猪粪干式厌氧消化系统稳定性及其耐氨氮机制分析

Analysis on System Stability and Ammonia Nitrogen Resistant Mechanism in Dry Anaerobic System of Swine Manure

随着我国畜牧业快速发展,畜禽粪便量激增,已经成为许多城市及农村的新兴污染。文章采用牛粪消化液为接种物,在中温(36℃)条件下,对猪粪进行了干式厌氧消化中试试验,旨在探索其最佳的进料量、系统稳定性和潜在的氨抑制问题。研究结果表明,当进料量为600 kg·d^(-1)时,沼气产量,甲烷含量,VS降解率,物料产气率,甲烷产率分别为45~55 m^3·d^(-1),62%,50%,117~143 mL·g^(-1)VSd^(-1),72~88 mL·g^(-1)VSd^(-1)。从综合产气率和VS降解率两方面评价,当进料量为600 kg·d^(-1),该干式厌氧消化中试系统运行稳定、处理效率高,并可获得较好的产气效果。在该条件下,氨氮与游离氨浓度与系统产气性能没有直接线性关系,且在浓度分别高达5000 mg·L^(-1)和1100 mg·L^(-1)时系统没有明显的抑制作用,因为系统内的微生物尤其是产甲烷菌在高浓度氨氮的环境下受到一定程度的驯化,对高浓度氨氮有了更强的抵抗力。

With the rapid development of animal husbandry, the amount of livestock manure increasing rapidly, and has become emerging pollution of urban and rural areas. A pilot experiment of swine manure was carried out adopting a 24 m3 of dry anaerobic digester under mesophilic （36℃） condition with cow digestion liquid as inoculums, and its proper feed rate, the system stability, and the possible ammonia inhibition, were investigate. The results showed that, when the feed rate was 600 kg ·d-1 for the 24 m3 digester, biogas production, methane content, VS degradation rate, material gas pro duction rate and methane production rate were 45 -55 m3 · d-1 ,62% ,50%, 117 - 143 mL ·g-1 VS·d-1 and 72 -88 mL·g-1VS·d - 1, respectively. From aspects of comprehensive gas production rate and the VS degradation rate, the feed rate of 600 kg · d-1, could operate steadily and obtain high treatment efficiency. In addition, the concentration of TAN and FAN showed non-direct relations with the gas production, and the system performance was not obviously inhibited under high strength of ammonia （5000 mg·L-1 and 1100 mg ·L-1for TAN and FAN respectively）, inferring the microbes, especially methanogens, were domesticated under high concentration of ammonia environment in a certain degree and had high resistance to the high concentration of ammonia nitrogen.