ENE 620

Environmental Chemodynamics

Spring 1998


Lisa Axe
237 Colton Hall
e-mail: axe@adm.njit.edu

Course Background:

Environmental Chemodynamics deals with mechanisms and processes of chemical movement in the environment, and models that can be used to quantify the rates of transport. 

Prerequisites for the course are two semesters of calculus and two semesters of chemistry.  Some previous exposure to basic organic chemistry and differential equations would be helpful, but is not necessary. Students are encouraged to work in groups on all assigned homework problems.  Critical reading above and beyond what is covered during the class meeting is expected.  

Course Objectives:

The overall objective of this course is to introduce students to concepts, mechanisms, and models used to describe the transport of chemicals in the environment.  Specific objectives for each class meeting will usually be covered at the start of that class. 

Two of the most important parameters in mass transport are the driving force or concentration gradient and the transport mechanism.  Methods for defining these parameters are discussed during the first six weeks of the class.  Concepts and models presented in the first six weeks are applied to the air-water, sediment-water, and soil-air interfaces during the rest of the term.  The semester ends with a group project, where you are asked to apply material from the course to resolve a comprehensive problem.  

Grades will be determined as follows:

Homework       15%
Quizzes            10%
Paper               15%
Project             20%
Exam I             20%
Exam II            20%

Homework will usually be assigned each week and solutions will be due the following week.  You are encouraged to work together on the homework; just be sure that all the names are on the solutions.  If you will be unable to turn in the assignment on time, you must contact me in advance so we can make other arrangements. 

Quizzes may be given each week.  Some of these will be group efforts and some of these will be individual efforts.  Quizzes may cover any topic that has been covered in lecture or in the reading.  If you have to be out of town, please contact me in advance; we can usually arrange to transmit materials by FAX. 

Another assignment this term is to write a brief review paper.  This paper should be based on a published research paper that deals with the diffusion processes covered in class. The paper can be turned in anytime up to and including March 2.  Brief means no more than two typed pages.  On the first page include your name, social security number, and a complete citation for the paper (follow the format used in the list of references in the paper you review).  Also on the first page, list what you believe are the three most important points of the paper.  You should use no more than two sentences for each point.  On the second page, write three critical questions derived from the paper.  The definition of a critical question here is a question that is inspired by reading the paper, but the answer to the question is not found in the paper.  Likely sources for research papers include the following journals: Environmental Science and Technology, Journal American Water Works, Water Research, ASCE Journal of Environmental Engineering, Journal of Colloid and Interface Science, and Water Environment Research. 

A case study project will be assigned near the end of the term; you are encouraged to also make this project a group effort.  In this project, you will be given data on the concentration of a contaminant and a description of the environment.  Your objective is to qualitatively and quantitatively describe the fate and transport of the contaminant. 

There will be two exams this term. Both exams will be comprehensive.  You may use references and notes when taking the exams, but you must work alone. 






Course Introduction

Equilibrium at Environmental Interfaces


Chapter 1 & 2


Equilibrium at Environmental Interfaces

Chapter 2


Equilibrium at Environmental Interfaces

Chapter 2


Transport Fundamentals

Chapter 3


Transport Fundamentals

Chapter 3


Transport Fundamentals

Paper Due

Chapter 3


Exam I



Spring Break



Mass Transfer at the Air-Water Interface

Chapter 4


Mass Transfer at the Air-Water Interface

Chapter 4


Mass Transfer at the Sediment-Water Interface

Chapter 5


Mass Transfer at the Sediment-Water Interface

Chapter 5


Mass Transfer at the Soil-Air Interface

Chapter 6


Mass Transfer at the Soil-Air Interface

Chapter 6


Case Study Due

Intraphase Chemical Transport and Fate


Chapter 7


Exam II


*Thibodeaux, L. J. (1996)  Environmental Chemodynamics Movement of Chemicals in Air, Water, and Soil second edition, John Wiley & Sons, Inc., NY. 

ENE 620 - Specific objectives

Weeks 1,2,3 - Concepts and expressions for chemical equilibrium

Understand the concept of equilibrium and non-equilibrium. 

Be able to perform steady- and nonsteady-state mass balances. 

Use the concepts of chemical potential and fugacity to determine if a chemical is moving between phases and, if so, in which direction. 

Use Henrys law to describe partitioning at the air-water interface. 

Understand common isotherm models (Langmuir, Freundlich) and apply these models to sorption data. 

Predict the sorption of organic chemicals to soils. 

Weeks 4,5,6 - Fundamentals of mass transfer

Fundamental descriptions of diffusion.  Fick’s law, steady state, and transient cases. 

Compare and contrast molecular diffusion and eddy (turbulent) diffusion. 

Descriptions of diffusion with a mass transfer coefficient; theories of mass transfer coefficients. 

Dimensionless groups and correlations for mass transfer coefficients. 

The two-film theory of mass transfer at an interface. 

Fundamentals of turbulence and boundary layers. 

Velocity distribution at interfaces. 

Fundamentals of heat transfer. 

Week 7 - Exam I

Weeks 8,9 - Mass transfer at the air-water interface

Use correlations to obtain air-water exchange mass transfer coefficients. 

Use laboratory data to obtain air-water exchange mass transfer coefficients. 

Understand and use the two-film theory to model air-water exchange in lakes and streams, and in the presence of suspended solids. 

Weeks 10,11 - Mass transfer at the sediment-water interface

Estimates of mass transfer coefficients at the sediment-water interface; forced convection and natural convection systems. 

Effective diffusivity in sediments. 

Mass balance models for contaminants in lakes. 

Weeks 12,13 - Mass transfer at the soil-air interface

Understand the concept of atmospheric thermal stability. 

Predict chemical fluxes from a soil. 

Predict chemical movement within a soil.

Weeks 14 - Case Study

Week 15 - Exam II