Rainwater measurements

Fig. 43 Tritium concentration in rainwater, measured at the station Hof-Hohensaas, Germany (latitude 50.32 °N, longitude 11.88 °E, height 567 m NN) from 1962 to 1997...

Olszyna, K. J., J. F. Meagher, and E. M. Bailey. 1988. Gas-phase, cloud and rainwater measurements of hydrogen peroxide at a high-elevation site. Atmos. Environ. 22 1699-1706. 

Fig. 3. The pH of Rainwater Measured at Several Sites in New York State over a Period of Years (Source U.S. Geological Survey)...

Other radioisotopes known to be produced by cosmic rays include Be, H, Na, Be, and Of these Be, P, and P have activities that are high enough to be measured in rainwater. In several instances, notably 0 and Be, these radioactive elements are useful as tracers. 

Higher levels of lead in soil can be measured near roadways. This accumulation came from car exhaust in the past. Once lead falls onto soil, it usually sticks to soil particles. Small amounts of lead may enter rivers, lakes, and streams when soil particles are moved by rainwater. Lead may remain stuck to soil particles in water for many years. Movement of lead from soil particles into underground water or drinking water is unlikely unless the water is acidic or "soft." Movement of lead from soil will also depend on the type of lead salt or compound and on the physical and chemical characteristics of the soil. 

Spectrophotometric determination with 4-hexylresorcinol and a fluorometric method with m-aminophenol are the most commonly used procedures for the determination of acrolein. However, gas chromatography and high-performance liquid chromatography procedures are also used (USEPA 1980 Kissel etal. 1981 Nishikawa and Hayakawa 1986). Acrolein concentrations in rainwater between 4 and 200 pg/L can be measured rapidly (less than 80 min) without interference from related compounds the method involves acrolein bromination and analysis by gas chromatography with electron capture detection (Nishikawa and Hayakawa 1986). Kissel etal. (1981) emphasize that water samples from potential acrolein treatment systems require the use of water from that system in preparing blanks, controls, and standards and that acrolein measurements should be made at the anticipated use concentrations. 

As informed Dr. A.I. Korableva from Institute for Environmental Management and Ecology under the National Academy of Sciences of Ukraine in the report "Environmental impact of automobile transport by example of Dnepropetrovsk", Dnepropetrovsk with its annual discharge of air pollutants of 177,000 t (as of 1996) is among the worst affected cities in Ukraine. In these, the automobile transport was found to be responsible for at least 30 % of the total emissions which are 15 times the maximum permissible level. Aside from the dust, chemical, photochemical and noise pollution, there is the aspect of street washout of automobile-related pollutants into the River Dnieper. The measured annual receipts of lead, particulates and petroleum derivatives via rainwater and thaw water to the river are 0.45, 80,000+ and 1.8+ t respectively. The actual levels of petroleum derivatives in storm water sometimes were 206 times the maximum permissible concentration (MPC) for the fishery basins. At 34 km downstream from the city, the estimated levels of petroleum derivatives and particulates are 61 and 10.8 times the respective MPCs. The airborne lead is mainly accumulated in the soil of housing areas. 

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). 

To determine the leaching of chemical constituents from SWMs/COMs under conditions of constant surface renewal, columns (2.5 cm in diameter, 25 cm long) filled with SWMs/COMs were leached with distilled water at three different flow rates. The column tests were used to simulate leaching of highway materials under conditions of subsurface percolation of rainwater. Effluent samples from the column were taken with time for up to 80 h. The filtered solutions were measured for TOC and/or individual compound concentrations, and for toxicity. 

Yoshizumi, K.. Aoki, K., Nonchi, I., Okita,T.,Kobayashi, T.,KamaknraS.,andTajima, M. Measurements of the concentration in rainwater and of the Henry s law constant of hydrogen peroxide, Atmos. Environ., 18(2) 395-401, 1984. 

Studies of rainwater composition typically Include the measurement of the concentrations of a number of chemical species, conductivity, and rain volume and sometimes Include supporting measurement of winds or other meteorological parameters. Much of the desired... 

Spatial Interrelationships In the chemical composition among two or more blocks (sites) can be calculated by partial least squares (PLS) (9 ). PLS calculates latent variables slmlllar to PG factors except that the PLS latent variables describe the correlated (variance common to both sites) variance of features between sites. Regional Influences on rainwater composition are thus Identified from the composition of latent variables extracted from the measurements made at several sites. Gomparlson of the results... 

With emission source chemical signatures and corresponding aerosol or rainwater sample measurements PLS can be used Co calculate a chemical element mass balance (CEB). Exact emission profiles for the copper smelter and for a power plant located further upwind were not available for calculation of source contributions to Western Washington rainwater composition. This type of calculation Is more difficult for rainwater Chan for aerosol samples due Co atmospheric gas to particle conversion of sulfur and nitrogen species and due Co variations In scavenging efficiencies among species. Gatz (14) has applied Che CEB to rainwater samples and discussed Che effect of variable solubility on the evaluation of Che soil or road dust factor. 

Although the measurement uncertainties limit the conclusions which can be drawn from these results, the data set proved useful for the determination of general Influences on rainwater composition In the Seattle area and for the demonstration of the application of these exploratory data analysis techniques. Current efforts to collect and analyze aerosol and rainwater samples over meteorologically appropriate time scales with precise analytical techniques are expected to provide better resolution of the factors controlling the composition of rainwater. 

D. Rainwater Analysis. IC is also being applied to the analysis of ions in rainwater (13). Measurements of precipitation samples are being collected at remote or baseline stations to provide an estimate of the natural ion concentration observed in rain unaffected by man s activity. These measurements will provide data, to study increases of certain constituents with time due to energy and industrial oroduction. 

The term acid precipitation refers to any form of precipitation, such as rain, snow, sleet, or hail, with a pH less than that typical of rainwater. You may recall that pH is a measure of the concentration of hydrogen ions in a solution, an indication as to how acidic the solution is. Plain water has a pH of 7.0, while acidic solutions have a pH less than 7 and basic solutions, a pH of greater than 7. 

If the pH of natural rain were measured, you might expect a pH of around 7.0. Because a pH of 7.0 indicates neutral conditions, many people assume this to be the pH of rain. The theoretical pH of pure rainwater is actually about 5.6. Pure rain is acidic due to the equilibrium established between water and carbon dioxide in the atmosphere. Carbon dioxide and water combine to give carbonic acid ... 

Grosjean (1989, 1992) estimated that about 40% of the HCOOH and 75% of the CH3COOH measured at Claremont, just east of Los Angeles, are due to direct emissions. This is qualitatively consistent with carbon isotope measurements of l3C/l2C of formic and acetic acids in rainwater collected in this area, which show HCOOH is from a combination of direct emissions and secondary oxidation chemistry and CH3COOH is primarily from direct emissions (Sakugawa and Kaplan, 1995). 

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). 

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