EVALUATION OF THE FATE AND TRANSPORT OF METHANOL IN THE ENVIRONMENT Prepared For: American Methanol Institute 800 Connecticut Avenue, NW, Suite 620 Washington, DC 20006 Prepared By: Malcolm Pirnie, Inc. 180 Grand Avenue, Suite 1000 Oakland, California 94612 JANUARY 1999 3522-002 TABLE OF CONTENTS Page EXECUTIVE SUMMARY .............................................................................................ES-1 1.0 BACKGROUND .................................................................................................... 1 1.1 Purpose and Scope of Report........................................................................ 1 1.2 Introduction and History of Use ................................................................... 1 1.3 Methanol Production..................................................................................... 3 1.4 Chemical and Physical Properties................................................................. 4 1.5 Release Scenarios ......................................................................................... 5 1.6 Fate in the Environment ............................................................................... 7 2.0 PARTITIONING OF METHANOL IN THE ENVIRONMENT........................... 9 2.1 Methanol Partitioning Between Environmental Compartments .................. 9 2.2 Air/Water Partitioning.................................................................................. 9 2.3 Soil/Water Partitioning................................................................................. 10 2.4 LNAPL Dissolution...................................................................................... 10 2.5 Comingling/Cosolvency Effects................................................................... 12 3.0 FATE AND TRANSPORT OF METHANOL IN THE ENVIRONMENT........... 14 3.1 Soil and Groundwater Release ..................................................................... 14 3.1.1 Sources of Methanol in Soil and Groundwater.................................. 14 3.1.2 Losses of Methanol in Soil and Groundwater ................................... 15 3.1.2.1 Biodegradation...................................................................... 15 3.1.2.1.1 Presence of Indigenous Methanol-Degrading Microbes ................................................................. 15 3.1.2.1.2 Availability of Electron Acceptors ......................... 17 3.1.2.1.3 Availability of Nutrients ......................................... 18 3.1.2.1.4 Adequate pH and Temperature Levels ................... 18 3.1.2.1.5 Reports of Methanol Biodegradation Under Various Redox Conditions...................................... 19 3.1.2.2 Adsorption............................................................................ 22 3.1.2.3 Volatilization from Groundwater ......................................... 22 3.2 Surface Water ............................................................................................... 23 3.2.1 Sources of Methanol in Surface Water .............................................. 23 3.2.2 Losses of Methanol in Surface Water................................................ 23 3.2.2.1 Biodegradation...................................................................... 24 3.2.2.2 Abiotic Degradation.............................................................. 24 3.2.2.3 Bioaccumulation ................................................................... 25 3.2.2.4 Volatilization ........................................................................ 25 3.3 Methanol / BTEX Comingled Plumes .......................................................... 26 3.4 Conclusions................................................................................................... 27 4.0 METHANOL ADDITIVES .................................................................................... 28 4.1 Purpose and Background of Additives ......................................................... 28 4.2 Fate and Transport of Three Known Additives............................................ 28 Technical Memorandum i MALCOLM PIRNIE, INC. 4.2.1 Luminosity........................................................................................... 28 4.2.2 Taste .................................................................................................... 29 4.2.3 Colorant............................................................................................... 31 4.3 Conclusion .................................................................................................... 32 5.0 REMEDIATION AND TREATMENT................................................................. 33 5.1 Remediation for Methanol ........................................................................... 33 5.2 Impetus for Drinking Water Treatment........................................................ 33 5.3 Air Stripping................................................................................................. 34 5.4 Activated Carbon.......................................................................................... 34 5.5 Advanced Oxidation..................................................................................... 35 5.6 Membranes ................................................................................................... 36 5.7 Biological Treatment (Biologically Activated Filters)................................. 36 5.8 Conclusions.................................................................................................. 37 6.0 METHANOL TOXICOLOGY............................................................................... 38 6.1 Health Effects of Methanol ......................................................................... 38 6.1.1 Inhalation............................................................................................ 38 6.1.2 Ingestion ............................................................................................. 40 6.1.3 Dermal Exposure................................................................................ 40 6.2 Aquatic Toxicity........................................................................................... 41 6.2.1 Toxicity of Methanol to Microbial Populations ................................ 42 7.0 FUTURE RESEARCH NEEDS ............................................................................. 43 8.0 CONCLUSIONS..................................................................................................... 45 8.1 Fate and Transport ......................................................................................... 45 8.2 Methanol Additives........................................................................................ 45 8.3 Remediation and Treatment.......................................................................... 46 8.4 Human and Aquatic Toxicity........................................................................ 46 9.0 ACKNOWLEDGEMENTS.................................................................................... 48 10.0 REFERENCES ........................................................................................................ 49 LIST OF TABLES Table No. Description Page Technical Memorandum ii MALCOLM PIRNIE, INC. 1-1 Global Methanol Capacity and Demand............................................................ 3 1-2 A Summary of Physical and Chemical Properties of Methanol, Gasoline (BTEX), and Benzene......................................................................... 5 1-3 Estimated Releases of Methanol for the United States...................................... 6 1-4 Estimated Half-Lives of Methanol in the Environment..................................... 7 2-1 Effects of Methanol on Aqueous BTEX Solubility ........................................... 13 3-1 Selected Types of Aerobic and Anaerobic Respiration Involved In Microbial Metabolism of Organic Matter .......................................................................... 16 3-2 Comparative Rate Constants for Anaerobic and Aerobic Degradation............. 19 3-3 Comparative Values of Octanol-Water Coefficients and Bioconcentration Factors ................................................................................... 25 4-1 Select Chemical and Physical Properties of Potential Luminosity Additives ... 29 4-2 Select Chemical and Physical Properties of Bitterant Additives....................... 30 4-3 Select Chemical and Physical Properties of Colorant Additives....................... 31 6-1 Hazard Summary .............................................................................................. 38 6-2 Methanol Toxicity Exposure Limits.................................................................. 39 6-3 Lethal Doses of Methanol in Rats and Rabbits.................................................. 40 6-4 Reported Median Lethal and Median Effective Concentrations for Methanol. 41 6-5 Biological Effects of Methanol on Various Microorganisms as Measured by the Toxicity Threshold from a cell Multiplication Inhibition Test............... 42 LIST OF FIGURES Figure No. Description Page 3-1 Methane Oxidation Pathway of Methanotrophic microorganisms.................... 16 Technical Memorandum iii MALCOLM PIRNIE, INC. EXECUTIVE SUMMARY The purpose of this report is to summarize the existing information regarding methanol— its fate and transport in the environment and potential impacts, if any, on human health and the environment. Pure methanol (M100) which is expected to be used in fuel cell vehicles