Wastewater treatment has been made a regulatory requirement in many countries world-over. As a result biological methods are finding widespread usage due to their improved nutrient removal efficiency. Nutrient enrichment of receiving watercourses has prompted the need for enhanced nutrient removal systems. It is against this background that this book outlines nitrogen removal in activated sludge systems through a real case study. The book is a must read for all academics with interest in Activated Sludge Systems. It provides vital insights into wastewater treatment in a tropical environment. The book attempts at establishing the applicability of SASSPro V2 modelling and simulation software in simulating nitrogen removal from wastewater treatment plants. From the case study, it was discovered that the software could predict nitrogen removal to very high levels of precision under different sludge retention times.