物质的数量。最好的方法是寻找替代的化学产品，它们能起到一样的作用但毒害性较小。如果不能寻找到一种有毒化学物质的替代品，那么比较好的战略思想是开发一种就地生产的工艺，而且只生产当时所需要的那么多的数量。
Innovative new chemistry has begun delivering environmentally sound processes, that use energy and raw materials more efficiently. Recent advances in catalysis, for example, permit chemical reactions to e run at lower temperatures and pressures. This change, in turn, reduces the energy demands of the processes and simplifies the selection of construction materials for the processing facility. Novel catalysts are also being uses to avoid the production of unwanted by-products. 革新的化学方法已开始设计对环境合理的工艺过程，以便更为有效的使用能量和原材料。例如，催化剂方面的近期进展使化学反应可以在较低的温度和压力下进行。反过来，这种改变又减少了这些过程的能量需求，简化了制造加工设备对构成材料的选择，新的催化剂还用于避免生产不希望的副产品。
4. Control of Power Plant Emissions
Coal-, oil-, and natural-gas-fired power generation facilities contribute to the emissions of carbon monoxide, hydrocarbons, nitrogen oxides, and a variety of other undesired by-products such as dust and traces of mercury. A rapidly increasing array of technologies are now available to reduce the emissions of unwanted species to meet national or local standards. Chemists and chemical engineers have made major contributions to the state of the art, and catalytic science is playing a critical role in defining the leading edge. 4. 发电厂排放物的控制
通过燃煤、燃油和燃烧天然气产生能量的设备都会排放出一氧化碳、碳氢化合物、氮氧化物以及许多其它不受欢迎的副产物如灰尘和痕量的汞。现在可以采用一系列不断发展的技术来减少不希望有的物质的排放以适应国家和地区标准的要求。化学家和化学工程师对工业水平的进步做出了巨大的贡献。而催化科学为开辟这些前沿领域正在扮演重要的角色。
The simultaneous control of more than one pollutant is the aim of some recently developed catalyst or sorbent technologies. For example, catalytic methods allow carbon monoxide to be oxidized at the same time that nitrogen oxides are being chemically reduced in gas turbine exhaust. Other research efforts are aimed at pilot-plant evaluation of the simultaneous removal of sulfur and nitrogen oxides from flue gas by the action of a single sorbent and without the generation of massive volumes of waste products.
同时控制多种污染物是近年来开发先进的催化剂或吸附剂技术的目的。例如，催化方法可以使汽车尾气中CO氧化的同时，还原氮的氧化物。另一些研究工作则定位于在中试阶段通过一种吸附剂的作用同时去除烟道气中的硫和氮氧化物，而不会产生大量的废物。
5. Environmentally Friendly Products
Increased understanding of the fate of products in the environment had led scientists to design ―greener‖ products. A significant early example comes from the detergent industry in the 1940s and 1950s, new products were introduced that were based on synthetic surfactants called branched alkylbenzene sulfonates. These detergents had higher cleaning efficiency, but it was subsequently discovered that their presence in waste water caused foaming in streams and rivers. The problem was traced to the branched alkylbenzene sulfonates; unlike the soaps used previously, these were
not sufficiently biodegraded by the microbes in conventional sewage treatment plants. An extensive research effort to understand the appropriate biochemical processes permitted chemists to design and synthesize another new class of surfactants, linear alkylbenzene sulfonateas,. The similarity in molecular structure between these new compounds and the natural fatty acids of traditional soaps allowed the microorganisms to degrade the new formulations, and the similarity to the branched alkybenzene sulfonates afforded outstanding detergent performance. 5． 对环境友善的产品
对产品在环境中的变化越来越了解使得科学家们开始设计“绿色”产品。一个重要的例子来自1940-1950s的洗涤剂工业。当时以支链烷基苯磺酸盐为表面活性剂的新产品被引入。这些洗涤剂洗涤效率更高。但其后发现这些物质残留在废水中在河面上形成泡沫。问题追溯到这些支链的烷基苯磺酸盐：它不像以前人们所使用的肥皂。它不能被传统污水处理厂的细菌所有效地生物降解。经过深入的研究工作了解了生物化学过程使化学家们设计和合成了另一类新型的表面活性剂，为直链烷基苯磺酸盐。这些新的化合物与传统肥皂中的脂肪酸有相似的分子结构，因而微生物可以降解这些组分，而它与支链烷基苯磺酸盐的相似性又使其具有卓越的洗涤性能。
Novel biochemistry is also helping farmers reduce the use of insecticides. Cotton plants, for example, are being genetically modified to make them resistant to the cotton bollworm. A single gene from a naturally occurring bacterium, when transferred into cotton plants, prompts the plant to produce a protein that is ordinarily produced by the bacterium. When the bollworm begins to eat the plant, the protein kills the ins4ct by interrupting its digestive processes.
新的生物化学也正在帮助农民减少使用杀虫剂.例如,棉作物可以通过改变基因而具备对棉螟蛉的抵抗力.天然存在的细菌中一个基因当被转移到棉作物中时,能够祖师作物产生一种原来有细菌产生的蛋白质.当螟蛉虫开始吃作物时,这种蛋白质通过切断螟蛉的消化过程从而杀死害虫.
6. Recycling
Increasing problems associated with waste disposal have combined with the recognition that some raw material exist in limited supply to dramatically increase interest in recycling. Recycling of metals and most paper is technically straightforward, and these materials are now commonly recycled in many areas around the world. Recycling of plastics presents greater technical challenges. Even after they are separated from other types of waste, different plastic materials must be separated from each other. Even then, the different chemical properties of the various types of plastic will require the development of a variety of recycling processes. 6. 处理
越来越多的环境问题与废物的排放有关,而一些原材料又存在供给有限的问题.这二者的联系引起了人们对处理这一课题越来越大的兴趣.金属和大多数纸张的处理从技术上来说是简单的,这些物质在世界很多地方都已普遍进行了处理.塑料的处理则面临着较大的技术方面的挑战.即使把它们与其它类型的废品分离开来以后，不同种类的塑料还需要再彼此分离。即使如此，不同类型的塑料具有不同的化学性质，因而也需要开发不同的处理工艺.
Some plastics can be recycled by simply melting and molding them or by dissolving them in an appropriate solvent and then reformulating them into a new plastic material. Other materials require more complex treatment, such as breaking down large polymer molecules into smaller
subunits that can subsequently be used as building blocks for new polymers. Indeed, a major program to recycle plastic soft drink bottles by this route is now in use.
一些塑料可以通过简单地熔化注塑或用合适的溶剂进行分解再重新塑造成新塑料的方法进行处理。比如，把大的聚合物分子裂解成较小的亚单元,再以此作为新聚合物的结构单元。确实，用这种方法处理软塑料瓶的计划正在进行中。
A great deal of research by chemists and chemical engineers will be needed to successfully develop the needed recycling technologies. In some cases, it will be necessary to develop entirely new polymers with molecular structures that are more amenable to the recycling process.
化学家和化学工程师们所做的大量的研究工作需要被成功地开发为所需要的处理技术。有时，也需要开发一些全新的聚合材料.它们具有更容易进行处理的分子结构.
7. Separation and Conversion for Waste Reduction
New processes are needed to separate waste components requiring special disposal from those that can be recycled or disposed of by normal means. Development of these processes will require extensive research to obtain a fundamental understanding of the chemical phenomena involved. 7. 通过分离和转换减少废物量
把一些需要进行特殊处理的成分从那些可用常规方法处理或处置的废物中分离出来需要新的工艺过程。而开发这些过程则需要深入研究以从根本上了解所涉及的化学现象.
Metal-bearing spent acid waste. Several industrial processes produce acidic waste solutions in large quantities. Could this waste be separated into clean water, reusable acid, and a sludge from which the metals could be recovered? Such processes would preserve the environment, and their costs could be competitive with disposal costs and penalties.
含金属离子的酸性废水.一些工业过程产生了大量的酸性废水.这些废水可以分离成干净的水、可再利用的酸、以及可从中提取出可回收金属的淤渣吗？这样的处理过程既可以保护环境，所需费用又与处置废水所需成本及罚款相差无几。
Industrial waste treatment. The hazardous organic components in industrial wastewater could be destroyed with thermocatalytic or photocatalytic processes. A promising line of research employs ―supercritical‖ water at high temperatures and pressures. Under these conditions, water exhibits very different chemical and physical properties. It dissolves reactions of many materials that are nearly inert under normal conditions. 工业废水处理。工业废水中的有害有机物能被热催化或光催化的过程破坏。一项前景很好的研究工作是利用高温高压下的超临界水。在这种条件下，水表现出截然不同的物理和化学性质，它可以溶解并有助于那些在常态下的水中几乎是惰性的物质发生反应。
High-level nuclear waste. Substantial savings would be achieved if the volume and complexity of nuclear waste requiring storage could be significantly reduced; this reduction would require economic separation of the radioactive components from the large volumes of other materials that accompany the nuclear waste. The hazardous chemical waste mighty then be disposed of separately. The dispose of nuclear waste will require major research and development efforts over many years.
高辐射的核废料。如果需要储藏的核废料其数量和组成能够显著地减少，就可以节省一大笔
的费用。这种减少需要用经济的方法把放射性成分与大量其它与核废料共存的物质分离开来，这样有害的化学废料就可以分别地进行处置，核废料的处置仍将需要今后许多年进行大量的研究和开发工作。
Membrane technology. Separations involving semi permeable membranes offer considerable promise. These membranes, usually sheets of polymers, are impervious to some kinds of chemicals but not to others. Such membranes are used to purify water, leaving behind dissolved salts and providing clean drinking water. Membrane separations are also applicable to gases and are being used for the recovery of minor components in natural gas, to enhance the heating value of natural gas by removal of carbon dioxide, and for the recovery of nitrogen from air. Research challenges include the development of membranes that are chemically and physically more resilient, that are less expensive to manufacture, and that provide better separation efficiencies to reduce processing costs.
膜技术。应用半渗透性薄膜进行分离大有希望获得成功。这些膜通常是片状聚合物。能够让一些化学物质通过而不让另一些物质通过。这些膜常用来纯化水，阻挡住一些溶解的盐类提供干净的饮用水。膜分离技术也用来提纯制造厂出来的废水。膜分离还可以用在气体方面，用来回收天然气中的微量组分。通过清除CO提高天然气的热值，以及从空气中得到氮气。研究中的难点包括开发化学和物理学方面更有弹性的膜。这样可以使制造费用不那么贵，并且可以提供更好的分离效率以降低分离成本。
Biotechnology. Scientists have turned to nature for help in destroying toxic substances. Some microorganisms in soil, water, and sediments can adapt their diets to a wide variety of organic chemicals; they have been used for decades in conventional waste treatment systems. Researchers are now attempting t coax even higher levels of performance from these gifted microbes by carefully determining the optimal physical, chemical, and nutritional conditions for their existence. Their efforts may lead to the design and operation of a new generation of biological waste treatment facilities. A major advance in recent years is the immobilization of such microorganisms in bioreactors, anchoring them in a reactor while they degrade waste materials. Immobilization permits high flow rates that would flush out conventional reactors, and the use of new, highly porous support materials allows a significant increase in the number of microorganisms for each reactor.
生物技术。科学家们已经向自然界寻求帮助战胜有毒物质。土壤、水和沉积物中的一些微生物能以许多有机化学物质为食。数十年来它们一直被用于传统的水处理系统。研究者们正通过仔细测量微生物生存的最佳物理、化学和营养条件致力于处理强度更高的对象。他们的工作可能导致设计和生产新一代生物废水处理设备。近年来的一个很大的进展是生物反应器内微生物的固定。即把微生物固定在反应器内降解废物。这种固定可以允许有更高的流速。传统反应器内流速过高会冲走微生物。新的多孔载体的使用也使每个反应器中微生物的数量明显提高。
Excel in Your Engineering
When I reflect on my 20-plus years of experience as a chemical engineer, I realize how wonderful my profession is. As engineers, we provide the essential link between technology and humanity. Our job is to make the world better for its human inhabitants while protecting the environment. And we fulfill our mission amongst the demands and guidelines of the business world.
But sometimes we get so bogged down in the everyday aspects of our jobs that we lose sight of the big picture. We forget to appreciate engineering—though it is challenging, creative, interesting, significant, and even fun.
For example, there‘s nothing like getting engrossed in a tough technical problem and coming up with a neat solution. Do you find yourself hurrying to the office because you look forward to working? Do you ever wake up in the middle of the night thinking about a problem and lie there working out the details of a brilliant solution? Do you get up to write notes so you won‘t forget your breakthrough in the morning?
Engineering can be that wonderful. And being involved in your work doesn‘t mean you‘re a nut or a workaholic. We should like what we do: Enjoying something and doing it well is a ―chicken-and-egg‖ situation. We tend to like activities we perform well, and to be good at things we enjoy. So here‘s some advice for both enjoying and improving your engineering work. 1. Enhance technical skills
Engineering provides many opportunities to develop existing skills and to learn new ones. In fact, we have to keep learning or we atrophy--that‘s the nature of any profession. The ability to grow is one reward of a good job. As your interests and involvements change, and as technology changes, you need to keep learning.