T. Wind, J. Steber, J. Tolls
April 2, 2013
The gradually increasing detergents consumption in Germany since 1950 resulted in higher emissions of their ingredients to the environment. The first generation of mineral oil-based surfactants, tetrapropylene benzene sulfonate (TPS), exhibited poor biodegradability and caused public environmental concerns. These prompted Henkel in 1958 to start a systematic measurement of some main detergent constituents in the river Rhine in Germany. Since then, a number of monitoring activities regarding the determination of detergent ingredients concentrations and freights in rivers and waste water treatment plants (WWTP) followed. This paper summarizes 50 years experience at Henkel in monitoring of detergent ingredients in the aquatic environment. The long-term monitoring results on the river Rhine provides an impressive record of the development of the environmental burden by surfactant emissions and of the gradual improvement of river water quality over time. The reasons for the changes are discussed. Further monitoring activities on WWTPs have shown for the first time, that domestic wastewater treatment plants (DWTP) are similarly suitable for the removal of surfactants like municipal ones. The good removal of prominent organic detergent ingredients was shown by several time-proportional sampling campaigns in municipal WWTPs. Finally the positive impact of the modernisation of a municipal WWTP on the chemical and biological water quality on a small river creek is reported over the time period of 7 years. All of the reported studies indicate a low environmental burden due to the use of detergents ingredients today. The learnings from the different activities in environmental monitoring by Henkel have contributed to a solid understanding of the fate of detergent ingredients in the environment. This in turn was the prerequisite for development of reliable exposure prediction models. Today, Henkel employs both, environmental monitoring and modeling instruments, for assessing the environmental exposure of chemicals.