Effect of ammoniacal nitrogen on one-stage and two-stage anaerobic digestion of food waste
Effect of ammoniacal nitrogen on one-stage and two-stage anaerobic digestion of food waste
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DOI：
10.1016/j.wasman.2014.12.001
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发表时间：
2015-04-01
期刊：
影响因子：
8.1
通讯作者：
Pirozzi, Francesco
中科院分区：
文献类型：
--
作者：
Ariunbaatar, Javkhlan;Di Perta, Ester Scotto;Pirozzi, Francesco
这项研究比较了半连续供给食物垃圾的一级和两级厌氧连续搅拌釜反应器 (CSTR) 系统的运行情况。主要目的是研究氨氮对厌氧消化过程的影响。与一级系统相比，两级系统的运行更加可靠，因为： (i) 更好的 pH 自调节能力； (ii) 更高的抗有机负荷冲击能力； (iii) 有机底物向生物甲烷的转化率更高。两级反应器的第一级还检测到少量生物氢，使得该系统对生物乙烷生产具有吸引力。由于沼渣中含有氨氮，其再循环可以为系统提供必要的碱度，从而防止挥发性脂肪酸 (VFA) 积累而导致最终故障。然而，再循环也导致铵积累，从而降低生物甲烷产量。根据批量实验结果，计算出总氨氮对产甲烷活性的50%抑制浓度为3.8 g/L，相当于本研究所用接种物的游离氨为146 mg/L。两级系统比一级系统受到抑制的影响更大，因为它需要较少的碱度，并且物理分离的产甲烷菌对抑制因子（例如铵和丙酸）更敏感。 (C) 2014 Elsevier Ltd. 保留所有权利。
This research compares the operation of one-stage and two-stage anaerobic continuously stirred tank reactor (CSTR) systems fed semi-continuously with food waste. The main purpose was to investigate the effects of ammoniacal nitrogen on the anaerobic digestion process. The two-stage system gave more reliable operation compared to one-stage due to: (i) a better pH self-adjusting capacity; (ii) a higher resistance to organic loading shocks; and (iii) a higher conversion rate of organic substrate to biomethane. Also a small amount of biohydrogen was detected from the first stage of the two-stage reactor making this system attractive for biohythane production. As the digestate contains ammoniacal nitrogen, re-circulating it provided the necessary alkalinity in the systems, thus preventing an eventual failure by volatile fatty acids (VFA) accumulation. However, re-circulation also resulted in an ammonium accumulation, yielding a lower biomethane production. Based on the batch experimental results the 50% inhibitory concentration of total ammoniacal nitrogen on the methanogenic activities was calculated as 3.8 g/L, corresponding to 146 mg/L free ammonia for the inoculum used for this research. The two-stage system was affected by the inhibition more than the one-stage system, as it requires less alkalinity and the physically separated methanogens are more sensitive to inhibitory factors, such as ammonium and propionic acid. (C) 2014 Elsevier Ltd. All rights reserved.