ABSTRACT
Wastewater contains many types of human enteric organisms that are associated with various waterborne diseases. This chapter presents various alternative methods of disinfection, the advantages and disadvantages of chlorination, chlorine chemistry, ozonation, and ultraviolet radiation. It discusses step-by-step design procedures of a UV disinfection facility in the design example. The disinfection efficiency of physical or chemical agents depends upon the following major factors: concentration of dosage or intensity of disinfection agent, contact time, temperature, and number of organisms, type of organisms, and other impurities in the liquid. The reaction of free chlorine with many organic compounds in the effluent may produce halogenated organics or organic halides. A chlorination system for disinfection of wastewater effluent consists of four separate subsystems: chlorine supply, storage, and safety; chlorine feed and application; mixing and contact; and control systems. The chapter discusses design considerations of each system.
