خيارات البحث
النتائج 1421 - 1430 من 62,595
Evaluation of fate and exposure models - Pesticides and groundwater quality protection - Calibrating a simple model for ranking the contamination potential.
1994
Bacci E. | Franchi A. | Bensi L. | Gaggi C.
A simple approach for ranking the leaching of pesticides from surface soil presented and tentatively calibrated with field data from an agricultural a The approach is based on the calculation of a leaching index indicating the proportion of active ingredient, with respect to the quantity applied, leac from a soil model in a given time interval (one year). In the selected area wells tapping an unconfined aquifer were sampled for groundwater pesticide residue analysis, in order to explore the index region between leachers and nonleachers.
اظهر المزيد [+] اقل [-]Observations on long-term air-soil exchange of organic contaminants.
1994
Jones K.C.
Evidence for long-term changes in the soil composition of selected organic compounds, brought about by exchanges with the atmosphere, is briefly reviewed. In the case of some compounds - such as benzo(a)pyrene and octachlorodibenzo-p-dioxin, soils may be significant long-term environmental sinks for atmospherically-derived material. In other cases - such as phenanthrene and some of the lighter PCBs, de-gassing or volatilisation from soil back to the air can occur under certain conditions. Hence the soil may act as a "short-term" sink, and a potential source to atmosphere. Indeed, for some 'semi-volatile' compounds used in large quantities in the past - such as PCBs, soil outgassing may actually be an extremely important source to contemporary air. Furthermore, soil outgassing from areas of former high use may provide an important driving mechanism for continued "global cycling" of a range of semi-volatile organochlorine compounds.
اظهر المزيد [+] اقل [-]Evaluation of fate and exposure models - Fate of pulp mill effluent compounds in a Finnish watercourse.
1994
Trapp S. | Rantio T. | Paasivirta J.
Chloroorganic chemicals emitted from the pulp and paper mill at Nekoski in central Finland were monitored for several years. Concentration time series are used for evaluating the environmental fate and the applicability and validity of an exposure models. Fitted elimination rates of 3,4,5-Tri-, 4,5,6-Tri-, Tetrachloroguaiacol and 2,4,6-Trichlorophenol are approx. 0.22 per day, or rather the half-lives are approx. 3 days. The elimination is most likely by biodegradation and transport-controlled. For 2,3,6-trichloro-p-cymene, fate simulations indicate significant volatilization and sedimentation. Good agreement is achieved with a one-dimensional steady-state box model, except for concentrations in fish. For a reliable assessment of environmental damage, laboratory experiments, monitoring and simulations need to be in tune.
اظهر المزيد [+] اقل [-]Changes in chemistry and mineralogy of forest soils by acid rain.
1992
Rampazzo N. | Blum W.E.H.
Effects of dietary aluminum on reproduction in Japanese quail Coturnix coturnix japonica.
1990
Wolff B.G. | Phillips R.E.
Foliar leaching and root uptake of Ca, Mg and K in relation to acid fog effects on Douglas-fir.
1990
Turner D.P. | Tingey D.T.
Forest decline and soil nutritional problems in Pacific areas.
1990
Mueller Dombois D.
Nutrient response to diagnostic fertilization of Norway spruce Picea abies (L.) Karst plantations in western Quebec, Canada.
1990
Janicki W. | Jones A.R.C.
Gas-bubble disease in three fish species inhabiting the heated discharge of a steam-electric station using hypolimnetic cooling water.
1990
McInerny M.C.
Second rotation decline in P. radiata plantations in South Australia has been corrected.
1990
Woods R.V.
