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Rainwater organic acid acidity

The pH of rainwater in equUibrium with atmospheric CO2 is 5.6, a value frequendy cited as the natural background pH. However, in the presence of other naturaUy occurring species such as SO2,, NH, organic acids, sea salt, and alkaline cmstal dust, the natural values of unpoUuted rainwater vary... [Pg.377]

In addition to the acid—base components shown in Figure 9, various organic acids are often found. Many of these acids are by-products of the atmospheric oxidation of organic matter released into the atmosphere. Of special interest are formic, acetic, oxaUc, and benzoic acids, which have been found in rainwater in concentrations occasionally exceeding a few micromoles per Hter. [Pg.213]

A variety of chemicals may be leached from the aerial portions of plants by rainwater or by fog-drip (16) including organic acids, sugars, amino acids, pectic substances, gibberellic acids, terpenoids, alkaloids, and phenolic compounds. Colton and Einhellig (17) suggested that leaf leachates of velvetleaf (Abutilon theophrasti) may be inhibitory to soybean (Glycine maxT We have recently discovered specialized hairs on the stems of velvetleaf plants which exude toxic chemicals. [Pg.3]

As regards the pollutants monitoring, from the measurements available so far it could be concluded that acid rain is coming to be a major problem in Asia. In many industrially developed and new developed countries such as Japan, China, Taiwan, South Korea, Thailand etc., values of pH <5 are encountered at many sites, and they represent more than 50% of monitored rain events on a regional scale. In some developing countries of South-East Asia (Myanmar, Laos, Cambodia) most rainwater pH measurements tend to be around 5.6, the pH of natural rainwater, and the acid rain precipitation is mainly due to localized industrial pollution. There is some evidence that pH values below 5 at unpolluted sites may be due to the contribution of weak organic acids, such as formic and acetic acids (Radojevic, 1998). [Pg.344]

Sakugawa, H., I. R. Kaplan, and L. S. Shepard, Measurements of H202, Aldehydes, and Organic Acids in Los Angeles Rainwater Their Sources and Deposition Rates, Atmos. Environ., 27B, 203-219 (1993). [Pg.346]

Esterification with alcohols using the Lewis catalyst BF3 is a well-established procedure. Organic acids are derivatized with BF3/butanol to their corresponding butylesters and then extracted into hexane. For dicarboxylic acids derivatizations, excess butanol was removed to avoid interference with the analytes.Butylesters are preferred over methylesters since these are more easily separated from the solvent peak due to their higher boiling points. Dicarboxylic acids as well as a-ketoacids were quantified with this procedure in rainwater samples. [Pg.472]

Kieber, R.J. et al.. Dissolved organic carbon and organic acids in coastal New Zealand rainwater, Atmos. Environ., 36, 3557, 2002. [Pg.404]

Sulfur Dioxide. Sulfur dioxide and nitrogen oxides, which are produced in modern society when coal, gas, and oil are burned in cars, power plants, and factories, react with water vapor in the air to form acids that negatively affect organic materials and even metals and stone when dissolved in airborne rainwater, the oxides of sulfur and nitrogen are the main cause of the formation of acid rain (see below). [Pg.445]

The alkali in these water pools reacts with organic matter such as algae and moss growing on the stone. The most common of these reactions is saponification (see p. 240), which causes naturally occurring esters to split, to form the respective carboxylic acid and an alcohol. Once formed, this carboxylic acid reacts with more alkaline rainwater to form a metal carboxylate, according to... [Pg.245]


See other pages where Rainwater organic acid acidity is mentioned: [Pg.570]    [Pg.538]    [Pg.171]    [Pg.175]    [Pg.67]    [Pg.377]    [Pg.49]    [Pg.50]    [Pg.145]    [Pg.145]    [Pg.155]    [Pg.373]    [Pg.195]    [Pg.408]    [Pg.409]    [Pg.86]    [Pg.94]    [Pg.127]    [Pg.128]    [Pg.619]    [Pg.954]    [Pg.957]    [Pg.111]    [Pg.1030]    [Pg.1031]    [Pg.21]    [Pg.244]    [Pg.426]    [Pg.404]    [Pg.195]    [Pg.542]    [Pg.298]    [Pg.335]    [Pg.446]    [Pg.446]    [Pg.286]    [Pg.156]    [Pg.322]   
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