Environmental problems examples

Many of these research opportunities will involve work at the interfaces with other disciplines or interdisciplinary collaborations with scientists and engineers from those disciplines. Just as these collaborations have led to significant progress in the past, they should be expected to play an important role in the future to fully understand and solve environmental problems. Examples include the need to understand (or better understand)... 

Relief systems are expensive and introduce considerable environmental problems. Sometimes it is possibly to dispense with relief valves and all that comes after them by using stronger vessels, strong enough to withstand the highest pressures that can be reached. For example, if the vessel can withstand the pump delivery pressure, then a relief valve for overpressurization by the pump may not be needed. However, there may still be a need for a small relief device to guard against overpressurization in the event of a fire. It may be possible to avoid the need for a relief valve on a distillation column... 

Leaking fi om process flows may pose operational risks and cause environmental problems as well as economic losses. Two examples of tracer methods for testing, localising and quantifying leaks are given below. 

Acetic anhydride and acetic acid increase the solubiUty of the two phases in each other, and they are employed for the commercial N-nitration of hexamethylenetetramine [100-97-0] (11) to form cyclotrimethylenetrinitramine [121-82-4] (RDX), (CH2)3(NN02)3. Renewed consideration has been given to replacing H2SO4 with an improved soHd catalyst to reduce the environmental problems of disposal or reconcentration of the waste acid and to increase production of desired nitrated isomers. For example, a catalyst with suitable pore size might increase the production of 4-MNT and reduce that of 3-MNT when toluene is nitrated. 

XPS has been used in almost every area in which the properties of surfaces are important. The most prominent areas can be deduced from conferences on surface analysis, especially from ECASIA, which is held every two years. These areas are adhesion, biomaterials, catalysis, ceramics and glasses, corrosion, environmental problems, magnetic materials, metals, micro- and optoelectronics, nanomaterials, polymers and composite materials, superconductors, thin films and coatings, and tribology and wear. The contributions to these conferences are also representative of actual surface-analytical problems and studies [2.33 a,b]. A few examples from the areas mentioned above are given below more comprehensive discussions of the applications of XPS are given elsewhere [1.1,1.3-1.9, 2.34—2.39]. 

The first environmental problem encountered would be air turbulence. The light travels a 200 m path from center of curvature to the mirror and back. To give an example of the potential problem, assume the temperature of the air... 

The above analysis is somewhat oversimplified and is considered an Incomplete assessment of the existing environmental problems caused by pesticides. Again, it must be emphasized that there is no completely satisfactory way to summarize all of the environmental and social costs in terms of dollars. For example, it is impossible, if not unethical to place a monetary value on human lives either lost, diseased, or disabled because of pesticide use. It is equally difficult to place a monetary value on total wildlife losses. Good health, and Indeed life itself have no price tag. 

The non-technical nature of the problem becomes apparent when we consider a specific example. For instance, plastic bottles, which are tighter and cheaper than those made from glass, have superseded the traditional material in all sectors of the modern drinks industry. In Britain five billion plastic bottles are used a year, which leads to serious environmental problems. They are difficult to recycle or reuse and expensive to dispose of. They cannot be reused because of the need for sterility. Sterilising is done using high temperatures, which would cause softening or even melting if applied to plastics. 

Today s society asks for technology that has a minimum impact on the environment. Ideally, chemical processes should be clean in that harmful byproducts or waste are avoided. Moreover, the products, e.g. fuels, should not generate environmental problems when they are used. The hydrogen fuel cell (Chapter 8) and the hydrodesulfurization process (Chapter 9) are good examples of such technologies where catalysts play an essential role. However, harmful emissions cannot always be avoided, e.g. in power generation and automotive traffic, and here catalytic clean-up technology helps to abate environmental pollution. This is the subject of this chapter. 

Attempts have been made to apply the structure-activity concept (Hansch and Leo 1995) to environmental problems, and this has been successfully applied to the rates of hydrolysis of carbamate pesticides (Wolfe et al. 1978), and of esters of chlorinated carboxylic acids (Paris et al. 1984). This has been extended to correlating rates of biotransformation with the structure of the substrates and has been illustrated with a number of single-stage reactions. Clearly, this approach can be refined with the increased understanding of the structure and function of the relevant degradative enzymes. Some examples illustrate the application of this procedure ... 

As mentioned earlier, a major cause of high costs in fine chemicals manufacturing is the complexity of the processes. Hence, the key to more economical processes is reduction of the number of unit operations by judicious process integration. This pertains to the successful integration of, for example, chemical and biocatalytic steps, or of reaction steps with (catalyst) separations. A recurring problem in the batch-wise production of fine chemicals is the (perceived) necessity for solvent switches from one reaction step to another or from the reaction to the product separation. Process simplification, e.g. by integration of reaction and separation steps into a single unit operation, will provide obvious economic and environmental benefits. Examples include catalytic distillation, and the use of (catalytic) membranes to facilitate separation of products from catalysts. 

The environmental problem of sulfur dioxide emission, as has been pointed out, is very much associated with sulfidic sources of metals, among which a peer example is copper production. In this context, it would be beneficial to describe the past and present approaches to copper smelting. In the past, copper metallurgy was dominated by reverberatory furnaces for smelting sulfidic copper concentrate to matte, followed by the use of Pierce-Smith converters to convert the matte into blister copper. The sulfur dioxide stream from the reverberatory furnaces is continuous but not rich in sulfur dioxide (about 1%) because it contains carbon dioxide and water vapor (products of fuel combustion), nitrogen from the air (used in the combustion of that fuel), and excess air. The gas is quite dilute and unworthy of economical conversion of its sulfur content into sulfuric acid. In the past, the course chosen was to construct stacks to disperse the gas into the atmosphere in order to minimize its adverse effects on the immediate surroundings. However, this is not an en-... 

The usual method for disposing of pesticides in the USSR was walling them into spent quarries and mine shafts. For example, more than 3000 tons of pesticides were walled into unfitted vertical boreholes in the Krasnodar Krai. The complete destruction of pesticides has become a large environmental problem, comparable in scale to the problem of destroying chemical weapons stocks. About 40,000 tons of unused pesticides (banned or too old to be used) had accumulated in the countries of the former Soviet Union, about half of which are located in Russia. 

All of the conditions for an efficient market are being studied in different subbranches of economics. Environmental and health impacts are examples of the violation of the condition no external effects which is an area studied mainly by environmental economists. In other words, environmental problems are to an economist considered as a market failure, or more precisely a negative externality. 

Increasingly, guidelines resulting from political decision process of the European Union influence national markets and global competition. In order to have an influence on behalf of the interests of the plastics industry, the Association of Plastics Producing Industries, (VKE), is reported to wish to intensify its communication with European political institutions. The VKE sees the discussion about the EU book on the environmental problems relating to PVC as particularly controversial, and does not consider that it takes important points of view sufficiently into account. The treatment of the PVC theme, is examined as an example of so-called europisation of the work of associations. (Article translated from Kunststoffe 91 (2001) 4, pp.26-27). 

Soil salinization is the first stage of environmental destruction caused by sahnity and is related to river and lake salinization. For example, the diversion of the Amu Darya and Syr Darya Rivers caused significant desiccation of the Aral Sea, but it also caused salinization of associated agricultural land (e.g., Funakawa et al. 2000 Spoor 1998). In Australia, soil salinization is the most severe environmental problem on the continent, causing dramatic changes in landscape, industry, and the future of farmland (e.g., Dehaan and Taylor 2002). 

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