ABSTRACT
Wastewater treatment units generally fall into two broad divisions: unit operations and unit processes. In the unit operations, the treatment or removal of contaminants is brought about by the physical forces. Wastewater treatment plants utilize a number of unit operations and processes to achieve the desired degree of treatment. Wastewater treatment is generally achieved in tanks or reactors in which physical, chemical, and biological changes occur. The principal types of reactors used for wastewater treatment are batch reactor, plug-flow or tubular-flow reactor, complete-mixed or continuous-flow stirred tank reactor (CFSTR), and arbitrary-flow reactor. The chapter discusses unit operations and processes applicable to the treatment of liquid and solid portions. It summarizes different unit operations and processes in the design of primary, secondary, and advanced wastewater treatment facilities. The chapter provides stream quality and operational performance data of various sludge-processing facilities. It shows several process diagrams for sludge processing.
