determined a decrease from 65 ml H2/gVS to 25 ml H2/gVS on
hydrogen yield. The contribution of the BP fraction was thus determinant
on hydrogen production yield values. The hydrogen production
potentials positively correlated with carbohydrate
contents of the three mixtures and particularly with the starch
content, while lipid content correlated negatively (lower H2 yields
with higher lipid content).
Mix A characterised by the highest content of the fraction BP. On
the contrary the lowest hydrogen production potential was measured
for mixture Mix B characterised by the highest content of
MFC. Sample Mix C presented a hydrogen production yield that
was intermediate between the yields of the other two samples,
but nevertheless closer to the yield of sample Mix A. Taken
together, the fractions F, V and U constituted approximately 80%
of all samples referred to wet weight. A variation in amount of
the BP fraction from 19% to 12% (on wet weight basis) produced
a decrease in hydrogen production from 85 ml H2/gVS to 65 ml
H2/gVS. A further change from 12% to 2% (on wet weight basis)