The aim of this study was to evaluate the agricultural reuse of the digestate products (DPs) obtained from mesophilic anaerobic co-digestion of different organic wastes (sludge, cattle slurries and organic fraction of municipal solid wastes). At this scope, the content of faecal indicators and pathogens as well as the heavy metal concentration of DPs was monitored. The fertilizing performance of the DPs was also investigated. Co-digestion trials were performed using laboratoryscale (LRs) and pilot-scale reactors (PRs). The microbiological analysis of DPs showed the common presence of Salmonella and an inadequate reduction of indicator organisms during the digestion process, both in the LRs and the PRs. Moreover, the presence of pathogens (e.g. Listeria monocytogenes) in some DP samples highlighted the importance of the microbiological quality evaluation of the DPs to study the possible health risks for consumer. In several samples of DPs, the Cu, Ni and Zn contents exceeded the maximum admissible concentration for fertilizer, as specified by Italian law, suggesting possible environmental contamination if the DPs are used for agricultural purposes. Considering the fertilizing performance, significant differences of growth parameters were observed only for the DPs that were produced by LRs. In conclusion, this work can be considered as a preliminary study to evaluate the possible agricultural reuse of the digestate obtained from different organic wastes.

Agricultural Reuse of the Digestate from Anaerobic Co-Digestion of Organic Waste: Microbiological Contamination, Metal Hazards and Fertilizing Performance

BONETTA, SILVIA;BONETTA, Sara;GILLI, Giorgio;CARRARO, Elisabetta
2014

Abstract

The aim of this study was to evaluate the agricultural reuse of the digestate products (DPs) obtained from mesophilic anaerobic co-digestion of different organic wastes (sludge, cattle slurries and organic fraction of municipal solid wastes). At this scope, the content of faecal indicators and pathogens as well as the heavy metal concentration of DPs was monitored. The fertilizing performance of the DPs was also investigated. Co-digestion trials were performed using laboratoryscale (LRs) and pilot-scale reactors (PRs). The microbiological analysis of DPs showed the common presence of Salmonella and an inadequate reduction of indicator organisms during the digestion process, both in the LRs and the PRs. Moreover, the presence of pathogens (e.g. Listeria monocytogenes) in some DP samples highlighted the importance of the microbiological quality evaluation of the DPs to study the possible health risks for consumer. In several samples of DPs, the Cu, Ni and Zn contents exceeded the maximum admissible concentration for fertilizer, as specified by Italian law, suggesting possible environmental contamination if the DPs are used for agricultural purposes. Considering the fertilizing performance, significant differences of growth parameters were observed only for the DPs that were produced by LRs. In conclusion, this work can be considered as a preliminary study to evaluate the possible agricultural reuse of the digestate obtained from different organic wastes.
225
8 (article number 2046)
1
11
anaerobic co-dgestion; agricltural reuse; fertilizer; fecal indicator bacteria; pathogenic bacteria; heav metals
Silvia Bonetta; Sara Bonetta; Elisa Ferretti; Giorgio Fezia; Giorgio Gilli; Elisabetta Carraro
File in questo prodotto:
File Dimensione Formato  
pubblicato.pdf

Accesso riservato

Tipo di file: PDF EDITORIALE
Dimensione 250.25 kB
Formato Adobe PDF
250.25 kB Adobe PDF   Visualizza/Apri   Richiedi una copia
POST-PRINT_Bonetta.pdf

Accesso aperto

Tipo di file: POSTPRINT (VERSIONE FINALE DELL’AUTORE)
Dimensione 438.73 kB
Formato Adobe PDF
438.73 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2318/147796
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 47
  • ???jsp.display-item.citation.isi??? 46
social impact