Environmental issues pollutants emission

Cement plants in the United States are now carehiUy monitored for compliance with Environmental Protection Agency (EPA) standards for emissions of particulates, SO, NO, and hydrocarbons. AH plants incorporate particulate collection devices such as baghouses and electrostatic precipitators (see Air POLLUTION CONTROL methods). The particulates removed from stack emissions are called cement kiln dust (CKD). It has been shown that CKD is characterized by low concentrations of metals which leach from the CKD at levels far below regulatory limits (63,64). Environmental issues continue to be of concern as the use of waste fuel in cement kilns becomes more widespread. 

Presently, there is a general consensus that heterogeneous catalytic processes play an important role in environmental issues regarding their high selectivity towards the removal of undesired side products, such as atmospheric pollutants, in comparison with that obtained from non-catalysed processes. However, such a benefit could be disputed in the future with the implementation of severe restrictions on standard emission of those atmospheric pollutants, particularly nitric oxide, which is a very challenging aspect. 

Although in principle stationary and transport-specific energy chains can be analysed, here the assessment of the latter is explained in more detail, and is then referred to as well-to-wheel (WTW) analysis. The primary focus of WTW analysis in Europe is on global environmental impact, i.e., greenhouse-gas emissions expressed as C02-equivalents. Other issues of interest are (a) primary energy demand (which equals resource utilisation), (b) local pollutant emissions and (c) full energy or fuel supply costs. Well-to-wheel analysis covers the entire fuel supply chain from feedstock extraction, feedstock transportation, fuel manufacturing and fuel distribution to fuel use in a vehicle. 

Concerns about the environmental effects of emissions resulting from the combustion of fossil fuels, particularly coal, continue to increase as the utilization of these fuels grows. The large amounts of sulfur dioxide and nitrogen oxides emitted into the atmosphere and the attempts to tie these fossil-fuel-derived pollutants directly to the undeniably difficult problem of acid rain have caused heated debates, numerous research studies, government actions, and serious efforts to reduce pollution. The issues are extremely complex, and our understanding of the origin, properties, behavior, and effects of these pollutants is incomplete. Often, theories are contradictory. 

A key factor in reducing indoor air pollution is an improvement in public information. To increase public awareness of how individual activities and consumer choices affect the environment could make cleanup efforts more successful. More pubhc information is also helpful to keep the public interested in current environmental issues and to foster their sense of responsibility to work for a better and greener world. It would also increase public pressure for pollution reforms, which would in turn leverage more money from the government for emission controls and environmental cleanups. 

On the other hand, when environmental issues due to the human mobility are considered, the specific aspect of global CO2 emissions cannot be disjoined by the evaluation of other environmental impacts at local level (especially in metropolitan areas, as well documented worldwide) connected to pollutant emissions typical of the internal combustion engines, which represent the current and mature technology the road transportation means are almost totally based on. 

In 1997, the U.S. Environmental Protection Agency (EPA) issued two reports on Hg and its effects on public health to the U.S. Congress. The first of these reports, the Mercury Study Report to Congress (EPA 1997a,b,c), assessed the source and amount of Hg emissions in the United States, the detrimental effects of Hg on humans and wildlife, and the feasibility of control technologies. The second report, the Study of Hazardous Air Pollutant Emissions from Electric Utility Steam Generating Units. Final Report to Congress (EPA 1998), looked specifically at emissions from utility companies and cited Hg as a major contaminant. 

The U.S. Environmental Protection Agency (EPA) has compiled emission factors for a variety of sources and activity levels (such as production or consumption), reporting the results since 1972 in AP-42 Compilation of Air Pollutant Emission Factors, for which supplements are issued regularly. Emission factors currently in use are developed from only a... 

Recent concern about environmental issues regarding cutting fluids has raised the problem of using lubricants containing chlorinated chemical compounds because chlorine causes serious air pollution in connection with dioxin emission when they are disposed by incineration. At the moment, the most practicable replacement... 

The main application technique in the decorative area is still by hand (brush). Hence, future trends continue to reflect attention on worker exposure and environmental issues. This is already seen in the move to low aromatic content white spirits and isoparaffin solvents in conventional systems. High solids and waterborne technologies are being developed and both possess certain advantages and disadvantages, mainly relating to appearance and ease of use. Water-based systems bring, in principle, increased potential for water pollution, as consumers continue to rinse their brushes and paint rollers under the tap and transfer the water-soluble components such as amines and biocides to the aqueous environment. The consequence of diffuse water emissions of this type is still under debate. 

---