ABSTRACT
2There has been a minimal revision in this chapter compared to the first edition. A section on simulating nutrient dynamics has been included to illustrate a recent application of the electrical double-layer theory in modeling and in transport of interacting solutes. The objective of the chapter remains — providing students a simple and complete mathematical explanation of double-layer theory. A thorough discussion of the strengths and weaknesses of double-layer theory has been sacrificed for completeness of theory and its derivation. Many steps that are omitted in advanced papers on the subject are included for clarity and continuity in this chapter. The aim of this chapter is to entice a larger number of scientists to adopt and apply the double-layer theory. Double-layer theory remains underutilized in aquatic chemistry and particularly in soil science because potential users have not learned the basic relationships that comprise it.
