During the last decade use of supercritical fluids in environmental applications have increased due to their unique properties. Technologies have already been developed for extraction of organic compounds from aqueous and solid environmental matrices and research on extraction of metals is in progress. In most applications, supercritical carbon dioxide is the solvent of choice because it is environmentally benign, safe, and abundant at a low cost. Recent research focus is on use of supercritical fluids as separation and reaction media. Especially as the reaction media, supercritical fluids offer properties that may significantly affect reaction rates and selectivities. The most important property is the control of solvency power through density. This aspect may be used to eliminate side reactions, exceed thermodynamic yield limitations, or control polymer chain lengths and molecular weight distributions. In the separations area, supercritical fluids can be exploited for adsorptive separations of structurally very similar compounds and for selective extraction of thermally labile compounds from natural products.

“Freely-dissolved” aqueous concentrations of 9 trichlorothrough heptachlorobiphenyls are reported, alongside those in sediments and fish from the R. Severn. For most congeners, BSAFs and lipid-normalised BAFs for pike exceed those for eels. Whilst R. Severn BSAFs are comparable with those for L. Ontario trout and New Bedford Harbour flounder, R. Severn BAFs are 1–2 orders of magnitude lower. This discrepancy may be due to inter-species variability, as well as inter-laboratory differences between operational definitions of “freely-dissolved” aqueous PCB, underlining that the same operational definition must be employed if R. Severn BAFs are extrapolated elsewhere. For eels, correlation of Log Kᵒʷ with Log BAF is better (R² = 0.66) than with BSAF (R² = 0.13), whilst similar correlation coefficients (R² = 0.81 and 0.82) were observed for pike. When Log Kᵒʷ is plotted against BSAF and Log BAF for both species combined, better correlation is observed for Log BAF (R² = 0.65), than BSAF (R² = 0.36). For both species combined, the observed relationship between Log BAF and Log Kᵒʷ for trichloro-through heptachlorobiphenyls is: Log BAF = 0.96 * Log Kᵒʷ −0.24.

Environmental properties of organic matter contained halogen and sulfur were studied in sediments of bleached kraft pulp mill effluent (BKME) recipient lakes and 2 m³ outdoor enclosures (mesocosms). The BKME contributed to 1% (v/v) of the total water flow in the lake downstream of the pulp mill where the sediments contained 1.7 to 4 mg of tetrahydrofuran extractable organic halogen (EOX-Cl) and 0.6 to 0.8 mg of tetrahydrofuran extractable organic sulfur (EOS-S) g⁻¹ of organic matter. Upstream sediment contained 0.03 mg of EOXCl and 0.7 mg of EOS-S g⁻¹ of organic matter. EOX was a better indicator for the influence of BKME in the recipient sediment than EOS. The polarity of BKME contained EOX corresponded to log Kᵒʷ of < 1, and that of the downstream sediment contained EOX to > 4.5. HP-SEC analysis of the molecular weight distribution (MWD) of the EOX showed a peak between 300 to 600 g mol⁻¹ for the BKME and between 1000 to 2000 g mol⁻¹ for the downstream sediment. The MWD of the BKME contained EOS peaked at 300 to 1000 g mol⁻¹, and that of the downstream sediment contained EOS at 1000 to 5000 g mol⁻¹. These results indicate that BKME contained organic halogen and sulfur undergo major structural transformations when incorporated into sediment. The biota-to-sediment accumulation factor (BSAF) of EOX from sediments formed downstream of the mill and in the mesocosms to the lipids ofLumbriculus variegatus was 0.4 to 0.7. This is of a similar order of magnitude to the BSAF reported for 2,3,7,8-tetrachlorodibenzop-dioxin and 2,3,7,8-tetrachlorodibenzofuran.

Curricula for Environmental Chemistry have become established, not only recently in the US, but also in European countries. This article discusses the current situation in Germany. German students can make their choice among four possibilities: 1. full-time studies in environmental sciences, 2. classical chemistry program followed by an environmental supplementary program, 3. classical chemistry program with a mandatory choice between environmental or ecological chemistry, 4. classical introductory chemistry followed by a major course of studies in environmental subjects.The background of this development is the attempt to reform the German chemical curricula (Würzburger Modell) which emphasizes practice and the environmetally related subjects.

Extraction of dried sage and coriander seed was carried out using near critical carbon dioxide to obtain oleoresin, non-volatile oil and essential oil extracts. Extractions were carried out in both a 4 litre and 75 litre extraction plant, to determine the effects of the particle size, carbon dioxide flow rate, bulk density and extraction temperature and pressure on the yield and extraction time. The rate of extraction of oleoresin from sage depended only on the particle diameter, and was limited by intra-particle diffusion. The rate of extraction of non-volatile oil from coriander seed was limited both by its solubility in carbon dioxide, and intra-particle diffusion. The results were satisfactorily correlated with a mathematical model. Scale-up calculations were performed to enable the economics of the extraction process to be evaluated.