矿化垃圾对高含固剩余污泥厌氧发酵产酸的影响行为及作用机制

Anaerobic fermentation of high solid sludge has been widely studied for its advantages of small facility size, low water and energy consumption. However, anaerobic fermentation of high solid sludge is slow, which limits the accumulation of short chain fatty acids (SCFA), an intermediate value product. Aged refuse is a by-product of landfill, and it contains substantial enzymes, humus, heavy metals and functional microorganisms. Therefore, aged refuse can be used to enhance the anaerobic fermentation of high solid sludge to produce SCFA, however, to date, there are few reports on the effect of aged refuse on the anaerobic fermentation of high solid sludge and the related mechanism. Therefore, this project intends to explore the effects of aged refuse on SCFA production from anaerobic fermentation of high solid sludge by means of gas chromatography, mass spectrometry-liquid chromatography, atomic absorption, high-throughput sequencing, FISH and q-PCR molecular genetic technology, and reveal the relevant mechanism of this action, and explore the dynamic evolution of microbial community in this process. The relationship between them and SCFA production by anaerobic fermentation of high solid sludge were analyzed, and the coupling relationship between aged refuse and solubilization, hydrolysis and acidification of organic matter was analyzed. The project aims to reveal the effects of aged refuse on the SCFA production by anaerobic fermentation of high solid sludge, and provide theoretical basis and technical support for promoting the technological progress of anaerobic fermentation of high solid sludge.

高含固污泥厌氧发酵具有设施体积小，能耗低等优势。然而高含固污泥厌氧发酵过程缓慢从而限制了中间价值产物短链脂肪酸（SCFA）的积累。矿化垃圾是填埋场垃圾降解的主体产物，其含有大量的酶，腐殖质及功能微生物等，具有强化高含固污泥厌氧发酵产酸的潜质。然而到目前鲜有报道矿化垃圾对高含固污泥厌氧发酵产酸的影响行为及相关机制。因此，本项目拟采用气相色谱，质谱-液相色谱、ICP-OES、高通量测序、宏转录等手段探究矿化垃圾对高含固污泥厌氧发酵产SCFA的影响行为并揭示相关作用机制，探寻此过程中微生物群落的动态演替规律以及它们与高含固污泥厌氧发酵产酸的联系，解析矿化垃圾关键组分与有机物溶解、水解及酸化过程之间的耦联规律。项目旨在揭示矿化垃圾对高含固污泥厌氧发酵产酸的影响行为和作用机制，为高含固污泥资源化利用提供必要的理论依据和技术参考。

高含固污泥厌氧发酵具有设施体积小，能耗低等优势。高含固污泥厌氧发酵过程缓慢从而限制了中间价值产物短链脂肪酸（SCFA）的积累。矿化垃圾（AR）是填埋场垃圾降解的主体产物，其含有大量的酶，腐殖质及功能微生物等，具有强化高含固污泥厌氧发酵产酸的潜质。然而，应用AR强化污泥高含固厌氧发酵积累SCFA的可行性及相关机制鲜有探究。本项目旨在考察AR对污泥高含固厌氧发酵积累SCFA的影响并揭示相关机制。结果表明，AR能显著改善高含固污泥厌氧水解和酸化过程，并提高SCFA的积累量。当AR含量为400 mg/g DS时，SCFA的积累量高达183.9 mg/g，对应的发酵时间为5d。AR 提高了溶解性COD、蛋白质及多糖在发酵体系内的积累，SCOD可高达5240 mg/L，显著高于空白组。AR内主要成分如腐殖酸、重金属、关键酶、微生物群落能影响污泥的水解和酸化过程，且关键酶及微生物对污泥厌氧水解和酸化过程具有积极影响。AR存在能改变高含固污泥厌氧发酵内微生物群落特征，提高Clostridium和Sporanaerobacter的相对丰度。外界操作条件初始pH对低温下AR强化高含固污泥厌氧发酵具有显著影响。当初始pH为7时，甲烷的最大产率为102.2±4.8 mL/g，而当初始pH为11时，SCFA的最大产率为85.6±2.8 mg/g。弱酸或弱碱pH有利于WAS的水解酸化，但抑制甲烷生成。本项目探究了AR对高含固污泥厌氧发酵的影响，并通过有机质的转化、水解、酸化过程关键酶活性及微生物群落特征等揭示了AR对高含固污泥厌氧发酵的强化机制。研究结果为污泥等有机废物高效资源化利用提供一定理论依据。基于上述成果，共发表期刊论文11篇，其中SCI 检索9篇，申请国家发明专利2项，培养研究生2名，协助培养博士研究生1名。