogeton maackianus Hydrilla Watermifoil Pteris vit-tata and Potamogeton crispus) were collected from NansiLake and thoroughly rinsed with tap water to remove debrisand sediments Then the washed plants were trimmed tosimilar shape size and leave density

All the chemicals used in the experiments were ofanalytical grade The As (III) stock solution was preparedby dissolving sodium arsenite (NaAsO

2 AR) in deionized

water The As (III) solutions were prepared by dilution of thestock solution of 1000mgL with deionized water pH wascontrolled to 70 by 10molL HCl and 01molL NaOH

In order to evaluate the possibility of the release of Asfrom above these submerged plants a control experimentwas also set up with deionized water Only minute quantity(negligible ppb level) of arsenic was found

22 Measurement of Adsorption Isotherm studies were car-ried out by adding dead submerged plants of 10 g in a 100mLof 0025 0050 0100 0500 and 1000mgL arsenite solutionat pH 70The solution was shaken at 120 rpm at 13∘C for 24 hAfter equilibrium was reached the solutions were filteredthrough 022120583m polytetrafluoroethylene (PTFE) film andthe filtrates were analyzed to determine the concentrationof residual As (III) with atom fluorescence spectroscopy(AFS) The instrument involves using a beam of light froman excitation source of lamps The light excites the electronsin molecules of certain compounds and causes them to emitlight Absorption spectroscopy is measured by recordingthe emission spectra resulting from a range of excitationwavelengths The adsorption capacity of plants could becalculated using the following equation [29]

119902119890=

(1198620minus 119862119890) 119881

119898

(1)

where 119902119890(mgg) is As (III) uptake 119862

0and 119862

119890(mgL) are the

initial and equilibrium As (III) concentration respectively119881(L) is the volume of solution and 119898 (g) is the dry weight ofplant used Triplicate experiments were performed

Kinetic studies were carried out by adding dead sub-merged plants of 10 g into a 100mL of 1000mgL arsenitesolution at pH 70The solution was shaken at 120 rpm at 13∘Cfor up to 24 h At 15min 30min 60min 180min 300min600min and 1440min a small aliquot of the solution wastaken and filtered and the concentration of residual As (III)was determined byAFSTheadsorbedAs (III) amount at time119905 (min) 119902

119905(mgmg) was calculated by the following equation

[29]

119902119905=

(1198620minus 119862119905) 119881

119898

(2)

where 1198620and 119862

119905(mgL) are the concentrations of As (III) at

initial time and time 119905(min) respectively119881 (L) is the volumeof solution and119898 (g) is the weight of plants used

23 Adsorption Isotherm The relationship between the equi-librium adsorption capacity of the plants and the equilibriumconcentration of As (III) at constant temperature can beexpressed by isothermal models In order to establish thebest-fit isotherm equation for adsorption data interpretationand prediction the experimental equilibrium data werefitted into three isotherm models namely the FreundlichLangmuir and Dubinin-Radushkevich equations

The Freundlich adsorption isotherm model describesthe adsorption equilibrium on heterogeneous surfaces TheFreundlich equation can be expressed as follows [30]

119902119890= 119870F sdot 119862119890

1119899 (3)

where 119902119890(mgkg) represents the amount of As (III) adsorbed

at equilibrium by unit weight of plant 119862119890(mgL) is the

equilibriumconcentration ofAs (III) in the bulk solution andthe Freundlich constant119870F ((mgkg)(Lmg)1n) indicates theadsorption capacity of the plants A high value of 119870F implieshigh adsorptive capacities of plants 1119899 is the heterogeneity




log 119902119890= log119870F +

1

119899

log119862119890 (4)


119902119890=

119902119898sdot 119870119886sdot 119862119890

1 + 119870119886sdot 119862119890

(5)

where 119902119898



1

119902119890

=

1

119902119898sdot 119870119886sdot 119862119890

+

1

119902119898

(6)


log 119902119890= log 119902

119898minus 119870DRsdot120576

2 (7)


120576 = 119877119879 log(1 + 1119862119890

) (7)



119864 =

1






log (119902119890minus 119902119905) = log 119902

119890minus

1198961

2303

119905 (9)

0 2 4 6 8 10



t (h)

minus15

minus10

minus05

00

05

10

15

log(qeminusqt)





119890minus 119902119905) versus 119905 (h)


119902119890at 119905 = 119905



119905

119902119905

=

1

1198962(119902119890)2+

119905

119902119890

(11)




119902119905= 119896119894sdot 11990512+ 119862 (10)






119890versus log 119862


119890versus





1119899 1198772 119902

1198981198701198861198772 119870DR 119902

119898119864

1198772


0

1

2

3

4




minus1

0

ln Qe

(mg

kg)






0

1

2

3

minus1

minus2

ln Qe

(mg

kg)


minus12057620




119890minus 119902119905) versus 119905 119905119902

119905versus 119905 and 119902

119905versus 11990512




119890values






1198772 119902

119890cal 1198702

1198772 119870

119894119862

1198772


0 2 4 6 8 10t (h)

minus15

minus10

minus05

00

05

10

15

log(qeminusqt)










119898


4 Conclusions




0 5 10 15 20 250

1

2

3

4

5

6

7

8

t (h)



tqt

(kgmiddot

hm

g)


5 10 15 20 25 30 35 400

5

10

15

20

25

30

35

40

t12 (h12)

Qt

(mg

kg)






Acknowledgments



References





















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




log 119902119890= log119870F +

1

119899

log119862119890 (4)


119902119890=

119902119898sdot 119870119886sdot 119862119890

1 + 119870119886sdot 119862119890

(5)

where 119902119898



1

119902119890

=

1

119902119898sdot 119870119886sdot 119862119890

+

1

119902119898

(6)


log 119902119890= log 119902

119898minus 119870DRsdot120576

2 (7)


120576 = 119877119879 log(1 + 1119862119890

) (7)



119864 =

1






log (119902119890minus 119902119905) = log 119902

119890minus

1198961

2303

119905 (9)

0 2 4 6 8 10



t (h)

minus15

minus10

minus05

00

05

10

15

log(qeminusqt)





119890minus 119902119905) versus 119905 (h)


119902119890at 119905 = 119905



119905

119902119905

=

1

1198962(119902119890)2+

119905

119902119890

(11)




119902119905= 119896119894sdot 11990512+ 119862 (10)






119890versus log 119862


119890versus





1119899 1198772 119902

1198981198701198861198772 119870DR 119902

119898119864

1198772


0

1

2

3

4




minus1

0

ln Qe

(mg

kg)






0

1

2

3

minus1

minus2

ln Qe

(mg

kg)


minus12057620




119890minus 119902119905) versus 119905 119905119902

119905versus 119905 and 119902

119905versus 11990512




119890values






1198772 119902

119890cal 1198702

1198772 119870

119894119862

1198772


0 2 4 6 8 10t (h)

minus15

minus10

minus05

00

05

10

15

log(qeminusqt)










119898


4 Conclusions




0 5 10 15 20 250

1

2

3

4

5

6

7

8

t (h)



tqt

(kgmiddot

hm

g)


5 10 15 20 25 30 35 400

5

10

15

20

25

30

35

40

t12 (h12)

Qt

(mg

kg)






Acknowledgments



References





















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




1119899 1198772 119902

1198981198701198861198772 119870DR 119902

119898119864

1198772


0

1

2

3

4




minus1

0

ln Qe

(mg

kg)






0

1

2

3

minus1

minus2

ln Qe

(mg

kg)


minus12057620




119890minus 119902119905) versus 119905 119905119902

119905versus 119905 and 119902

119905versus 11990512




119890values






1198772 119902

119890cal 1198702

1198772 119870

119894119862

1198772


0 2 4 6 8 10t (h)

minus15

minus10

minus05

00

05

10

15

log(qeminusqt)










119898


4 Conclusions




0 5 10 15 20 250

1

2

3

4

5

6

7

8

t (h)



tqt

(kgmiddot

hm

g)


5 10 15 20 25 30 35 400

5

10

15

20

25

30

35

40

t12 (h12)

Qt

(mg

kg)






Acknowledgments



References





















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of





1198772 119902

119890cal 1198702

1198772 119870

119894119862

1198772


0 2 4 6 8 10t (h)

minus15

minus10

minus05

00

05

10

15

log(qeminusqt)










119898


4 Conclusions




0 5 10 15 20 250

1

2

3

4

5

6

7

8

t (h)



tqt

(kgmiddot

hm

g)


5 10 15 20 25 30 35 400

5

10

15

20

25

30

35

40

t12 (h12)

Qt

(mg

kg)






Acknowledgments



References





















































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


0 5 10 15 20 250

1

2

3

4

5

6

7

8

t (h)



tqt

(kgmiddot

hm

g)


5 10 15 20 25 30 35 400

5

10

15

20

25

30

35

40

t12 (h12)

Qt

(mg

kg)






Acknowledgments



References





















































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










Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

Documents

Research Article Adsorption of Arsenite by Six Submerged ...downloads.hindawi.com/journals/jchem/2014/450790.pdf · Research Article Adsorption of Arsenite by Six Submerged Plants