Water and Wastewater Engineering

‘Clean water and sanitation’ is one of the seventeen Sustainable Development Goals set by the United Nations General Assembly in 2015 and is to be achieved globally by 2030. Access to safe drinking water is considered a basic human right and more than 1 billion people in the world continue to suffer due to water-related diseases, resulting in many deaths.

Achieving this goal will require designing appropriate water supply and wastewater treatment systems. The first part of this book provides background information that is essential for understanding and designing these systems. The first step in the design of water supply systems is to identify a sustainable water source for the community. These water sources can be surface water or groundwater and are described in the first chapter. Methods for withdrawal of water from these sources are included. The extent to which these sources are contaminated will determine the degree of treatment that is necessary.

The next important step in the design of water supply systems is to determine the quantity and quality of the water that is needed. Water demand varies both temporally and spatially. Temporal variations on a daily and seasonal basis need to be accounted for in design. Spatial variations in water demand are mainly due to the size of the population that is to be served. Accurate forecasting of future populations is an extremely important step in determining the size and design of both water supply and wastewater systems. Factors that influence water demand are addressed in Chapter 2. Water quality requirements have become more stringent over time necessitating higher levels of treatment. Major water quality parameters of importance in water supply and wastewater systems are described with examples in Chapter 3.

Finally, basic principles of reaction kinetics and reactor design are described in Chapter 4. These principles are necessary for understanding the transport and transformation of contaminants within water and wastewater treatment systems and are applied to the design of treatment processes which are covered in the second part of the book.