资源、环境管理与经济发展——发展中国家的资源环境管理与经济政策

在许多地区,自然资源基础(通常是经济发展的关键)正受到人口迅猛增长的威胁和破坏,只有进行有效的政策干预,才能改变国家经济生活中与环境有关的开发利用资源的各种活动。因此,自然资源管理应该成为宏观经济与部门经济中必须考虑的问题。政府要消除有关的制度和体制方面的障碍,制定新的政策和法令,以增进部门间的合作,避免权限重叠,防止由于既得利益的影响使新政策不能发挥效力。     

UNITTree A multimedia compartment model to estimate the fate of lipophilic compounds in plants

A dynamic model was developed for the distribution of chemicals in plants, and was applied to describe the distribution in 15 year old spruce (Picea abies). A scenario with underlying air and rain concentrations, and emission onto plant surfaces into soilwater and on air particles is calculated for 2,4-Dichlorophenol, 2,3,7,8-TCDD, simazine, hexachlorobenzene and lindane for a period of 5000 h.     

Prediction of soil organic partition coefficients by a soil leaching column chromatographic method

The soil organic partition coefficient (Koc) is one of the most important parameters to depict the transfer and fate of a chemical in the soil-water system. Predicting Koc by using a chromatographic technique has been developing into a convenient and low-cost method. In this paper, a soil leaching column chromatograpy (SLCC) method employing the soil column packed with reference soil GSE 17201 (obtained from Bayer Landwirtschaftszentrum, Monheim, Germany) and methanol-water eluents was developed to predict the Koc of hydrophobic organic chemicals (HOCs), over a log Koc range of 4.8 orders of magnitude, from their capacity factors. The capacity factor with water as an eluent (k'w) could be obtained by linearly extrapolating capacity factors in methanol-water eluents (k'w) with various volume fractions of methanol (symbol in text). The important effects of solute activity coefficients in water on k'w and Koc were illustrated. Hence, the correlation between log Koc and log k'w (and log k') exists in the soil. The correlation coefficient (r) of the log Koc vs. log k'w correlation for 58 apolar and polar compounds could reach 0.987, while the correlation coefficients of the log Koc -log k' correlations were no less than 0.968, with (symbol in text)ranging from 0 to 0.50. The smaller the (symbol in text), the higher the r. Therefore, it is recommended that the eluent of smaller (symbol in text), such as water, be used for accurately estimating Koc. Correspondingly, the r value of the log Koc -log k'w correlation on a reversed-phase Hypersil ODS (Thermo Hypersil, Kleinostheim, Germany) column was less than 0.940 for the same solutes. The SLCC method could provide a more reliable route to predict Koc indirectly from a correlation with k'w than the reversed-phase liquid chromatographic (RPLC) one.     

QSAR generated octanol-water partition coefficients of selected mixed halogenated dibenzodioxins and dibenzofurans

We have calculated the values of pk_ow, water solubility, and K_oc for chlorinated, brominated and mixed halogenated dibenzodioxins and dibenzofurans that have been identified in environmental samples. From the results it can be concluded that brominated and mixed halogenated dioxins and furans will show an ecological behaviour similar to that of the pure chlorinated compounds.     

Prediction of the retentions of polybrominated dibenzo-p-dioxins (PBDDs) by using the retentions of polychlorinated dibenzo-p-dioxins (PCDDs)

The retention equations In k' = A + B/T of 49 polychlorinated dibenzo-p-dioxins (PCDDs) and 4 polybrominated dibenzo-p-dioxins (PBDDs) in gas chromatography (GC) have been investigated to evaluate the properties of regression coefficients A and B. The quantitative relationships between A and B values of PCDDs and those of PBDDs are found. The regression equations derived have correlation coefficients greater than 0.997. The A, B values of any PBDD can be predicted by using the A, B values of the PCDD according to these relationships. Using these predicted A and B values, the retention times of all PBDDs can be predicted at any temperature program. It is very useful to identify the peak position of any PBDD because at present there are only a few standards of PBDDs available.     

Die Isolierung eines kristallisierten Peptids aus Tabakmosaikvirus

The Science of Nature -     

Peak identification for PCDD/Fs in environmental samples at different temperature programs

A method has been developed for peak recognition of 136 polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) at different temperature programs. Their retention behaviours are predicted on the basis of an identification database of retention values (A, B) of gas chromatography. By the retention times of 13C labelled 2,3,7,8-substituted PCDD/F internal standards, the retentions of all PCDDs and PCDFs can be calculated. After comparison with the retentions of practical environmental samples, the predicted values have been proved to be very accurate.     

Verteilungskoeffizienten chlorierter Kohlenwasserstoffe zwischen Muskulatur und Leber bei Fischen

Measured partition coefficients (KL_M/L) related to lipid-concentrations between the muscle (C_ML) and liver (C_LL) tissue of two fish species (Abramis brama, Zoarces viviparus) exhibit nominal values of unity according the relationship KL_M/L=C_ML/C_LL=1 for persistent compounds such as highly chlorinated PCB and values above one for degradable compounds for example chlorinated cyclohexanes or DDT. The corresponding theory is presented. The relationship holds for samples for single fish as well as for pooled samples.     

Toxiwasp∗

TOXIWASP combines most of the kinetic structure of EXAMS 2 with the transport capabilities of WASP (Water Analysis Simulation Program). TOXIWASP uses variable chemical degradation rates from chemical properties and the environmental conditions of the aquatic ecosystem. These rates are reduced from pseudo first‐order rates to first‐order rates including the processes hydrolysis, biotransfor‐mation, phototransformation, oxidation, and volatilisation. Assuming ultimate local equilibrium, and using a chemical dependent partition coefficient as well as spatially varying environmental carbon fractions, sorption onto sediments and biomass is calculated. Environmental alternations could be specified in any time scale by providing monitoring data.

TOXIWASP generates total sediment and chemical concentrations every time step in every segment, including surface water, subsurface water, surface bed and subsurface bed. Advection, dispersion, mass loading, sedimentation, and scour affect sediment concentration in the water column and in the bed sediment concentrations depend on burial and erosion. In addition chemical concentrations are influenced by degradation, sediment‐water dispersion, and percolation. Lateral transport of chemical within the bed is neglected and transport data are not calculated in the program. TOXIWASP is developed to model stratified lakes, reservoirs, large rivers, estuaries, and coastal waters. As for EXAMS 2 (Burns et al.²) the TOXIWASP user has to accept the model's inability to connect the water body to a chemically contaminated atmosphere.