| Title | Techno-economic and environmental assessment of upgrading alternatives for sludge stabilization in municipal wastewater treatment plants |
| Abstract | In this work we have performed a feasibility study of two upgrading alternatives for sewage sludge stabilization aimed to the reduction of the produced sludge and to the improvement of its qualitative characteristics with respect to its final destination: agricultural use or incineration. The first upgrading (1) proposes the separated thickening: primary sludge is thickened by gravity while dynamic thickening is applied to secondary sludge. The second upgrading (2) introduces a post-aerobic digestion stage (after the anaerobic one), in addition to separate thickening. Technical-economic and environmental assessments have been performed in comparison to a conventional wastewater treatment plant, which operates with gravity thickening and anaerobic digestion of mixed sludge. In the post-aerobic stage, operated with intermittent aeration, additional volatile solids removal of 45% and nitrification and denitrification efficiencies of 97% and 70%, respectively, were achieved. Both upgrading alternatives gained a positive technical evaluation with the only exceptions of the item "Thermal energy consumption" in upgrading 1 for agricultural reuse, and, to a minor extent, the "Energy available for external recovery" for incineration in both upgrading options. Cost analysis showed that the two upgrading alternatives are generally cheaper than the conventional plant, even if the results are dependent on local conditions, which have to be considered. Results of the environmental assessment showed that the upgrades with incineration perform better than the reference for all impact categories except freshwater eutrophication, with upgrading 2 as the best option. For the agricultural use, different results were obtained for the different impact categories with critical aspects mainly related to phosphorus and ammonia emissions for upgrading 1. |
| Source | Journal of cleaner production 112, pp. 3106–3115 |
| Keywords | Decision support systemEnvironmental assessmentLife cycle assessmentSludge stabilizationTechno-economic assessmentWastewater treatment plant upgrading |
| Journal | Journal of cleaner production |
| Editor | Butterworth-Heinemann,, Oxford, Regno Unito |
| Year | 2016 |
| Type | Articolo in rivista |
| DOI | 10.1016/j.jclepro.2015.10.017 |
| Authors | Tomei M.C.; Bertanza G.; Canato M.; Heimersson S.; Laera G.; Svanstrom M. |
| Text | 354814 2016 10.1016/j.jclepro.2015.10.017 Scopus 2 s2.0 84958125202 ISI Web of Science WOS WOS 000368207400090 Decision support system Environmental assessment Life cycle assessment Sludge stabilization Techno economic assessment Wastewater treatment plant upgrading Techno economic and environmental assessment of upgrading alternatives for sludge stabilization in municipal wastewater treatment plants Tomei M.C.; Bertanza G.; Canato M.; Heimersson S.; Laera G.; Svanstrom M. Water Research Institute, C.N.R., via Salaria km 29.300 C.P. 10, Monterotondo Stazione, Rome, 00015, Italy; Department of Civil, Environmental, Architectural Engineering and Mathematics, University of Brescia, via Branze 43, Brescia, 25123, Italy; Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Goteborg, SE 412 96, Sweden; Water Research Institute, C.N.R., viale De Blasio 5, Bari, 70132, Italy In this work we have performed a feasibility study of two upgrading alternatives for sewage sludge stabilization aimed to the reduction of the produced sludge and to the improvement of its qualitative characteristics with respect to its final destination agricultural use or incineration. The first upgrading 1 proposes the separated thickening primary sludge is thickened by gravity while dynamic thickening is applied to secondary sludge. The second upgrading 2 introduces a post aerobic digestion stage after the anaerobic one , in addition to separate thickening. Technical economic and environmental assessments have been performed in comparison to a conventional wastewater treatment plant, which operates with gravity thickening and anaerobic digestion of mixed sludge. In the post aerobic stage, operated with intermittent aeration, additional volatile solids removal of 45% and nitrification and denitrification efficiencies of 97% and 70%, respectively, were achieved. Both upgrading alternatives gained a positive technical evaluation with the only exceptions of the item Thermal energy consumption in upgrading 1 for agricultural reuse, and, to a minor extent, the Energy available for external recovery for incineration in both upgrading options. Cost analysis showed that the two upgrading alternatives are generally cheaper than the conventional plant, even if the results are dependent on local conditions, which have to be considered. Results of the environmental assessment showed that the upgrades with incineration perform better than the reference for all impact categories except freshwater eutrophication, with upgrading 2 as the best option. For the agricultural use, different results were obtained for the different impact categories with critical aspects mainly related to phosphorus and ammonia emissions for upgrading 1. 112 Published version http //www.scopus.com/inward/record.url eid=2 s2.0 84958125202 partnerID=q2rCbXpz Techno economic and environmental assessment of upgrading alternatives for sludge stabilization in municipal wastewater treatment plants Tipo documento pdf file Permessi per l accesso al file Riservato su sistemi CNR previa autenticazione JCLP Routes2016.pdf Articolo in rivista Butterworth Heinemann, 0959 6526 Journal of cleaner production Journal of cleaner production J. clean. prod. Journal of cleaner production. giuseppe.laera LAERA GIUSEPPE mariaconcetta.tomei TOMEI MARIA CONCETTA TA.P07.002.005 Rimozione di composti xenobiotici da acque di scarico |
