餐厨垃圾淀粉类代表组分生熟大米中温厌氧发酵产氢性能

The composition and chemical properties of starch in food waste are important factors affecting its hydrogen productivity during the anaerobic fermentation. In this study, the rice, as a representative component of starch in food waste, was used as substrate before and after being cooked (raw rice, RR vs. cooked rice, CR), and a series of mesophilic batch tests were carried out at different substrate/inoculation (S/I) ratios to investigate the effects of chemical properties of starch on hydrogen production potential. The results showed that the hydrogen production efficiency of both raw and cooked rice increased with S/I ratio, and the optimal S/I ratio was 1:1. Under the optimal condition, the cooked rice gained the highest cumulative hydrogen yield of 166.97 mL·g⁻¹ VS whereas it was only 59.62 mL·g⁻¹ VS for raw rice. The main fermentation by-products were determined to be acetic acid and n-butyric acid, indicating the occurrence of butyric acid-type fermentation; moreover, the higher n-butyrate/acetate ratios, the better hydrogen productivity was observed. Additionally, soluble sugar, soluble protein, and pH level showed a rapid drop tendency during the whole process, while TVFA were accumulated rapidly and became stabilized gradually at the end of operation. Pearson correlation analysis further showed that the cumulative hydrogen yield was mainly governed by the degradation of soluble sugar and the production of acetic acid. It could be concluded that significantly higher hydrogen production from CR than RR was due to the liberation of more soluble sugar in virtue of cooking or steaming process.