Response surface methodology (RSM) with central composite design (CCD) was applied to optimize key factors affecting
hydrogen production (HP) from diluted acid hydrolysate of water-hyacinth stem (WHS) by heat-treated anaerobic sludge
in a batch fermentation process. Key factors affecting namely substrate concentration and initial pH was investigated.
The results indicated that substrate concentration and initial pH had significantly effects on HP (p<0.05). A maximum HP
hydrogen production rate and hydrogen yield of 182.7 mmol H2
/L, 2.81 mmol H2
/L h and 0.84 mol H2
/mol hexose were
obtained under the optimum conditions i.e. substrate concentration of 4.06 g/L and initial pH of 5.81. The total energy
production from the fermentative of WHS hydrolysate was 1.97 kJ.