catalytically facilitated sequestration and transformation of...

Catalytically Facilitated Sequestration and Transformation of Catalytically Facilitated Sequestration and Transformation of Persistent Organic Pollutants in Soils and SedimentsPersistent Organic Pollutants in Soils and Sediments

Energy and Environment Program Energy and Environment Program Department of Chemical EngineeringDepartment of Chemical EngineeringThe University of Michigan, Ann ArborThe University of Michigan, Ann Arbor

Walter J. Weber, Jr.Walter J. Weber, Jr.

March 25, 2004

Technology Benchmarking Workshop for Sediment and Floodplain Remediation

Ann Arbor, Michigan

Natural Organic Matter TransformationNatural Organic Matter Transformation

Biopolymers

Humic Acids

Fulvic Acids

Small Labile Molecules

Fulvic Acids

Humic Acids

Kerogens

Mineralization

Polymer Decomposition

Contaminant Degradation

Increasing Molecular Size

Contaminant ImmobilizationDetoxification

Humification

Catalyzed Oxidative CouplingCatalyzed Oxidative Coupling

•• Oxidative coupling Oxidative coupling •• SubstratesSubstrates

•• Phenols, anilinesPhenols, anilines•• NOM building blocksNOM building blocks

•• Mediated by a variety of naturally occurring catalystsMediated by a variety of naturally occurring catalysts•• Peroxidases, laccases, tyrosinases (plants, bacteria, fungi)Peroxidases, laccases, tyrosinases (plants, bacteria, fungi)•• Certain crystalline forms of manganese and iron oxides and hydroCertain crystalline forms of manganese and iron oxides and hydroxidesxides

•• Mechanisms Mechanisms •• EnzymeEnzyme--mediated oxidation followed by couplingmediated oxidation followed by coupling

•• Leads to polymerization Leads to polymerization

•• Applications being researchedApplications being researched•• Water treatment Water treatment •• Soil and sediment decontaminationSoil and sediment decontamination

O OHOH

PeroxidasesPeroxidases

HRPHRP--Mediated Catalytic CycleMediated Catalytic Cycle

1

23

.AH

E0 Ei

Eii

H2O2

AH2

AH2

H2O

+ H2O.AH

( Huang Q., Selig H., Weber ( Huang Q., Selig H., Weber W.J.JrW.J.Jr., ES&T, 36, 19, 2002)., ES&T, 36, 19, 2002)

Phenol Conversion via HRPPhenol Conversion via HRP--Mediated CouplingMediated Coupling

[NEP] = 234.8 [E]0

R2 = 0.994

0

50

100

150

200

250

300

0 0.2 0.4 0.6 0.8 1 1.2

HRP Dosages (unit/mL)

NE

P ( µ

M)

Formation of Non-extractable Products in HRP-mediated Aqueous Systems(Initial phenol concentration = 0.5 mM , H2O2 concentration = 2 mM)

( Huang Q. and Weber ( Huang Q. and Weber W.J.JrW.J.Jr., ES&T, in review) ., ES&T, in review)

Catalytically Facilitated Sequestration and Transformation (Catalytically Facilitated Sequestration and Transformation (CFaSTCFaST) ) of of POPsPOPs in Phenolin Phenol--Based Oxidative Coupling SystemsBased Oxidative Coupling Systems

•• Phenanthrene transformation in semiPhenanthrene transformation in semi--batch reactorsbatch reactors

0

20

40

60

80

100

120

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5

Time (days)

Phen

anth

rene

con

cent

ratio

n ( µ

g/L

)

0

1000

2000

3000

4000

5000

6000

Phen

ol C

onve

rsio

n ( µ

M)

Extracted phenanthrene

Dissolved phenanthrene

Phenol conversion

Phenanthrene Disappearance in Solution and in 50% Methanol Extractions and Phenol Conversion

(0.25mM phenol, 0.25mM H2O2, and 1unit/mL HRP were added repeatedly five times a day)

( Weber ( Weber W.J.JrW.J.Jr. and Huang Q., ES&T, 37,18, 2003). and Huang Q., ES&T, 37,18, 2003)

CFaSTCFaST of of POPsPOPs in Phenolin Phenol--Based Oxidative Coupling SystemsBased Oxidative Coupling Systems

•• Phenanthrene transformation in Phenanthrene transformation in CFaSTCFaST systems of different reaction strengthsystems of different reaction strength

Phenanthrene Disappearance in Solution under Varying Reaction ConditionsThe ratio of inputs (Phenol: H2O2:HRP) are maintained constant for different CFaST systems

( Weber ( Weber W.J.JrW.J.Jr. and Huang Q., ES&T 37,18, 2003). and Huang Q., ES&T 37,18, 2003)

0

20

40

60

80

100

120

0 1 2 3 4 5Time (days)

Dis

solv

ed p

hena

nthr

ene

( µg/

L)

Dilution effect0 mM Phenol0.005 mM Phenol0.025 mM Phenol0.125 mM Phenol0.25 mM Phenol


•• Phenanthrene removed and extractability in sorption and Phenanthrene removed and extractability in sorption and CFaSTCFaST systemssystems

•• Points of notePoints of note•• Greater sorption in the Greater sorption in the CFaSTCFaST systemsystem•• Lower extractability in the Lower extractability in the CFaSTCFaST system system

0102030405060708090

100

0 200 400 600 800 1000 1200 1400 1600 1800 2000

Precipitated Coupling Products (mg/L)

% P

hena

nthr

ene

Extracted phenanthrene in sorption system

Dissolved phenanthrene in sorption system

Dissolved phenthrene in CFaST system

Extracted phenanthrene in CFaST system


•• Analysis of precipitated productsAnalysis of precipitated products

Radioactivity HPLC(µg/g) 102.1 88.87 69.23 5.74Std 1 1.59 1.29 0.13

CFaST % 100 87.04 67.81 5.62% std 0.98 1.56 1.26 0.12(µg/g) 19.64 18.5 18.74 6.93E-04

Sorption std 0.55 0.38 0.69 5.20E-03% 100 94.21 95.44 0

% std 2.78 1.93 3.49 0.03

Remained radioactivity after MSESystem

Phenanthrene Concentration

Total radioactivity before MSE

MSE Extracts

•• Points of notePoints of note•• Chemical binding occurs; phenanthrene apparently activated by Chemical binding occurs; phenanthrene apparently activated by

radical transfer mechanismsradical transfer mechanisms•• Physical sequestration still plays an important role, but is enhPhysical sequestration still plays an important role, but is enhancedanced


•• Processes in simple sorption systemsProcesses in simple sorption systems

Sorbent Sorption Diffusion Aging

Phenanthrene Polymer formation Polymer growth Polymer reformation

•• Processes in Processes in CFaSTCFaST systemssystems

•• Points of notePoints of note•• CFaSTCFaST process is mechanistically different than physical sequestratioprocess is mechanistically different than physical sequestration n •• Higher capacity, lower Higher capacity, lower leachabilityleachability, loss of chemical identity, dynamic , loss of chemical identity, dynamic

processes having potential for further transformation processes having potential for further transformation

Sorbent Effects on Sorbent Effects on CFaSTCFaST with Phenol as a Surrogate “POP”with Phenol as a Surrogate “POP”

Biopolymers

Humic Acids

Fulvic Acids

Small Labile Molecules

Fulvic Acids

Humic Acids

Kerogens

Mineralization

Polymer Decomposition

Contaminant Degradation

Increasing Molecular Size

Contaminant Immobilization/Detoxification

Humification

0

100

200

300

400

500

0 50 100 150 200 250

Solid/water ratio (g/L)

NE

P ( µ

M)

PMScellulosesillica sand

A

0

100

200

300

400

500

0 50 100 150 200 250


NE

P ( µ

M)

PMScellulosesillica sand

A

0

100

200

300

400

500

0.00 0.20 0.40 0.60 0.80 1.00 1.20


NE

P ( µ

M)

lignin B

0

100

200

300

400

500

0.00 0.20 0.40 0.60 0.80 1.00 1.20


NE

P ( µ

M)

lignin B


Formation of non-extractable products (NEP) in systems containing different solids initial phenol concentration = 0.5 mM, H2O2 concentration = 2 mM, HRP = 0.5 unit/mL



0

0.3

0.6

0.9

1.2

1.5

1.8

0 10 20 30 40 50


HR

P in

activ

atio

n ra

te c

onst

ant

(mL

/uni

t-m

in)

cellulosesilica sandPMS

0

0.3

0.6

0.9

1.2

1.5

1.8

0 10 20 30 40 50


HR

P in

activ

atio

n ra

te c

onst

ant

(mL

/uni

t-m

in)

cellulosesilica sandPMS

0

0.3

0.6

0.9

1.2

1.5

1.8

0 0.2 0.4 0.6 0.8 1

Solid/water ratio (g/L)H

RP

inac

tivat

ion

rate

con

stan

t(m

L/u

nit-

min

)

lignin

0

0.3

0.6

0.9

1.2

1.5

1.8

0 0.2 0.4 0.6 0.8 1

Solid/water ratio (g/L)H

RP

inac

tivat

ion

rate

con

stan

t(m

L/u

nit-

min

)

lignin

HRP inactivation rate constants in systems containing different solids

initial phenol concentration =500 µM, H2O2 concentration = 2 mM, HRP = 0.5 unit/mL

( Huang Q. and Weber ( Huang Q. and Weber W.J.JrW.J.Jr., ES&T, in review ) ., ES&T, in review )


0

20

40

60

80

100

0 50 100 150 200 250


Disso

lved

enz

yme

(%)

Native HRP

Compound-I

Compound-II

A

0

20

40

60

80

100

0 50 100 150 200 250


Dis

solv

ed E

nzym

e (%

)

B

0

20

40

60

80

100

0 50 100 150 200 250


Dis

solv

ed e

nzym

e (%

)

C

0

20

40

60

80

100

0 2 4 6 8 10 12


Dis

solv

ed e

nzym

e (%

)

D


•• HRP sorption on different solidsHRP sorption on different solids


100

200

300

400

500

600

700

0.6 0.8 1.0 1.2

(k in') -1 (unit-min/mL)

CTN

(nm

ole/

unit)

Cellulose Silica Sand

Lignin PMS


Relationship between turnover capacity (CTN) and HRP inactivation rate constants (kin’)

Conclusions Regarding Conclusions Regarding CFaSTCFaST of of POPsPOPs in Phenolin Phenol--Based Oxidative Coupling SystemsBased Oxidative Coupling Systems

•• Chemical transformation and irreversible sequestrationChemical transformation and irreversible sequestration•• Activation of Activation of POPsPOPs through radical transfer processesthrough radical transfer processes

•• Hydrogen abstractionHydrogen abstraction•• Free radical additionFree radical addition

•• Incorporation in products through covalent bondingIncorporation in products through covalent bonding•• Permanently immobilizedPermanently immobilized•• Loose chemical identity Loose chemical identity •• Detoxified Detoxified

•• Enhanced physical sequestrationEnhanced physical sequestration•• Concomitant sorption and sorbent formation processesConcomitant sorption and sorbent formation processes

•• Sorbate distribution profilesSorbate distribution profiles•• Desorption energies Desorption energies

Conclusions RegardingConclusions RegardingSorbent Effects on Sorbent Effects on CFaSTCFaST with Phenol as a Surrogate “POP”with Phenol as a Surrogate “POP”

•• Mitigation of enzyme inactivationMitigation of enzyme inactivation•• Enzyme sorptionEnzyme sorption•• Relatively hydrophilic and oxygenRelatively hydrophilic and oxygen--containing solidscontaining solids

•• CrossCross--couplingcoupling•• Aromatic featuresAromatic features•• SubstituentsSubstituents•• Lignin > Chelsea soil > Lachine shale > PMS > CelluloseLignin > Chelsea soil > Lachine shale > PMS > Cellulose

•• Lignin > Lachine Shale > PMSLignin > Lachine Shale > PMS•• Lignin > Chelsea Soil > CelluloseLignin > Chelsea Soil > Cellulose

Conclusions RegardingConclusions RegardingSorbent Effects on Sorbent Effects on CFaSTCFaST with Phenol as a Surrogate “POP”with Phenol as a Surrogate “POP”

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

2.2

2.4

0 0.2 0.4 0.6 0.8 1 1.2

H/C

O/C

Chelsea Soil

Cellulose

LigninLachine ShalePMS

Conclusions Regarding Conclusions Regarding Technology Development NeedsTechnology Development Needs

•• Creating optimal NOM conditionsCreating optimal NOM conditions•• Engineered geosorbents amendmentsEngineered geosorbents amendments

•• SubSub--critical water treatment of geosorbents critical water treatment of geosorbents

•• Facilitating chemical sequestration and transformations Facilitating chemical sequestration and transformations of specific of specific POPsPOPs•• PCBs, PCBs, PCDDsPCDDs, , PCDFsPCDFs•• Different catalysts Different catalysts •• Enzyme consortiaEnzyme consortia

•• Hydroxylation + Coupling Hydroxylation + Coupling

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