细化搜索
结果 1-5 的 5
Microbiological Properties in Acidic Forest Soils with Special Consideration of KCl Extractable Al
2003
Illmer, Paul | Obertegger, Ulrike | Schinner, Franz
To determine the importance of Al-availability for soil micro-organisms 95 forest soils from Tyrol/Austria with comparable topography, vegetation, climatic conditions, soil type and with low soil pH (median = 3.9) were investigated for their physical (percentage of stable aggregates, water holding capacity), chemical (pH, electrical conductivity, contents of organic matter, concentrations of easily extractable aluminium, calcium, potassium, magnesium and phosphorus) and microbiological characteristics (microbial biomass and respiration, metabolic quotient, content of ATP, activities of protease and CM-cellulase, cfu-values of total and Al-tolerant bacteria and fungi). A highly significant negative correlation was detected between concentrations of KCl-extractable aluminium and soil pH. By the application of multivariate statistical methods, the effect of the concentration of KCl-extractable aluminium on abundance and activities of soil micro-organisms could be revealed. Al turned out to be of great importance for micro-organisms and often outmatched the significance of other well known soil properties like organic matter, pH or water holding capacity. However, due to very healthy trees at the sites under investigation no effect of Al or soil acidification on forest decline could be detected.
显示更多 [+] 显示较少 [-]Adsorption, Desorption And Mobility of Fomesafen in Chinese Soils
2003
Guo, Jiangfeng | Zhu, Guonian | Shi, Jianjun | Sun, Jinhe
Fomesafen, 5-[2-chloro-4-(trifluoromethyl)phenoxy]-N-(methylsulfonyl)-2-nitrobenzamide, is used widely for weed control in soybeans since its introduction to China. Little information is available on its adsorption, desorption and movement in Chinese soils. The adsorption, desorption and mobility of fomesafen in six Chinese soils was studied. Adsorption isotherms agreed with the Freundlich equation very well. The results of regressionanalysis indicated that soil pH was more important than organic matter for fomesafen adsorption. Fomesafen was more readily desorbed from soils with 0.01 M CaSO₄solution. Soil TLC and column leaching studies showed that fomesafen and its metabolites was less mobile in Chinese soils. About 89.82% of applied fomesafen and its metabolites still remained in upper 5 cm layer 60 days after treatment under field conditions.
显示更多 [+] 显示较少 [-]Sediment quality in the iron gate reservoir [Serbia, Serbia&Montenegro]. [Preliminary communication from scientific-research project]
2003
Damjanovic, M. | Babic-Mladenovic, M. (Institut za vodoprivredu Jaroslav Cerni, Beograd (Serbia and Montenegro))
Regular monitoring of water quality of the Danube river in the backwater zone includes analysis of the sediment. It is well known that sediment is a sink place for the non degradable compounds and it reveales the long term water quality status in the reservoir. This paper presents the general results on the Iron Gate reservoir siltation. as well as some data regarding pollution level, based on investigations carried in the period of 2001-2002. The investigations included organic load of the sediment, heavy metals and organic pollutants content. The degree of pollution is evaluated on the basis of various criteria, also compared to results of previous case studies.
显示更多 [+] 显示较少 [-]Effects of preozonation on natural organic matter removal from groundwater by coagulation and flocculation processes
2003
Agbaba, J. (Prirodno-matematicki fakultet, Novi Sad (Serbia and Montenegro). Departman za hemiju) | Dalmacija, B. | Klasnja, M. | Ivancev-Tumbas, I.
The paper deals with pilot-scale investigations of the effect of preozonation on NOM removal from groundwater by coagulation and flocculation processes. It was found that the preozonation increased the efficiency of organic matter removal by coagulation and flocculation from 23.6 to 47.2% as judged on the basis of KMnO4 values. From the aspect of the change of content of trihalomethanes precursors preozonation exhibits both the positive and negative effects if their content in the water after coagulation is considered in dependence of the applied ozone dose. The obtained values siggest the necessity of careful optimization of the processes of preozonation, coagulation, and flocculation, especially from the aspect of the change in content of the precursors of disinfection byproducts.
显示更多 [+] 显示较少 [-]Dependence of trihalomethanes forming on contents of natural organic matters in coagulated water
2003
Bajevic, Lj. (Visa tehnicka skola, Zrenjanin (Serbia and Montenegro)) | Karlovic, E. | Jasin, D. | Agbaba, J. | Djeric, J.
The paper deals with determining the dependence of trihalomethanes forming (chloroform, bromdichlormethane, dibromchlormethane and bromoform) on the contents of natural organic matters from groundwater. The analyses was made bay calculating correlation of trihalomethanes forming potential (THMPF) with UV absorbance and permanganate number as surogates parameters for defining in content NOM in water. These were used to observe the changes in the content of organic matters after coagulation. A good correlation of THMPF, PF chloroform and UV absorbance (254 nm) (coeficient of correlation 0.72 and 0.87) was observed as well as a good with UV absorbance (254 nm) (coeficient of correlation - 0.88) and with PN (coeficient of correlation - 0.80) in coeficient of correlation in bromated trihalomethanes forming.
显示更多 [+] 显示较少 [-]