Emission controls, environmental benefits

Implementation of cleaner production processes and pollution prevention measures can yield both economic and environmental benefits. The following production-related targets can be achieved by measures such as those described above. The numbers relate to the production processes before the addition of pollution control measures. In sulfuric acid plants that use the double-contact, double absorption process, emissions levels of 2 to 4 kilograms of sulfur dioxide... 

Environmental benefits of Emission Controls. Information in Figure 5 illustrate that the emission of sulphur in eastern North America has declined over the past decade. This decline allows for a possible verification of the dose-response relationships on which the environmental concerns for emissions have been based. A decline in sulphate deposition in Nova Scotia has apparently resulted in a decrease in acidity of eleven rivers over the period 1971-73 to 1981-82 (47), In the Sudbury, Ontario area where emissions have dechned by over 50% between 1974-76 and 1981-83, a resurvey of 209 lakes shows that most lakes have now become less acidic. Twenty-one lakes that had a pH < 5.5 in 1974-76 showed an average decline in acidity of 0.3 pH units over the period (48), Surveys of 54 lakes in the Algoma region of Ontario have shown a rapid response to a decline in sulphate deposition. Two lakes without fish in 1979 have recovered populations as pH of the water moved above 5.5 (49). Evidence is accumulating to support the hypothesis of benefits that were projected as a consequence of emission controls. This provides increased confidence in the projections. 

Throughout the 1980s, researchers and industry came to recognize some of the environmental benefits of gasification technology. More restrictive and stringent environmental standards aimed at controlling power plant emissions, and domestic and industrial waste landfills, and an increased... 

Some projects were easier to implement than expected, while others are still stymied by the system. As a result of some innovative refinery process engineering, the refinery was able to completely eliminate the use of the coker cooling pond (rather than just controlling its emissions), achieving twice the emissions reduction at a fraction of the original cost estimate. This is truly one of the noteworthy outcomes of the project. This is a textbook case where, faced with a costly option, the refinery experts teamed up to identify a cost-effective solution that provided the greatest possible environmental benefit—elimination of the emission source entirely. Costly emission controls were avoided. Furthermore, the reduction was accomplished with far fewer resources than originally estimated. 

This is the key to gain the maximum environmental benefit from the application of advanced emission control technology. It is important that the technology utilised should be durable for the defined, reasonable life of the vehicle and that the vehicle should be regularly checked to ensure that the systems installed on the vehicle are working properly and that they have not been abused or subject to inadequate maintenance. 

The impact of the emission cuts is beginning to be noticed, although more with respect to deposition than ecosystem recovery. The U.S. Environmental Protection Agency soon reported declines in wet sulphate deposition in the order of 10 to 25% across the eastern United States. There are also possible improvements with respect to dry deposition of sulphates, fine particulate matter concentrations, and visibility. Aquatic and terrestrial ecosystems respond slowly, and it is not surprising that evidence of ecosystem improvements would trail behind trends in reduced atmospheric transport and deposition. The EPA, while modest in its assessment of the environmental benefits to be accrued from reduced acidification, has been rather bullish about the investment in human health benefits represented by acid rain controls. It expects SO emission cuts to reduce American health costs by 10 billion annually, through reduced morbidity and mortality, and these savings are projected to rise to 40 billion annually by 2010 (EPA 1995). 

As with many environmental controls the benefits of restricting emissions from vehicles need to be quantified with respect to the energy penalty involved. Although it is evident that certain air quality objectives can be met by modest control of vehicle exhaust emissions it is equally clear that stringent emission controls lead to high energy penalities. 

Typical concerns relate to visual impact, noise, and landscaping, and for landraising to be effective, such concerns must be balanced against the potential environmental benefits. Because of the facility for increased control over emissions, e.g. collection and treatment of gas and leachate, landraising may also allow landfill development in areas otherwise considered to be too vulnerable for landfill development. Vulnerable sites include those located above aquifers, while those sited above, for example, clay could be considered as being suitable for development either with or without a complementary lining system. Other potential advantages include ... 

In most attempts at cost/benefit analysis of environmental control strategies, it is much easier to identify emission control costs than to assess the benefits that would be derived from such controls. A detailed cost/benefit analysis of control strategy options for limiting the environmental effects of acid pollutant emissions, and their derivatives, was outside the scope of the study. In any case, absence of data would render the exercise in some areas of damage fairly meaningless. 

The major advantages of the use of electric vehicles (EVs) and hybrid electric vehicles (HEVs) are reduced dependence on fossil fuels and environmental benefits. For electric vehicles, energy from electric utilities or renewable sources would be used for battery charging. These facilities can be operated more efficiently and with better control of effluents than automotive engines. Hybrid vehicles are expected to require less fuel per mile of travel than current vehicles. This not only results in lower petroleum consumption, but also in lower emissions of undesirable pollutants. 

Economic benefits include improved tender opportunities and reducing the cost of wastage (disposal, handling, transport, taxation, for example). Environmental benefits include reduced damage to the environment by control of emissions and adverse impacts on ecosystems, and reduced demands on natural resources. 

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