Fundamentals of Wastewater Treatment and Engineering

Book Preface

This book is designed for a course on wastewater treatment and engineering for senior level or early graduate level students. As the name suggests, the book covers the fundamental concepts of wastewater treatment followed by engineering design of unit processes for treatment of municipal wastewater. The students should have background knowledge of environmental chemistry and fluid mechanics. One important characteristic of this book is that each design concept is explained with the help of an underlying fundamental theory, followed by a mathematical model or formulation. Problems are presented and solved to demonstrate the use of the mathematical formulations and apply them in design.

Chapter 1 starts with a history of wastewater treatment, followed by current practices, emerging concerns, future directions, and pertinent regulations that have shaped the objectives and directions of this important area of engineering and research. Chapters 2 and 3 describe the fundamental concepts of reaction kinetics, reactor design, and wastewater microbiology. Biochemical oxygen demand (BOD) is presented in detail, as it is one of the most important measurements for wastewater characteristics. Chapter 4 introduces natural purification processes and the dissolved oxygen sag curve. The concept of simple mass balances is introduced in this chapter. Chapters 5 through 10 describe in detail the unit processes in primary and secondary treatment. Mass balance is used to develop design equations for biological treatment processes. A separate chapter, Chapter 11, is provided for anaerobic treatment, which is becoming more and more important due to the energy production potential from methane gas generation. Chapter 12 describes solids processing and disposal, together with pertinent regulations.

A number of problems and their solutions are given to demonstrate calculation of mass and volume of sludge, perform solids balance, and calculate the efficiency. The final chapter, Chapter 13, describes advanced and tertiary treatment processes. Removal of nutrients, such as nitrogen and phosphorus, is presented in detail, followed by processes for solids removal. Recent advances in nitrogen and phosphorus removal are provided. I have incorporated recent research advances in various sections of the book, wherever applicable.

The layout of the book is similar to the manner in which I have taught this course at George Washington University (GWU) for the last 18 years. At GWU, I teach this course as Environmental Engineering II, which is taken by senior level students in the Civil and Environmental Engineering Department. The material is covered in one semester consisting of 14 weeks. At the end of the course, the student should have an understanding of the fundamental concepts of wastewater treatment and be able to design the unit processes for treatment of municipal wastewater.