the samples were oven dried at 100 C, ground down and passed
through a 600 lm sieve. Each waste stream was sampled and
tested in triplicate for total carbon (C), hydrogen (H) and nitrogen
(N) on a total solids basis and was attained by ultimate analysis
using element analyser (CE 440 Model) at the Chemistry Department
in University College Cork, Ireland. The samples analysed
were given a range of ±0.5% error factor.
Table 2 highlights 4 samples of U. lactuca subjected to the pretreatment
processes described above. The dried samples of U. lactuca
had a DS content of 72% with a VS content of 40% (expressed as
a percentage of weight of sample). For the fresh and wilted samples
the DS content was in the range 19–32%; while the VS content was
in the range 11–16%. The day before the samples were digested
they were defrosted in a cold storage room for 24 h at 4 C. Samples
were passed through a bench top grinder to ensure a homogeneous
sample was prepared. The dried sample was easily broken to
a powder like consistency which ultimately would aid in its biodegradability.
All other samples were broken down to a sample
size of between 10 and 15 mm.