Phthalates and Nonylphenols in Roskilde Fjord

200NPNPDEConcentration, ng/g d.m.150100500Depth, cm0 5 10 15 20 25Age, yTwentyFortySixty EightyFigure 22NP and NPDE in sediment coreFor NP and NPDE, a very different and interesting pattern is observed inFigure 22, which display two pronounced maxima occurring at depths of7 and 18 cm, respectively. These maxima coincides approximately – butnot precisely - with those observed for DEHP and BBP. A probable explanationfor this observation may be a long-term variation in the consumptionof NPE, since these by an agreement between the detergent industryand the environmental authorities has been phased out in 1989.For the variation with depth, another factor of significance is the new andmore efficient WWTP, taken into operation in 1995. The current efficiencyis described by Fauser et al. (2000).For a more complete understanding of the variation with depth, a modeltaking care of the transport, adsorption and desorption as well as degradationwill be described in section 6.1.4. The model treats only the fateof DEHP, being the most abundant substance.5.3 Streams and lake5.3.1 WaterIn Table 17 the abundances of the substances in the stream and the lakewater are shown as mean and standard deviation of all samples45