Research Article Leaching of Major and Minor Elements

Research ArticleLeaching of Major and Minor Elements during the Transportand Storage of Coal Ash Obtained in Power Plant

Rada KrgoviT1 Jelena TrifkoviT2 Dušanka MilojkoviT-Opsenica2

Dragan ManojloviT2 and Jelena MutiT2

1 RTB Kolubara Svetog Save 1 Lazarevac Serbia2 Faculty of Chemistry University of Belgrade Studentski Trg 12-16 PO Box 51 11158 Belgrade Serbia

Correspondence should be addressed to Jelena Mutic jmuticchembgacrs

Received 7 May 2014 Revised 9 June 2014 Accepted 9 June 2014 Published 29 June 2014

Academic Editor Marcin Frankowski

Copyright copy 2014 Rada Krgovic 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

In power plant coal ash obtained by combustion is mixed with river water and transported to the dump Sequential extractionwas used in order to assess pollution caused by leaching of elements during ash transport through the pipeline and in the storage(cassettes) A total of 80 samples of filter ash as well as the ash from active (currently filled) and passive (previously filled) cassetteswere studied Samples were extracted with distilled water ammonium acetate ammonium oxalateoxalic acid acidic solution ofhydrogen-peroxide and a hydrochloric acid Concentrations of the several elements (Al As Cd Co Cu Cr Fe Ba Ca Mg NiPb and Zn) in all extracts were determined by inductively coupled plasma atomic emission spectrometry Pattern recognitionmethodwas carried out in order to provide better understanding of the nature of distribution of elements according to their originsResults indicate possible leaching of As Ca Cd Cu Zn and Pb Among these elements As Cd and Pb are toxicologically the mostimportant but they were not present in the first two phases with the exception of As The leaching could be destructive and causenegative effects on plants water pollution and damage to some life forms

1 Introduction

Coal ash is the fossil-fuel combustion residue from coalpower plants Deposits of fuel ashes as a source of pollution inenvironment could be a serious problem [1] Coal combustionin power plants generates large amounts of ash that ismarginally used or in most cases stored more or less unpro-tected in the environment where it can represent a significantsource of heavy metals PAHs and other pollutants [2]

A series of physicochemical transformations take placeduring the coal combustion in the power plants and oftencan change solubility and association patterns of variouselemental species After coal combustion coal ash is usuallystored in huge coal ash dumps either in dry or wet stateStorage of wet coal ash usually protects environment fromwind spreading but decreases the time necessary for leachingof various elements [3]

The environmental impact of coal ash production hasat least two aspects emission and deposition of enormous

amounts of coal ash polluting air water and soil and leachingof microelements (including toxic heavy metals) but alsomajor cations and anions from ash by atmospheric andsurface waters During the coal combustion in power plantsonly organic part of coal burns while the inorganic com-ponents mainly remain in the ash as by-product Inorganiccomponents of coal as well as many trace elements wereconcentrated in the ash [4]

In the literature various extraction procedures for soiland sediments were reported They were based on differentsequence schemes and various operating conditions [5ndash8]The use of sequential techniques provides researchers withessential information on the composition of materials as wellas the mobility of metals through environment [9] Alsovarious extraction procedures for the analysis of fly ash weredescribed [10ndash16]

Thermoelectric power plant (TPP) ldquoKolubarardquo is the old-est active plant in the systemof the electric power distributionof Serbia commissioned in 1956 With its five units with

Hindawi Publishing Corporatione Scientific World JournalVolume 2014 Article ID 212506 8 pageshttpdxdoiorg1011552014212506

2 The Scientific World Journal

total installed power of 270 megawatts at that time it wasthe largest power facility in the country Together with someother power plants it produces electricity for Belgrade areaand most of Serbia ldquoKolubarardquo power plant produces 11 times109 kWh annually as well as 6ndash8 times 109 kg of coal ash In that

sense the aim of this paper is to determine the impact ofleaching of minor and major elements on the environmentduring and after the transport of coal ash to dumps (activecassette) as well as direct deposition to soil (passive cassette)in order to obtain detailed data on coal ash and leaching ofvarious elements from it

2 Material and Method

21 Reagents All chemicals were analytical grade andsupplied by Merck (Darmstadt Germany) or SigmaAldrich (Taufkirchen Germany) High-purity water(resistivity gt16MΩcm) produced by reverse osmosisand demineralization was used Standard solutions wereprepared from multielement standard stock solutions(Merck 1000mgL) These multielement standards andblanks were prepared in the same matrix as the extractingreagents in order to minimize the matrix effects Thelaboratory glassware and plastic ware were cleaned byimmersing the vessels in 6molL HNO

3overnight and then

washed successively with deionized water

22 Samples Samples of filter ash were collected fromelectrofilter (EF) in power plant ldquoKolubarardquo (Veliki CrljeniSerbia) 05 kg sample was prepared from 5 kg of air-driedsample by ldquoquarteringrdquo method Twenty 1 g portions of 05 kgsample were analysed [17]

Filter ash from power plant was mixed with river waterand transported to active cassette Ten kilograms of ldquowetrdquofilter ash from active cassette (A) was sampled and air-driedat room temperature for 3 weeks Then by the quarteringmethod 05 kg sample was obtained and 20 portions wereanalysed

The active cassette becomes passive cassette after com-plete filling which can last up to ten or more years Passivecassette was near Lazarevac Serbia It has an area of 4 km2and coordinates 44∘ 291015840 2510158401015840 N and 20∘ 191015840 610158401015840 E Samplingsite at passive cassette has an area of 1 ha (100 times 100m)The samples from passive cassette were taken at two depths30 cm to 50 cm (PA) and 50 cm to 80 cm (PB) Sampling wasperformed by the principle of diagonal grid sampling and 1 kgof soil was taken from ten points at two depths covering theentire surface of the cassette [17] Composite samples of tensoil subsamples were air-dried at room temperature for threeweeksThe same quarteringmethodwas used to obtain 05 kgsample and 20 portions were taken (20 for PA and 20 for PB)

23 Sequential Extraction Procedure A five-step sequentialextraction procedure for coal ash was applied [4] Thefollowing solutions were used for sequential extraction of aportion (1 g air-dried) of each sample

(i) Distilled water (the weakest extractant) The samplewas transferred to an Erlenmeyer flask and 30mL

distilled water was added The mixture was shakenfor 6 h at ambient temperature in a horizontal rotarymechanical shaker at a speed of 200 rpm The extractwas separated from the solid residue by centrifuga-tion at 3000 rpm for 5min and decantation of thesupernatanat liquid into a glassThe solid residue wasretained for the next step

(ii) Ammonium-acetate concentration of 1molL Theresidue was shakenwith 30mL of ammonium-acetatesolution for 6 h and then centrifuged

(iii) Ammonium oxalate concentration of 02molL andoxalic acid concentration of 02molLThe extractionwas performed by adding 30mL of solution shakingfor 10 h and then centrifugingThe use of ammoniumoxalate for the extraction procedure causes the ana-lytical problems due to the crystallization In order toovercome these interferences samples are dilutedwithdistilled water 1 5 (vv) or another type of nebulizerwas used Burgener miramist nebulizer (Thermo Sci-entific) with enhanced parallel path design that canhandle high level of particulates in samples

(iv) Hydrogen-peroxide 30 solution adjusted to pH2 with concentrated HNO

3 10mL was added and

heated on a water bath at 85∘C in order to dis-solve organicsulfide matter Then 30mL of 32molLammonium-acetate solution was added and shaken30min in order to desorb eventually readsorbedelements

(v) The residue was treated 5 hwith 10mL of 6molLHCland solution in the flask was covered with watch glassat the water bath (85∘C) Then the liquid in the flaskwas evaporated To the dry cooled residue 5mL of6molL HCl solution was added heated for 4 h at thetemperature of 85∘C and centrifuged

After each extraction step all residues were washedwith distilled water the combined extracts and washingswere analyzed Also all solutions collected during sequentialextraction were filtered through medium quantitative filterpaper before the analysis

The sequential extraction procedure validated using cer-tified referencematerial ERM-CC141 (loam soil) JRC-IRMMBelgium obtaining recoveries with deviation below 5from certified values The results for each element obtainedby the treatment with aqua regia were equal (within theerror limits) to the corresponding reference values ldquo(seeTable S8 in Supplementary Material available online athttpdxdoiorg1011552014212506)rdquo

For the extraction a horizontal mechanical water bathshaker was employed A centrifuge was used for separationof the liquid phase from the precipitate

24 Instrumentation The concentrations of the metals fromall phases of sequential extraction were determined byinductively coupled plasma atomic emission spectrometry(Thermo Scientific United Kingdom) model 6500 Duoequipped with a CID86 chip detector This instrument oper-ates sequentially with both radial and axial view of plasma

The Scientific World Journal 3

The entire system was controlled with Iteva software Thewavelengths were 3961 nm (Al) 1890 nm (As) 4554 nm(Ba) 3933 nm (Ca) 2144 nm (Cd) 2286 nm (Co) 2835 nm(Cr) 3247 nm (Cu) 2599 nm (Fe) 2795 nm (Mg) 2216 nm(Ni) 2203 nm (Pb) and 2138 nm (Zn)

25 Data Analysis Principal component analysis (PCA)has been performed by means of PLS ToolBox v621for MATLAB 7120 (R2011a) PCA was carried out as anexploratory data analysis by using a singular value decom-position algorithm (SVD) and a 095 confidence level for119876 and 1198792 Hotelling limits for outliers Using only a limitednumber of principal components (PCs) the dimensionalityof the retention data space was reduced further analysis wassimplified and the parameters were grouped according tosimilarities

Descriptive statistics andKruskal-Wallis one-way analysisof variance by ranks test have been performed by means of ademo version of NCSS statistical software [18]

All data were pretreated (mean-centered and scaled to theunit standard deviation) before any statistical operations inorder to prevent highly abundant components to dominate inthe final result over the components present in much smallerquantities

3 Results and Discussion

The summarized parameters of descriptive statistics obtainedfrom the metal content analysis of filter ash and ash fromactive (currently filled) and passive (previously filled) cas-settes after five extraction steps are presented in TablesS1ndashS4The contents of thirteen elements of coal ash by phasesare presented in Figure S1

Transporting water was taken from ldquoKolubarardquo river andcontrolled quarterly A part of the results relating to theelements in the water were presented in Table S5

In addition in order to facilitate the perception of themultivariate data the mean values of content of each metalare presented in Figure 1 The content of macroelements(Ba Al Fe Ni and Mg) is shown on graphs (andashe) and thecontent of micro elements (Cd Co Cr Cu Pb Zn and Ca) isshown on graphs (gndashl) for each phase separately Figure 1(f)represents the content of As by phases Filter ash sampleswere collected during one day but for some elements highvariability among the data was found (Table S1) This isparticularly pronounced in the first phase of extraction forelements such as As Al Ba Cu and Zn For example contentof Al in first phase of the first depth was 1756mgkg andSD was 1024mgkg This might be an indication that theconcentration of Al varies significantly within this depth Ahigh variability among the data of the content of Al in passivecassette second depth was also observed (4489mgkg SD4102mgkg) The differences could be attributed to variouscompositions of coal combusted in power plant and tochanges in atmospheric conditions during long time inter-vals It is convenient to expect the heterogeneity of a hugenumber of real samples Samples from passive cassette weretaken from depth 30 to 50 cm and 50 to 80 cm in order to

avoid possible changes which could be expected if they hadbeen collected at the surface

The highest amounts of elements were extracted inthird (reducible) and fourth (organic-sulphide) phases ofextraction respectively (Figures 1(c) and 1(i))

The first phase of the extraction is characterized by highamount of Mg especially in the active cassette (Figure 1(a))Namely coal ash obtained by combustion might be mixedwith water and transported to the dump Samples frompassive cassette have a higher content of Mg compared tosamples from filter ash It could be explained by periodicalwashing of pipelines by hydrochloric acid which dissolvesprecipitated carbonates Magnesium is also extracted in thefifth phase with the slightly higher content in samples fromfilter ash and active cassettes The first phase was alsocharacterized with high amount of Ni extracted from samplesin active cassettes (Figure 1(a)) In all other extraction phasesNi was present in very small amount only in samples frompassive cassette Calcium was extracted only in the fifthphase with higher amount in samples from filter ash andactive cassettes (Figure 1(k)) which indicates that Ca wasbound to acid soluble residue such as detritus silicates andcrystalline Fe-oxide [19] Lower content of Ca in passivecassette indicates its leaching during transport However itsemission has no toxicological importanceThe third phase ofextraction was characterized with very high amount of Feparticularly in samples from active cassettes and filter ash(Figure 1(c)) Iron was also present in significant amount inthe fourth phase in samples from active cassettes and insecond phase only in samples from passive cassette (Figures1(d) and 1(b) resp) This could be attributed to the reducingconditions in passive cassette where the iron was reduced andtherefore became more available than in active cassettes Thehighest content of Al was detected after the third extractionin almost equal amounts in samples from all cassettes(Figure 1(c)) Significant amount of this element was alsofound after the fifth extraction especially in samples fromfilter ash and active cassettes (Figure 1(e)) It was also foundafter second extraction in samples from passive cassetteespecially from first depth (Figure 1(b)) Samples from filterash after the third fourth and first phases of extraction werecharacterized with high amount of Ba (Figures 1(a) 1(c) and1(d)) Lower content of Ba in all other cassettes suggested itleaches during the transport but without any environmentalpollution Significant amount of As in samples from activecassettes was also found during the first second and thirdextraction phases (Figure 1(e)) Arsenic is volatile duringthe combustion of coal it could be found at ash particles asthe result of condensation Such arsenic is on the surfaceand it could be easily extracted A considerable portion ofarsenic originates from transporting water to active cassettesand contributes to high amount of arsenic in the first phase(see Table S5) The content of As in samples of filter ashand active cassette is considerably higher than in passivecassette This could be attributed to their continual leachingto the environment that could be toxicologically importantConsidering its high toxicity as well as high production of ashit could be a serious environmental problem The contentsof minor and trace elements (Cr Cu Pb Zn and Co) are


0

50

100

150

200

250

Ba Al Fe Ni Mg

(a)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Ba Al Fe Ni Mg

(b)

0

1000

2000

3000

4000

5000

6000

7000

8000

Ba Al Fe Ni Mg

(c)

0

1000

2000

3000

4000

5000

6000

Ba Al Fe Ni Mg

(d)

Ba Al Fe Ni Mg0

200

400

600

800

1000

1200

1400

1600

(e)

0

50

100

150

200

250

300

I pha

se

II p

hase

III p

hase

IV p

hase

V p

hase

(f)

0

05

1

15

2

25

3

Cd Co Cr Cu Pb Zn Ca

(g)

Cd Co Cr Cu Pb Zn Ca0

1

2

3

4

5

6

7

8

9

10

(h)

0

5

10

15

20

25

30


(i)

0

5

10

15

20

25

EFA

PAPB


(j)


200

400

600

800

1000

1200

EFA

PAPB

(k)

0

05

1

15

2

25

Cd Co Cr Cu Pb Zn

EFA

PAPB

(l)

Figure 1 The content of twelve elements of coal ash (andashe) macroelements (Ba Al Fe Ni and Mg) for each phase of extraction respectively(f) content of As by phases (gndashl) micro and trace elements (Cd Co Cr Cu Pb Zn and Ca) for each phase of extraction respectively and(k) content of Ca in fifth phase

usually higher in samples from filter ash and active cassettescompared to samples from passive cassette indicating theirleaching (Figures 1(g)ndash1(j) and 1(l)) which could be a seriousproblem concerning their toxicity Cadmium was presentin samples in the smallest amount compared to all otherelements The highest content was observed for secondextraction phase Wadge and Hutton [20] found that 20 oftotal Cd in coal ash was in the exchangeable fraction (phases Iand II)The extraction data indicate themobility of Cd whichdepends on sample crystallinity Austin and Newland [21]

showed that Cd is a typical surface-adsorbent element in thecombustion process

For the statistical evaluation of the observed differencesin the metal content the Kruskal-Wallis test was employedfor each of the metals separately as variables taking the typeof cassette as a single factor for each phase of the extractionThe results are presented in Table S6 In the cases of theobserved a statistically significant difference between themedians Kruskal-Wallis multiple-comparison 119885-value testwas performed Cassettes with different content of a given


metal are denoted in parentheses (Table S6) A statisticallysignificant difference between metal content of samples fromdifferent origins could be observed in almost every phase ofextraction

In order to get the basic insight into the data structureand identify similarities and specific grouping patterns PCAhas been carried out on metal content data for each phaseseparately Statistical parameters (number of principal com-ponents (PCs) and percent variance captured by first threePCs) for five PCA models are presented in Table S7 Mutualprojections of factor scores and their loadings for the first twoPCs of five PCA models have been presented in Figure 2

PCA for the first phase of extraction resulted in a modelwhich explains 7741 of total variance Score plot (Fig-ure 2(a)) reveals three distinct groups of samples belonging tofilter ash active cassette and two types of passive cassetteTheloading plot (Figure 2(b)) implies that the most influentialmetals discriminating between samples from filter ash andthose from active and passive cassette are Zn Cr and BaThe major factors that lead to the separation of samplesfrom active cassette from the other types are Cu Pb NiAs Co Cd and Mg since they show a high positive impactalongside the PC1 direction The content of Al and Feseparates samples from passive cassette Therefore it wouldbe reasonable to expect higher values of Zn Cr and Ba infilter ash samples higher values of Cu Pb Ni As Co Cdand Mg in active cassette samples and higher amount ofAl that is Fe in passive cassette samples The content of Cadoes not significantly contribute to either PC1 or PC2 and itshould not be taken as a significant criterionwhen comparingsamples of different origins

PCA for the second phase of extraction resulted in amodel which explains 9233 of total variance Score plot(Figure 2(a)) reveals two groups of samples distinguishedalongside the PC2 direction One group consisted of samplesfrom filter ash and active cassette and four samples from PAAlso within this group two subgroups existed one is situatedin the upper left part of the graph and comprises samplesfrom active cassette and the other in the lower left partwith samples from filter ash The other main group consistedof samples from two types of passive cassette Loading plotimplies that As and Cd are parameters that have the mostpositive impact on PC2 direction The content of Co Ni FeCr Al and Pb significantly affects the PC1 component ina positive manner Higher values of As and Cd content inactive cassettes could be expected (Figures 2(a) and 2(b))Their high concentrations in this phase indicate that theycan be potential pollutants Also the content of Ba should behigher in samples from active and passive cassettes comparedto filter ash The content of Ca and Mg does not significantlycontribute to the model

PCA for the third phase of extraction resulted in a modelwhich explains 9442 of total variance Score plot (Fig-ure 2(a)) reveals three distinct groups of samples belongingto filter ash active cassettes and two types of passive cassetteThe major factors that lead to the separation of samplesfrom active cassette from the other types are As and Cd Thecontent of Co and Ba separates samples from filter ash whileNi content distinguished samples from passive cassette The

content of Mg should not be taken as a significant criterionwhen comparing samples of different origins

Differences between four origins are less pronouncedin fourth and fifth phases of extraction (Figure 2(a)) Stilltwo principal components differentiate samples from passivecassette from those in filter ash and active cassette PCAfor the fourth and fifth phases of extraction resulted in amodel which explains 6049 and 9402 of total variancerespectively In fourth phase the major factors that lead tothe separation of samples from active cassette are Fe of filterash samples are Ba and of samples from passive cassette (firstand second depth) are Pb and Co respectively (Figure 2(b))In fifth extraction phase all metals were extracted in higheramount in samples from filter ash and active cassette com-pared to samples from passive cassette (Figure 2(b))

Similarities in the content of all elements in all phases forpassive cassette are evident and they corroborate conclusionbased on Figure 1 and Tables S1ndashS4

The first two phases (adsorbed and ion-exchangeable) ofsequential extraction are environmentally accessible Some ofthe changes in samples could be observed Zn Cr and Bawere present in EF in adsorbed form while changes in ionicstrength of transportation water affect Cu Pb Ni As CoCd and Mg leaching which were in ion-exchangeable formsThe noticeable fraction of Zn Cr and Cu in filter ash andactive cassette associated with oxide of iron and manganesewas dissolved in the third phase (Figure 1(i)) Contrary thesemetals were found in the first two easily exchangeable phasesin passive cassette (Figures 1(h) and 1(g)) It means thatunder reduction conditions and lower pH Cr Cu and Znmigrated from easily reducible fraction to adsorbed and ion-exchangeable form [22 23] Chromium also was associatedwith organic-sulphide fraction as well as with aluminosilicatein V phase in all samples

In all samples Al and Fe with the same content wereassociated with oxide of iron and manganese in reduciblephase and organic-sulphide fraction Only in samples frompassive cassette Al and Fe extracted in ion-exchangeablephase indicated that they were sensitive to the change ofreduction conditions temperature and presence of anaerobicbacteria Leaching of lead from samples from filter ash activecassette and passive cassette was indicated by its distributionThe concentration of adsorbed magnesium is bigger in activecassette than in filter ash proving that river water influencesits leaching As it has been expected a small amount ofmagnesium was concentrated in the acid soluble residue(Figures 1(a) and 1(e)) It is known thatmetals associated withthe acid soluble residue are less bioavailable than the metalsassociated with nonresidual fractions

4 Conclusions

Filter ash samples were collected during one day but for someelements high variability among the data was found This isparticularly pronounced in the first phase of extraction forelements such as As Al Ba Cu and Zn Presence of As CdNi Pb Fe and Mg at least could originate from river waterused for transport of ash Total content of Ba and Co was


minus6 minus4 minus2 0 2 4 6

minus4

minus3

minus2

minus1

0

1

2

3

4

Scores on PC 1

Scor

es o

n PC

2

I phase


minus4

minus2

0

2

4

6

8

Scores on PC 1

Scor

es o

n PC

2

II phase

minus6 minus4

minus2

0 2 4 6

minus3

minus2

minus1

0

1

2

3

Scores on PC 1

Scor

es o

n PC

2

III phase

minus5 0 5

minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

IV phase V phase

minus8 minus6 minus4 minus2 0 2 4 6 8

minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

AEFPA

PB95 confidence level

AEFPA


(a)

As

Ba

Al

Cd Co

Cr

Cu

Fe

Ni Pb

Zn

Mg Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus08

minus06

minus04

minus02

0

02

04

06

PC 1

PC2

I phase

As

Ba

Al

Cd

Co

Cr

Cu

Fe Ni

Pb

Zn

Mg Ca

minus04

minus02 0

02

04

06

minus02

minus01

0

01

02

03

04

05

06

07II phase

As

Ba

Al

Cd

Co

Cr Cu Fe

Ni

Pb Zn

Mg

Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus04

minus02

0

02

04

06

08

1

PC 1

PC2

III phase

As

Ba Al

Cd

Co

Cr

Cu

Fe

Ni

Pb

Zn Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC 1

PC2

PC2

IV phase V phase

As

Ba

Al

Cd

Co Cr

Cu

Fe

Ni

Pb

Zn

Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC2

(b)

Figure 2 PCA (a) score plots for each phase of extraction respectively (b) loading plots for each phase of extraction respectively


higher in EF than in active cassette which could be due toloss during the transportation Some of the most importantmigration and changes in samples could be observed Zn Crand Ba were present in EF in adsorbed form while changesin ionic strength of transportation water affect Cu Pb Ni AsCo Cd and Mg leaching

The content of elements in passive cassette was notdramatically changed with depth although the filling of thesecassettes lasts several years Small differences between twodepths in passive cassette could be attributed to differentcomposition of coal combusted in power plant and to changesof atmospheric conditions On the other hand the sampleswere not taken from the surface where drastic changes inthe composition of the passive cassette may occur under theinfluence of atmospheric conditionsThe similarities betweenthe two depths of passive cassette are also observed on thePCA graphs where they are always found in the same groupAlso these results can be explained by fact that coal ash thatwas filling the passive cassette was somewhat different thanthe ash currently produced

Results of five phase sequential extraction indicate pos-sible leaching of As Ca Cd Cu Zn and Pb Amongthese elements As Cd and Pb are toxicologically the mostimportant but they were not present in the first two (easilyexchangeable) phases with the exception of As Arsenicextracted from adsorbed and ion exchange fractions of theactive ash cassette indicates a serious environmental problemPresence of As at least could originate from river water usedfor transport of ash

In order to get the basic insight into the data structure andidentify similarities and specific grouping patterns principalcomponent analysis has been carried out on metal contentdata for each phase separately Statistically significant dif-ferences were found between metal content of samples fromdifferent origins in almost every phase of extraction

Additional data on the bioavailability of these elementswill be obtained by studying their content in plants fromthese coal ash dumps These plants should be able to growunder aggravated conditions such as elevated concentrationof heavy metals poor nutrition and highly alkaline environ-ment Possibility of their use for phytoremediation will bestudied in further research Various plants will be tested inorder to reduce the risk of leaching of toxic contaminants togroundwater spreading and erosion

Conflict of Interests

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

Acknowledgment

This paper was financially supported by the Ministry ofEducation Science and Technological Development of theRepublic of Serbia Project nos 172030 and 172017

References

[1] A Smeda andW Zyrnicki ldquoApplication of sequential extractionand the ICP-AESmethod for study of the partitioning of metalsin fly ashesrdquoMicrochemical Journal vol 72 no 1 pp 9ndash16 2002

[2] A Popovic D Djordjevic and P Polic ldquoTrace and majorelement pollution originating from coal ash suspension andtransport processesrdquo Environment International vol 26 no 4pp 251ndash255 2001

[3] J Kalembkiewicz E Sitarz-Palczak and L Zapała ldquoA study ofthe chemical forms or species of manganese found in coal flyash and soilrdquo Microchemical Journal vol 90 no 1 pp 37ndash432008

[4] A Popovic D ETHorđevic D Relic and A Mihajlidi-ZelicldquoSpeciation of trace and major elements from coal combustionproducts of Serbian power plants (II) Obilic power plantrdquoEnergy Sources A Recovery Utilization and EnvironmentalEffects vol 33 no 24 pp 2309ndash2318 2011

[5] A Tessier P G C Campbell and M Blsson ldquoSequentialextraction procedure for the speciation of particulate tracemetalsrdquo Analytical Chemistry vol 51 no 7 pp 844ndash851 1979

[6] D Petrovic M Todorovic D Manojlovic and V D Krsman-ovic ldquoSpeciations of trace metals in the accumulation bogovinaon the cmi timok riverrdquo Polish Journal of Environmental Studiesvol 18 no 5 pp 873ndash884 2009

[7] D Bakircioglu Y B Kurtulus and H Ibar ldquoComparison ofextraction procedures for assessing soil metal bioavailability ofto wheat grainsrdquo CleanmdashSoil Air Water vol 39 no 8 pp 728ndash734 2011

[8] K F Mossop and C M Davidson ldquoComparison of originaland modified BCR sequential extraction procedures for thefractionation of copper iron lead manganese and zinc in soilsand sedimentsrdquo Analytica Chimica Acta vol 478 no 1 pp 111ndash118 2003

[9] E Soco and J Kalembkiewicz ldquoInvestigations on Cr mobilityfrom coal fly ashrdquo Fuel vol 88 no 8 pp 1513ndash1519 2009

[10] A Popovic and D Djordjevic ldquoSpeciation of selected trace andmajor elements in lignite used in ldquoNikola Tesla Ardquo power plant(Obrenovac Serbia)rdquo Journal of the Serbian Chemical Societyvol 70 no 12 pp 1497ndash1513 2005

[11] I Bodog K Polyak Z Csikos-Hartyanyi and J HlavayldquoSequential extraction procedure for the speciation of elementsin fly ash samplesrdquo Microchemical Journal vol 54 no 3 pp320ndash330 1996

[12] P van Herck B van der Bruggen G Vogels and C Van-decasteele ldquoApplication of computer modelling to predict theleaching behaviour of heavy metals from MSWI fly ash andcomparison with a sequential extraction methodrdquoWaste Man-agement vol 20 no 2-3 pp 203ndash210 2000

[13] S Landsberger J F Cerbus and S Larson ldquoElemental char-acterization of coal ash and its leachates using sequentialextraction techniquesrdquo Journal of Radioanalytical and NuclearChemistry Articles vol 192 no 2 pp 265ndash274 1995

[14] T Praharaj M A Powell B R Hart and S Tripathy ldquoLeacha-bility of elements from sub-bituminous coal fly ash from IndiardquoEnvironment International vol 27 no 8 pp 609ndash615 2002

[15] S Huang C Chang D T Mui F Chang M Lee and C WangldquoSequential extraction for evaluating the leaching behavior ofselected elements in municipal solid waste incineration fly ashrdquoJournal of HazardousMaterials vol 149 no 1 pp 180ndash188 2007

[16] H K Hansen A J Pedersen L M Ottosen and A VillumsenldquoSpeciation and mobility of cadmium in straw and wood


combustion fly ashrdquo Chemosphere vol 45 no 1 pp 123ndash1282001

[17] B Markert Ed Environmental Sampling for Trace AnalysisVCH Publishers New York NY USA 1994

[18] J Hintze NCSS and PASS Number Cruncher Statistical Sys-tems Kaysville Utah USA 2001

[19] D Reljic D Djordjevic A Popovic and T Blagojevic ldquoSpeci-ations of trace metals in the Danube alluvial sediments withinan oil refineryrdquo Environmental International vol 31 no 2 pp661ndash669 2005

[20] A Wadge and M Hutton ldquoThe leachability and chemicalspeciation of selected trace elements in fly ash from coalcombustion and refuse incinerationrdquo Environmental Pollutionvol 48 no 2 pp 85ndash99 1987

[21] D E Austin and L W Newland ldquoTime-resolved leaching ofcadmium and manganese from lignite and incinerator fly ashrdquoChemosphere vol 14 no 1 pp 41ndash51 1985

[22] E Soco and J Kalembkiewicz ldquoInvestigations of sequentialleaching behaviour of Cu and Zn from coal fly ash and theirmobility in environmental conditionsrdquo Journal of HazardousMaterials vol 145 no 3 pp 482ndash487 2007

[23] S Moller and J W Einax ldquoMetals in sedimentsmdashspatialinvestigation of Saale River applying chemometric toolsrdquoMicro-chemical Journal vol 110 pp 233ndash238 2013

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


total installed power of 270 megawatts at that time it wasthe largest power facility in the country Together with someother power plants it produces electricity for Belgrade areaand most of Serbia ldquoKolubarardquo power plant produces 11 times109 kWh annually as well as 6ndash8 times 109 kg of coal ash In that

sense the aim of this paper is to determine the impact ofleaching of minor and major elements on the environmentduring and after the transport of coal ash to dumps (activecassette) as well as direct deposition to soil (passive cassette)in order to obtain detailed data on coal ash and leaching ofvarious elements from it

2 Material and Method

21 Reagents All chemicals were analytical grade andsupplied by Merck (Darmstadt Germany) or SigmaAldrich (Taufkirchen Germany) High-purity water(resistivity gt16MΩcm) produced by reverse osmosisand demineralization was used Standard solutions wereprepared from multielement standard stock solutions(Merck 1000mgL) These multielement standards andblanks were prepared in the same matrix as the extractingreagents in order to minimize the matrix effects Thelaboratory glassware and plastic ware were cleaned byimmersing the vessels in 6molL HNO

3overnight and then

washed successively with deionized water

22 Samples Samples of filter ash were collected fromelectrofilter (EF) in power plant ldquoKolubarardquo (Veliki CrljeniSerbia) 05 kg sample was prepared from 5 kg of air-driedsample by ldquoquarteringrdquo method Twenty 1 g portions of 05 kgsample were analysed [17]

Filter ash from power plant was mixed with river waterand transported to active cassette Ten kilograms of ldquowetrdquofilter ash from active cassette (A) was sampled and air-driedat room temperature for 3 weeks Then by the quarteringmethod 05 kg sample was obtained and 20 portions wereanalysed

The active cassette becomes passive cassette after com-plete filling which can last up to ten or more years Passivecassette was near Lazarevac Serbia It has an area of 4 km2and coordinates 44∘ 291015840 2510158401015840 N and 20∘ 191015840 610158401015840 E Samplingsite at passive cassette has an area of 1 ha (100 times 100m)The samples from passive cassette were taken at two depths30 cm to 50 cm (PA) and 50 cm to 80 cm (PB) Sampling wasperformed by the principle of diagonal grid sampling and 1 kgof soil was taken from ten points at two depths covering theentire surface of the cassette [17] Composite samples of tensoil subsamples were air-dried at room temperature for threeweeksThe same quarteringmethodwas used to obtain 05 kgsample and 20 portions were taken (20 for PA and 20 for PB)

23 Sequential Extraction Procedure A five-step sequentialextraction procedure for coal ash was applied [4] Thefollowing solutions were used for sequential extraction of aportion (1 g air-dried) of each sample

(i) Distilled water (the weakest extractant) The samplewas transferred to an Erlenmeyer flask and 30mL

distilled water was added The mixture was shakenfor 6 h at ambient temperature in a horizontal rotarymechanical shaker at a speed of 200 rpm The extractwas separated from the solid residue by centrifuga-tion at 3000 rpm for 5min and decantation of thesupernatanat liquid into a glassThe solid residue wasretained for the next step

(ii) Ammonium-acetate concentration of 1molL Theresidue was shakenwith 30mL of ammonium-acetatesolution for 6 h and then centrifuged

(iii) Ammonium oxalate concentration of 02molL andoxalic acid concentration of 02molLThe extractionwas performed by adding 30mL of solution shakingfor 10 h and then centrifugingThe use of ammoniumoxalate for the extraction procedure causes the ana-lytical problems due to the crystallization In order toovercome these interferences samples are dilutedwithdistilled water 1 5 (vv) or another type of nebulizerwas used Burgener miramist nebulizer (Thermo Sci-entific) with enhanced parallel path design that canhandle high level of particulates in samples

(iv) Hydrogen-peroxide 30 solution adjusted to pH2 with concentrated HNO

3 10mL was added and

heated on a water bath at 85∘C in order to dis-solve organicsulfide matter Then 30mL of 32molLammonium-acetate solution was added and shaken30min in order to desorb eventually readsorbedelements

(v) The residue was treated 5 hwith 10mL of 6molLHCland solution in the flask was covered with watch glassat the water bath (85∘C) Then the liquid in the flaskwas evaporated To the dry cooled residue 5mL of6molL HCl solution was added heated for 4 h at thetemperature of 85∘C and centrifuged

After each extraction step all residues were washedwith distilled water the combined extracts and washingswere analyzed Also all solutions collected during sequentialextraction were filtered through medium quantitative filterpaper before the analysis

The sequential extraction procedure validated using cer-tified referencematerial ERM-CC141 (loam soil) JRC-IRMMBelgium obtaining recoveries with deviation below 5from certified values The results for each element obtainedby the treatment with aqua regia were equal (within theerror limits) to the corresponding reference values ldquo(seeTable S8 in Supplementary Material available online athttpdxdoiorg1011552014212506)rdquo

For the extraction a horizontal mechanical water bathshaker was employed A centrifuge was used for separationof the liquid phase from the precipitate

24 Instrumentation The concentrations of the metals fromall phases of sequential extraction were determined byinductively coupled plasma atomic emission spectrometry(Thermo Scientific United Kingdom) model 6500 Duoequipped with a CID86 chip detector This instrument oper-ates sequentially with both radial and axial view of plasma














0

50

100

150

200

250

Ba Al Fe Ni Mg

(a)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Ba Al Fe Ni Mg

(b)

0

1000

2000

3000

4000

5000

6000

7000

8000

Ba Al Fe Ni Mg

(c)

0

1000

2000

3000

4000

5000

6000

Ba Al Fe Ni Mg

(d)

Ba Al Fe Ni Mg0

200

400

600

800

1000

1200

1400

1600

(e)

0

50

100

150

200

250

300

I pha

se

II p

hase

III p

hase

IV p

hase

V p

hase

(f)

0

05

1

15

2

25

3


(g)


1

2

3

4

5

6

7

8

9

10

(h)

0

5

10

15

20

25

30


(i)

0

5

10

15

20

25

EFA

PAPB


(j)


200

400

600

800

1000

1200

EFA

PAPB

(k)

0

05

1

15

2

25

Cd Co Cr Cu Pb Zn

EFA

PAPB

(l)
















4 Conclusions




minus4

minus3

minus2

minus1

0

1

2

3

4

Scores on PC 1

Scor

es o

n PC

2

I phase


minus4

minus2

0

2

4

6

8

Scores on PC 1

Scor

es o

n PC

2

II phase

minus6 minus4

minus2

0 2 4 6

minus3

minus2

minus1

0

1

2

3

Scores on PC 1

Scor

es o

n PC

2

III phase

minus5 0 5

minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

IV phase V phase


minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

AEFPA


AEFPA


(a)

As

Ba

Al

Cd Co

Cr

Cu

Fe

Ni Pb

Zn

Mg Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus08

minus06

minus04

minus02

0

02

04

06

PC 1

PC2

I phase

As

Ba

Al

Cd

Co

Cr

Cu

Fe Ni

Pb

Zn

Mg Ca

minus04

minus02 0

02

04

06

minus02

minus01

0

01

02

03

04

05

06

07II phase

As

Ba

Al

Cd

Co

Cr Cu Fe

Ni

Pb Zn

Mg

Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus04

minus02

0

02

04

06

08

1

PC 1

PC2

III phase

As

Ba Al

Cd

Co

Cr

Cu

Fe

Ni

Pb

Zn Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC 1

PC2

PC2

IV phase V phase

As

Ba

Al

Cd

Co Cr

Cu

Fe

Ni

Pb

Zn

Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC2

(b)










Acknowledgment


References



































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of














0

50

100

150

200

250

Ba Al Fe Ni Mg

(a)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Ba Al Fe Ni Mg

(b)

0

1000

2000

3000

4000

5000

6000

7000

8000

Ba Al Fe Ni Mg

(c)

0

1000

2000

3000

4000

5000

6000

Ba Al Fe Ni Mg

(d)

Ba Al Fe Ni Mg0

200

400

600

800

1000

1200

1400

1600

(e)

0

50

100

150

200

250

300

I pha

se

II p

hase

III p

hase

IV p

hase

V p

hase

(f)

0

05

1

15

2

25

3


(g)


1

2

3

4

5

6

7

8

9

10

(h)

0

5

10

15

20

25

30


(i)

0

5

10

15

20

25

EFA

PAPB


(j)


200

400

600

800

1000

1200

EFA

PAPB

(k)

0

05

1

15

2

25

Cd Co Cr Cu Pb Zn

EFA

PAPB

(l)
















4 Conclusions




minus4

minus3

minus2

minus1

0

1

2

3

4

Scores on PC 1

Scor

es o

n PC

2

I phase


minus4

minus2

0

2

4

6

8

Scores on PC 1

Scor

es o

n PC

2

II phase

minus6 minus4

minus2

0 2 4 6

minus3

minus2

minus1

0

1

2

3

Scores on PC 1

Scor

es o

n PC

2

III phase

minus5 0 5

minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

IV phase V phase


minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

AEFPA


AEFPA


(a)

As

Ba

Al

Cd Co

Cr

Cu

Fe

Ni Pb

Zn

Mg Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus08

minus06

minus04

minus02

0

02

04

06

PC 1

PC2

I phase

As

Ba

Al

Cd

Co

Cr

Cu

Fe Ni

Pb

Zn

Mg Ca

minus04

minus02 0

02

04

06

minus02

minus01

0

01

02

03

04

05

06

07II phase

As

Ba

Al

Cd

Co

Cr Cu Fe

Ni

Pb Zn

Mg

Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus04

minus02

0

02

04

06

08

1

PC 1

PC2

III phase

As

Ba Al

Cd

Co

Cr

Cu

Fe

Ni

Pb

Zn Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC 1

PC2

PC2

IV phase V phase

As

Ba

Al

Cd

Co Cr

Cu

Fe

Ni

Pb

Zn

Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC2

(b)










Acknowledgment


References



































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


0

50

100

150

200

250

Ba Al Fe Ni Mg

(a)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Ba Al Fe Ni Mg

(b)

0

1000

2000

3000

4000

5000

6000

7000

8000

Ba Al Fe Ni Mg

(c)

0

1000

2000

3000

4000

5000

6000

Ba Al Fe Ni Mg

(d)

Ba Al Fe Ni Mg0

200

400

600

800

1000

1200

1400

1600

(e)

0

50

100

150

200

250

300

I pha

se

II p

hase

III p

hase

IV p

hase

V p

hase

(f)

0

05

1

15

2

25

3


(g)


1

2

3

4

5

6

7

8

9

10

(h)

0

5

10

15

20

25

30


(i)

0

5

10

15

20

25

EFA

PAPB


(j)


200

400

600

800

1000

1200

EFA

PAPB

(k)

0

05

1

15

2

25

Cd Co Cr Cu Pb Zn

EFA

PAPB

(l)
















4 Conclusions




minus4

minus3

minus2

minus1

0

1

2

3

4

Scores on PC 1

Scor

es o

n PC

2

I phase


minus4

minus2

0

2

4

6

8

Scores on PC 1

Scor

es o

n PC

2

II phase

minus6 minus4

minus2

0 2 4 6

minus3

minus2

minus1

0

1

2

3

Scores on PC 1

Scor

es o

n PC

2

III phase

minus5 0 5

minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

IV phase V phase


minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

AEFPA


AEFPA


(a)

As

Ba

Al

Cd Co

Cr

Cu

Fe

Ni Pb

Zn

Mg Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus08

minus06

minus04

minus02

0

02

04

06

PC 1

PC2

I phase

As

Ba

Al

Cd

Co

Cr

Cu

Fe Ni

Pb

Zn

Mg Ca

minus04

minus02 0

02

04

06

minus02

minus01

0

01

02

03

04

05

06

07II phase

As

Ba

Al

Cd

Co

Cr Cu Fe

Ni

Pb Zn

Mg

Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus04

minus02

0

02

04

06

08

1

PC 1

PC2

III phase

As

Ba Al

Cd

Co

Cr

Cu

Fe

Ni

Pb

Zn Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC 1

PC2

PC2

IV phase V phase

As

Ba

Al

Cd

Co Cr

Cu

Fe

Ni

Pb

Zn

Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC2

(b)










Acknowledgment


References



































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of












4 Conclusions




minus4

minus3

minus2

minus1

0

1

2

3

4

Scores on PC 1

Scor

es o

n PC

2

I phase


minus4

minus2

0

2

4

6

8

Scores on PC 1

Scor

es o

n PC

2

II phase

minus6 minus4

minus2

0 2 4 6

minus3

minus2

minus1

0

1

2

3

Scores on PC 1

Scor

es o

n PC

2

III phase

minus5 0 5

minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

IV phase V phase


minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

AEFPA


AEFPA


(a)

As

Ba

Al

Cd Co

Cr

Cu

Fe

Ni Pb

Zn

Mg Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus08

minus06

minus04

minus02

0

02

04

06

PC 1

PC2

I phase

As

Ba

Al

Cd

Co

Cr

Cu

Fe Ni

Pb

Zn

Mg Ca

minus04

minus02 0

02

04

06

minus02

minus01

0

01

02

03

04

05

06

07II phase

As

Ba

Al

Cd

Co

Cr Cu Fe

Ni

Pb Zn

Mg

Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus04

minus02

0

02

04

06

08

1

PC 1

PC2

III phase

As

Ba Al

Cd

Co

Cr

Cu

Fe

Ni

Pb

Zn Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC 1

PC2

PC2

IV phase V phase

As

Ba

Al

Cd

Co Cr

Cu

Fe

Ni

Pb

Zn

Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC2

(b)










Acknowledgment


References



































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of



minus4

minus3

minus2

minus1

0

1

2

3

4

Scores on PC 1

Scor

es o

n PC

2

I phase


minus4

minus2

0

2

4

6

8

Scores on PC 1

Scor

es o

n PC

2

II phase

minus6 minus4

minus2

0 2 4 6

minus3

minus2

minus1

0

1

2

3

Scores on PC 1

Scor

es o

n PC

2

III phase

minus5 0 5

minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

IV phase V phase


minus3

minus2

minus1

0

1

2

3

4

5

6

Scores on PC 1

Scor

es o

n PC

2

AEFPA


AEFPA


(a)

As

Ba

Al

Cd Co

Cr

Cu

Fe

Ni Pb

Zn

Mg Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus08

minus06

minus04

minus02

0

02

04

06

PC 1

PC2

I phase

As

Ba

Al

Cd

Co

Cr

Cu

Fe Ni

Pb

Zn

Mg Ca

minus04

minus02 0

02

04

06

minus02

minus01

0

01

02

03

04

05

06

07II phase

As

Ba

Al

Cd

Co

Cr Cu Fe

Ni

Pb Zn

Mg

Ca

minus08

minus06

minus04

minus02 0

02

04

06

08

minus04

minus02

0

02

04

06

08

1

PC 1

PC2

III phase

As

Ba Al

Cd

Co

Cr

Cu

Fe

Ni

Pb

Zn Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC 1

PC2

PC2

IV phase V phase

As

Ba

Al

Cd

Co Cr

Cu

Fe

Ni

Pb

Zn

Mg

Ca

minus04

minus02 0

02

04

06

minus03

minus02

minus01

0

01

02

03

04

05

06

PC 1

PC2

(b)










Acknowledgment


References



































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of









Acknowledgment


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 Leaching of Major and Minor Elements