College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China.
Western Scientific Observation and Experiment Station of Development and Utilization of Rural Renewable Energy of Ministry of Agriculture, Northwest A&F University, Yangling 712100, China.
Int J Environ Res Public Health. 2019 Jun 25;16(12):2239. doi: 10.3390/ijerph16122239.
Poultry manure is the main source of agricultural and rural non-point source pollution, and its effective disposal through anaerobic digestion (AD) is of great significance; meanwhile, the high nitrogen content of chicken manure makes it a typical feedstock for anaerobic digestion. The performance of chicken-manure-based AD at gradient organic loading rates (OLRs) in a continuous stirred tank reactor (CSTR) was investigated herein. The whole AD process was divided into five stages according to different OLRs, and it lasted for 150 days. The results showed that the biogas yield increased with increasing OLR, which was based on the volatile solids (VS), before reaching up to 11.5 g VS/(L·d), while the methane content was kept relatively stable and maintained at approximately 60%. However, when the VS was further increased to 11.5 g VS/(L·d), the total ammonia nitrogen (TAN), pH, and alkalinity (CaCO) rose to 2560 mg·L, 8.2, and 15,000 mg·L, respectively, while the volumetric biogas production rate (VBPR), methane content, and VS removal efficiency decreased to 0.30 L·(L·d), 45%, and 40%, respectively. Therefore, the AD performance immediately deteriorated and ammonia inhibition occurred. Further analysis demonstrated that the microbial biomass yield and concentrations dropped dramatically in this period. These results indicated that the AD stayed steady when the OLR was lower than 11.5 g VS/(L·d); this also provides valuable information for improving the efficiency and stability of AD of a nitrogen-rich substrate.
家禽粪便是农业和农村面源污染的主要来源，通过厌氧消化（AD）有效地处理它具有重要意义；同时，鸡粪的高氮含量使其成为厌氧消化的典型原料。本研究考察了连续搅拌罐式反应器（CSTR）中梯度有机负荷率（OLR）下基于鸡粪的 AD 的性能。根据不同的 OLR，整个 AD 过程分为五个阶段，持续了 150 天。结果表明，沼气产量随着挥发性固体（VS）的增加而增加，OLR 最高可达 11.5 g VS/（L·d），而甲烷含量相对稳定，保持在约 60%。然而，当 VS 进一步增加到 11.5 g VS/（L·d）时，总氨氮（TAN）、pH 值和碱度（CaCO3）分别上升至 2560 mg·L、8.2 和 15000 mg·L，而容积沼气产生率（VBPR）、甲烷含量和 VS 去除效率分别降低至 0.30 L/（L·d）、45%和 40%。因此，AD 性能立即恶化，出现氨抑制现象。进一步分析表明，在此期间微生物生物量产量和浓度急剧下降。这些结果表明，当 OLR 低于 11.5 g VS/（L·d）时，AD 保持稳定；这为提高富氮底物 AD 的效率和稳定性提供了有价值的信息。
