16: Environmental Chemistry

Last updated
Save as PDF

Page ID: 434966

\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

16.1: Chemistry is Good...and Unavoidable
During the roughly two centuries that chemical science has been practiced, it has enabled the production of a wide variety of goods that are valued by humans. However, there have also been unintended consequences for the environment as a result of poor management of by-products and wastes. As a result, chemical science and industry are moving towards environmental friendliness and sustainability through the practice of green chemistry.
16.2: Chemistry and the Environment
The environment in which we live is made up of five overlapping and interacting spheres. Each of these spheres are continuously exchanging enormous quantities of materials and energy. Thus, each of the spheres can be influenced by different fields of chemistry which can be grouped together under the discipline of environmental chemistry.
16.3: The Air We Breathe
The air that we breathe is a mixture of a wide variety of gases. The most prevalent components of the mixture are elemental nitrogen and oxygen.
16.4: Air Pollution
Many of the activities in which humans engage in the modern era are ones that generate pollutants that are released into the atmosphere. The most prevalent of these activities is the combustion of fossil fuels in transportation and generating electricity. These pollutants affect both human health and the environment around us.
16.5: Photochemical Smog
Smog is a unique product of the industrial era. It is formed by reactions involving emission products and sunlight and can be further augmented by particulate matter in the air. The result is a brownish haze which affects visibility and health.
16.6: Clean Air
The Clean Air Acts in the 1970s and 1990 established emission limits for industries and vehicles and allowed for their enforcement. We now utilize a variety of methods to remove particulates from gas emissions and have achieved greater efficiency in other areas as well. One such area is the increased efficiency of car engines. Newer technology has allowed both a reduction of emissions and an increase in gas mileage.
16.7: Global Warming
While some carbon dioxide in the atmosphere is necessary to keep the Earth at a temperature that supports life, the industrial age and the burning of fossil fuels which drives it has resulted in an ever-increasing level of this and other greenhouse gases. The effect of this has been a slowly rising average temperature of the Earth's atmosphere.
16.8: Climate Change – An Effect of Global Warming
As the Earth's temperature increases due to increasing levels of greenhouse gases, the higher temperatures cause shifts in weather patterns and precipitation. In addition to localized droughts and flooding, melting land ice and thermal expansion of water leads to a rise in sea levels. The increased concentration of carbon dioxide in the atmosphere also increases its concentration in oceans, leading to their acidification as the carbon dioxide interacts with the water.
16.9: Climate Mitigation Strategies
There are two practical strategies to deal with global warming and climate change. The first is adapting to changes in the environment which have already happened. The second is to mitigate climate change by adopting new behaviors that reduce the emission of greenhouse gases. This can include behaviors such as utilizing alternative energy sources or sequestering carbon in underground wells.
16.10: Water
Water is a unique molecule which is critical for life to exist. While there are large quantities of water on the planet, only a small fraction is actually available for human consumption and agricultural use. The quality of that water will vary depending on its source.
16.11: Groundwater Contamination
We flush a lot of things down the drain. Some of these wastes are treated by municipalities or are naturally filtered as the water travels through the soil. However, many of the compounds that we dispose of will eventually wind up in our groundwater and make it unsafe for consumption. Others have harmful effects on aquatic life by reducing the oxygen supply for fish and insects, resulting in their death.
16.12: Water Purification
Because water is such a good solvent, it can contain a variety of minerals and contaminants which make it less effective for our needs or harmful for consumption. Thus it is necessary to find ways to remove these impurities to provide safe water for all.
16.13: Acid Rain
Acid rain occurs at the intersection of the atmosphere and the hydrosphere. Air pollutants react to form sulfuric and nitric acid. These compounds present in the rain have detrimental effects on lakes, rivers, and soils. They also degrade certain types of rocks and metal used for buildings.
16.14: For Future Use
16.15: Exercises