Anaerobic Digestion of Olive Mill Wastewater in the Presence of Biochar
Biological treatments focused on stabilizing and detoxifying olive mill wastewater facilitate agronomic reuse for irrigation and fertilization. Anaerobic digestion is particularly attractive in view of energy recovery, but is severely hampered by the microbial toxicity of olive mill wastewater. In t...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-04-01
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| Series: | Energies |
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| Online Access: | https://www.mdpi.com/1996-1073/16/7/3259 |
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| author | Luca Micoli Giuseppe Di Rauso Simeone Maria Turco Giuseppe Toscano Maria A. Rao |
| author_facet | Luca Micoli Giuseppe Di Rauso Simeone Maria Turco Giuseppe Toscano Maria A. Rao |
| author_sort | Luca Micoli |
| collection | DOAJ |
| description | Biological treatments focused on stabilizing and detoxifying olive mill wastewater facilitate agronomic reuse for irrigation and fertilization. Anaerobic digestion is particularly attractive in view of energy recovery, but is severely hampered by the microbial toxicity of olive mill wastewater. In this work, the addition of biochar to the digestion mixture was studied to improve the stability and efficiency of the anaerobic process. Kinetics and yields of biogas production were evaluated in batch digestion tests with biochar concentrations ranging from 0 to 45 g L<sup>−1</sup>. The addition of biochar reduced sensibly the lag phase for methanogenesis and increased the maximum rate of biogas generation. Final yields of hydrogen and methane were not affected. Upon addition of biochar, soluble COD removal increased from 66% up to 84%, and phenolics removal increased from 50% up to 95%. Digestate phytotoxicity, as measured by seed germination tests, was reduced compared to raw wastewater. Addition of biochar further reduced phytotoxicity and, furthermore, a stimulatory effect was observed for a twenty-fold dilution. In conclusion, biochar addition enhances the anaerobic digestion of olive mill wastewaters by effectively reducing methanogenesis inhibition and digestate phytotoxicity, thus improving energy and biomass recovery. |
| first_indexed | 2024-03-11T05:37:42Z |
| format | Article |
| id | doaj.art-4fc449f4e9ab4bcfaf2704c204cc1dfa |
| institution | Directory Open Access Journal |
| issn | 1996-1073 |
| language | English |
| last_indexed | 2024-03-11T05:37:42Z |
| publishDate | 2023-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Energies |
| spelling | doaj.art-4fc449f4e9ab4bcfaf2704c204cc1dfa2023-11-17T16:39:34ZengMDPI AGEnergies1996-10732023-04-01167325910.3390/en16073259Anaerobic Digestion of Olive Mill Wastewater in the Presence of BiocharLuca Micoli0Giuseppe Di Rauso Simeone1Maria Turco2Giuseppe Toscano3Maria A. Rao4Dipartimento di Ingegneria Industriale (DII), Università degli Studi di Napoli Federico II, piazzale V. Tecchio 80, 80125 Napoli, ItalyDipartimento di Agraria, Università degli Studi di Napoli Federico II, via Università 100, 80055 Portici, ItalyDipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale (DICMaPI), Università degli Studi di Napoli Federico II, piazzale V. Tecchio 80, 80125 Napoli, ItalyDipartimento di Ingegneria Chimica, dei Materiali e della Produzione Industriale (DICMaPI), Università degli Studi di Napoli Federico II, piazzale V. Tecchio 80, 80125 Napoli, ItalyDipartimento di Agraria, Università degli Studi di Napoli Federico II, via Università 100, 80055 Portici, ItalyBiological treatments focused on stabilizing and detoxifying olive mill wastewater facilitate agronomic reuse for irrigation and fertilization. Anaerobic digestion is particularly attractive in view of energy recovery, but is severely hampered by the microbial toxicity of olive mill wastewater. In this work, the addition of biochar to the digestion mixture was studied to improve the stability and efficiency of the anaerobic process. Kinetics and yields of biogas production were evaluated in batch digestion tests with biochar concentrations ranging from 0 to 45 g L<sup>−1</sup>. The addition of biochar reduced sensibly the lag phase for methanogenesis and increased the maximum rate of biogas generation. Final yields of hydrogen and methane were not affected. Upon addition of biochar, soluble COD removal increased from 66% up to 84%, and phenolics removal increased from 50% up to 95%. Digestate phytotoxicity, as measured by seed germination tests, was reduced compared to raw wastewater. Addition of biochar further reduced phytotoxicity and, furthermore, a stimulatory effect was observed for a twenty-fold dilution. In conclusion, biochar addition enhances the anaerobic digestion of olive mill wastewaters by effectively reducing methanogenesis inhibition and digestate phytotoxicity, thus improving energy and biomass recovery.https://www.mdpi.com/1996-1073/16/7/3259wastewater valorizationbiogaspolyphenolsphytotoxicity |
| spellingShingle | Luca Micoli Giuseppe Di Rauso Simeone Maria Turco Giuseppe Toscano Maria A. Rao Anaerobic Digestion of Olive Mill Wastewater in the Presence of Biochar Energies wastewater valorization biogas polyphenols phytotoxicity |
| title | Anaerobic Digestion of Olive Mill Wastewater in the Presence of Biochar |
| title_full | Anaerobic Digestion of Olive Mill Wastewater in the Presence of Biochar |
| title_fullStr | Anaerobic Digestion of Olive Mill Wastewater in the Presence of Biochar |
| title_full_unstemmed | Anaerobic Digestion of Olive Mill Wastewater in the Presence of Biochar |
| title_short | Anaerobic Digestion of Olive Mill Wastewater in the Presence of Biochar |
| title_sort | anaerobic digestion of olive mill wastewater in the presence of biochar |
| topic | wastewater valorization biogas polyphenols phytotoxicity |
| url | https://www.mdpi.com/1996-1073/16/7/3259 |
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