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Assessment of Atmospheric Heavy Metals by Moss Monitoring with Isothecium Stoloniferum Brid. in the Fraser Valley, B.C., Canada
1998
Pott, Ute | Turpin, David H.
The atmospheric heavy metal pollution of the Fraser Valley, B.C., Canada was assessed in 1993 by analyzing 62 samples of the common woodland moss Isothecium stoloniferum for lead, cadmium, nickel, zinc, chromium, and manganese. The latter two metals did not show a distinct regional distribution, but lead, cadmium, nickel, and zinc showed distinct pattern along a west-east gradient. High values were found in the metropolitan Vancouver area, located in the west of the study region. Significantly lower values were recorded for mosses from the eastern more rural areas of the Fraser Valley. Metal pollutants are likely to be contained close to their emission sources by alternating south-east, north-west winds. Highest values overall were found in the North Shore Mountains, adjacent to Vancouver. This was related to higher precipitation and short range pollutant transport from the industrialized, heavily populated areas in the floodplain of the Fraser River.
اظهر المزيد [+] اقل [-]Influence of pH and Zinc Concentration on Cadmium Sorption in Acid, Sandy Soils
1998
Wilkins, B. J. | Brummel, N. | Loch, J. P. G.
Batch adsorption experiments were carried out with samples from an A-, Bh- and C-horizon of contaminated sandy soil of podzolic character from the Kempen region at the Dutch-Belgian border. Cadmium sorption was studied on 3 soil samples at 3 different pH-levels (3.6, 4.3 and soil buffered pH) and 3 different additions of zinc (0–40 mg l⁻¹).Adsorption of cadmium by acid sandy soils can be fitted by a Freundlich adsorption isotherm. Although zinc competes with cadmium for the sorption sites, we observe a two to three times stronger competition effect of the proton cation, which is explained by the chemical properties of both ions. The cadmium adsorption coefficient KF decreases considerably by an increase of the proton activity used in the sorption experiments. Organic matter content explains for a large part the variation of KF of te three soil samples. Desorption data do not fit the proposed regression model for adssorption. Not all the cadmium, intitially present in the polluted soil, will fylly desorb reversibly. Thus, part of the cadmium may be irreversible bound.
اظهر المزيد [+] اقل [-]Geographic Classification of Heavy Metal Concentrations in Mosses and Stream Sediments in the Federal Republic of Germany
1998
Berlekamp, Jürgen | Herpin, Uwe | Matthies, Michael | Lieth, Helmut | Markert, Bernd | Weckert, Vera | Wolterbeek, H. Th. | Verburg, Tona | Zinner, Hans-Jürgen | Siewers, Ulrich
The results of the first German moss monitoring programme to estimate heavy metal pollution in the Federal Republic of Germany were combined with other large-scale investigations carried out in Germany and then classified geographically in a new form. Using Monte Carlo assisted factor analysis, six factors indicating sources of pollution were identified from the sets of element data from the moss monitoring project (As, Cd, Cr, Cu, Fe, Ni, Pb, Ti, V, Zn) and the data sets for SO₂ and particulate. The geographic distribution patterns of the factor values showed the regions in which the various sources are to be found. By combining the data the primarily anthropogenic chromium concentrations of the mosses were compared with the mainly geogenic chromium concentrations of the stream sediments in the form of examples. After normalization, the transformed chromium concentrations were transferred to a map of the entire area using inverse distance weighting. Anthropogenic and geogenic influences are being discussed on the basis of the results.
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