Lecture

Surface Charge in Soil Behavior

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

In course

ENG-400: Water quality modeling

This course builds on environmental chemistry and microbiology taken in previous courses. The emphasis is on quantification using the public domain package, PHREEQC, which is an excellent computation tool. Numerous applications are investigated during the ...

Description

This lecture discusses the behavior of soils with oxide surfaces, focusing on variable charge arising from ionization of surface reactants. It covers amphoteric behavior of hydroxide surfaces, pH 'edges' for cation and anion sorption, and the Diffuse Double Layer Model. The lecture also explores surface reactions, apparent reaction constants, and the calculation of surface charge. Various models and assumptions for surface reactions are presented, along with the impact of surface charge on macroscopic soil behavior.

Instructor

David Andrew Barry

Research InterestsSubsurface hydrology, constructed wetlands, ecological engineering, in particular contaminant transport and remediation of soil and groundwater; more generally, models of hydrological and vadose zone processes; application of mathematical methods to hydrological processes; coastal zone sediment transport, aquifer-coastal ocean interactions; hydrodynamics and modelling of lakes.

Official source

Related concepts (32)

Surface charge

A surface charge is an electric charge present on a two-dimensional surface. These electric charges are constrained on this 2-D surface, and surface charge density, measured in coulombs per square meter (C•m−2), is used to describe the charge distribution on the surface. The electric potential is continuous across a surface charge and the electric field is discontinuous, but not infinite; this is unless the surface charge consists of a dipole layer. In comparison, the potential and electric field both diverge at any point charge or linear charge.

Electric charge

Electric charge is the physical property of matter that causes it to experience a force when placed in an electromagnetic field. Electric charge can be positive or negative (commonly carried by protons and electrons respectively, by convention). Like charges repel each other and unlike charges attract each other. An object with no net charge is referred to as electrically neutral. Early knowledge of how charged substances interact is now called classical electrodynamics, and is still accurate for problems that do not require consideration of quantum effects.

Double layer (surface science)

In surface science, a double layer (DL, also called an electrical double layer, EDL) is a structure that appears on the surface of an object when it is exposed to a fluid. The object might be a solid particle, a gas bubble, a liquid droplet, or a porous body. The DL refers to two parallel layers of charge surrounding the object. The first layer, the surface charge (either positive or negative), consists of ions which are adsorbed onto the object due to chemical interactions.

Surface science

Surface science is the study of physical and chemical phenomena that occur at the interface of two phases, including solid–liquid interfaces, solid–gas interfaces, solid–vacuum interfaces, and liquid–gas interfaces. It includes the fields of surface chemistry and surface physics. Some related practical applications are classed as surface engineering. The science encompasses concepts such as heterogeneous catalysis, semiconductor device fabrication, fuel cells, self-assembled monolayers, and adhesives.

Sorption

Sorption is a physical and chemical process by which one substance becomes attached to another. Specific cases of sorption are treated in the following articles: Absorption "the incorporation of a substance in one state into another of a different state" (e.g., liquids being absorbed by a solid or gases being absorbed by a liquid); Adsorption The physical adherence or bonding of ions and molecules onto the surface of another phase (e.g.

Related lectures (64)

Electric field and electric potential

Covers electric field, potential, field lines, and potential difference with practical examples.

Charged Solid-Liquid Interfaces: Electrical Double Layer & Debey-Hückel Theory

Explores charged solid-liquid interfaces, focusing on the Electrical Double Layer and the Debey-Hückel Theory.

Charge Modeling in MOS Junctions: N-Substrate Analysis

Covers charge modeling and electric field variations in MOS junctions on n-substrates.

Electric Fields and Currents

Explores electric fields, energy storage, charge displacement, DC currents, and historical aspects of electricity.

Osmotic Pressure: Electrochemical Potential