Morales Marjorie, Arp Hans Peter H, Castro Gabriela, Asimakopoulos Alexandros G, Sørmo Erlend, Peters Gregory, Cherubini Francesco
Industrial Ecology Programme (IndEcol), Department of Energy and Process Engineering, Norwegian University of Science and Technology (NTNU), 7034 Trondheim, Norway.
Department of Chemistry, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway; Norwegian Geotechnical Institute (NGI), 0886 Oslo, Norway.
J Hazard Mater. 2024 May 15;470:134242. doi: 10.1016/j.jhazmat.2024.134242. Epub 2024 Apr 10.
The high moisture content and the potential presence of hazardous organic compounds (HOCs) and metals (HMs) in sewage sludge (SS) pose technical and regulatory challenges for its circular economy valorisation. Thermal treatments are expected to reduce the volume of SS while producing energy and eliminating HOCs. In this study, we integrate quantitative analysis of SS concentration of 12 HMs and 61 HOCs, including organophosphate flame retardants (OPFRs) and per- and poly-fluoroalkyl substances (PFAS), with life-cycle assessment to estimate removal efficiency of pollutants, climate change mitigation benefits and toxicological effects of existing and alternative SS treatments (involving pyrolysis, incineration, and/or anaerobic digestion). Conventional SS treatment leaves between 24 % and 40 % of OPFRs unabated, while almost no degradation occurs for PFAS. Thermal treatments can degrade more than 93% of target OPFRs and 95 % of target PFAS (with the rest released to effluents). The different treatments affect how HMs are emitted across environmental compartments. Conventional treatments also show higher climate change impacts than thermal treatments. Overall, thermal treatments can effectively reduce the HOCs emitted to the environment while delivering negative emissions (from about -56 to -111 kg CO-eq per tonne of sludge, when pyrolysis is involved) and producing renewable energy from heat integration and valorization.
污水污泥（SS）中的高含水量以及潜在存在的有害有机化合物（HOCs）和金属（HMs），对其循环经济增值构成了技术和监管方面的挑战。热处理有望减少污水污泥的体积，同时产生能源并消除有害有机化合物。在本研究中，我们将对12种金属和61种有害有机化合物（包括有机磷酸酯阻燃剂（OPFRs）和全氟和多氟烷基物质（PFAS））在污水污泥中的浓度进行定量分析，与生命周期评估相结合，以估算现有和替代污水污泥处理方法（包括热解、焚烧和/或厌氧消化）的污染物去除效率、缓解气候变化的效益以及毒理学影响。传统的污水污泥处理方法会使24%至40%的有机磷酸酯阻燃剂无法得到有效处理，而全氟和多氟烷基物质几乎不会降解。热处理可以降解超过93%的目标有机磷酸酯阻燃剂和95%的目标全氟和多氟烷基物质（其余部分排放到废水中）。不同的处理方法会影响金属在不同环境介质中的排放方式。传统处理方法对气候变化的影响也比热处理更大。总体而言，热处理可以有效减少排放到环境中的有害有机化合物，同时实现负排放（当涉及热解时，每吨污泥约为-56至-111千克二氧化碳当量），并通过热整合和增值产生可再生能源。
