The book provides technical information on the operation of wastewater treatment plants and strategies to be adopted for the design of plants, assessment, processes and technologies for wastewater treatment and reuse for irrigation and industry, including protecting the environment. It discusses the crucial parts that science, technology, and innovation play in formulating, implementing, and administrating wastewater treatment policy. It highlights the challenges that must be overcome to successfully adopt the wastewater treatment infrastructure regulations and provides some answers.  It investigates how the operation of wastewater treatment plant technology can be used in a wide variety of fields, apart from other on-the-shelf publications on the market. It also delves into the core concepts of the operation of wastewater treatment plants. It explores how these concepts can be modified to fit a variety of contexts and uses. Applications such as managing facilities, dealing with pandemics, urban wastewater treatment and reuse, farming, and other applications are included in this book. Consequently, this book's content is engaging, and it will pique the interest of a diverse audience of readers who come from a wide variety of professional backgrounds.  This book will be helpful to industrialists, researchers, entrepreneurs, professionals, planners, policymakers, environmental engineers, and others interested in the operation of wastewater treatment system management strategies through the application of breakthroughs in the operation of wastewater treatment plants.   The book constitutes a database that can help companies guide the choice of a treatment technique considering operating and investment costs. Similarly, the book presents several solutions to problems encountered during the operation of treatment plants, particularly the challenges encountered at the biological and physicochemical treatment levels. The book also illustrates some design and sizing methods and methods for good practice to organize the extension of a treatment plant, if necessary, properly.  The book also deals with options for resource recovery and wastewater governance, thus establishing a clear link between the performance of a treatment plant and obtaining treated water that could be used for irrigation, which is often the missing link in current debates on the issue of making wastewater an asset. The chapters present experiences from developed and developing countries, including case studies on design, eco-efficiency, and the circular economy applied to wastewater. The book presents advanced methods for evaluating advanced solutions with low investment and operating costs. In addition, the authors and co-authors are key international experts in the field of wastewater treatment.