3.1. Characteristics and BMPs of food waste and straw
The characteristics of FW and the composition of straw were
shown in Tables 2 and 3, respectively. The organic contents of FW
included sugar, protein, fat and cellulose, and the organic fractions
of straw were cellulose, hemicellulose and lignin. The C/N
of FWand straw were 28.4 and 43.4 (Table 4), respectively, while
the optimum C/N for sole straw fermentation was in the range of
25 e 30 [18]. It was found that the C/N of FW was lower than the
optimum C/N of anaerobic fermentation, while the C/N of straw
was higher than that, which meant that both of the nitrogen
content of FW and the carbon content of straw were on the high
side. Experimental results showed that the total methane production
in BMP tests for FWand straw was 0.26 and 0.16 m3 CH4/
kg-VS, respectively, which indicated that the FW was easily
biodegradable waste while the straws were difficultly biodegradable
wastes.