Using a combination of first order and second order kinetics for
the degradation of organic material, a Matlab programme was
developed to process all data from BMP assays to determine a set
list of parameters. Eq. (2), is used to develop decay constants, K.
The modified Gompertz formula (3) (Nopharatana et al., 2007)
was used to determine the lag phase D, which was calculated for
each BMP assay to establish the time taken to initiate biomethane
production within the vessels. A regression coefficient R2, was obtained
for each BMP trial substrate to determine how well the
curve fit expression worked on each graph of biomethane production.
The half life determined the time taken for half of the biomethane
production to be produced.