The first edition of the bestselling book Biological Wastewater Treatment: Principles, Modelling and Design has been thoroughly revised and updated. In addition to the inclusion of six new chapters, a further two chapters have been rewritten and ten chapters substantially revised. The new chapters cover Microbial growth, Wastewater characterization, kinetics and stoichiometry, Effluent disinfection, Sulphur conversion and removal, Granular sludge, and Emerging contaminants removal.Since publication of the first edition in 2008, the knowledge and understanding of wastewater treatment have continued to advance extensively embracing chemistry, microbiology, physical and bioprocess engineering, and mathematics. For a new generation of young scientists and engineers entering the wastewater treatment profession, the quantity, complexity and diversity of these new developments can be overwhelming, particularly in developing countries where access is not readily available to advanced level tertiary education courses in wastewater treatment. The second edition of Biological Wastewater Treatment addresses this challenge. It assembles and integrates the postgraduate course material of a dozen or so professors from research groups around the world that have made significant contributions to the advances in wastewater treatment. Readers of the book will benefit from a deeper insight and advanced knowledge of the modern approach to modelling and simulation of wastewater treatment plant design and operation, be it activated sludge, granular sludge, biological nitrogen, sulphur and phosphorus removal, secondary settling tanks or biofilm systems.