Ionic Composition Of Rainwater Research Articles

Ionic Composition of Rainwater at Selected Sites of Kuantan, Pahang, Malaysia: A Preliminary Study

A short-term investigation on the chemical composition of rainwater was carried out at five selected sampling stations in Kuantan district, Pahang, Malaysia. Sampling of rainwater was conducted by event basis between September and November 2011. Rainwater samples were collected using polyethylene containers and the parameters measured were cations (sodium, potassium, ammonium, calcium and magnesium) and anions (chlorides, nitrates and sulphates). The average pH value for rainwater samples was 6.0 ± 0.57 in which most of the sampling sites exhibited pH values >5.6. Calcium and sulphate were the most abundant cation and anion, respectively, whilst the concentrations of other major ions varied according to sampling location.

Acid rain and particulate matter dynamics in a mid-sized Andean city: The effect of rain intensity on ion scavenging

Acid rain phenomenon (average WVM pH = 4.9) and a strong association of sulfate scavenging and rain intensity (R2 = 0.8118) were observed over a seven-month period (October 2010–April 2011) at a densely populated mid-sized Andean city (pop 380,000) that occupies mountain ridge topography (2150 m.a.s.l.). Rain chemistry and PM10 were fairly consistent over four sampling sites representing various scenarios of urban density and topography. All stations exhibited differences in the sulfate content in PM10 between dry and wet periods, further illustrating the sulfate scavenging dynamic. Concentration of major ions evaluated in rain were in order of sulfates (35.2–53.5 μeq L−1) > calcium (14.6–17.3 μeq L−1) > chlorides (3.5–5.1 μeq L−1) > nitrates (2.1–3.1 μeq L−1). Major chemical constituents of PM10 were related with ionic composition of rainwater through scavenging ratios (SRs). High sulfate SRs associated with increased rain intensity reflected higher sulfate ion solubility. Significant contribution of sulfates to total ionic content, higher than 50% at all monitoring stations, suggests important contributions of SO2 emissions, which could come from three principal sources: vehicular emissions due to Colombian fuels with elevated sulfur content, industrial emissions at southeast of the city, and sulfur gas emissions from a nearby active volcano, Nevado del Ruiz, located 27 km southeast of the city.

Rainwater chemistry at a regional representative urban site: influence of terrestrial sources on ionic composition

Abstract In the present investigation, the rainwater chemistry is studied over a one year period at a regional representative urban site, Tirupati. A continuous record of 67 events were included that ranged from 0.5 to 74.6 mm (annual total 850.2 mm), from which 35 events (52%) were chemically analyzed during the period for major inorganic ion composition viz. F, Cl, NO3, SO4, Na, K, Ca, and Mg as well as NH4. The volume-weighted mean (VWM) of the measured ionic sum is 501.28 μeq l−1 and the crustal ion contribution dominating over the acidic ions with a ratio of total cation to that of anions (Σcations/Σanions) is 1.4. Only the Ca and SO4 together made up more than 55% of the total ion, whereas Ca alone contributed about 51% of the total cation. All the rain samples analyzed showed alkaline pH always, to that of reference level 5.6, with VWM of 6.78. On the basis of good correlation between the crustal ions (Ca, Mg, K and NH4) and SO4 ( r = 0.95 ) and NO3 ( r = 0.91 ) as well as order of neutralization factors Ca (0.88)>Mg (0.33)>NH4 (0.11), it has been determined that the acid neutralization is brought about by crustal ions, particularly calcium, in the region. The data were subjected for correlation analysis. A good correlation observed between Ca and SO4 and NO3 ( r = 0.92 and 0.90) and Mg and SO4 and NO3 ( r = 9.83 and 0.77), respectively, reveals that the ionic composition of rainwater in the region is strongly influenced by terrestrial sources rather than anthropogenic and marine sources.

Evaluation of Air Quality over the Black Sea: Major Ionic Composition of Rainwater

This article attempts to put the light on the air quality of the Black Sea region of Turkey. In addition to that, it endeavors to locate the possible sources of the different pollutants at local, regional and long range transported scales. About 196 rainwater samples were collected over the Black Sea region of Amasra between 1995 and 1999, and analyzed for major ions and trace elements using spectrophotometric techniques. Andersen wet only rain samples were used to collect rain events, where the rain sample was filtered inline using 0.45 μm cellulose acetate filters. Major anions (SO4 2-, NO3 - and Cl-) were determined using ion chromatography, whereas metals (Ca, Mg, Al, Fe, Na, K), werequantified using ICP-AES. This study shows that, the Black Sea region receives different amounts and types of anthropogenic pollutants via long-range transport according to trajectory models. Although the pH of rain water is not considered acidic (pH = 5.21) yet the neutralizing species are lower than other sites around Europe.

タイ北部の降水の性状について １９９８年６月から９月の結果

1998年6月から9月まで, タイ北部 (チェンマイ地区, ランポーン地区, メモ地区およびランパン地区) で, 自作のBulk samplerとWet only sampler (堀場分割採取器) によって降水を採取した.その結果, Bulk samplerで捕集した降水のpHの平均値は6.30, 電気伝導度 (EC) は20.3μS/cmであった.アニオンの含有率ではSO42-が高く40～60%で, カチオンではCa2+であった.pHを目的変数として重回帰分析を実施すると, 従変数としてK+, Mg2+およびSO42-で重相関係数: 0.8の回帰式が得られた.また, 石炭火力発電所があるメモ地区のデータは残りの地区のデータよりもpHが低く, イオン濃度が高かった.これに対して, Wet only samplerで捕集した降水 (1mm分割) pHの平均値は6.24, ECは17.1μS/cmでBulk samplerで捕集した値と大きな差は認められなかった.さらに, 1992年10月に大気汚染事故が発生したSob Pad村で8月17日にpHは中性ながら, EC-300μS/cmの雨が観測され, SO42-濃度は2083μEq/lおよびCa2+濃度が1863μEq/lで排ガス処理の何らかの事故の発生が疑われた.同方法で, 測定した四日市におけるpHは4.88 (Bulk sampler) および4.34 (Wet only sampler: 1mm分割) , ECが37.0μS/cm (Bulk sampler) と77.3μS/cm (Wet only sampler) で, タイ北部の降水のpHは中性であり, ECも四日市より低かった.さらに, イオン組成をみると, 捕集法の如何によらず, タイ北部では四日市よりもアニオンではSO42-の含有率が高く, NO3-の含有率が低く, カチオンではCa2+含有率が高かった.

An Analysis of the Representative Composition of Rainwater at Six Locations in Hong Kong

A 3-year weekly data set on the ionic composition of rainwater from 6 sampling sites in Hong Kong representing the 1990-92 period was resolved employing factor analysis. Two-to-three factors explaining cumulative variances of 78-93% of the total in the 9 ionic parameters studied are utilised in the interpretation. The procedure is repeated on the screened data sets obtained on the basis, among other constraints, of a cut-off ion balance of 15%. The results indicate that: (i) the 'mixed' (residential-industrial) area, Central-Western has a 7- membered 'degenerate' first factor which fails to resolve into smaller groups; (ii) the quasi-rural site, Junk Bay has a partially neutralised acid (PNA) and a pure sea salt (SS) component; (iii) two other mainly residential areas, Hong Kong South - whose factors resemble those for industrial Kwun Tong - and Tai Po have a third factor containing potassium, and additional chloride, respectively. The latter factor, V/W, for Tai Po believed to be due to burning vegetation/waste incineration is similar only to that for the industrial Kwai Chung. On the other hand, the process of data screening has no effect on the factorial sequence or make-up, except in the cases of the two industrial locations, where the order of the resolved factors in two of their sets are swapped among two different factors; and, in the case of one of them, a variable (ion) shifts its loading to a different factor upon screening. Finally, stepwise multiple regression corroborates our earlier provisional conclusion that the free acidity of rainwater in Hong Kong is also contributed by acids other than H2SO4 and HNO3, possibly by oxalic, formic and acetic acids, among some others.

Ionic composition of rainwater and atmospheric aerosols in Sardinia, southern Mediterranean

The ionic composition of 55 aerosol samples and 31 precipitation events collected in a coastal site in southem Sardinia (Capo Carbonara, 39~ ' N; 09"31' E) were compared. The samples were collected during one year period (Oct'90/Oct'91) and showed high variability in composition according to meteorological conditions. Rain and soluble part of aerosol showed a strikingly similar ionic composition: most significant anions were chlorine and sulphate, and sodium is the principal cations, followed by magnesium and calcium. The acid events are associated with N-NW trajectories (anthropogenic influxes from N. Europe) with avg. pH=4.65, non sea salt (nss) Ca=60 tazq/1 and NO3/nssSO4=0.6. Southem precipitations are influenced by Saharan dust alkaline effects, with avg. pH=6.75, nssCa=271 p.eq/t and NO3/nssSO4--0.4. Na/CI ratio in rain is similar to sea water (0.87), whilst in aerosols there is a CI loss (Na/CI=I.10), probably due to reaction with nitric acid. Total fluxes of Ca, Mg, NO 3 and SO 4 were 104, 9, 64 and 113 ~tg/cm z, and wet deposition exceeded (65-90%) dry deposition. Scavenging ratios (SR) as defined by the equation: SR=((Ci)rain/(Ci)air)*d, (d= 1200g/m 3) were calculated, using geometric means (Ci) of precipitation and aerosols collected concurrently during the period (a total of 23 samples). The SR values are Ca=3400, C1=2400, Na, K, SO4= 1700, Mg=1000 and NO 3 =750. These numbers could be useful to infer total fluxes by

Saharan dust in the Amazon Basin

Saharan dust is shown to enter the Central Amazon Basin (CAB) in bursts which accompany major wet season rain systems. Low-level horizontal convergence feeding these rain systems draws dust from plumes which have crossed the tropical Atlantic under the large-scale circulation fields. Mass exchange of air between the surface and 4 km over the eastern Amazon basin is calculated using rawinsonde data collected during storm events. Mean concentrations of dust observed by aircraft over the western tropical Atlantic are used to calculate the amount of dust injected into the Basin. Individual storm events inject some 480,000 tons of dust into the north-eastern Amazon Basin. Storm and dust climatology suggest that the annual importation of dust is in the order of 13 Mtons. In the north-eastern basin, this may amount to as much as 190 kg ha -1 yr -1 . Deposition of trace species, such as phosphate, associated with this dust ranges from 1-4 kg ha -1 yr -1 . Uncertainties in these estimates are not believed to be greater than ± 50% and may be as low as ± 20%. The deposition fluxes from Saharan dust are essentially identical to the CAB wet deposition fluxes from precipitation in the wet season; a result that implies that the major ionic composition of rain water in the CAB wet season may be strongly influenced by inputs of material originating on the African continent nearly 5000 km away. The total amount of Saharan dust calculated to enter the Amazon basin is 1/2 to 1/3 of that estimated to cross 60°W longitude between 10° and 25°N latitude. We conclude that part of the productivity of the Amazon rain forest is dependent upon critical trace elements contained in the soil dust originating in the Sahara/Sahel. This dependence should be reflected by expansions and contractions of the Amazon rain forest in direct relationship to expansions and contractions of the Sahara/Sahel. Turnover rates for nutrient species deposited with Saharan dust in the Amazon Basin suggest a time scale of 500 to 20,000 years. We believe the dependence of one large ecosystem upon another separated by an ocean and coupled by the atmosphere to be fundamentally important to any view of how the global system functions. Any strategy designed to preserve the Amazonian rain forest or any part thereof should equally concern itself with the inter-relationship between the rain forest, global climate and arid zones well removed from Amazonia. DOI: 10.1034/j.1600-0889.1992.t01-1-00005.x

The ionic composition of rainwater at Katherine, NT. and its part in the cycling of plant nutrients

Rainwater was collected from individual showers at Katherine, Northern Territory, Australia, during the 1958–59 wet season, and again in 3.4 mm portions of individual showers during the 1959–60 wet season. Strict precautions were taken during rainless periods to prevent particulate material from accumulating in the rain collector. The laboratory examination of the samples included determinations of nitrate, ammonium, sodium, potassium, magnesium, and chloride ions, and of insoluble silica. Soil and plant material samples collected in the surroundings of Katherine were also analysed for a number of elements. In spite of a total annual average rainfall of 925 mm the annual total amount of soluble material in the rainwater was less than 6–7 kg 'ha. The concentration of all ions decreased during the progress of a shower, and from shower to shower, during the progress of the season. Correlation coefficients between the different ions were all positive and generally high. No relation could be detected between the nitrate content in the rainwater and the incidence of lightning. The correlation between chloride content and amount of insoluble silica was high (+ 0.73). It is argued that most of the material in the rainwater is part of a terrestrial cycle and cannot be regarded as a true accession.