Schinkel Lena, Lara-Martín Pablo A, Giger Walter, Hollender Juliane, Berg Michael
Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.
Department of Physical Chemistry, Faculty of Marine and Environmental Sciences, University of Cadiz, Puerto Real 11510, Spain.
Sci Total Environ. 2022 Feb 20;808:151361. doi: 10.1016/j.scitotenv.2021.151361. Epub 2021 Nov 20.
Surfactants are high-production-volume chemicals that are among the most abundant organic pollutants in municipal wastewater. In this study, sewage sludge samples of 36 Swiss wastewater treatment plants (WWTPs), serving 32% of the country's population, were analyzed for major surfactant classes by liquid chromatography mass spectrometry (LC-MS). The analyses required a variety of complementary approaches due to different analytical challenges, including matrix effects (which can affect adduct ion formation) and the lack of reference standards. The most abundant contaminants were linear alkylbenzene sulfonates (LAS; weighted mean [WM] concentration of 3700 μg g dry weight), followed by secondary alkane sulfonates (SAS; 190 μg g). Alcohol polyethoxylates (AEO; 8.3 μg g), nonylphenol polyethoxylates (NPEO; 16 μg g), nonylphenol (NP; 3.1 μg g), nonylphenol ethoxy carboxylates (NPEC; 0.35 μg g) and tert-octylphenol (tert-OP, 1.8 μg g) were present at much lower concentrations. This concentration pattern agrees with the production volumes of the surfactants and their fates in WWTPs. Branched AEO homologues dominated over linear homologues, probably due to higher persistence. Sludge concentrations of LAS, SAS, and NP were positively correlated with the residence time in the anaerobic digester. Derivation of the per capita loads successfully revealed potential industrial/commercial emission sources. Comparison of recent versus historic data showed a decrease in NPEO and NP levels by one or two orders of magnitude since their ban in the 1980s. By contrast, LAS still exhibit similar concentrations compared to 30 years ago.
表面活性剂是产量高的化学品，是城市废水中最丰富的有机污染物之一。在本研究中，对服务于该国32%人口的36个瑞士污水处理厂（WWTPs）的污泥样本进行了液相色谱质谱联用（LC-MS）分析，以检测主要的表面活性剂类别。由于存在不同的分析挑战，包括基质效应（可影响加合物离子形成）和缺乏参考标准品，这些分析需要多种互补方法。最主要的污染物是直链烷基苯磺酸盐（LAS；干重加权平均[WM]浓度为3700μg/g），其次是仲烷基磺酸盐（SAS；190μg/g）。醇聚氧乙烯醚（AEO；8.3μg/g）、壬基酚聚氧乙烯醚（NPEO；16μg/g）、壬基酚（NP；3.1μg/g）、壬基酚乙氧基羧酸盐（NPEC；0.35μg/g）和叔辛基酚（叔-OP，1.8μg/g）的浓度要低得多。这种浓度模式与表面活性剂的产量及其在污水处理厂中的归宿一致。支链AEO同系物比直链同系物占主导地位，可能是由于其持久性更高。LAS、SAS和NP的污泥浓度与厌氧消化器中的停留时间呈正相关。人均负荷的推导成功揭示了潜在的工业/商业排放源。近期数据与历史数据的比较表明，自20世纪80年代被禁止以来，NPEO和NP的水平下降了一两个数量级。相比之下，LAS的浓度与30年前仍相似。
