U. lactuca is detrimental to the amenity of a bay. This paper
indicates that it is a viable source of third generation gaseous biofuel.
Three pre-treatments were undertaken to assess the best
method of optimising digestion. A combination of washing and
drying yielded the best BMP result. A yield of 250 L CH4/kg VS
was achieved which is equivalent to 100 m3 CH4/t of substrate.
This is significant. Digestion of sea lettuce can be problematic
due to the low C:N ratio. Co-digestion of fresh and dried Ulva with
dairy slurry was assessed at various ratios. The slurry had a C:N ratio
of 20. In all cases synergistic effects were noted. For example
co-digestion of fresh Ulva and dairy slurry (75% VS in Ulva: 25%
VS in slurry) resulted in 17% more biomethane than the sum of
mono-digestion of the substrates.