3.2.Hexane Inhibition in Digestion. Thetoxic effect of hexane
on anaerobic digesting microorganism might be responsible
for the lowyield obtained fromthe pretreatedwastes. In order
to confirm this hypothesis, batch digestion with addition of
hexane to the digesting system was conducted. For comparison,
the toxicity of limonene was also examined using the
same method. The result showed that, at the same concentration,
hexane was more toxic than limonene to anaerobic
digesting system. Addition of hexane at concentration of
13g/L resulted in 28.6% reduction of methane production
compared with the control experiment (Figure 2).