Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA.
Department of Environmental and Sustainable Engineering, University at Albany, State University of New York, 1400 Washington Avenue, Albany, NY, 12222, USA.
Environ Pollut. 2021 Sep 15;285:117276. doi: 10.1016/j.envpol.2021.117276. Epub 2021 Apr 30.
Sewage sludge has become a sink of per- and polyfluoroalkyl substances (PFAS) due to the ineffectiveness of PFAS removal during conventional activated sludge treatment process. In this study, we evaluated the performance of an enhanced method for PFAS extraction from sewage sludge. Significant matrix effect was observed for samples derived from untreated and hydrothermally treated sludge. Extra steps for removing potential interferences were thus needed to reduce these matrix effects and improve the accuracy of PFAS quantification. Hydrothermal treatment at 165 °C for 0.5/2 h and 250 °C for 0.5 h increased the concentration of extractable PFAAs in treated sludge. Increasing the temperature to 300 °C resulted in complete degradation of PFCAs after hydrothermal processing, but still increased the concentrations of PFSAs and PFAA precursors. The concentration increase could be due to the conversion of PFAA precursors to PFAAs and the release of PFAAs from sewage sludge during thermal treatment. Ca(OH) addition to hydrothermal treatment completely removed PFAA precursors but significantly increased the extractable PFAAs, except PFHpA and PFHxS, at 165 °C and all PFSAs at 300 °C. This study revealed the difficulties in extracting and quantifying PFAS in sludge and demonstrated the need for further research on finding suitable solutions for complete removal or destruction of PFAS in highly heterogeneous sewage sludge.
由于传统活性污泥处理过程中无法有效去除全氟和多氟烷基物质 (PFAS)，因此污水污泥已成为 PFAS 的汇。在这项研究中，我们评估了从污水污泥中提取 PFAS 的增强方法的性能。未经处理和水热处理的污泥衍生样品中观察到明显的基质效应。因此，需要额外的步骤来去除潜在的干扰，以减少这些基质效应并提高 PFAS 定量的准确性。在 165°C 下处理 0.5/2 小时和在 250°C 下处理 0.5 小时会增加处理污泥中可提取的 PFAAs 浓度。将温度升高到 300°C 会导致水热处理后 PFCAs 完全降解，但仍会增加 PFSAs 和 PFAA 前体的浓度。浓度增加可能是由于 PFAA 前体转化为 PFAAs 以及在热处理过程中从污水污泥中释放 PFAAs 所致。在水热处理中添加 Ca(OH)2 可完全去除 PFAA 前体，但在 165°C 时会显著增加除 PFHpA 和 PFHxS 以外的可提取 PFAAs，以及在 300°C 时所有 PFSAs 的浓度。本研究揭示了从污泥中提取和定量 PFAS 的困难，并表明需要进一步研究以寻找完全去除或破坏高度异质污水污泥中 PFAS 的合适解决方案。
