Environmental impact leaching

Karakoussis, V., Brandon, N.P., Leach, M., van der Vorsf R. 2001. The environmental impact of manufacturing planar and tubular solid oxide fuel cells. J. Power Sources 101 10-26. 

As stated by Sahuquillo et al. (2003), there is an increased use of widely different leaching tests. Again, selection of appropriate and cost-effective methods used to assess environmental impact must provide a basis for long-term prediction of hazard and ecocompatibility. 

Incineration is often regarded as a very efficient technique for municipal solid waste (MSW) management. However, the environmental impacts of MSW incineration need to be carefully taken into account. The most relevant problem with MSW incineration is flue gas treatment. However, another often overlooked issue is the disposal of solid byproducts of the incineration process. MSW incinerators essentially produce two types of solid by-products, that is, slag, or bottom ash, and fly ash, often mixed with various other chemicals used for flue gas treatment. Bottom ash and—even more—fly ash are regarded as dangerous wastes mainly due to their potentially toxic elements (PTE) content and their tendency to leach such PTE to the environment. 

If all of these elements are incorporated into a basic hydrologic flow model, then detailed modelling of the behavior of the leaching system will be possible. The development of such comprehensive models will not only aid in the optimization of solution compositions for the most effective uranium recovery, but will also allow a more realistic environmental impact assessment and corrective measures if required. 

Researehers have demonstrated that wood treated with heavy metals ean be chipped or flaked and reused to form durable panel produets or wood-cement composites. However, this type of reuse has not gained commercial acceptance beeause of eoneems with processing the treated wood, with the introduction of pesticides into the panel fabrication process, and with the leaching or environmental impacts from the final product (Kartal and Clausen, 2001). 

Two of the most important factors which control the solubility of chemical compounds are the pH and the redox potential of the environment in which the material is present. Many contaminants exhibit a sharp change in solubility over small changes in pH or redox potential (van der Sloot etal. 1997). For all leaching tests and assessments of environmental impact, it is important to identify the critical zone in the pH value or redox potential and how it relates to the environment in which the material is located or into which it will be placed and how the pH and redox potential of that environment may change with time. 

Commonly, leaching tests are selected for use without full consideration of what they will and will not take into account. The most common factors considered in the selection of tests are convenience of application, cost, time to perform the test and minimisation of the number of leachate samples which must be analysed. Whilst these factors are very important considerations, they must be balanced against the risk of obtaining meaningless data which cannot be used correctly in an assessment of environmental impact. 

One environmental concern is that around the world there are landfill areas where over the years chromite ore processing residues (COPR) have been dumped, and chromium from these landfills is being leached into the ground water. The environmental impact of chromium in soils and sediments is dependent on specia-tion and on the response of the matrix to biological and physico-chemical conditions. These factors control the mobilization of chromium from the solid into the aquatic phase and uptake and transfer into living systems (Hursthouse 2001). 

Applications of scrap tires in hydraulic engineering benefits the environment through waste reduction, yet people naturally ask, for example, whether scrap tires leach compounds that may adversely affect the environment. Practical issues and potential problems related to environmental impact of scrap tires in hydraulic structures include chemical leaching, toxicity, soil contamination, water pollution, structural integrity, and aesthetical feature. 

The purpose of this chapter is to provide a comprehensive review of water movement in roadways so that this knowledge may be incorporated into fate/ transport models for use in risk assessment. The focus of the chapter is on the environmental impact of leaching of contaminants and aspects of subsurface hydrology as they relate to contaminant leaching. More specifically, the goal of this chapter is to provide answers to the following questions ... 

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