An understanding of the nature of wastewater is essential in the design and operation of collection, treatment, and reuse facilities, and in the engineering management of environmental quality. To promote this understanding, the information in this chapter is presented in eight sections dealing with (1) an introduction to the constituents found in wastewater

一、人类活动对环境的双重效应 环境问题是伴随着人类的活动而产生的，人类的活动对自然环境的作用是一个双 重效应。一方面是人类从自然界中取得资源，这些资源包括水、新鲜空气、土地、矿 藏、石油、动物和植物，而且人类的活动占据了越来越多的土地、空间，上至几千 米 的山峰，下到几千米的海洋深渊，都有人类活动的足迹

The safe and reliable long-term disposal of solid waste residues is an important component of integrated waste management. Solid waste residues are waste components that are not recycled, that remain after processing at a materials recovery facility, or that remain after the recovery of conversion products and/or energy. Historically, solid waste has been placed in the soil in the earth's surface or deposited in the oceans

Important physical characteristics of MSW include specific weight, moisture content, particle size and size distribution, field capacity, and compacted waste porosity. The discussion is limited to an analysis of residential, commercial, and some industrial solid wastes. Note, however, that the fundamentals of analysis presented in this and the following chapter are applicable to all types of solid wastes

Solid wastes include all solid or semisolid materials that the possessor no longer considers of sufficient value to retain. The management of these waste materials is the fundamental concern of all the activities encompassed in solid waste management—whether the planning level is local, regional or subregional, or state and federal. For this reason, it is important to know as much about municipal solid waste (MSW) as possible. The purpose of this chapter is to identify the sources, types, and composition of solid wastes

Solid wastes comprise all the wastes arising from human and animal activities that are normally solid and that are discarded as useless or unwanted. The term solid waste as used in this text is all-inclusive, encompassing the heterogeneous mass of throwaways from the urban community as well as the more homogeneous accumulation of agricultural, industrial

The control of particulates and VOCs is mostly accomplished by physical processes (cyclones, ESPs, filters, leakage control, vapor capture, condensation) that do not involve changing the chemical nature of the pollutant. Some particles and VOCs are chemically changed into harmless materials by combustion. This chapter and the next concern pollutants--sulfur oxides and nitrogen

Volatile organic compounds (VOCs) are liquids or solids that contain organic carbon (carbon bonded to carbon, hydrogen, nitrogen, or sulfur, but not carbonate carbon as in CaCO3 nor carbide carbon as in CaC2 or CO or CO2), which vaporize at significant rates. VOCs are probably the second-most widespread and diverse class of emissions after particulates

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

一、工程学及其与基础科学的关系 人类的一切科学活动不外乎有两个目的：一是认识自然，一是适应自然、保护自然 和改造自然。前者对应着自然科学中的基础科学，也称为理学，后者则对应着自然科学 中的工程技术科学，也称为工程学或工学；工程学和基础科学之间的这种目的的差异是 它们相互区别的根本所在，也反应了这二大学科的变质所在