Bioremediation of Explosive Contaminants

Bioremediation of Explosive Contaminants

Matt MahlerMatt Mahler

IntroductionIntroduction

In the late 19th century many nitramine compounds were created through the process of nitration.

During WW I and WW II their application for industrial and military purposes was investigated.

By 1945 an estimated 1.2 million tons of soil surrounding production plants had been contaminated.

(Lewes et.al, 2004)

In the late 19th century many nitramine compounds were created through the process of nitration.

During WW I and WW II their application for industrial and military purposes was investigated.

By 1945 an estimated 1.2 million tons of soil surrounding production plants had been contaminated.

(Lewes et.al, 2004)

Introduction Cont’dIntroduction Cont’d

Enter the environment through wastewater from production plants.

Many bioremediation techniques are currently being investigated.

Compounds Discussed: TNT, RDX, HMX and CL-20

(Lewes et.al, 2004)

Enter the environment through wastewater from production plants.

Many bioremediation techniques are currently being investigated.

Compounds Discussed: TNT, RDX, HMX and CL-20

(Lewes et.al, 2004)

Bioremediation of RDXBioremediation of RDX

Readily degradable in avariety of environments.

Aerobic and Anaerobic Mechanisms

Two-Electron Reductive Pathway and Denitration

(Crocker et. al, 2006)

Readily degradable in avariety of environments.

Aerobic and Anaerobic Mechanisms

Two-Electron Reductive Pathway and Denitration

(Crocker et. al, 2006)

RDX - Two Electron Reductive PathwayRDX - Two Electron Reductive Pathway

Mechanism Bacteria Invlolved Intermediates End Products

Mechanism I Enterobacteria, E. Coli Mono, Di and Tri-nitroso-RDX Ethanol and Formaldehyde

Mechanism II or McCormick's

PathwayClostridium Acetylbutilecum

MNX, hydroxyl amino, 1,3,5-triamino-1,3,5-triazine

Ethanol and Formaldehyde

Mechanism III Aspirgillus Niger MNXAmmonium, Nitrous Oxide,

Formaldehyde

RDX - Two Electron Reductive Pathway Cont’d

RDX - Two Electron Reductive Pathway Cont’dSpecial Notes

Mechanism II: No Ring Cleavage

Mechanism III: Uses Oxireductase

Still Disagreement Among Researchers

Special NotesMechanism II: No Ring Cleavage

Mechanism III: Uses Oxireductase

Still Disagreement Among Researchers

RDX - DenitrationRDX - Denitration

Believed to be the most common method of RDX Degradation.

Occurs aerobically and anaerobically

Believed to be the most common method of RDX Degradation.

Occurs aerobically and anaerobically

RDX - Denitration Cont’dRDX - Denitration Cont’d

Pathway Bacteria Invlolved Intermediates End Products

AerobicRhodococcus rhodochrous, Williamsia and

Gordonia-

NDAB, nitrous oxide, ammonium, formaldehyde

and carbon dioxide

Anaerobic K. pneumonia, C. bifermentans MNXWater, Nitrous Oxide and

Formaldehyde

RDX - Denitration Cont’dRDX - Denitration Cont’d

Special NotesAerobic:

NDAB is Readily Degraded by Many Organisms

In the anaerobic denitration process two electrons are added prior to ring cleavage.

Special NotesAerobic:

NDAB is Readily Degraded by Many Organisms

In the anaerobic denitration process two electrons are added prior to ring cleavage.

Bioremediation of HMXBioremediation of HMX

Most methods that degrade RDX have also been shown to degrade HMX.

Also involves aerobic and anaerobic processes.

Bioremediation of HMXBioremediation of HMX

AerobicMethylobacterium Cometabolize HMX with

Carbon Dioxide

AerobicMethylobacterium Cometabolize HMX with

Carbon Dioxide

AnaerobicSome process as RDX , however McCormick’s Pathway not aplicable.

Bioremediation of CL-20Bioremediation of CL-20

Recently Developed Nitramine

20% More Powerful Than HMX

Degradation Mechanisms Similar To Those of RDX and HMX.

Recently Developed Nitramine

20% More Powerful Than HMX

Degradation Mechanisms Similar To Those of RDX and HMX.

Bioremediation of CL-20Bioremediation of CL-20

Anaerobic DegradationCloistridium Utilizes CL-20 for Cell

Growth

Catalyzed by Dehydrogenase

End Products: Acetic Acid, Glyoxal, Nitrous Oxide and Nitrogen Dioxide

Anaerobic DegradationCloistridium Utilizes CL-20 for Cell

Growth

Catalyzed by Dehydrogenase

End Products: Acetic Acid, Glyoxal, Nitrous Oxide and Nitrogen Dioxide

Bioremediation of CL-20Bioremediation of CL-20

Aerobic DegradationWhile possible, CL-20 most occur in

high concentrations for process to take place.

In environments that support fungal growth, white-rot fungi is responsible for aerbic mineralization of CL-20.

Aerobic DegradationWhile possible, CL-20 most occur in

high concentrations for process to take place.

In environments that support fungal growth, white-rot fungi is responsible for aerbic mineralization of CL-20.

Enhancing Anaerobic Nitramine TreatmentEnhancing Anaerobic Nitramine Treatment

Anaerobic Treatment of HMX, RDX and TNTCurrent Limiting Step in Process is

the Availability of Substrate.

Historically Starch Has Been Used

Anaerobic Treatment of HMX, RDX and TNTCurrent Limiting Step in Process is

the Availability of Substrate.

Historically Starch Has Been Used

Enhancing Anaerobic Nitramine TreatmentEnhancing Anaerobic Nitramine Treatment

Anaerobic Treatment of HMX, RDX and TNTRecent Research Introduced

Propylene Glycol and Ethanol to Cultures

Consumption of these Molecules Produces Hydrogen Gas

Anaerobic Treatment of HMX, RDX and TNTRecent Research Introduced

Propylene Glycol and Ethanol to Cultures

Consumption of these Molecules Produces Hydrogen Gas

Enhancing Anaerobic Nitramine TreatmentEnhancing Anaerobic Nitramine Treatment

Enhancing Anaerobic Nitramine TreatmentEnhancing Anaerobic Nitramine Treatment

ConclusionAddition of Propylene Glycol and

Ethanol Did Increase Rate of Degradation

Not Necessary for TNT and RDX Degradation.

ConclusionAddition of Propylene Glycol and

Ethanol Did Increase Rate of Degradation

Not Necessary for TNT and RDX Degradation.

Enhancing Nitramine Treatment

Enhancing Nitramine Treatment

Enhancing Treatment CL-20Added Sucrose, Pyruvate, Yeast, Acetate,

Glucose and Starch to act as Carbon Sources

Enhancing Treatment CL-20Added Sucrose, Pyruvate, Yeast, Acetate,

Glucose and Starch to act as Carbon Sources

Enhancing Ntramine Treatment

Enhancing Ntramine Treatment

ConclusionsThe addition of these substrates does

increase the rate of CL-20 Degradation.

Process is independent of microbial cell growth.

Over half randomly selected microbes could degrade CL-20.

ConclusionsThe addition of these substrates does

increase the rate of CL-20 Degradation.

Process is independent of microbial cell growth.

Over half randomly selected microbes could degrade CL-20.

Aerobic Degradation of CL-20

Aerobic Degradation of CL-20

Researchers investigated the use of P. Chrysosporium for its use as a CL-20 degrading molecule.

At the end of the 8 day experiment concentrations of CL-20 were virtually non-existant.

Growth of fungi was observed.

Researchers investigated the use of P. Chrysosporium for its use as a CL-20 degrading molecule.

At the end of the 8 day experiment concentrations of CL-20 were virtually non-existant.

Growth of fungi was observed.

Case StudyCase Study

Louisiana Army Ammunition PlantCurrently disposes of waste through

dumping and incineration.

Experiment performed to analyze the potential use of land farming and soil slurry as potential methods of waste treatment

Louisiana Army Ammunition PlantCurrently disposes of waste through

dumping and incineration.

Experiment performed to analyze the potential use of land farming and soil slurry as potential methods of waste treatment

Case StudyCase Study

ResultsSoil Slurry showed 99% removal of

TNT and near complete removal of HMX and RDX at the end of the 182 day experiment

Land Farming showed 82% removal of TNT and little to know RDX and HMX removal after same amount of time.

ResultsSoil Slurry showed 99% removal of

TNT and near complete removal of HMX and RDX at the end of the 182 day experiment

Land Farming showed 82% removal of TNT and little to know RDX and HMX removal after same amount of time.

ConclusionConclusion

The production of nitramines is only expected to increase.

More efficient and economical degradation mechanisms must be found.

The production of nitramines is only expected to increase.

More efficient and economical degradation mechanisms must be found.

ConclusionConclusionMolecule Name of Degradation Method Bacteria I nvolved

RDX Two -Electron Reductive Pathway Enterobacteira, E. Coli, Clostridium Acetylbutilecum, Aspirgillus Niger

RDX Anaerobic Denitration K. pneumonia, C. bifermentans

RDX Aerobic Denitration Rhodococcus rhodochrous, Williamsia and

Gordonia

HMX Aerobic Degradation Methylobacterium

HMX Anaerobic Denitration K. pneumonia, C. bifermentans

CL-20 Aerobic Degradation P. C hrysosporium CL-20 Anaerobic Degradation Clostridium

QUESTIONS?QUESTIONS?