illustrates the cumulative biogas production normalised
to the total initial g COD where the pH of the reactor was controlled
within pH 6.8–8.0 using 2M NaOH. Monitoring the pH
within optimum methane production conditions resulted in a
higher concentration of methane production for the 90:10,
75:25 and 50:50 substrates. The higher the starch content within
the substrate the higher the quantity of biogas produced, further
iterating that starch degrades more rapidly than polyvinyl
alcohol.