The biogas production by the digestions of FVW alone and the
co-digested wastes is shown in Fig. 2. Analysis of biogas production
profiles for the substrates combinations showed that there were
significant differences among the combinations tested. The results
for co-digested substrates are better than those obtained from
digestion of FVW. The average biogas production rate varied
between 1.53 l d1 and 2.53 l d1, with value being highest for both
mixtures W2 and W3 and lowest for 100% FVW. The specific biogas
productions for the four digestion processes (R1–R4) were 0.403,
0.611, 0.580 and 0.436 l g1 removal VS.