Oil refinery experience with the assessment of refinery effluents and receiving waters using biologically based methods.

The trend in discharges of petroleum-related substances from refineries in Europe shows a consistent picture of declining emissions, since first measured in 1969. This decline coincides with enhanced internal capture or recycling procedures and increasing use of physical and biological treatments. At the same time, and partly in response to legislative drivers, there has been an increase in the use of chronic (long-term) toxicity tests and alternative methods for assessing the quality of effluent discharges.

Environmental properties of long chain alcohols. Part 1: Physicochemical, environmental fate and acute aquatic toxicity properties.

This paper summarises the physicochemical, biodegradation and acute aquatic ecotoxicity properties of long chain aliphatic alcohols. Properties of pure compounds are shown to follow somewhat predictable trends, which are amenable to estimation by quantitative structure-activity relationships ((Q)SARs). This allows predictions of data relating to human and environmental safety profiles and patterns.

Toxicity reduction evaluation, toxicity identification evaluation and toxicity tracking in direct toxicity assessment.

Toxicity reduction evaluations (TREs) in the River Esk and Lower Tees Estuary were based on the approach described by USEPA, but adapted to tackle the specific problems of the two sites. A combination of toxicity tracking and toxicity identification evaluation (TIE) was used at both locations to enhance the understanding of source and type of toxicants present. The assessment of toxicity at Langholm focussed on pesticides present in the sewerage network.

Estimating spatial patterns of effluent exposure concentrations in direct toxicity assessment studies.

Hydrodynamic models of differing scale and complexity were used to estimate spatial patterns of effluent concentration in discharge plumes in the River Esk and the Lower Tees Estuary. The output from the Tees model was used, in conjunction with measurements of toxicity determined in short-term oyster embryo tests, to predict contours/zones of toxicity in the estuary associated with effluent discharges from four chemical processing sites. One of the discharges also combined the input from a municipal sewage treatment works.