Chapter 24 Wastewater Treatment and Biosolids Reuse

Gerba, Charles P.; Pepper, Ian L.

Publisher Summary The primary goal of wastewater treatment is the removal and degradation of organic matter under controlled conditions. This chapter describes the nature and modern treatment of waste water, land applications of waste water, and methods of land applications of biosolids and animal wastes. The amount of organic matter in domestic wastes determines the degree of required biological treatment. Various tests are used to assess the amount of organic matter: biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC). The complete sewage treatment comprises three major steps: primary, secondary, and tertiary treatment. Tertiary treatment processes involving physicochemical processes can be effective in reducing the concentration of pathogens. The treated domestic wastewater may be disposed of via land application for crop irrigation or as a means of additional treatment and disposal through the three basic methods that include low-rate irrigation, overland flow, and high-rate infiltration.