Ensiling of Invasive Elodea sp., a Novel Aquatic Biomass Feedstock for the Sustainable Biogas Production: Effects of Wheat Straw and Silage Additives on Silage Quality and Methane Production

This study investigates for the firsttime the invasive Elodea sp. as a novelaquatic biomass feedstock forthe production of renewable energy in the form of methane (CH4) via anaerobic digestion (AD). For a commercial AD, to overcomethe issue of biomass seasonality and the fact that aquatic biomassexhibits high moistures that complicate storage and hence biomassand CH4 conservation, we propose the ensiling of Elodea biomass as an effective preservation methodthat provides a consistent, reliable, and predictable supply. Theeffects of inclusion of wheat straw to ensiled Elodea (Elodea and mixture silages) andsilage additives (added alone or in combination) on silage qualityand CH4 production were evaluated. Results revealed thatthe inclusion of wheat straw played a key role in the Elodea biomass and CH4 preservation andwas responsible for any apparent effects of silage additives. Specifically,increased silage quality as evidenced by higher lactic acid (LA) andlower pH correlated strongly with inclusion of wheat straw. In addition,wheat straw impacted CH4 production through the preservationof Elodea biomass. Toward the utilizationof this invasive aquatic biomass, ensiling Elodea biomass only with wheat straw suggests a significant alternativeand is perhaps crucial for its efficient preservation and CH4 production.