生物电化学强化污泥堆肥的微生物种间互作及病原菌定向抑制

A novel method is introduced to realize sludge resource and energy reclamation using bioelectrochemical system which combines both organic waste treatment and energy recovery. The results of our earlier studies showed that the sludge stabilization was promoted by using dewatered sludge to produce electricity. But the efficiency improvements of electricity production and sludge composting are still in the bottleneck, the in-depth and systematic theoretical guidance is lack, especially some key scientific problems remain unsolved in the aspects of the strengthening mechanism of sludge compost by BES and the mechanism of interactions between microbial species. In this study, BES enhanced sludge composting system is set up, the substrate conditions and operating parameters effects on the sludge electricity generation and composting would be studied, and bioelectrochemical regulatory mechanism in the BES enhanced sludge composting process could be confirmed. The high-throughput sequencing, BIOLOG ECO plate and other methods are used to deeply analyze microbial species interaction mechanism and metabolic fingerprint characteristics during the sludge composting process enhanced by BES, to find out the function and status of different microorganism species, and to reveal the evolution behavior of the dominant microorganism, functional microorganism and pathogenic microorganism during the sludge electricity generation and composting process. The structure and function of microflora would be optimized by adjusting the BES operational parameters in order to accelerate sludge stabilization, improve the efficiency of electricity generation, and inhibit the growth of pathogenic microorganism.

生物电化学系统（Bioelectrochemical System，BES）可兼顾有机废物处理和能源回收，为污泥的资源化和能源化提供了新思路。申请者前期研究表明利用脱水污泥进行产电的同时可促进污泥稳定化，但其产电堆肥效能的提高还处于瓶颈期，缺乏系统深入的理论指导，特别是在BES强化污泥堆肥机理和微生物种间互作机制方面仍存在一些关键性的科学问题亟待解决。本研究构建了BES强化污泥堆肥系统，深入研究底物条件、运行参数对污泥产电堆肥效能的影响，建立BES强化污泥堆肥的调控机制。利用高通量测序和BIOLOG ECO板等方法，深度解析BES强化污泥堆肥过程中的微生物种间互作机制和代谢指纹特征，揭示不同微生物种群在产电同步堆肥过程中的地位和功能，以及优势种群、功能种群和病原微生物的演化行为。通过优化BES运行参数，进而优化微生物的群落结构和功能，达到加速污泥稳定化，提高产电效率，抑制病原菌生长的目的。

污泥产量大，处置难是国内外污水处理厂普遍存在的难题。利用微生物电化学系统（BES）阳极强化污泥降解，以电能形式回收污泥有机物中蕴藏的化学能，并原位利用生物电能进行脱盐是一种新型的污泥能源化和资源化技术。本研究通过优化微生物电化学系统结构和阳极底物组成，达到提高污泥产电、脱盐、堆肥效能的目的。利用宏基因组测序技术解析不同底物条件、不同运行阶段阳极污泥中微生物种群结构的演化行为。进一步基于阴极和阳极的电化学行为特征，研究阴极材料优化策略。研究结果表明：BES处理后的脱水污泥有机质、植物毒性明显降低，腐殖酸和速效养分含量增加明显，重金属赋存形态向更稳定的残留态转化。污泥底物添加了餐厨垃圾的BES在产电、堆肥效能方面明显好于添加农田秸秆。高通量测序结果显示，Proteobacteria是阳极底物中占绝对优势的菌门。Betaproteobacteria为优势纲。单一污泥为底物时，Rhodanobacter为优势菌属，其中的优势菌种为Rhodanobacter_sp._Soil772。添加餐厨垃圾和农田秸秆时，优势菌属分别由初期的Ardenticatena和Dechloromonas转化为末期的Pirellula，优势种属均由运行初期的Ardenticatena_noname转化为运行末期的Pirellula_staleyi。其中部分人类致病微生物丰度降低明显。在阴极电极表面沉积Ni和Co后可明显提高ORR活性，特别是镍纳米阵列结构，可有效促进阴极反应速率，提高系统性能。本研究对促进污泥安全有效的资源化能源化利用具有重要的科学意义。