Chromium, Its Behavior and Complex at Ions in Soil and Water

8/6/2019 Chromium, Its Behavior and Complex at Ions in Soil and Water

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CHROMIUM, ITS BEHAVIORAND COMPLEXATIONS IN

SOIL AND WATERAbdullah Dehwah,

Ali Zahi,

Jake Kinsella,Nicholas Davidson,

Samer Al-Mashharawi


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Outlineyes! It is going to be a micro century

Introduction

Cr in Unsaturated Soil

Cr in Groundwater Cr in Fresh Water

Cr in Lagoon (Estuarine) Water

Cr in Waste Water Conclusion


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INTRODUCTION

Mr. Cr, who is he


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IntroductionBackground about Cr and his family


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IntroductionBackground about Cr and his family


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SOURCES

Where we can find Cr


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IntroductionWhere is it


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Natural Sources

worldwide resources >12 billionmetric tons of FeCr2O4(chromite)

%95 in sou the rn S ou thA frica

, ,In d e p e n d e n t S ta te s th e P h ilip p in e s a n d o th e rco u n trie s

,Testa et al


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Anthropogenic Sources

Case Studies:Europe

commercial sourcescontribute 30 60% of thetotal Cr waste

Domestic sources contribute20-40%.

e.g. Car washes as the majorpotential source.

China

On the last two decades: 6-

million tons of toxic Crwaste are piled around 20, )Wilkie et al 1996


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BIOLOGICAL FUNCTIONS:GLUCOSE METABOLISMAND OTHERS

Is Cr important to living organisms


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IntroductionBiological functions: Glucose metabolism and others

:// . . / / - -; http www speciation net Glossary chromium picolinate 501:// . . / . = - & = & = http www scielo br scielo php?pid S1517 86922005000500003 script sci_arttext tlng en
http://www.speciation.net/Glossary/chromium-picolinate-;501http://www.speciation.net/Glossary/chromium-picolinate-;501http://www.scielo.br/scielo.php?pid=S1517-86922005000500003&script=sci_arttext&tlng=enhttp://www.scielo.br/scielo.php?pid=S1517-86922005000500003&script=sci_arttext&tlng=enhttp://www.scielo.br/scielo.php?pid=S1517-86922005000500003&script=sci_arttext&tlng=enhttp://www.speciation.net/Glossary/chromium-picolinate-;501


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IntroductionBiological functions: Glucose metabolism and others

( , . . , )Irwin R J et al 1997


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ANTHROPOGENICSOURCES

Where Cr Can be used


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IntroductionAnthropogenic sources

://http . . / / / / / .upload wikimedia org wikipedia commons 7 77 MohawkNiagraFacadeSculpture jpg:// . . / / / / / .http upload wikimedia org wikipedia commons f f3 Laidlaw_school_bus jpg
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CR THE BAD GUY

Wanted dead or alive!

Ch i (VI) i


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Chromium (VI) is somebad shit

, .Eh close enough

The true face ofErin Brockovich

:// . . . /~ / / / .http www bio miami edu cmallery 150 memb ion_channel_lg1 jpg

Ch i (III) t ti l


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Chromium (III) potentialtoxicity

Galacturonic acid Glucuronic acid

Alginic

acid,etin et al 2009


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THE UNSATURATED SOILENVIRONMENT

Cr is soil, saturated and unsaturated

Th t t d il


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The unsaturated soilenvironment

Cr +3 Cr +6hv

,Chattopadhyay et al 2010

( ) ( )Cr III usually found as Cr OH 3precipitate or as strongly bound cation

( )Forms a solid monolayer on other metal oxides particularly Mn

( ) (Cr VI oxyanions CrO4-2 & Cr2O7

-2 ) -weakly bound to pH dependent sites

Binding minimal when pH is above PZC of soil particles

Primary cause of Cr oxidation is photooxidation at the soil surface

The nsat rated soil


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( )n VII

( )n IV( )e III( )r III

e- e-

e-

Mn showed to be more efficient in( ) oxidizing Cr VI as compared to Fe,Chaddopadhyay et al 2010

Al

O

O

O-

Si

O

Al OH

O-O Cr + [H2AsO4-]

K+

. ( )Hu et al 2010 found that Cr could help to bind As in soil by providin more positive binding sites on soi particle surfaces

used to be considered the primary,factor for subterranean Cr oxidation

but recent experiments have shown( )that Mn VII has the largest influence

The unsaturated soil


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. ( ) ( )Leita et al 2009 found that humic acid could bind Cr VI and would protect it from natural reduction and artificial remediation

- -No sign of change in conformation of acid X ray spec

( ) - -No sign of reduction of Cr VI during experiment UV vis spec

: ~ ,Humic acid MW 10 000


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BEHAVIOR IN GROUNDWATER AQUIFERS

Cr in groundwater aquifers


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Cr Species in groundwater The chromium speciation in ground

water depends on two factors:

1-PE( redox potential)

2-pH


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Pe

Cr(VI) is predominate under the highredox

Cr(III) is predominate under the lowredox

( .Jerome O Nriagu,Evert Nieboer, )1988
http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Evert+Nieboer%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Evert+Nieboer%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Evert+Nieboer%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22


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pH Cr((VI))

Dominant species

HCrO4-

and CrO42-

HCrO4- ------------------- CrO 4

2- +H+

PH level H+ concentration Dominance species

Low high HCrO4-

High low CrO42-


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pH (Cr(III))

Predominant Species

Cr(OH)2+ , Cr3+ ,Cr(OH)30 and

Cr(OH)4

-

Cr3+ +H2O -------------------------

CrOH2+ + H+ CrOH2+ +H2O --------------------

Cr(OH)2+ + H+

Cr(OH)2+ +H2O ------------------ ( .Jerome O Nriagu,Evert Nieboer, ).1988
http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Evert+Nieboer%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Evert+Nieboer%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Evert+Nieboer%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Evert+Nieboer%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22http://www.google.com/search?tbs=bks:1&tbo=p&q=+inauthor:%22Jerome+O.+Nriagu%22


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ContinuePH level H+ concentration Dominance species

(6-8) Cr(OH)2+

low high(more acidic) (CrOH)2+ and Cr3+

High low(more alkaline) Cr(OH)30andCr(OH)4

-


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Solubility


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Bye bye Cr(VI) welcomeCr(III) Cr(VI) is converted to the less toxic and

much less mobile form of Cr(III) byreduction reactions. The corresponding

oxidation of Cr(III) to Cr(VI) also occurs,particularly in the presence of MnO2 and

bacteria. However, the kinetics areslow.


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Continue

Cr(VI) forms :1-soluble compoundsIf it reacts with alkali (e.g. Na, K) andalkaline earth (e.g. Mg, Ca) metalcations.2-soluble saltsOtherwise it will form sparingly solublesalt (e.g. with barium Ba), which ispresent everywhere in ground water

. , )obert G et al 2007


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Adsorption andcomplexation:

Cr(VI):the adsorption occurs as aresult of chemical reaction between

aqueous Cr(VI) species and sites atmineral surfaces.

.If the value of pH is above 8 5 then little or noadsorption will occur

Iron hydroxides are considered to be strong( )adsorbates of Cr VI

. , ).rederick T Stanin and Malcolm Pirnie 2004


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Continue

Cr(III):positive charge of Cr(III) ions areattractive to adsorbent surfaces with negativecharge.

The clay minerals (negatively charged) areconsidered to be very good adsorbents forCr(III).

Some species of chromium such as chromium(III)hydroxide (Cr(OH)3) is insoluble at site

groundwater conditions and will sorb to soilparticles and become part of the soil matrix.


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Complexation

Cr(VI) commonly does not form complexes withinorganic or organic ligands

Cr(III) forms complexes with many organic

ligands, as well as fluoride, ammonia ,cyanide,

thiocyanate, oxalate and sulfate.

( , )LORENZO GIUSTI and SABINE BARAKAT 2004


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CR IN FRESH WATER

Cr behavior in fresh water


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Chromium in watersystems Originate from natural sources: weathering of rock

elements, dry fallout from the atmosphere and run-off.

The Chromium concentration in rivers and lakes is typicallywithin the range of 0.5100 nM although concentrationsin polluted environments much higher.

.,eaublen et al 1994


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Chromium in watersystems In natural waters, two stable oxidation states, Cr(III) and Cr(VI).

Occurrence & ratio depend on: redox transformation,precipitation/dissolution and adsorption/desorption reactions.

Anoxic conditions, Cr(III) = only form.

Oxygenated solutions, Cr(III) calculated by thermodynamiccalculations as the stable species at pH7, CrO- ions should dominate .

Intermediary pH, Cr(III)/Cr(VI) ratio relies on O concentration, pH& O concentration but nature/concentration of reducers,oxidation mediators and complexing agents.

, , ,panella 1996 Kieber and Helz 1992

h i i


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Chromium in watersystems Cr(III) speciation surface waters shows hydroxo

complexes prevailing under circumstancespredominant in natural waters

Although Cr(III) can form many diversecomplexes with organic materials, eg. humicand other acids This complexing decreases Cr(OH) precipitation at pH

conditions present in natural waters.

The majority of Cr(III) complexes become immobilized bymacromolecular compounds and taken out of solution.

In addition to this, hydroxo Cr(III) complexes have a strongtendency to be adsorbed by naturally occurring solids(Rai et al., 1989) contributing to a reduction of Cr(III)mobility and bioavailability.

, , .,zynski and Kieber 1994 Rai et al 1989


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Transport in water ways

Transport in water systems significantly affected bychemical speciation.

The main way Cr moves from earth to SW systems isthrough surface run-off. As well as Cr(VI), the solubleCr(III) complexed by organic ligands can be conveyed to

groundwater and within water systems

, , .,zynski and Kieber 1994 Rai et al 1989


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Lakes and Rivers

Speciation conditions: depth, temperature, degree ofmixing, redox conditions and quantity of organic matter.

The transport of metals in rivers is related suspendedparticles.

The amount of dissolved Cr river water is decreased duringpassage through turbid coastal environments (estuarineremoval processes)

Lakes have high biological activity, a high ratio of sedimentto water surface area, and dissimilar mixing conditions. organic matter = reductive and complexing agent, which

favours Cr(VI) reduction to Cr(III) precipitated oradsorbed into sediment

May be remobilized into the surrounding water

.,hterberg et al 1997


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Seasonally Anoxic Lakes

Complex transport paths arise in seasonally anoxic lakes

In which deep basin water during summer becomes anoxic- biological productivity - thermal stratification.

In this type of lake concentration and speciation ofChromium were discovered to fluctuate as a function ofdepth and season.

.,hterberg et al 1997


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A decrease in the dissolved Cr concentration between Juneand September was detected. Furthermore, the Cr(VI)and Cr(III) dominance zones become separated to thesurface and to dee er la ers res ectivel .


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T h is b e h a v io r is co n siste n t w ith th a t e x p e cte d fro m th e se a son a l,in cre a se in tem p e ra tu re a d e cre a se in p H a n d ox yg e n con te n t in

( ( )th e d e e p e r w ate r th e ox yg e n a te d w ate r fa vo u rs C r V I w h ile th e


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CR BEHAVIOR INBRACKISH AND LAGOON(ESTUARINE) WATER

How does Cr behave in lagoon (estuarine) water


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Cr in Lagoon WaterGeneral Background

( , . . , )Irwin R J et al 1997


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Cr in Lagoon WaterWhy lagoon/ estuarine water?

( , . . , )Irwin R J et al 1997


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Cr in Lagoon WaterWhat is interesting

( , . . , )Irwin R J et al 1997( . . , )Emile M Lores and Jonathan R Pennock 1998


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CASE STUDIES

An attempt to understand Cr


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Case StudiesPaper discussed


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Case StudiesArousa Estuary (North West Spain)

LocationandSamplin

g Working

Frame

(2002-2010)

During

Different( . - , )P Pazos Capens et al 2010


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Results: Redox potential versus pH values obtained in


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Results: Time evolution of pH and redox potential values in


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Results: Contamination factors of chromium considering every

sampling station in all the campaigns in Arousa

( . - , )P Pazos Capens et al 2010


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CR IN WASTEWATER

Cr as a waste How to deal with this tough guy?

i


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Cr in wastewaterCr Behavior in WW and Industrial Disposal

Forms and Standards

Industries generate mainly a large amount of (Cr VI) [toxic] and(Cr III) [essential nutrients].

Forms depend mainly on pH and on organic and/or inorganicwastes coming from the industrial processing.

EPA standards: [Cr] in WW discharge < 0.5 mg/L {othercountries: 0.1-0.5mg/l}

Industrial effluents contain [Cr(VI)] 10 to 100mg/L

(Mohammad Abul Hossain and Mikio Kumita, 2005), (Motzer, 2005), (ICDA, 2007).

v Mobility Solubility Influence of pH Influence of redox

:r Release by Industry Sector : ,Dust or Fume Phase chromite ore mining ferrochromium

, .industry stainless steel and chromium alloy industries : Wastewater Disposal chromium metal industry and chemical.industry

C i


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Cr in wastewaterCr Treatment in WW and Industrial Disposal

Ion exchange, Precipitation, Reverse Osmosis RO, Evaporation, ChemicalReduction, Electro-dialysis and Granular Activated Carbon GAC.

Chemical Reduction:

, ( ) ( )Adding an electron donor such as S Fe II or Fe 0

(Elisabeth L. Hawley, 2004)

C i


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Membrane Filtration RO membranes operate at higher pressure NF

Thin Film Charged Surface (TFCS) nanofiltration membraneused for Cr(VI) removal.

MF or UF membranes, pretreatment is performed to complexthe Cr(III) or Cr(VI) by larger molecules e.g.Hexadecylpyridine chloride

. ., ) , ( , )afiarle et al 2000 Bohdziewicz 2000

NEW Adsorption

Using waste materials as low-cost adsorbents e.g. bagasse fly ash, aquaticplants, fungi etcHossainet al Used Black Tea Leaves (UBTLs) has proved to be a low costand high efficient in removing Cr (VI) in wastewater

Cr in wastewaterCr Treatment in WW and Industrial Disposal


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Any Questions !!

Chromium (VI) is a bad xxx But dont worry, it can be

fixed

C o n clu sio nO h w e m a d e it

Documents

Chromium, Its Behavior and Complex at Ions in Soil and Water