The Ministers' Declaration from the 2nd North Sea Conference recommended a goal to be set to diminish the discharge of hazardous substances via rivers by 50% over the next 10 years, e.g. to diminish the discharge of persistent halogenated compounds from pulp and paper mill effluents. The Paris Convention adopted this recommendation later.
Based on a study conducted for the EEC Commission, we have arrived at the following conclusions to fulfil this goal.
For historic reasons the regulation of the pulp and paper industry includes some parameters which may not be the most appropriate ones, e.g. BOD5 and AOX. To regulate the bleached pulp mills by AOX/TOC1 is not recommendable.
PCDD/PDDFs are very difficult to regulate at present. Regulation of polychlorinated phenolics (PoCPs) in the effluent may prove to be a valid indirect measure of TCDD-equivalents, but this has yet to be proven.
To ensure sufficient removal of hazardous compounds, we recommend that standards for TSS be stringent, as the major fraction of hazardous compounds is associated with suspended solids (including PoCPs and PCDD/PCDFs).
Effluent control should be based on pH, COD (Chemical Oxygen Demand using dichromic acid), TSS (total suspended solids) and PoCPs.
At present there are not sufficient data available to establish a regulation based on these parameters. So, further data should be obtained.