Refinery BREF related environmental parameters for aqueous discharges from refineries in Europe

Report No. 2/10: This report is prepared as part of the Industry input to the revision process for the Refinery Best Available Technique (BAT) Reference Document (BREF) that is being undertaken by the European IPPC Bureau.

Five effluent parameters were selected for consideration on the basis that these are addressed in the current refinery BREF. These are Total Hydrocarbon Content (THC), Total Nitrogen (TN), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Total Suspended Solids (TSS). The data are presented in this report document as cumulative frequency plots of the measured concentrations (mg/l), as reported and where possible the associated determined loads in grammes per tonne of Crude oil processed.

The analysis reveals that there is no obvious correlation between concentrations and loads of these five parameters and type of wastewater treatment process. Further analysis indicates that the level of complexity of a refinery (as characterised by the industry standard Nelson Complexity Index) have no bearing on the quality of the final effluent.

It is, therefore, concluded that it is not possible, from this set of data, to specify a level of effluent quality that can be achieved or be expected from these two aspects of refinery technology. It is more likely that effluent quality is determined by a complex combination of operational process and waste-stream management parameters and that management of these on a site-specific basis is likely to present the most effective way of meeting effluent quality objectives.