Xenobiotics: Dispersal of LAS, nonylphenols and phthalates in the environment

A new report by the National Environmental Research Institute examines how three important groups of xenobiotics are dispersed in a typical Danish catchment area. The report describes how LAS, phthalates and nonylphenols are removed at Roskilde Wastewater Treatment Plant and how Di-(2ethylhexyl)-phthalate (DEHP) spreads from sources to wastewater treatment plants, fields and estuaries.

The study shows that a modern Danish wastewater treatment plant removes the majority of these xenobiotics from wastewater. Thus the removal rate was 85–90% with all three groups of substances. Most of what is removed is degraded and only between 15% and 35% of the wastewater content of these xenobiotics ends up in the sewage sludge.

The highest concentrations of the xenobiotics are found in arable land treated with large amounts of sewage sludge, as well as in estuary sediment. The concentrations are so low, though, that the presence of the substances is not expected to have any biological effects.

The main source of contamination of Roskilde Fjord with DEHP and other phthalates are watercourse transport and atmospheric deposition. The phthalates predominantly derive from their uses as plasticizer in PVC.

In the estuaries the phthalates bind to particles that are deposited in the sediment, where the half-life is around 11 years. The phthalates therefore accumulate in the upper 10–15 cm of the sediment.

Further information: Patrik Fauser, National Environmental Research Institute. Phone: +45 4630 1236. E-mail: paf@dmu.dk or Jørgen Vikelsøe, National Environmental Research Institute. Phone: +45 4630 1245. E-mail: jv@dmu.dk

The report “Phthalates and nonylphenols in Roskilde Fjord. A field study and mathematical modelling of transport and fate in water and sediment. The aquatic environment” by J .Vikelsøe et al. (NERI Technical Report No. 339, 2001) is available at:http://www.dmu.dk/1_viden/2_Publikationer/3_fagrapporter


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