Lecture

Surface Complexation Equilibrium: Speciation Calculations

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Description

This lecture covers the surface complexation equilibrium in solution, focusing on ligand-induced dissolution, complex formation, and its influence on solubility. It also explains speciation calculations and the role of complexation in determining free equilibrium concentrations of species.

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Instructors (2)

Florian Frédéric Vincent Breider

Florian Breider obtained his PhD in the field of the stable isotope biogeochemistry from the University of Neuchatel in 2013. This was followed by seven months of postdoc at EPFL in the Atmospheric Particles Research Laboratory and two years as research associate at Tokyo Institute of Technology (Japan) where he conducted studies on nitrous oxide biogeochemistry in oceans. From 2015 to 2018, he was research scientist in the Laboratory for Water Quality and Treatment at EPFL where he conducted research on disinfection by-products and antibiotic resistant bacteria. Since May 2018, he is director of the Central Environmental Laboratory at the Institute of Environmental Engineering of EPFL.

Christian Ludwig

2005 - today: Adjunct Professor at EPFL in the field of Solid Waste Treatment and head of the Chemical Processes and Materials research group (CPM) at Paul Scherrer Institute (PSI). Joint EPFL-PSI Professorship on Solid Waste Treatment. 2000 - today: Head, Group of Chemical Processes and Materials (CPM) at Paul Scherrer Institut (PSI). In 2009 the LEM unit was closed and the CPM group is now affiliated to the Bioenergy and Catalysis Laboratory (LBK) of the Energy and Environment Research Division (ENE). Since June 2002 permanent position ("tenure"). 1997 - 1999: Senior Scientist. Paul Scherrer Institut (PSI), General Energy Research Department, Element Cycles Section. 1995 - 1997: Research Fellow. Swiss Federal Institute for Environmental Science and Technology (EAWAG), Department of Resource and Waste Management. 1993 - 1995: Post-doc Fellow. University of California Davis, Department of Land, Air, and Water Resources (LAWR). 1990 - 1993: PhD Student. University of Berne, Department of Inorganic, Analytical, and Physical Chemistry. 1989 - 1990: Master Student. University of Berne, Department of Inorganic, Analytical, and Physical Chemistry.

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Related concepts (32)

Determination of equilibrium constants

Equilibrium constants are determined in order to quantify chemical equilibria. When an equilibrium constant K is expressed as a concentration quotient, it is implied that the activity quotient is constant. For this assumption to be valid, equilibrium constants must be determined in a medium of relatively high ionic strength. Where this is not possible, consideration should be given to possible activity variation. The equilibrium expression above is a function of the concentrations [A], [B] etc.

Equilibrium constant

The equilibrium constant of a chemical reaction is the value of its reaction quotient at chemical equilibrium, a state approached by a dynamic chemical system after sufficient time has elapsed at which its composition has no measurable tendency towards further change. For a given set of reaction conditions, the equilibrium constant is independent of the initial analytical concentrations of the reactant and product species in the mixture.

Chemical equilibrium

In a chemical reaction, chemical equilibrium is the state in which both the reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system. This state results when the forward reaction proceeds at the same rate as the reverse reaction. The reaction rates of the forward and backward reactions are generally not zero, but they are equal. Thus, there are no net changes in the concentrations of the reactants and products.

Dynamic equilibrium

In chemistry, a dynamic equilibrium exists once a reversible reaction occurs. Substances transition between the reactants and products at equal rates, meaning there is no net change. Reactants and products are formed at such a rate that the concentration of neither changes. It is a particular example of a system in a steady state. In physics, concerning thermodynamics, a closed system is in thermodynamic equilibrium when reactions occur at such rates that the composition of the mixture does not change with time.

Chemical reaction

A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking of chemical bonds between atoms, with no change to the nuclei (no change to the elements present), and can often be described by a chemical equation. Nuclear chemistry is a sub-discipline of chemistry that involves the chemical reactions of unstable and radioactive elements where both electronic and nuclear changes can occur.

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