The fate of detergent surfactants in sewer systems

Abstract

The fate of detergent surfactants in the sewer can be studied both in laboratory tests and in field experiments. The laboratory studies can be used to determine the rate of disappearance of a test molecule as a function of residence time and estimate its half-life in a given habitat. In addition, important information can be obtained on the mechanism of degradation. Field studies can determine the actual environmental concentrations of surfactants in raw sewage which can then be compared with the expected concentration based on consumption volumes. The difference between the measured and predicted concentration provides an estimate for the disappearance of the test chemical during its travel in the sewer and confirms the results of the laboratory tests. This paper focuses on the fate of a number of important representative anionic, nonionic and cationic surfactants, in the sewer. The results of laboratory die-away studies showed that, in general, the half-life for disappearance in the sewer was in the order of hours for Fatty Alcohol Ethoxylate (AE), Fatty Alcohol Ethoxy Sulphate (AES) and Di-Ethyl-Ester Di-methyl-Ammonium Chloride (DEEDMAC). These laboratory findings for AES were confirmed by monitoring actual raw sewage reaching municipal sewage treatment plants. In addition, a field study demonstrated that the concentration of glucose amides (GA) is considerably reduced during its travel in the sewer. These complementary laboratory and field studies provide key information for the safety assessment of surfactants. They demonstrate that the concentration of surfactants can be significantly reduced in the sewer resulting in a rapid reduction of the environmental loading, which is particularly important in environmental situations where inadequate or no sewage treatment exists.

Study on industrial macropollutants discharges in Milan sewer system

“…Wastewater includes substances with chemical and biological reactivity, so that the sewer network is not only a collection and conveyance system, but also a chemical and biological reactor for transformation of wastewater (Hvitved-Jacobsen et al, 2013;Matthijs et al, 1995;Houhou et al, 2009;Thai et al, 2014;Mourato et al, 2003). Nowadays in-sewer processes should be considered for an "efficient, environmentally acceptable and sustainable transport of the sewage" (Hvitved-Jacobsen et al, 2013).…”

Estimating Cancer Risk Increment from Air Pollutant Exposure for Sewer Workers Working in an Industrial City

“…Sanitary sewer system air is influenced by regional environment type and sewage exhaust characteristics (Matos and Aires, 1995;Matthijs et al, 1995;Muezzinoglu, 2003;Paxeus, 1996;Veldkamp and Wiggers, 1997;Gostelow et al, 2001). Besides, sewer pipe environments are characterized owing to being enclosed and poorly ventilated.…”

Practical considerations optically sensing rhodamine WT in water impacted by municipal biosolids

“…Municipal biosolids have a vast range of chemical-biological constituents, significant amounts of solids (relatively high amounts of organic matter), and surfactant materials (Sommers 1977;Wild and Jones 1992;Matthijs et al 1995;Forster 2002;Lapen et al 2008) that could potentially confound optical sensing of RWT in water impacted by such products (Smart and Laidlaw 1977;Ellis et al 2003). Therefore, constraints associated with optical sensing RWT in liquid where biosolids occur might be functionally different relative to optically sensing RWT in water impacted by materials that have a less complex chemical and physical constituency.…”