Operators play a vital role in protecting public health and the environment-and understanding the biology behind wastewater treatment is essential to that mission. Microorganisms such as bacteria, protozoa, metazoa, algae, and fungi are the engines of pollutant removal, working at every stage from preliminary screening to advanced disinfection. With updated guidance reflecting today's regulatory standards and treatment challenges, this edition empowers operators to manage biological systems with confidence, clarity, and purpose.
