纳米零价铁和零价铁对餐厨垃圾暗发酵制氢过程铁离子和酶活性的影响

通过投加不同浓度的纳米零价铁(NZVI)和零价铁(ZVI)，考察了暗发酵制氢过程中铁离子组成和浓度变化、氢化酶和脱氢酶活性，研究了2种添加剂强化餐厨垃圾高温((55±1) ℃)暗发酵制氢的作用机制。结果表明：投加NZVI和ZVI均可提高餐厨垃圾暗发酵制氢性能；当投加100 mg·L⁻¹ ZVI时，产氢效果最佳，最大产氢潜力和最大产氢速率分别为425.72 mL和66.32 mL·h⁻¹，是投加NZVI实验组的1.64倍和1.34倍，代谢途径是以乙醇型发酵为主的混合型发酵；在投加NZVI和ZVI后，暗发酵制氢末端产物的Fe²⁺和Fe³⁺浓度升高，投加300 mg·L⁻¹ NZVI和100 mg·L⁻¹ ZVI实验组Fe²⁺浓度最大，是未投加实验组的2倍和1.87倍；与反应前相比，Fe²⁺显著升高，Fe³⁺由于微生物利用与转化浓度降低，同时可有效提高氢化酶活性。投加100 mg·L⁻¹ ZVI不仅可提高氢化酶活性，还可提高脱氢酶活性。以上结果可为提高餐厨垃圾等复杂有机废物的高效能源化提供参考。

Effect of nano zero valent iron and zero valent iron on the iron ion composition and enzyme activity during dark fermentation of food waste for hydrogen production

The composition and concentration changes of iron ion, hydrogenase and dehydrogenase activity in the process of dark fermentation were analyzed by adding different concentrations of nano zero valent iron (NZVI) and zero valent iron (ZVI). The mechanism of dark fermentation hydrogen production of food waste at (55±1) ℃ strengthened by both additives was investigated. The results showed that the NZVI or ZVI addition could improve the hydrogen production performance of food waste dark fermentation. When the concentration of ZVI was 100 mg·L−1, the hydrogen production effect was the best. The maximum hydrogen production potential and hydrogen production rate were 425.72 mL and 66.32 mL·h−1, respectively, which were 1.64 times and 1.34 times as much as those of the NZVI group. The metabolic pathway was identified as a type of mixed fermentation mainly based on ethanol fermentation. After the addition of NZVI and ZVI, the concentration of Fe2+ and Fe3+ in the end product of dark fermentation increased. The concentration of Fe2+ reached the highest for the test group with 300 mg·L−1 NZVI or 100 mg·L−1 ZVI addition, respectively, which was 2 times or 1.87 times as high as that of the test group without addition. Compared with that before the reaction, the concentration of Fe2+ increased significantly and the concentration of Fe3+ decreased due to the microorganisms utilization and conversion. Meanwhile, the hydrogenase activity increased effectively. Of which 100 mg·L−1 ZVI addition not only improved hydrogenase activity, but also improved the dehydrogenase activity. The above results can provide scientific basis for further improving the high effective energy conversion of complex organic wastes such as food waste.