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Journal of Environmental Accounting and Management
António Mendes Lopes (editor), Jiazhong Zhang(editor)
António Mendes Lopes (editor)

University of Porto, Portugal


Jiazhong Zhang (editor)

School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China

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Alternative Options for Sewage Sludge Treatment and Process Improvement Through Circular Patterns: LCA-based Case Study and Scenarios

Journal of Environmental Accounting and Management 3(1) (2015) 77--85 | DOI:10.5890/JEAM.2015.03.007

Salvatore Mellino$^{1}$, Gaetano Protano$^{1}$, Elvira Buonocore$^{1}$, Giuseppe De Angelis$^{2}$, Gengyuan Liu$^{2}$, Linyu Xu$^{2}$, Sergio Ulgiati$^{1}$,$^{2}$

$^{1}$ Department of Sciences and Technologies, Parthenope University of Naples, Centro DirezionaledIsola C4, 80143 Naples, Italy

$^{2}$ State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Beijing Normal University, Beijing 100875, China

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In the pursuit of more sustainable wastewater treatment (WWT) processes, life cycle assessment (LCA) can be used as a valuable tool to evaluate the environmental impacts associated to WWT plants. In this study LCA is applied to compare the environmental performance of three scenarios for sludge disposal in a WWT plant located in southern Italy. The first business-as-usual scenario is based on the actual sludge management performed within the case-study plant: after mechanical treatment, dewatered sludge is transported by truck to a landfill for final disposal. The second scenario assumes a circular pattern, with anaerobic fermentation of sludge to biogas, and biogas use for electricity and heat cogeneration: electricity is feedback to WWT, while heat is used for digestate drying, in addition to thermal energy from previously recovered waste cooking oil (WCO). The third scenario suggests an improved circular pat-tern where the dried sludge is further gasified for syngas production and syngas is added to biogas for heat and electricity production. Scenario results suggest that increased circularity through recycling would be capable of reducing both the contribution to environmental impact categories and the fossil energy consumption up to 50%.


Sergio Ulgiati, Linyu Xu, Gengyuan Liu and Giuseppe De Angelis gratefully acknowledge the support from the National Science & Technology Pillar Program, China (No. 2012BAC05B02). Sergio Ulgiati also acknowledges the contract by the School of Environment, Beijing Normal University, within the framework of the National “One Thousand Foreign Experts Plan”, and the Fundamental Research Funds for the Central Universities.


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