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Dynamics of chemical interactions
Applied Geochemistry,Vol. 3, p. 92~ 1988
0883-2927/88 $3.00 + .00 Pergamon Press plc
Printed in Great Britain
Dynamics of chemical interactions JOHN W . MORSE Department of Oceanography, Texas A & M University, College Station, TX 77843, U.S.A.
MOST models for the chemistry of seawater are firmly rooted in equilibrium thermodynamic theory. They are, therefore, severely limited in their ability to deal with the real ocean, in which nonequilibrium processes often dominate and are certainly the most interesting aspect of ocean chemistry. It is essential that irreversible thermodynamic concepts be applied to oceanic processes and that much greater emphasis be placed on the dynamics of chemical interactions taking place in the ocean. Following are several specific questions or topics related to this central concept. (1) What are the kinetics of ionic interactions where strong ion-ligand interactions occur? How can these be studied? What role can surfaces or other components of the marine environment play in the transformation of chemical species? (2) Can metal-organic interactions be properly treated by classic ion pairing or association models?
What about substances such as humic acids which appear to slowly change their structural form or type of bonding after initial complexing? (3) What is the role of ionic interactions of metals with organics and surfaces in controlling redox reactions? How reversible are such reactions when complex pathways are involved? More complex yet, what role may organisms play in such processes? (4) Can nonequilibrium reaction sequences be understood in terms of minimization of entropy production or other fundamental irreversible thermodynamic concepts? How can we better understand the formation metastable species or forms? (5) How can we better treat the interracial region to understand interactions between solids and seawater? Specifically, are there any means for determining surface activities and speciation which would make possible a better approach to adsorptiondesorption reactions and solubility?
92
0883-2927/88 $3.00 + .00 Pergamon Press plc
Printed in Great Britain
Dynamics of chemical interactions JOHN W . MORSE Department of Oceanography, Texas A & M University, College Station, TX 77843, U.S.A.
MOST models for the chemistry of seawater are firmly rooted in equilibrium thermodynamic theory. They are, therefore, severely limited in their ability to deal with the real ocean, in which nonequilibrium processes often dominate and are certainly the most interesting aspect of ocean chemistry. It is essential that irreversible thermodynamic concepts be applied to oceanic processes and that much greater emphasis be placed on the dynamics of chemical interactions taking place in the ocean. Following are several specific questions or topics related to this central concept. (1) What are the kinetics of ionic interactions where strong ion-ligand interactions occur? How can these be studied? What role can surfaces or other components of the marine environment play in the transformation of chemical species? (2) Can metal-organic interactions be properly treated by classic ion pairing or association models?
What about substances such as humic acids which appear to slowly change their structural form or type of bonding after initial complexing? (3) What is the role of ionic interactions of metals with organics and surfaces in controlling redox reactions? How reversible are such reactions when complex pathways are involved? More complex yet, what role may organisms play in such processes? (4) Can nonequilibrium reaction sequences be understood in terms of minimization of entropy production or other fundamental irreversible thermodynamic concepts? How can we better understand the formation metastable species or forms? (5) How can we better treat the interracial region to understand interactions between solids and seawater? Specifically, are there any means for determining surface activities and speciation which would make possible a better approach to adsorptiondesorption reactions and solubility?
92