Xu Heng, Gong Shufen, Sun Yuanzi, Ma Hailing, Zheng Mingyue, Wang Kaijun
a State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment , Tsinghua University , Beijing 100084 , Peoples Republic of China.
Environ Technol. 2015 Jan-Feb;36(1-4):529-37. doi: 10.1080/09593330.2014.979886. Epub 2014 Nov 18.
Hydrogenotrophic methanogenesis has been proved to be a feasible biological method for biogas upgrading. To improve its performance, the feasibility of typical anaerobic granules as the inoculum was investigated in both batch and continuous experiments. The results from batch experiments showed that glucose-acclimated granules seemed to perform better than granules acclimated to acidified products (AP, i.e. acetate, propionate and ethanol) in in situ biogas upgrading systems and a slightly higher H2 consumption rate (1.5 mmol H2 g VSS(-1) h(-1)) was obtained for glucose-acclimated granules. For AP-acclimated granules, the inhibition on anaerobic digestion and pH increase (up to 9.55±0.16) took place, and the upgrading performance was adversely affected. In contrast, better performance for AP-acclimated granules was observed in ex situ systems, possibly due to their higher hydrogenotrophic methanogenic activities (HMA). Moreover, when gas-liquid mass transfer limitations were alleviated, the upgrading performance was significantly improved (three-fold) for both glucose-acclimated and AP-acclimated granules. The HMA of anaerobic granules could be further enhanced to improve biogas upgrading performance via continuous cultivation with H2/CO2 as the sole substrate. During the three months' cultivation, secondary granulation and microbial population shift were observed, but anaerobic granules still remained intact and their HMA increased from 0.2 to 0.6 g COD g VSS(-1) d(-1). It indicated that the formation of hydrogenotrophic methanogenic granules, a new type of anaerobic granules specialized for high-rate hydrogenotrophic methanogenesis and biogas upgrading, might be possible. Conclusively, anaerobic granules showed great potential for biogas upgrading.
氢营养型产甲烷作用已被证明是一种可行的生物法用于沼气提质。为提高其性能，在批次实验和连续实验中研究了典型厌氧颗粒作为接种物的可行性。批次实验结果表明，在原位沼气提质系统中，葡萄糖驯化的颗粒似乎比酸化产物（AP，即乙酸盐、丙酸盐和乙醇）驯化的颗粒表现更好，葡萄糖驯化的颗粒获得了略高的氢气消耗率（1.5 mmol H2 g VSS(-1) h(-1)）。对于AP驯化的颗粒，发生了对厌氧消化的抑制和pH升高（高达9.55±0.16），提质性能受到不利影响。相比之下，在异位系统中观察到AP驯化的颗粒表现更好，这可能是由于它们较高的氢营养型产甲烷活性（HMA）。此外，当气液传质限制得到缓解时，葡萄糖驯化和AP驯化的颗粒的提质性能均显著提高（提高了三倍）。通过以H2/CO2作为唯一底物进行连续培养，可以进一步提高厌氧颗粒的HMA以改善沼气提质性能。在三个月的培养过程中，观察到了二次造粒和微生物种群转移，但厌氧颗粒仍然保持完整，其HMA从0.2增加到0.6 g COD g VSS(-1) d(-1)。这表明可能形成氢营养型产甲烷颗粒，这是一种专门用于高速率氢营养型产甲烷作用和沼气提质的新型厌氧颗粒。总之，厌氧颗粒在沼气提质方面显示出巨大潜力。
