4A10 Construction Research & Innovation BioGeoChemistry Professor Mark Dyer TrinityHaus

Hanworth Case Study – Plan (after Dyer 2004) Former Metal Plating Works

Hanworth Case Study – Plan (after Dyer 2004) Diesel Storage Tank (BTEX) Benzene Toluene Ethyl Benzene Xylene Solvent Bath (TCE) Trichloroethene and Metal Salts CN- Cr VI

Hanworth Furniture Factory

Hanworth - Geological Cross-Section

What type of parameters influence the in-situ biodegradation ? pH6-8 Temperature10-40 deg C (mesophilic range) (40-60 deg C thermophilic range) NutrientsNitrogen (nitrate, ammonium salts) Phosphorus (phosphates) Electron Acceptors for Oxidation Oxygen, Nitrates, Sulphates, (Chlorinated Solvents) Electron Donors for Reduction Carbon Substrates (methanol, sugars, hydrogen)

Groundwater Chemistry pH6-8 Temperature10-40 deg C (mesophilic range) (40-60 deg C thermophilic range) NutrientsNitrogen (nitrate, ammonium salts) Phosphorus (phosphates) Electron Acceptors for Oxidation Oxygen, Nitrates, Sulphates, (Chlorinated Solvents) Electron Donors for Reduction Carbon Substrates (methanol, sugars, hydrogen) Parameters influencing in-situ biodegradation

Groundwater Chemistry pH6-8 Temperature10-40 deg C (mesophilic range) (40-60 deg C thermophilic range) NutrientsNitrogen (nitrate, ammonium salts) Phosphorus (phosphates) Electron Acceptors for Oxidation Oxygen, Nitrates, Sulphates, (Chlorinated Solvents) Electron Donors for Reduction Carbon Substrates (methanol, sugars, hydrogen) Parameters influencing in-situ biodegradation

Groundwater Chemistry pH6-8 Temperature10-40 deg C (mesophilic range) (40-60 deg C thermophilic range) NutrientsNitrogen (nitrate, ammonium salts) Phosphorus (phosphates) Electron Acceptors for Oxidation Oxygen, Nitrates, Sulphates, (Chlorinated Solvents) Electron Donors for Reduction Carbon Substrates (methanol, sugars, hydrogen) Methods for Obtaining Groundwater Data?

Site Characterisation Sampling and testing of groundwater chemistry at Hanworth, London Borehole

Groundwater Sampling and Analysis Field Equipment pH meter Conductivity probe DOC meter (Dissolved Oxygen) Redox meter

Groundwater Sampling and Analysis Field Equipment pH meter Conductivity probe DOC meter Redox meter Groundwater sampling and laboratory analysis (GCMS): DOC and redox potential Electron acceptors Aqueous phase contaminants

Typical Field Data for Hanworth BoreholeWater Depth (m) pHTemp ( 0 C) Conductivity (  S/cm) DOC (%) Redox (mV) 1c c c c c th June 1999 Burmarc Multiline P4 Probe

Typical Field Data for Hanworth BoreholeWater Depth (m) pHTemp ( 0 C) Conductivity (  S/cm) DOC (%) Redox (mV) 1c c c c c th June 1999 Burmarc Multiline P4 Probe

Typical Field Data for Hanworth BoreholeWater Depth (m) pHTemp ( 0 C) Conductivity (  S/cm) DOC (%) Redox (mV) 1c c c c c th June 1999 Burmarc Multiline P4 Probe What is Redox Potential ?

Basic Science – Redox Potential Zn rod dissolves and Cu deposited on the copper rod in a galvanic cell and changes the oxidation states Zn ++ Cu++ Cu Zn Flow of electrons for metals with different redox potential generates a voltage mV KCl

Redox Potential – Half Reactions Zn rod dissolves and Cu deposited on the copper rod in a galvanic cell and changes the oxidation states Zn (s) + Cu ++ (aq) = Zn ++ (aq) + Cu (s) Zn (s) = Zn ++ (aq) + 2e 2e + Cu ++ (aq) = Cu (s) Reaction can also be separated into two half reactions as follows and can be measured relative to oxidation of molecular hydrogen Oxidation States

Redox Potential – Half Reactions Zn rod dissolves and Cu deposited on the copper rod in a galvanic cell and changes the oxidation states Zn (s) + Cu ++ (aq) = Zn ++ (aq) + Cu (s) Zn (s) = Zn ++ (aq) + 2e 2e + Cu ++ (aq) = Cu (s) Reaction can also be separated into two half reactions as follows and can be measured relative to oxidation of molecular hydrogen Oxidation States

Standard Redox Potentials Zn (s) = Zn ++ (aq) + 2e 2e + Cu ++ (aq) = Cu (s) Zn (s) + Cu ++ (aq) = Zn ++ (aq) + Cu (s) mV mV mV Zn ++ (aq) + 2e - = Zn (s) H+ (aq) + e - = ½ H2 (g) Cu ++ (aq) + 2e- = Cu (s) Ag + (aq) + e- = Ag (s) mV 0.00 mV mV mV Preferential reaction

Standard Redox Potentials Zn (s) = Zn ++ (aq) + 2e 2e + Cu ++ (aq) = Cu (s) Zn (s) + Cu ++ (aq) = Zn ++ (aq) + Cu (s) mV mV mV Preferential reaction Zn ++ (aq) + 2e - = Zn (s) H+ (aq) + e - = ½ H2 (g) Cu ++ (aq) + 2e- = Cu (s) Ag + (aq) + e- = Ag (s) mV 0.00 mV mV mV

Relevance of Redox to In-situ Bioremediation O2O2 NO 3 - MnO 2 Fe 3+ SO 4 2- CO 2 Decreasing redox potential (mV) Aerobic e- biodegradation e.g. BTEX Anaerobic e - biodegradation Electron Acceptors

Relevance of Redox to In-situ Bioremediation O2O2 NO 3 - MnO 2 Fe 3+ SO 4 2- CO 2 Decreasing redox potential (mV) Aerobic e- biodegradation e.g. BTEX Anaerobic e - biodegradation Electron Acceptors Flow of Electrons  From electron donor (eg Benzene, Methanol, Propane) To electron acceptor (eg Oxygen, Nitrate, Ferric Iron, Sulphate)

Relevance of Redox to In-situ Bioremediation O2O2 NO 3 - MnO 2 Fe 3+ TCE SO 4 2- CO 2 Decreasing redox potential (mV) Aerobic e- biodegradation e.g. BTEX Anaerobic e - biodegradation Electron Acceptors

Field Characterisation – Data Patterns Redox +800 to -500 mV DOC 0 to 100% saturation e.g. 10mg/l Alternative Electron Acceptors e.g. NO 3-,Fe 3+, SO 4 2- pH TOC Temperature

Typical Field Data for Hanworth BoreholeWater Depth (m) pHTemp ( 0 C) Conductivity (  S/cm) DOC (%) Redox (mV) 1c c c c c th June 1999 Burmarc Multiline P4 Probe

Hanworth Field Data I

Self Assessment Q’s SAQ2 A spillage of petroleum fuel and chlorinated solvents have taken place at an industrial site. Described five groundwater parameters that would need to be analysed in order to assess whether the pollutants were biodegrading in-situ.

Self Assessment Q’s SAQ3 A spillage of petroleum fuels and chlorinated solvent (trichloroethylene) has taken place at an industrial site. The results from chemical analyses of groundwater samples from 3 boreholes are shown below. Comment on suitability for aerobic or anaerobic biodegradation of each contaminant at each of the three boreholes by using as many measured parameters as possible.

Hanworth Case Study Assignment You are required to write a brief interpretative report for a former metal plating works that is being redeveloped as a manufacturing factory. The site is contaminated with hydrocarbon fuels, chlorinated solvents and metal ions. The site investigation data contains results from the latest groundwater monitoring exercise along with the associated laboratory chemical analyses. The report is limited to 1200 words with supporting graphs and figures to consider whether natural attenuation is occurring and to propose a remediation strategy.

Hanworth Case Study – Plan (after Dyer 2004) Former Metal Plating Works

Hanworth Case Study – Plan (after Dyer 2004) Diesel Storage Tank (BTEX) Benzene Toluene Ethyl Benzene Xylene Solvent Bath (TCE) Trichloroethene and Metal Salts CN- Cr VI

Hanworth Furniture Factory

Hanworth - Geological Cross-Section

Acknowledgments TNO, The Netherlands Intergral Geotechnique CIRIA