shows the impact of the S/X ratio upon MYgenerated from
the acidic effluent by mixed anaerobic cultures in UASB granules.
MY increased with increasing S/X ratio in the range of 0.47e0.80 g-
VSsub/g-VSinoculum. Therewas a significant decrease in MY when the
S/X ratio was greater than 0.80 g-VSsub/g-VSinoculum as shown in
Fig. 3 a, b. This indicates that an S/X rationwas inappropriately high.
When the S/X ratio was outside of its optimal range, there was a
large impact upon hydrogen production. At high S/X ratios, the
substrate inhibition occurs due to more substrate than needed