Ursachen fuer die Schaumentwicklung auf kommunalen Klaeranlagen unter Beruecksichtigung des Beitrags oberflaechenaktiver Stoffe Teil2: Diskussion der Ergebnisse der chemischen Analyse

摘要

In the past few years, foam and scum have become more and more of a problem for municipal sewage treatment plants worldwide. Up to now, not all relevant causes for the formation of these foams have been identified. Little is known, in particular, about the impact of anthropogenic and biogenous surface-active agents, so-called surfactants, on foam formation in sewage treatment works. That is why in the framework of this study, whenever there was an increase In foam and scum formation, surfactants were determined both quantitatively, by using the German Standard Procedure for Testing Water, Was-tewater, and Sludge (DEV), as well as qualitatively, by using substance-specific mass spectrometry (MS) methods. Results showed that surface-active agents in biological wastewater treatment processes play a major role when it comes to foam formation in activated sludge tanks. Both anthropogenic as well as biogenous surfactants have an impact on increased foam formation. When determining surfactants pursuant to the standard DEV procedure, results turned out to be tower because surface-active agents were not recorded, or false positive results were obtained because of interferences between reagents and non-surfactant agents. MS methods, on the other hand, were able to identify these surfactants and made a substance-specific, quantitative assessment of these agents possible. Furthermore, MS methods were able to distinguish between biogenous and anthropogenic surfactants, and primary degradation products (metabolites) of anthropogenic surfactants were successfully detected and identified.