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[en] IVL, has described the effects of five scenarios of future forest management on recovery from acidification of soil and run off during a rotation. The study was conducted by use of the dynamic model MAGIC. The calculations were applied on a forest site in the southern part of Sweden with acidified soil and a productive spruce forest, which is common in the southwestern part of Sweden. The soil of the studied site was acidified several decades ago when the emissions of air pollutants in Europe, especially sulphur, increased according to the model calculations. At the same time a productive spruce forest was established, which also contributed to the acidification by cation uptake and ion exchange with H+. The reduction of the emissions of sulphur after 1980 enabled a recovery process, indicated by, for example, increased ANC and decreased concentrations of inorganic aluminium in soil water. But the recovery will not be complete and the achieved degree of recovery will be depending of the type of forest management according to the calculations. The model calculations show that the combination between deposition of air pollutants and growing forests have resulted in a yearly net loss of 36 meq/m2 of base cations (resulting in soil acidification) from the soil during the period 1850 to 2015. The future yearly net loss of base cations, with lower deposition, could reach 15 meq /m2 with whole tree harvesting (including needles) during one rotation between 2015 and 2085. The amount of branches, tops and needles left after clear cutting and thinning contribute to the variation between 4 and 15 meq/m2 in average yearly net loss of base cations from the soil depending of the amount of biomass removed by harvest. The model calculations of the historic and future development of acidification in this study involve several sources of uncertainty. The long time span, assumed removal of biomass by harvest and compensatory fertilisation contributes to the uncertainties. In spite of that the method has proved to be a valuable tool to assess the need of additional reductions of emissions of air pollutants and also the impact of different forest management methods on future soil and water acidification. But the method need to be further developed and applied to assess the role of acidifying air pollutants in relation to forest management for recovery in acidified areas
[en] A common basic assumption in civil engineering is that rainwater is chemically neutral (pH = 7.0). However, even under pristine conditions, rainwater is often more acidic due to natural emissions of organic acids. Even natural rain acidity may be very aggressive against natural stones and concrete. A harmful impact of UV radiation on the concrete durability was discussed by the authors for the first time in 2006. The objective of the current research was the characterization of weathering processes occurred in the wet cast concrete subjected to the normal acidic rain and UV radiation, and the evaluation of their possible effect on the reinforced concrete durability. It was revealed that organic acids contained in rain of the natural acidity promote an intense concrete carbonation, even when a permeability of concrete looks to be low.
[en] Using a radioactive multitracer and model acid rain (HCl or H2SO4 solution), batch experiments were performed to examine the pH effect on the adsorption-desorption equilibrium of 16 elements on soils as a model study of an acid rain effect. Kaolin, black soil (original and with organic matter almost removed) and Kureha soil (original and with organic matter almost removed) were used as adsorbents. Characteristic dependence on the pH value of the suspension was observed for the adsorption of the elements on kaolin and the soils. The results of this model study indicate that acid rain decreases the retention of cations, while it increases or does not change the adsorption of anions on soils. Organic matter in soils has a positive effect on the extent of adsorption of most elements investigated. (author)
[en] This research was aimed to study the effects of groundwater and acid rain upon the mobility of radionuclides (Cs-134 and Co-60) in contaminated top soil. Clay soil was homogeneously packed in columns with dimension φ.12.5 cm. * 50 cm.. At the top 5 cm. of the columns, soil contaminated with radionuclides was added with the same consistency. Column were kept standing for 4 months in an artificial water table kept at 3 cm. from the bottom. During this period artificial acid rain with pH3, 4.5 and 6 was applied weekly at the top. Soil samples were taken every 30 days for examination of total and extracable radioactivity. It was shown that with the aide of the rain radionuclide movement down the profile was greater, with Co-60 > Cs-134. However acidity of the rain shown no effect on their movement
[en] This paper illustrates a simple technique of performing space-time analysis of precipitation-weighted SO42- concentration data across the eastern US that were collected by the National atmospheric deposition program. Using a moving average filter and two-dimensional spatial data filtering algorithm on the time series of precipitation-weighted SO42- concentrations, we show that decreases of about 50% have occurred in SO42- concentrations in Minnesota, Wisconsin, and over the northeastern US between 1985 and 1998, generally consistent with SO2 emissions' reductions over this period. The decreases in SO42- concentrations tended to be smaller in the midwest and south. (author)
[en] A research programme for water- and groundwater-acidification was realized in the catchment-area of the shallow groundwater-gallery ''Kalter Born'', which is part of the public water supply of Wiesbaden. The water chemistry of the sources and galleries shows the strongest acidification in the upper part of the aquifer, whereas the deeper groundwater sections show less acidification symptoms. Therefore the water of the deep gallery ''Kellerskopfstollen'' is nearly free of acidification signs in consequence of its long percolation distance (about 200-300 m) between the infiltration level and the gallery. On the other hand, we get an absolutely acid water with pH-values of about 4 and aluminium-concentrations of about 6 mg/l from the upper sources representing the highest groundwater level in the investigation area. As a whole, the aquifer can at least be separated in 4 levels of well distinguishable acidification rates. An exact analysis of the change of ion-concentrations by the water passage between the different water sections shows, that a considerable part of the acid depositions (H+) is temporarily neutralized by the aluminium puffer close below the infiltration level. So the acid is transported downwards masked as aluminium sulfates. In deeper regions the masked acid is converted and finally neutralized by contact with carbonates. (orig.)
[de]Im Einzugsgebiet einer Wassergewinnungsanlage des Wiesbadener Hochtaunus, dem Flachstollen ''Kalter Born'', wurde im Rahmen eines UBA-Projektes ein umfangreiches Untersuchungsprogramm zur Erfassung der Gewaesserversauerung durchgefuehrt. Fuer den Grundwasserkoerper konnte anhand von chemischen Analysen der Quellen und Stollen dieses Einzugsgebietes ein tiefengerichteter Versauerungsgradient mit der staerksten Versauerung in den obersten Aquiferteilen und abnehmender Versauerung mit zunehmender Tiefe nachgewiesen werden. Das Tiefstollenwasser kann nach einer Sickerstrecke von 200 bis 290 m Gebirgsueberdeckung als nahezu unversauert gelten. Die hoechstgelegenen Quellen des Untersuchungsgebietes foerdern dagegen ein absolut saures Wasser mit pH-Werten um 4 und Al-Gehalten von 6 mg/l. Eine genaue Analyse der Ionengehaltsaenderungen bei den Uebergaengen zwischen den verschiedenen Wasserstockwerken zeigt, dass die eingetragene Saeure (H+) oberflaechennah zunaechst voruebergehend ueber den Aluminium-Puffermechanismus neutralisiert und in der Form von Aluminium-Sulfaten als ''gebundene Saeure'' in die Tiefe verlagert und dort schliesslich ueber Carbonatfreisetzungen endgueltig neutralisiert wird. (orig.)
[en] The criticisms that followed the first allowance trades remain a mystery - why, if trading produces efficiencies, has the public been critical? Perhaps there is a better reason to support trading
[en] In the national forest at the foot of Mount Tarumae which is located in the northwestern part of Tomakomai City, Hokkaido, large scale artificial afforestation of larch, spruce, white fir and other trees was carried out in the area damaged by the typhoon in 1954. However, the afforested ground suffered deadly damage by freezing and frost and the spread of disease and insect harms. Since 1960s, pines storobus which is strong to coldness and grows quickly has been planted in the area of about 2000 ha. At first its growth was good, but since 1967, the abnormal leaf falling due to unknown cause and the obstruction of growth became to be observed. At the point of time when the damage spread to several hundreds ha of the afforested ground, the causes of the potassium shortage in soil nutriment, the harms due to cold wind, salt wind and atmospheric pollution and so on were discussed. Of those, the strongest hypothesis was the obstruction of growth due to the potassium shortage in the unripe soil with the composition of volcanic released substances from Mount Tarumae. The environment in the area where abnormal leaf falling occurred, the features of the damage, the analysis of rainwater, and the mechanism of the decline are reported. (K.I.)
[en] The Brazilian sandy coastal plain named restinga is frequently subjected to particulate and gaseous emissions from iron ore factories. These gases may come into contact with atmospheric moisture and produce acid rain. The effects of the acid rain on vegetation, combined with iron excess in the soil, can lead to the disappearance of sensitive species and decrease restinga biodiversity. The effects of iron ore dust deposition and simulated acid rain on photosynthesis and on antioxidant enzymes were investigated in Eugenia uniflora, a representative shrub species of the restinga. This study aimed to determine the possible utility of this species in environmental risk assessment. After the application of iron ore dust as iron solid particulate matter (SPMFe) and simulated acid rain (pH 3.1), the 18-month old plants displayed brown spots and necrosis, typical symptoms of iron toxicity and injuries caused by acid rain, respectively. The acidity of the rain intensified leaf iron accumulation, which reached phytotoxic levels, mainly in plants exposed to iron ore dust. These plants showed the lowest values for net photosynthesis, stomatal conductance, transpiration, chlorophyll a content and electron transport rate through photosystem II (PSII). Catalase and superoxide dismutase activities were decreased by simulated acid rain. Peroxidase activity and membrane injury increased following exposure to acid rain and simultaneous SPMFe application. Eugenia uniflora exhibited impaired photosynthetic and antioxidative metabolism in response to combined iron and acid rain stresses. This species could become a valuable tool in environmental risk assessment in restinga areas near iron ore pelletizing factories. Non-invasive evaluations of visual injuries, photosynthesis and chlorophyll a fluorescence, as well as invasive biochemical analysis could be used as markers.