The optimal pretreatment condition of coconut husk by physicochemical methods for biogas production was investigated. The coconut husk was dried and ground into powder (~0.1 nm) and was then determined for chemical contents such as cellulose hemi-cellulose and lignin respectively. The chemical contents of cellulose hemi-cellulose and lignin were 35.67±2.02 7.41±0.69 and 40.82±0.62 w/w respectively. After pretreatment with 4 different methods the results showed that the pretreatment of sodium hydroxide 30 % (w/w) gave the highest chemical contents of cellulose hemi-cellulose and lignin with 43.30±0.03 33.69±7.48 and 27.36±0.03 w/w respectively. As for the biogas production the result showed that the ratio of coconut husk to cow dung of 1:4 with C:N ratio of 23:1 gave the highest cumulative biogas of 442.6 ml for 30 days. Methane and carbon dioxide contents were 46.1 and 23.1 %. Moreover the removal percentages of the total solids (TS) volatile solid (VS) suspended solids (SS) and COD were 69.3 32.5 50.0 and 58.4 % respectively. The coconut husk could be used as an alternative material for the application of biogas production with cow dung in the near future.

The aim of this research was to develop a process for making an inoculum from cow dung. Consequently the inoculum together with food waste was employed to produce hydrogen gas. A total of four different inoculums were experimented including 1). Fresh inoculum 2). Autoclaved inoculum 3). Natural dried inoculum and 4). Hot air dried inoculum. The experimental results revealed that the autoclaved inoculum is the most effective in terms of producing a volatile fatty acid in a maximum value of 9.55 g/l. In addition a maximum hydrogen gas of 136.46 ml/g (of sugar) and also having an average pH of 4.85 and the sugar concentration of 0.33 g/l could be obtained. Furthermore it was found that creating an inoculum by using the autoclaved inoculum produces an inoculum powder having a concentration of 20%. This suggests that the autoclaved inoculum is the best in terms of producing the hydrogen gas from using food waste is 35 litre/litre (of food waste).