1. The Environment and Environmental Engineering 环境和环境工程学 Simply said, the environment can be defined as ones surroundings. In terms of the environmental engineers involvement, however, a more specific definition is needed. To the environmental engineer, the word environment may take on global dimensions, may refer to a very localized area in which a specific problem must be addressed, or may, in the case of contained environments, refer to a small volume of liquid, gaseous, or solid materials within a treatment plant reactor. 简单的说，环境可以定义为我们的周围。 但是就环境工程师参与的角度来说， 需要一个 更加明确的定义。 对于环境工程师来说， 环境这个词可能包含全球范围； 也可能专指非常局 部的一个地区，在这个地区中涉及到一些具体要解决的问题；或者也可能在密闭的环境中， 指处理厂反应器内的一小块液体、气体或固体。 The global environment consists of the atmosphere, the hydrosphere and the lithosphere in which the life-sustaining resources of the earth are contained. The atmosphere, a mixture of gases extending outward from the surface of the earth, evolved from elements of the earth that were gasified during its formation and metamorphosis. The hydrosphere consists of the oceans,the lakes and streams and the shallow groundwater bodies that interflow with the surface water.The lithosphere is the soil mantle that wraps the core of the earth. 全球环境由大气圈、水圈和岩石圈所组成， 其中包含了维系地球上生命的资源。 大气圈， 从地球表面向外延伸的一种混合气体， 它从地球的形成和变化过程中气化产生的元素演变而 来。水圈由海洋、湖泊、溪流以及与地表水互通的浅层地下水体所组成。岩石圈是指包围地 核的土质地幔。 The biosphere, a thin shell that encapsulates the earth, is made up of the atmosphere and lithosphere adjacent to the surface of the earth, together with the hydrosphere. It is within the biosphere that the life forms of earth, including humans, live. Life-sustaining materials in gaseous, liquid, and solid forms are cycled through the biosphere, providing sustenance to all living organisms. 生物圈是包裹住地球的薄薄的外壳， 是由大气圈和地表附近的岩石圈， 以及水圈组成的。 地球上的生命形式，包括人类、动物存在于生物圈内。气态、液态和固态形式的生命维持物 在生物圈内循环，向所有生命体提供营养物质。 Life-sustaining resources air, food, and water are withdrawn from the biosphere. It is also into the biosphere that waste products in gaseous, liquid, and solid forms are discharges. From the beginning of time, the biosphere has received and assimilated the wastes generated by plant and animal life. Natural systems have been ever active, dispersing smoke from forest fires, diluting animal wastes washed into streams and rivers, and converting debris, of past generations of plant and animal life into soil rich enough to support future populations. 维持生命的资源 空气、食物和水 是从生物圈内提取的。 废物也是以气态、 液态 和固态形式排放到生物圈中的。 从刚开始的时候起， 生物圈就接受和消化植物和动物产生的 废弃物。自然生态系统已经空前活跃， 将森林大火产生的烟扩散， 稀释冲入小溪和河流中的 动物排泄物以及把过去几代植物和动物的残骸转化成足以供养后续生物的肥沃土壤。 For every natural act of pollution, for every undesirable alteration in the physical, chemical or biological characteristics of the environment, for every incident that eroded the quality of the immediate, or local environment, there were natural actions that restored that quality. Only in recent years has it becomes apparent that the sustaining and assimilative capacity of the biosphere, though tremendous, is not, after all, infinite. Though the system has operated for millions of years, it has begun to show signs of stress, primarily because of the impact of humans upon the environment. 对于每种自然行为的污染，对于环境在每种物理、化学、生物特性上不可取的变化，对 于每种侵蚀当下或当地环境质量的事件， 有自然行为会恢复那种质量。 只是到了近几年， 生 物圈的维持和消化能力尽管巨大， 但毕竟不是无限的这一事实才变得明显。 尽管系统运行了 几百万年，但它开始发出有压力的信号，主要是由于人类对环境的影响。 Environmental engineering has been defined as the branch of engineering that is concerned with protecting the environment from the potential, deleterious effects of human activity, protecting human population from the effects of adverse environmental factors, and improving environmental quality for human health and well-being. 环境工程被定义为工程学的一个分支， 其主要关注保护环境不受人类活动的潜在有害影 响，保护人类不受不利环境因素的影响以及为人类的健康和幸福而改善环境质量。 As the above definition implies, humans interact with their environment sometimes adversely impacting the environment and sometimes being adversely impacted by pollutants in the environment. An understanding of the nature of the environment and of human interaction with it is a necessary prerequisite to understanding the work of the environmental engineer. 上述定义表明，人类与环境相互影响 有时对环境造成不利影响， 有时受到环境污染 物的不利影响。了解环境的本质以及人类与环境的相互作用， 是了解环境工程师工作的一个 必要的先决条件。 2. Ecology 生态学 The recognition that all life forms are inextricably dependent on one another and on the physical environment is a fairly recent phenomenon. The word ecology was not even invented until the mid-1800s, and the study of ecology as a branch of natural sciences was not widespread until a few decades ago. 所有生命形式不可避免的相互依赖且依赖自然环境是一个最近认识到的现象。 生态学 这个单词直到 19世纪中叶才发明，而直到几十年前生态学才作为一门自然学科流传开来。 The science of ecology defines ecosystems as groups of organisms which interact with each other and the physical environment, and which affect the population of the various species in the environment. For example, the simplest type of ecosystem consists of two animals such as the hare and the lynx. If the hare population in a specific locality is high, the lynx have an abundant