Phase equilibrium measurements in systems of CO2 and fish oil fatty acid ethyl esters (FAEEs) at 70 degrees C are presented. Three different mixtures were investigated, a natural FAEE mixture from the oil of the sand eel (Ammodytes sp.), a urea fractionated mixture prepared from the natural FAEE mixture, and a concentrate of omega 3 FAEEs. The measurements were performed in a static type apparatus making it possible to sample both the vapor and liquid phases. The results presented include solubilities and equilibrium ratios. The experimental results are used to evaluate a process for the recovery of C20:5 omega 3 (EPA) and C22:6 omega 3 (DHA) at 70 degrees C.

The selection of chromatographic techniques in determination of physicochemical properties over conventional static methods is due to quick data turnaround with such systems and readily available commercial equipment. Supercritical fluid chromatography is and can be applied to physicochemical property estimation and its use for this purpose has received considerable attention especially more recently. Moreover, some techniques that are used for determining properties of gas-solid systems using gas chromatography can easily be applied to supercritical fluid chromatography.

In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method is presented. SFA aims at providing the relevant information for a country’s overall management strategy regarding single substances or coherent groups of substances. This article is dedicated to the presentation of a threestep general framework for SFA-type studies, and elaborates on its first step the systems definition. Attention is given to the definition of the external and internal system boundaries, the categorization of the system’s elements, aspects of materials choice, time, and space, and how these depend on the aim of the conducted study. Moreover, a broader discussion is started on the need for standardization of materials flow studies in general.In the tradition of the study of materials flows through society, the Substance Flow Analysis (SFA) method and its software tool SFINX are presented. SFA aims at providing the relevant information for a country’s overall management strategy regarding single substances or coherent groups of substances. Three modelling techniques and their possibilities and limitations are discussed: Bookkeeping, static modelling, and dynamic modelling. The computer program SFINX can be used for varoius purposes: (1) to obtain an overview of stocks and flows of a substance in, out and through a nation’s economy and environment for a specific year, (2) to trace the origins of specific pollution problems, and (3) to estimate the effectiveness of certain abatement measures. Each application has its own requirements with regard to data and modelling.

The basic idea of LCA is that all environmental burdens connected with a product or service have to be assessed, back to the raw materials and down to waste removal. Therefore, the term “Life Cycle Assessment” is more precise than the German “Ökobilanz” or the French “écobilan”. This basic idea is undoubtedly true, and LCA is the only environmental assessment tool which avoids positive ratings for measurements which only consists in the shifting of burdens.In the years from 1990 to 1993, SETAC and SETAC-Europe shaped the development of LCA in a series of important workshops culminating in the “Code of Practice” of 1993. The results of these workshops can be illustrated by the famous SETAC-triangle. It shows the basic structure which is now underlying the standardizing activities of ISO: 1. Goal definition and scoping, 2. Inventory analysis, 3. Impact assessment, 4. Improvement assessment.The structure recently defined by ISO differs from the SETAC structure only in the last element which is called “Interpretation” in the international standard 14040. According to ISO, “Improvement Assessment” is only one of the many activities which may follow LCA but is not part of the true analysis.The components of an LCA are described and interpreted in detail, SETAC vs. ISO. Recent developments and activities initiated by ISO, SPOLD and other organisations complete the review.

The equilibrium partitioning theory may be used to describe the partitioning of nonionic organic chemicals between water, sediment, and aquatic biota. This paradigm was employed to compare the relative magnitudes of organic carbon-normalized sediment-quality criteria that are intended to protect either benthic organisms from the direct toxic effects of sediment-associated chemicals or humans from the indirect health effects posed by the ingestion of contaminated aquatic animals. Comparison of calculated sediment-quality criteria for a variety of hydrophobic chemicals suggests that human health-based end points often result in more restrictive criteria than aquatic effects-based values. Review of published field data indicates that the equilibrium partitioning paradigm may, depending on contaminant class, either over- or underestimate the extent to which sediment-associated contaminations are bioaccumulated. Despite the limitations of adopting this simple theory for criteria development, calculations reveal that regulatory decisions involving sediments contaminated with such chemicals may be dictated by human health concerns if current risk assessment methodologies are applied.

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.

The ability of a plant cytochrome P450 to bind and metabolise plant endogenous molecules and xenobiotics was investigated. The work was performed on the yeast-expressed CYP73A1, a cinnamate 4-hydroxylase isolated fromHelianthus tuberosus. CYP73 controls the general phenylpropanoid pathway and is likely to be one of the most abundant sources of P450 in the biosphere. The enzyme shows a high selectivity toward plant secondary metabolites. Nevertheless, it oxygenates several small and planar xenobiotics with low efficiency, including an herbicide (chlorotoluron). One xenobiotic molecule, 2naphthoic acid, is hydroxylated with an efficiency comparable to that of the physiological substrate. This reaction was used to devise a fluorimetric test for the rapid measurement of enzyme activity. A series of herbicidal molecules (hydroxybenzonitriles) are shown to bind the active site without being metabolised. These molecules behave as strong competitive inhibitors of CYP73 with a Kᵢ in the same micromolar range as the Kₘ for the physiological substrate. It is proposed that their inhibition of the phenylpropanoid pathway reinforces their other phytotoxic effects at the level of the chloroplasts. All our results indicate a strong reciprocal interaction between plant P450s and xenobiotics.

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.