Enhanced Anaerobic Digestion of Cow Manure and Rice Straw by the Supplementation of an Iron Oxide-Zeolite System

The aim of this study is to investigate the effect of a novel iron oxide-zeolite system on the anaerobic digestion of cow manure and rice straw. The results showed that the.cumulative methane yield during the 40 days of digestion with the supplementation of the newly-formed' additive reached as high as 394.38 mL/g of VSadd, which was 74.11% higher than that with the mixture of iron oxide and zeolite as the additive (226.51 inLig of VSadd) and 372.85% higher than the control (83.05 ri-LL/g of VSadd). The introduction of the iron oxide zeolite system also brought a more stable pH condition, higher total VFA, and lower ammonia concentration. In terms of the substrate degradation, a better bioavailability of the lignocellulosic biomass has been obtained. The coenzyme F420 assay demonstrated a significantly strengthened methanogen activity by the addition of the iron oxide-zeolite-system: Considering its high efficiency and good performance, the iron oxide zeolite system can be extended to practical engineering 'application for biomethane production.