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Effect of freshwater washing pretreatment on Sargassum muticum as a feedstock for biogas production

Effect of freshwater washing pretreatment on Sargassum muticum as a feedstock for biogas production

Milledge, John J. ORCID: 0000-0003-0252-6711, Nielsen, Birthe V. ORCID: 0000-0002-0849-4987, Sadek, Manar S. and Harvey, Patricia J. ORCID: 0000-0001-7193-4570 (2018) Effect of freshwater washing pretreatment on Sargassum muticum as a feedstock for biogas production. Energies, 11 (7):1771. ISSN 1996-1073 (Online) (doi:

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The pretreatment of seaweed by washing in freshwater is often used in seaweed biofuel research studies. However, the effect of washing seaweed prior to anaerobic digestion (AD) does not appear to have been greatly studied. This study examines washing Sargassum muticum with freshwater and its effect on ultimate and proximate analyses, salt content, methane production from anaerobic digestion, and leachate loss from ensiling. Washing with freshwater significantly (P < 0.01) increased moisture content (unwashed 85.6%, washed 89.1%) but significantly (P < 0.05) reduced ash (unwashed 32.7% dry weight dw, washed 30.6% dw) and salt content (unwashed ash containing 51.5%, washed 42.5%). The dry biomass higher heating value was significantly (P < 0.05) increased by washing due to the lower ash content (11.5 to 12.6 kJ g−1 dw). There was no significant change in the protein or lipid content, although washing increased the nitrogen content (3.85–4.77% dw). Washing significantly (P < 0.05) increased leachate losses during ensiling, with total leachate losses increasing after washing (12.7–25.2%). The methane yield from anaerobic digestion (28 days) was not statistically significantly different (P > 0.05) between unwashed (0.225 L CH4 g−1 VS) and washed samples (0.177 L CH4 g−1 VS). However, washing delayed biomethane production

Item Type: Article
Additional Information: © 2018 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 (
Uncontrolled Keywords: Sargassum muticum; washing; anaerobic digestion; seaweed; pretreatment; ensiling; macroalgae
Subjects: G Geography. Anthropology. Recreation > GE Environmental Sciences
Faculty / Department / Research Group: Faculty of Education, Health & Human Sciences > Department of Life & Sports Sciences
Faculty of Engineering & Science
Faculty of Engineering & Science > Algal Biotechnology Research Group
Faculty of Engineering & Science > School of Science (SCI)
Last Modified: 15 May 2020 02:30
Selected for GREAT 2016: None
Selected for GREAT 2017: None
Selected for GREAT 2018: None
Selected for GREAT 2019: GREAT 2
Selected for REF2021: REF 3

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