F/M及HRT对果蔬垃圾厌氧发酵产氢的影响

通过中温半连续厌氧消化实验,考察了果蔬垃圾在不同食微比(0.5、0.75、1.0和1.5)及不同水力停留时间(2、3和4d)下的产氢性能.结果表明,当食微比较低(0.5和0.75)时,各水力停留时间下均不适宜连续产氢,且在水力停留时间为3 d和4 d时容易产生大量甲烷;当食微比较高(1.0和1.5)时,可以实现稳定连续产氢,发酵过程中几乎无甲烷产生.当食微比及水力停留时间分别为1.0及3 d时可获得最佳连续产氢效率,其最高容积产氢量和平均容积产氢量分别为451m L·(L·d)~(-1)和(186±29)m L·(L·d)~(-1),最高挥发性固体产氢率和平均挥发性固体产氢率(以VS计)分别为133 m L·g~(-1)和(27±5)m L·g~(-1),氢气含量可达20%~30%.

Effect of the Food to Mass Ratio and Hydraulic Retention Time on Hydrogen Production from Fruit and Vegetable Waste

Semi-continuous biogas production from fruit and vegetable waste by medium temperature anaerobic fermentation was conducted. Hydrogen production under different food-microorganism ratios (F/M 0.5, 0.75, 1.0, 1.5) and hydraulic retention times (HRT) (2, 3, 4 d) were investigated. The results show that in the case of a smaller F/M values (0.5 and 0.75), not all HRT stages were conducive to the continuous production of hydrogen, however, they were conducive to producing methane, especially when HRT was 3 or 4 d. Continuous hydrogen production was viable when the F/M ration was relatively higher (1.0 and 1.5), however, this was not conducive to the production of methane, with almost no methane production detected in this process. A F/M of 1.0 and a HRT of 3 d provided the best conditions for continuous hydrogen production from fruit and vegetable waste. Meanwhile, the highest and average daily volume of hydrogen production were 451.2 mL·(L·d)^-1 and (186±29) mL·(L·d)^-1 respectively, whereas the highest and average hydrogen production rate of volatile solids were 133 mL·g^-1 and (27±5) mL·g^-1 respectively. The hydrogen content was 20%-30%.