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ChemicalOceanographyOrganics III
Dr. David K. RyanDepartment of ChemistryUniversity of Massachusetts Lowell&Intercampus Marine Science (IMS) Program
http://faculty.uml.edu/david_ryan/84.653
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Humification ofOrganic Matter(possible scheme)
Libes, 1992
Hydrocarbons, Fats, WaxesOils, Sterols, Vitamins, etc.
Biotic
Abiotic
Macromoloecules
aggregationagglomeration
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Humification ofOrganic Matter(another scheme)
Libes, 1992
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Emerson & Hedges Figure 8.2
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Morel & Hering,1993See also Emerson & HedgesFigure 8.11 & 8.12
6Humic Structure Proposed by Schnitzer (Rashid 1985)
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Structure Attributed to Gamble et al. (1985)
8Morel & Hering (1993) Based on Aiken et al. (1985)
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Possible StructuralUnits Set Forth byAverett, Leenheer,McKnight & Thorn(1989) From Morel& Hering, 1993
10Kleinhempel reprinted from Albrecht Thaer Archiv (1970)
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Organic Solute Macromolecule (ORSMAC) Leenheer 1985)
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Davies & Ghabbour, 1999
Carbon atoms-greenOxygen atoms-redNitrogen-blueHydrogen not shown
Molecular model of the lowestenergy conformation ofhumic acid building blocks
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Importance of Humic MaterialsGlobal Carbon ReservoirTake Part in Interfacial PhenomenaUndergo Coagulation and AggregationInvolved in Photochemical ReactionsContain RadicalsKnown Reducing AgentsMethylate MetalsForm Chlorinated Species, THMs DBPsDetoxify MetalsLimit Bioavailability of MetalsAlter SolubilityInfluenceBind Metals & Organic PollutantsTerminal Electron Transport Acceptor for Bacteria
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Sea Foam caused by naturally occuring surface active agents
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Air-Sea Interfacial Chemistry
Surface active compoundsconcentrated at interface
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Importance of Humic MaterialsGlobal Carbon ReservoirTake Part in Interfacial PhenomenaUndergo Coagulation and AggregationInvolved in Photochemical ReactionsContain RadicalsKnown Reducing AgentsMethylate MetalsForm Chlorinated Species, THMs DBPsDetoxify MetalsLimit Bioavailability of MetalsAlter SolubilityInfluenceBind Metals & Organic PollutantsTerminal Electron Transport Acceptor for Bacteria
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Fox, 1983
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Importance of Humic MaterialsGlobal Carbon ReservoirTake Part in Interfacial PhenomenaUndergo Coagulation and AggregationInvolved in Photochemical ReactionsContain RadicalsKnown Reducing AgentsMethylate MetalsForm Chlorinated Species, THMs DBPsDetoxify MetalsLimit Bioavailability of MetalsAlter SolubilityInfluenceBind Metals & Organic PollutantsTerminal Electron Transport Acceptor for Bacteria
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Millero, 1996
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CDOM = Chomophoric (or Colored) Dissolved Organic Matter
Photochemistry
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Importance of Humic MaterialsGlobal Carbon ReservoirTake Part in Interfacial PhenomenaUndergo Coagulation and AggregationInvolved in Photochemical ReactionsContain RadicalsKnown Reducing AgentsMethylate MetalsForm Chlorinated Species, THMs DBPsDetoxify MetalsLimit Bioavailability of MetalsAlter SolubilityInfluenceBind Metals & Organic PollutantsTerminal Electron Transport Acceptor for Bacteria
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Quinone radicalpresent in humic material
Scott, McKnight, Blunt-Harris, Kolesar & Lovely (1998) Environ. Sci. Technol. 32, 19
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Importance of Humic MaterialsGlobal Carbon ReservoirTake Part in Interfacial PhenomenaUndergo Coagulation and AggregationInvolved in Photochemical ReactionsContain RadicalsKnown Reducing AgentsMethylate MetalsForm Chlorinated Species, THMs DBPsDetoxify MetalsLimit Bioavailability of MetalsAlter SolubilityInfluence TransportBind Metals & Organic PollutantsTerminal Electron Acceptor for Bacteria
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Humics involved in many reduction reactions
Cr(IV) to Cr(III)Fe(III) to Fe(II)Hg(II) to Hgo
As, Se and V species
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Importance of Humic MaterialsGlobal Carbon ReservoirTake Part in Interfacial PhenomenaUndergo Coagulation and AggregationInvolved in Photochemical ReactionsContain RadicalsKnown Reducing AgentsMethylate MetalsForm Chlorinated Species, THMs DBPsDetoxify MetalsLimit Bioavailability of MetalsAlter SolubilityInfluence TransportBind Metals & Organic PollutantsTerminal Electron Acceptor for Bacteria
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Metal Complexationby Humic Materials
Leenheer et al. (1998)Morel (1983)
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Importance of Humic MaterialsGlobal Carbon ReservoirTake Part in Interfacial PhenomenaUndergo Coagulation and AggregationInvolved in Photochemical ReactionsContain RadicalsKnown Reducing AgentsMethylate MetalsForm Chlorinated Species, THMs DBPsDetoxify MetalsLimit Bioavailability of MetalsAlter SolubilityInfluence TransportBind Metals & Organic PollutantsTerminal Electron Acceptor for Bacteria
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Humic material will aggregate & may“salt out” when it binds a cation
Leenheer, J.A. et al. (1998) Environ. Sci. Technol. 32, 2410
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Importance of Humic MaterialsGlobal Carbon ReservoirTake Part in Interfacial PhenomenaUndergo Coagulation and AggregationInvolved in Photochemical ReactionsContain RadicalsKnown Reducing AgentsMethylate MetalsForm Chlorinated Species, THMs DBPsDetoxify MetalsLimit Bioavailability of MetalsAlter SolubilityInfluence TransportBind Metals & Organic PollutantsTerminal Electron Acceptor for Bacteria
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Maturation and Fossilization are terms that refer to the formation of fossil fuels (coal, petroleum) from plant and animal material (biomolecules).The overall process can be split into two or three
major parts:Marine Diagenesis, Catagenesis, MetagenesisTerrestrial Humification, Coalification
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FossilizationPathway of theCarbon CycleHartenstein, 1981Van Krevelen plot
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from Hartenstein, 1981
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Libes, 1992 “…diagenetic changes …occur under anoxic conditions at temperatures less than 50 oC.”
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Sediment Diagenesis includes more thanOrganic Matter Transformations – Many redox processes occur
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Libes, 1992
PetroleumMaturationProcess
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Libes,1992
Evolutionof FossilFuels
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Morel & Hering,1993
