Also, the yield of 4 mL/day occurred at day 3 for control while 1:10 gave maximum yield of 50 mL/day at day 4, as shown in Fig. 3.
Using brewer's spent grains; Onwosi [22] reported an improved biogas production at the dilution of 1:4 w/v but biogas production decreased as the dilution increased to 1:10 w/v.