Food waste addition for enhanced giant reed ensilage and methane production

Ensilage can be a good storage option to preserve biomass feedstock for anaerobic digestion (AD). In this study, the effects of food waste addition and storage duration on ensilage and AD of giant reed were evaluated. Results showed that addition of 7% food waste (dry weight basis) to giant reed successfully decreased silage pH to 4.0 within one week, enhanced the production of lactic acid, and obtained a low total solids (TS) loss of 0.2% after 28 days' ensilage. Addition of 3% and 7% (dry weight basis) food waste increased cumulative methane yield by 6.8% and 23.3%, respectively, compared to fresh giant reed. A 28-day ensilage process increased cumulative methane yield of giant reed silage with 3% food waste by 5.2% compared to that not ensiled, but had less effect on giant reed with 7% food waste added. Addition of food waste to giant reed enhanced both ensilage and AD processes.