Acid rain neutralizing effects

The effects of acid rain are particularly severe in areas where the bedrock is granite or other materials incapable of neutralizing H+ ions. As the concentration of acid builds up in a lake, aquatic life, from algae to brook trout, dies. The end product is a crystal-clear, totally sterile lake. 

The detrimental effects of acid rain are a major reason why legislation such as the Clean Air Act places strict limitations on sulfur and nitrogen emissions. It is also a reason why low sulfur coal is preferred over high sulfur coal. To reduce sulfur dioxide emissions, industry also uses a technique call scrubbing. Industrial scrubbers employ a variety of physical and chemical processes to remove sulfur dioxide from emissions. Another technique used to combat acidification of lakes is to treat these systems with lime. The lime acts to neutralize the acid, but such techniques are usually costly and are only a temporary remedy for combating the problem. 

Acid rain primarily affects sensitive bodies of water, that is, those that rest atop soil with a limited ability to neutralize acidic compounds (called buffering capacity ). Many lakes and streams examined in a National Surface Water Survey (NSWS) suffer from chronic acidity, a condition m which water lias a constant low (acidic) pH level. The survey investigated tlie effects of acidic deposition in over 1,000 lakes larger than 10 acres and in thousands of miles of streams believed to be sensitive to acidification. Of the lakes and streams surveyed in the NSWS, arid rain has been determined to cause acidity in 75 percent of the acidic lakes and about 50 percent of tlie acidic streams. Several regions in the U.S. were identified as containing many of the surface waters sensitive to acidification. They include, but are not limited to, the Adirondacks. the mid-Appalachian highlands, the upper Midwest, and the high elevation West. 

To illustrate the effect of ionic strength on degradation of calcium carbonate we have calculated the solubility of calcium carbonate in deionized water, acid at pH = 4.0 and acid rain at pH = 4.0 with an ionic strength of 7.2 x 10 in the absence of CO2. The results of these calculations are shown in Table 2 and are plotted in Figure 3. These data show that the ionic strength contribution of sea spray and other atmospheric sources are as significant as the neutralization reaction with acid at pH = 4.0 in the degradation of coquina by acid rainfall. 

Additional information on how leaf litter potentially interacts with acid rain was contributed by Lee V7eber (2 ). In their experiments, acid rain was simulated in a field situation on sugar maple and red alder. Rain as throughfall was allowed to interact with leaf litter and the leachate was collected. Litter leachate was found to be higher in S0 , Ca+ and Mg+, and the pH was found to have increased. Thus, they hypothesized that the litter was neutralizing the simulated acid rain, with red alder litter being more effective than sugar maple. 

Unpolluted rain is not harmful. However, many industrial and power plants burn coal and oU. The smoke produced may contain large quantities of sulfur oxides, suspended particles, and nitrogen oxides. Automobiles also contribute to the problem by emitting similar oxides. These chemicals react with water in the air to form acids, such as sulfuric acid. These acids reach the surface of Earth in fog, rain, snow, and dew. Acid rain can have a disastrous effect when it reaches bodies of water and waterways. But if a lake has a high limestone content, it is able to somewhat neutralize the acid. 

This problem, and many others, require you to use the reaction of an acid with a base. Whether you re trying to neutralize stomach acid or predict the effects of acid rain on a forest, lake, or sculpture, the primary reactions are acid-base reactions. 

It is believed that the corrosion products that form when items are exposed to acid rain are more hygroscopic than those formed under more neutral conditions. This, say Haynie et al. (1990), effectively lowers the critical relative humidity from 90% to 75%, although this value is higher than the critical relative humidity for steel corrosion. The effects have been demonstrated both in the laboratory and by examples of corrosion occurring... 

Reactions of Acids and Bases Neutralization reactions are common in our everyday lives. Antacids, for example, are bases fhaf read with acids from fhe stomach to alleviate heartburn and sour stomach. Acid-metal and acid-metal oxide reactions show the corrosive nature of acids. In both of these reactions, the acid dissolves the metal or the metal oxide. Some of the effects of fhese kinds of reactions can be seen in the damage to building materials caused by acid rain. Since acids dissolve metals and metal oxides, any building materials composed of fhese substances are susceptible to acid rain. 

Q15 Calcium oxide is added to a lake to neutralize the effects of acid rain. The pH value of the lake water rises from 4 to 6. What is the change in concentration of H+(aq) in the lake water ... 

Acid rain adversely affects aquatic organisms in bodies of water that lack a pH buffering capacity because of lack of contact with minerals that can neutralize acid, especially limestone, CaC03. The greatest adverse effect is on fish fingerlings that do not thrive in acidic water. 

The best way to deal with acid rain is to eliminate its production by limiting emissions of sulfur and nitrogen oxides. Consideration may need to be given to growing crops that are relatively less susceptible to the adverse effects of acid rain and the nitrogen and sulfur oxides that form it. Acid in excessively acidic bodies of water can be neutralized by treatment with CaC03. 

In high-altitude areas, such as the Adirondack Mountains of New York, forests are bathed directly in high-acidity clouds, or acidfog. The devastating effects on these forests have been well documented. When acid rain falls in areas with little natural capacity to neutralize it the pH of lakes and ponds has been known to fall to as low as 5.2, and aquatic and plant life have greatly suffered. 

In practical application cases, experience shows that acid-active influences are dominant (HCl cleavage at elevated temperatures, SOj, acid rain, etc.). Therefore, an acid buffer with sufficient capacity in the neutral range together with thermostabilizers is advantageous. Epoxy compounds have shown to be effective, because they bind harmful acids and remove them from the reaction under formation of very stable hydrines [202]. 

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