ABSTRACT
This chapter describes briefly the principal processes used to achieve the various degrees of preapplication treatment and the quality of the effluents produced. Although irrigation with wastewater is in itself an effective form of wastewater treatment, some degree of treatment must be provided to untreated municipal wastewater before it can be used for agricultural or landscape irrigation. Preapplication treatment of wastewater is practiced for the following reasons: protect public health, prevent nuisance conditions during storage, and prevent damage to crops and soils. To discuss wastewater treatment processes and the characteristics of effluent produced by them, it is first necessary to describe the characteristics of untreated municipal wastewater. The physical properties and the chemical and biological constituents of wastewater are important parameters in the design and operation of collection, treatment, and disposal facilities and in the engineering management of environmental quality. High-rate biological processes are characterized by relatively small basin volumes and high concentrations of microorganisms compared with the low-rate processes.
