Hydrocarbons environmental challenges

The detoxification of hydrocarbon pollutants is one of the global environmental challenges [531-533]. The complete catalytic oxidation of hydrocarbons to carbon dioxide and water has received much attention in order to reduce their emission from motor vehicles and processing plants [531,533,534]. 

In one of the founding studies in immunotoxicology, Friend and Trainer [77] demonstrated that exposure to polychlorinated biphenyls (PCBs) increased mortality of mallard (Anas platyrhynchos) ducklings challenged with duck hepatitis virus. Since then the field of avian immunotoxicology has expanded to show that both the structure and function of the avian immune system often is affected by a diverse array of environmental contaminants, including heavy metals, pesticides, petroleum hydrocarbons, and organic industrial chemicals. Wild birds have proven to be excellent sentinel species for assess-... 

Free-phase NAPL refers to NAPL that exists as an independent phase, not as a dissolved component in the pore water or pore atmosphere. The environmental concerns associated with sites affected with free-phase NAPLs revolve around hydrocarbon-impacted soil (residual hydrocarbon), the NAPL itself (which can serve as a continued source for groundwater contamination), dissolved hydrocarbon constituents in groundwater, and hydrocarbon vapors. The detection of free-phase NAPLs in the subsurface presents many challenges. Two questions frequently arise at sites impacted by NAPLs how much is there and how long will it take to clean up. Before one can address these two questions, assessments of the type and subsurface distri-... 

Due to strict environmental regulations, turbine engine manufacturers and users are facing great challenges in reducing NO, SO , CO, and hydrocarbons to meet the compliance limits. To date, several innovative methods have been developed and introduced into the market to combat these problems. However, often, while reducing NOj, or other pollutants, new problems arise. These problems are lower turn-down ratio, poor thermal efficiency, flame instability, uneven temperature distribution in the combustor, and noise. These problems are even more pronounced in a liquid fuel fired turbine combustor. Therefore, the present research... 

Over the past decade, NHPI has emerged as a powerful and popular catalyst for organic oxidation reactions where, together with acetaldehyde, it has been employed as oxidation mediator . The use of molecular oxygen for the selective oxidation of organic substrates, especially hydrocarbons under mild conditions, is still a major challenge for organic chemistry. It constitutes an environmentally safe alternative to more... 

In fact, most of us benefit from the use of catalysis. Automotive catalytic converters have represented the most massive application of environmental catalysis and one of the most challenging and successful cases in catalysis, generally. Automobile catalysts deseive a few more comments. The engine exhaust emission is a complex mixture, whose composition and flow rate change continuously depending on a variety of factors such as driving conditions, acceleration, and speed. Despite the variability of the conditions, three-way catalysts have achieved the reduction of exhaust carbon monoxide, hydrocarbons, and... 

The NOx reduction for the exhaust from lean-burn engine is one of the greatest challenges in environmental protection, and a lot of researchers have strived to develop more effective catalysts by many ways. Their efforts could be possibly categorized into four approaches (1) NOx direct decomposition, (2) selective catalytic reduction on NOx with hydrocarbons (HC SCR),... 

Hydrocarbons and their transformations play a major role in chemistry. Industrial applications, basic to our everyday life, face new challenges from diminishing petroleum supplies, regulatory problems, and environmental concerns. Chemists must find answers to these challenges. Understanding the involved chemistry and finding new approaches is a field of vigorous development. 

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