高蛋白有机废弃物厌氧消化系统稳定性及其耐氨氮机制解析

病死及自然灾害产生的大量畜禽尸体的不恰当处理处置会带来较为严重的环境卫生和公众安全隐患.本研究利用厌氧消化技术对畜禽尸体这类高蛋白有机废弃物的无害化处理进行尝试,旨在探索其适宜的有机负荷条件、系统的稳定性及潜在的氨抑制风险.研究表明高蛋白有机废物(以猪肉作为实验样品)作为厌氧消化基质时,系统稳定运行的有机负荷能够达倒(4.76±0.41)kg·m~(-3)·d~(-1);同时,VS降解率、单位体积沼气产率、单位添加VS沼气产率、单位降解VS沼气产率以及甲烷含量分别能达到95%、(3.72±0.21)L·L~(-1)·d~(-1)、(0.78±0.02)m~3·kg~(-1)、(0.82±0.02)m~3·kg~(-1)以及65%.在该条件下,TAN和FAN的浓度与系统产气性能没有直接线性关系,且在浓度高达5700 mg·L~(-1)和700 mg·L~(-1)时未呈现对系统的明显抑制作用.454高通量焦磷酸测序法对系统内古菌种群相对密度的分析结果表明,系统中氨抑制问题得到一定程度的缓解或者消除的原因可能为甲烷八叠球菌属(Methanosarcina)的优势地位并未受到明显影响,以及整个产甲烷菌种群在系统运行过程所得到的明显驯化.

Anaerobic digestion of protein-rich organic wastes: system stability and the mechanism on resistance of ammonia nitrogen

The improper treatments of large numbers of dead animals caused by diseases and natural disasters always bring serious dangers for environmental health and public safety. In this study, anaerobic digestion technology was tried to dispose dead animals aiming to explore the proper organic loading rate, the stability of system and the potential ammonia inhibition risks. The system could be stably performed under the organic loading rate up to (4.76±0.41) kg·m^-3·d^-1. VS reduction, biogas production based on effective working volume, biogas yield based on VS_added and VS_reduced and methane content were 95%, (3.72±0.21) L·L^-1·d^-1, (0.78±0.02) m³·kg^-1, (0.82±0.02) m³·kg^-1 and 65%, respectively. In addition, the concentration of FAN and TAN in the system do not showdirect relationship with the biogas production, and the performance of the system was not obviously inhibited under high ammonia concentration (5700 and 700 mg·L^-1 for TAN and FAN).Through the analysis of archaea population by using 454 pyrosequencing, it was found that the consistent predominance of Methanosarcina in the system and the domestication of archaea population during the operation process might contribute to the mitigation ammonia inhibition.