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© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.

Abstract

The management and disposal of wastewater treatment sludge can be a costly and resource-intensive process. To provide a cost-effective and sustainable alternative, Sludge Treatment Wetlands (STW) have emerged as a viable solution for enhancing sludge quality through dewatering and biodegradation. In this study, the effectiveness of a full-scale STW for stabilizing and dewatering digested microalgal biomass from a domestic and agricultural wastewater treatment system was evaluated. The properties of the treated digestate in the STW were assessed after 35 weeks of operation and a resting period of 4 weeks. The dry matter content was found to be 12.8%, and the average macronutrient content was K: 3.8 mg/g DW, P: 4.9 mg/g DW, and Ca: 95 mg/g DW. The highest contents of micronutrients were for Fe: 7.8 mg/g DW and Mg: 7.6 mg/g DW, while heavy metals and pathogen contents were below the EC limits for sewage sludge reuse in agriculture. The STW was found to be a cost-effective and environmentally friendly option for treating mixed wastewater-based sludge for land application. The STW outperformed reference systems using centrifuge dewatering techniques, particularly in terms of eutrophication potential and acidification potential. However, the STW’s economic performance was slightly worse than that of the dewatering system in terms of unit production cost. This study is the first in the literature to investigate the use of STW for treating digested microalgae and its possible reuse in arable land, suggesting that STW infrastructures have great potential for the development of sustainable and eco-friendly sludge treatment technologies.

Details

Title
Sludge Treatment Wetland for Treating Microalgae Digestate Grown in Agricultural Runoff: A Technical, Economic, and Environmental Assessment
Author
Gonzalez-Flo, Eva 1   VIAFID ORCID Logo  ; Ortiz, Antonio 2 ; Arias, Carlos A 3   VIAFID ORCID Logo  ; Díez-Montero, Rubén 4 ; Kohlheb, Norbert 5 ; Ulf-Henning Schauser 6 ; García, Joan 2   VIAFID ORCID Logo  ; Gregersen, Peder K S 7 

 GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Escola d’Enginyeria de Barcelona Est (EEBE), Universitat Politècnica de Catalunya-BarcelonaTech, Av. Eduard Maristany 16, Building C5.1, E-08019 Barcelona, Spain 
 GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain 
 Department of Biology, Aarhus University, 8000 Aarhus, Denmark 
 GEMMA-Group of Environmental Engineering and Microbiology, Department of Civil and Environmental Engineering, Universitat Politècnica de Catalunya-BarcelonaTech, c/Jordi Girona 1-3, Building D1, E-08034 Barcelona, Spain; GIA-Group of Environmental Engineering, Department of Water and Environmental Sciences and Technologies, Universidad de Cantabria, Avda. Los Castros s/n, 39005 Santander, Spain 
 Helmholtz-Zentrum Fuer Umveltforschung GMBH–UFZ (“UFZ”), 04318 Leipzig, Germany 
 N.A.T., Ingenieurökologisches Planungsbüro, 24340 Eckernförde, Germany 
 Center for Recirkulering v/Peder S, 6870 Gregersen Ölgod, Denmark 
First page
2159
Publication year
2023
Publication date
2023
Publisher
MDPI AG
e-ISSN
20734441
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2829889757
Copyright
© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.