Part I Wastewater Engineering 1 Wastewater Engineering: An Overview Every community produces both liquid and solid wastes and air emissions. The liquid waste-wastewater is essentially the water supply of the community after it has been used in a variety of applications. From arried wastes removed from residences. institutions. and commercial and industrial establishmer ogether with such groundwater surface water and stormwater as may be present. When wastewater accumulates and is allowed to go septic, the decomposition of the organic matter it contains will lead to nuisance conditions including the production of malodorous gases. In addition, untreated wastewater contains numerous pathogenic microorganisms that dwell in the human intestina tract. Wastewater also contains nutrients, which can stimulate the growth of aquatic plants, and may contain toxic compounds or compounds that potentially may be mutagenic or carcinogenic. For these reasons, the immediate and nuisance-free removal of wastewater from its sources of generation, followed by treatment, reuse, or dispersal into the environment is necessary to protect public health and the environment Wastewater engineering is that branch of environmental engineering in which basic principles of science nd engineering are applied to solving the issues associated with the treatment and reuse of wastewater. goal of wastewater engineering is the protection of public health in a manner commensurate with environmental, economic, social and political concerns. To protect public health and the environment. it is necessary to have knowledge of (D) environment,(3)the transformation and wastewater. and (5) methods for Combined sewer beneficial use or disposal of solids To provide an initial perspective on the field of wastewater engineering, common terminology is defined and introduced first Fig. 1-1 Schematic diagram of management infrastructure 1-1 Terminology In the literature, and in governmental regulations, a variety of terms have been used for individual constituents of concern in wastewater. The terminology used commonly for key concepts and terms in the field of wastewater management is summarized in Table 1-1 In some cases, confusion and undue negative perceptions arise with the use of the terms contaminants, impurities, and pollutants, which are often used interchangeably. To avoid confusion, the term constituent is used in this text in place of an individual compound or element, such as ammonia nitrogen. The term 1-11-1 Part I Wastewater Engineering 1 Wastewater Engineering:An Overview Every community produces both liquid and solid wastes and air emissions. The liquid waste-wastewater, is essentially the water supply of the community after it has been used in a variety of applications. From the standpoint of sources of generation, wastewater may be defined as a combination of the liquid or water-carried wastes removed from residences, institutions, and commercial and industrial establishments, together with such groundwater, surface water, and stormwater as may be present. When wastewater accumulates and is allowed to go septic, the decomposition of the organic matter it contains will lead to nuisance conditions including the production of malodorous gases. In addition, untreated wastewater contains numerous pathogenic microorganisms that dwell in the human intestinal tract. Wastewater also contains nutrients, which can stimulate the growth of aquatic plants, and may contain toxic compounds or compounds that potentially may be mutagenic or carcinogenic. For these reasons, the immediate and nuisance-free removal of wastewater from its sources of generation, followed by treatment, reuse, or dispersal into the environment is necessary to protect public health and the environment. Wastewater engineering is that branch of environmental engineering in which basic principles of science and engineering are applied to solving the issues associated with the treatment and reuse of wastewater. The ultimate goal of wastewater engineering is the protection of public health in a manner commensurate with environmental, economic, social, and political concerns. To protect public health and the environment, it is necessary to have knowledge of (1) constituents of concern in wastewater, (2) impacts these constituents when wastewater is dispersed into the environment, (3) the transformation and long-term fate of these constituents in treamtent processes, (4) treatment methods that can be used to remove or modify the constituents found in wastewater, and (5) methods for beneficial use or disposal of solids generated by the treatment systems. To provide an initial perspective on the field of wastewater engineering, common terminology is defined and introduced first. Fig. 1-1 Schematic diagram of a wastewater management infrastructure 1-1 Terminology In the literature, and in governmental regulations, a variety of terms have been used for individual constituents of concern in wastewater. The terminology used commonly for key concepts and terms in the field of wastewater management is summarized in Table 1-1. In some cases, confusion and undue negative perceptions arise with the use of the terms contaminants, impurities, and pollutants, which are often used interchangeably. To avoid confusion, the term constituent is used in this text in place of an individual compound or element, such as ammonia nitrogen. The term