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ChemicalOceanographyRyan Lecture 10 - April 14, 2005

Dr. David K. RyanDepartment of ChemistryUniversity of Massachusetts Lowell&Intercampus Graduate Schoolof Marine Sciences and Technology

http://faculty.uml.edu/David_Ryan/84.653

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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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Cauwet, 1978

Distribution ofOrganic Carbon

(a)Major compartmentsin the global ocean

(b) Major compartmentsfor the planet

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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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Sea Foam caused by naturally occuringsurface active agents

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Air-Sea Interfacial Chemistry

Surface active compoundsconcentrated at interface

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Morel & Hering,1993

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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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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 SolubilityInfluence TransportBind Metals & Organic PollutantsTerminal Electron 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 SolubilityInfluence TransportBind Metals & Organic PollutantsTerminal Electron Acceptor for Bacteria

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The quinone radical is known to be present 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 Complexation by Humics

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, 1981

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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