초록
<P><B>Abstract</B></P> <P>Pre-treatment can enhance anaerobic digestion of seaweed; however, seasonal variation in the biochemical composition of seaweed has a significant impact on the pre-treatment effect. In this study, various pre-treatments were employed for the brown seaweed <I>Laminaria digitata</I> harvested in March (with high ash content and low carbon to nitrogen (C:N) ratio) and September (with low ash content and high C:N ratio). Washing of <I>L. digitata</I> harvested in March with hot water (defined as 40 °C) removed 54% of the ash and improved the volatile solids (VS) content by 31% leading to an improved biomethane yield of 282 L CH<SUB>4</SUB> kg VS<SUP>−1</SUP>. This pre-treatment affected a 16% increase in biodegradability, reduced salt accumulation in the digestate by 54%, and increased specific methane yield per wet weight by 25%. This level of effect was not noted for seaweed harvested in September, when the biodegradability is higher.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Maceration after hot washing of <I>L. digitata</I> significantly affected biogas yield. </LI> <LI> Impact of the pre-treatment was more significant on March harvest than September. </LI> <LI> The pre-treatment removed 54% of ash whilst increasing VS content by 31%. </LI> <LI> Bio-digestibility was enhanced by 16% with 54% less salt accumulation in digester. </LI> <LI> Specific methane yield of <I>L. digitata</I> per weight wet was increased by 25%. </LI> </UL> </P>