An extensive monitoring program was executed jointly by the Dutch Soap Association (NVZ) and the Dutch authorities. Flow proportional samples of raw, settled, and treated sewage from seven representative municipal sewage treatment plants were collected over three consecutive days. The samples were analyzed for detergent surfactants, including linear alkylbenzene sulfonate (LAS), alcohol ethoxylate (AE), alcohol ethoxylated sulfate (AES), alcohol sulfate, (AS) and soap, using state-of-the-art analytical methods. All surfactants were removed by more than 99% during sewage treatment. The concentrations of the surfactants in the treated sewage averaged 39 g/L for LAS, 6.2 g/L for AE, 6.5 g/L for AES, 5.7 g/L for AS, and 174 g/L for soap. These measured surfactant concentrations form the basis for the exposure element of the aquatic risk assessment for the surfactants studied. In addition, the field studies indicated that in-sewer removal can play a significant role in reducing the concentrations of surfactants entering the sewage treatment plant.

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Trace analysis of ethoxylated nonionic surfactants in samples of influent and effluent of sewage treatment plants by high-performance liquid chromatography. Kiewiet, A.Th.; van der Steen, J.M.D.; Parsons, J.R. Disclaimer/Complaints regulationsIf you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible. Yeast and hyphal walls of Candida albicans were extracted with sodium dodecyl sulfate (SDS). Some of the extracted proteins reacted with a specific ␤-1,6-glucan antiserum but not with a ␤-1,3-glucan antiserum. They lost their ␤-1,6-glucan epitope after treatment with ice-cold aqueous hydrofluoric acid, suggesting that ␤-1,6-glucan was linked to the protein through a phosphodiester bridge. When yeast and hyphal walls extracted with SDS were subsequently extracted with a pure ␤-1,3-glucanase, several mannoproteins that were recognized by both the ␤-1,6-glucan antiserum and the ␤-1,3-glucan antiserum were released. Both epitopes were sensitive to aqueous hydrofluoric acid treatment, suggesting that ␤-1,3-glucan and ␤-1,6-glucan are linked to proteins by phosphodiester linkages. The possible role of ␤-glucans in the retention of cell wall proteins is discussed.