Fats, Oils, and Greases Increase the Sensitivity of Anaerobic Mono- and Co-Digester Inoculum to Ammonia Toxicity
Fats, Oils, and Greases Increase the Sensitivity of Anaerobic Mono- and Co-Digester Inoculum to Ammonia Toxicity
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DOI：
10.1089/ees.2021.0119
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发表时间：
2021-12
影响因子：
1.8
通讯作者：
A. Berninghaus;T. Radniecki
中科院分区：
文献类型：
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作者：
A. Berninghaus;T. Radniecki
近年来，人们对脂肪、油和油脂（FOG）厌氧共消化的兴趣越来越大，从而导致了提高这些系统稳定性和增加沼气产量的研究努力。氨抑制对污水处理厂城市污泥的厌氧消化已经得到了很好的应用。然而，在FOG存在下发生的抑制作用通常被FOG的长链脂肪酸抑制所掩盖。在存在和不存在FOG的情况下，氨本身的影响还没有被分离和深入研究。本研究考察了从单底物和共底物厌氧消化池接种的间歇式厌氧消化池在存在和不存在无抑制浓度的FOG的情况下对氨的抑制作用。当总氨氮（TAN）浓度超过1700 mg/L时，两种接种剂的甲烷产率均下降，滞后期时间增加。低于这个阈值，单消化器接种比共消化器接种对氨更敏感。TAN的抑制作用被氨耐受微生物如胞单胞菌的存在所减轻。andMethanoculleusspp。这两种情况在共消化菌接种物中更为普遍。与单消化器接种相比，共消化器接种的产甲烷菌数量也增加了两倍，使其更能抵抗有机酸的积累，并降低了甲烷的产率。最后，FOG的存在增加了氨对本实验中测试的两个消化器的抑制作用，表明氨敏感性随着代谢活性的增加而增加。在雾存在的情况下，这种对氨的敏感性增加可能直接影响雾共消化系统的强化，从而增加甲烷产量。
Interest in anaerobic co-digestion of fats, oils, and greases (FOG) has increased recently, resulting in research efforts to enhance stability of these systems and increase biogas production. Ammonia inhibition has been well-established for anaerobic digestion of municipal sludge from wastewater treatment plants. However, the inhibitory effects that occur in the presence of FOG are typically overshadowed by long chain fatty acid inhibition from the FOG. The effects of ammonia itself have not been separated and thoroughly studied in the presence and absence of FOG. This study investigated ammonia inhibition in batch anaerobic digesters inoculated from mono-substrate and co-substrate anaerobic digesters in the presence and absence of noninhibitory concentrations of FOG. Above a 1,700 mg/L total ammonia nitrogen (TAN) threshold, both inocula exhibited decreased methane production rates and increased lag phase times. Below this threshold, the mono-digester inoculum was more sensitive to ammonia than the co-digester inoculum. TAN inhibitory effects were mitigated by the presence of ammonia-tolerant microbes such asSyntrophomonasspp. andMethanoculleusspp., which were both more prevalent in the co-digester inoculum. The co-digester inoculum also had a twofold increase in methanogens compared with the mono-digester inoculum, making it more resistant to organic acid accumulation and decreased rates of methane production. Finally, the presence of FOG increased the inhibitory effects of ammonia for both digesters tested in this experiment, suggesting that ammonia sensitivity is increased with increased metabolic activity. This increased sensitivity to ammonia in the presence of FOG could have direct implications on the intensification of FOG co-digestion systems for increased methane production.