| Popis: |
Batch laboratory-scale anaerobic digestion experiments were carried out with the aim of investigating the effect of nickel and iron, singly and in combination, on the methane yield of napiergrass stem. Iron, nickel and an iron-nickel mixture were added to the substrate as iron (III) chloride (FeCl ), nickel (II) chloride (NiCl ), and a 1:1 FeCl and NiCl molar mixture, respectively. The inoculum used to inoculate the digestion experiments was obtained from the rumen fluid of a freshly slaughtered 5 year old male bovine. The biogas produced was collected for 30 days by 2 days intervals and the methane yield was measured using gas chromatography (GC). The results obtained show that the cumu- lative methane yield, rate of methane production, and time lag before methane production were enhanced with the addi- tion of iron, nickel, and the iron-nickel mixture. The study also show that the cumulative methane yield of the napiergrass stem increased as the amount of added FeCl , NiCl , and FeCl -NiCl mixture increased. Furthermore, the cumulative methane yield was highest when nickel ion was added. Addition of iron and nickel ions to substrate reduced the time lag before methane production from 8 days to 6 days and addition of the iron-nickel ions mixture to substrate reduced the time lag to 4 days. |
