Analysing the characteristics of the two substrates we can
notice their complementarity contributing for the optimization of
the AD process, for example the C/N ratio of PLF is about 9 times
higher than the LCM’s. Regarding LCM, total COD values averaged
40.7 ± 4.8 g L1 and VS 24.0 ± 4.5 g L1, representing 71% of TS.
The average values of NH4 + -N and Norg were 0.8 ± 0.1 and
0.3 ± 0.02 g L1, respectively. The PLF had a water content around
82% and an acidic pH (4.6 ± 1.1). Total COD values were in the same
range as LCM, averaging 35.8 ± 5.1 g L1, but with different availability
to the co-digestion process. VS presented average values
of 16.5 ± 8.4 g L1 (92% of TS). Nitrogen was present in both organic
and ammonium forms, 0.04 ± 0.01 and 0.03 ± 0.023 g L1,
respectively.