This extensively revised third edition reflects the latest advances and industry best practices and now explicitly addresses nutrient removal.

Get this guide to solve performance issues and improve operations.

Activated Sludge and Nutrient Removal, MOP OM-9, 3rd Edition, helps operators and other wastewater treatment professionals understand the activated sludge process, solve performance problems, and improve operations. This extensively revised third edition reflects the latest advances and industry best practices, and now explicitly addresses nutrient removal. As the primary reference for the operation of the activated sludge process, operators are guided through selecting an appropriate sludge age, calculating wasting rates, optimizing return activated sludge (RAS) flow, managing clarifier blankets, and setting DO and ORP set points.

Key features of the third edition:

  • Delivers comprehensive, industry best practices for the operation of the activated sludge process
  • Discusses a range of approaches to activated sludge process control
  • Authored and peer-reviewed by leading water sector professionals
  • Serves as the primary reference for both novice and experienced professionals
  • Explores Return Activated Sludge (RAS) and Waste Activated Sludge (WAS)


New to this edition:

  • New! Provides activated sludge process troubleshooting charts
  • New! Laboratory chapter with detailed directions for common sludge process control tests
  • New! Offers an introduction to biological process modeling
  • New! Presents advanced concepts in nutrient removal
  • New! Offers practice questions to enhance reader understanding and reinforce concepts presented
  • Expanded! Updated activated sludge process control section with step-by-step examples for calculations
  • NEW! Available as an e-book

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Table of Contents

  • Chapter 1 Introduction
  • Chapter 2 Activated Sludge Process Fundamentals
  • Chapter 3 Activated Sludge Microbiology
  • Chapter 4 Process Control for the Activated Sludge Basin
  • Chapter 5 Process Control Methods for the Secondary Clarifier
  • Chapter 6 Process Control Tests
  • Chapter 7 Process Troubleshooting
  • Chapter 8 Advanced Concepts in Nutrient Removal
  • Chapter 9 Sludge Process Simulators

Here's what Readers are saying about Activated Sludge and Nutrient Removal, MOP OM-9, 3rd Edition

This book is great to read, easy to follow and I love the practice questions at the end of the chapters. As the Operator in Responsible Charge, it helped me restructure the way we do our daily plant rounds. We are going to use it to update some of our Standard Operating Procedures (SOP’s). It helps as a quick reference when troubleshooting an issue with our processes and helps to optimize our process where available. A great tool for any wastewater treatment operator.

Manuel Freyre, Chief Plant Operator for Wastewater
City of Northglenn, CO.


This extensively revised third edition of Activated Sludge and Nutrient Removal, Manual of Practice No. OM-9, reflects best practices and the latest advances. This is one of the best books ever published by WEF. The book is not only a primary reference for the design and operation of the activated sludge process, but also an excellent supplemental college textbook for environmental biotechnology courses.

Lawrence K. Wang is a professor and Mu-Hao Sung Wang is a consultant at the Lenox Institute of Technology (Newtonville, N.Y.).

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Design of Water Resource Recovery Facilities, MOP 8, 6th Edition
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Standard Methods for the Examination of Water and Wastewater, 23rd Edition
Since 1905, Standard Methods for the Examination of Water and Wastewater has represented "the best current practice of American water analysts." This comprehensive reference covers all aspects of water and wastewater analysis techniques. Standard Methods is a joint publication of the American Public Health Association (APHA), the American Water Works Association (AWWA), and the Water Environment Federation (WEF). Standard Methods is available in print and as an online subscription. To subscribe to Standard Methods Online, visit www.StandardMethods.org. Order the Print Edition Here.

How to Order

Online www.wef.org/ShopWEF
Call 1.800.666.0206
Email [email protected] 

Other Nutrient Resources

Nutrient Removal, MOP 34
The latest methods for Nutrient Removal from wastewater.

Operation of Nutrient Removal Facilities, MOP 37
Your guide to successfully operating a stable, reliable, and efficient facility to remove nitrogen and/or phosphorus, while simultaneously minimizing operations and maintenance costs.

Operation of Water Resource Recovery Facilities, MOP 11
The water industry’s cornerstone text – updated to reflect the latest trends, technologies, and regulations. Now presented in a single volume for easy reference.

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The premier water research journal that provides groundbreaking research on the world’s most important resource.

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