自养型同步脱氮颗粒污泥处理猪场粪污的效能障碍因子识别及其微生物学机理研究

Anaerobically digested swine wastewater contains high amounts of ammonium, but its organic carbon is not sufficient to satisfy the demand of the traditional nitrification-denitrification process. Hence, it has shown some weakness for removing nitrogenous compounds from digested swine wastewater. Using synthetic wastewater, the applicant has successfully developed an autotrophic nitrogen removal (ANR) granular sludge, in which the aerobic ammonium oxidation and anerobic ammonium oxidation (Anammox) were being carried out in single granule and the ammonium was being converted into nitrogen gas. Due to advantages of the ANR granular sludge such as cost effectiveness, high efficiency and environmental-friendly, this process has wider prospects to control the nitrogenous pollution of digested swine wastewater. However, our further studies indicated that the high amounts of inhibitors in swine slurry hindered the application of ANR granular sludge compared with the synthetic wastewater and it resulted in granular sludge disassembly and poor performance. The inhibitors causing the poor performance of autotrophic nitrogen removal granular sludge treating swine wastewater and its microbiological mechanisms would be studied in this research in the light of previous research. The study would involve identification of the key inhibitors causing poor performance by batch activity tests and analysis of the microbial community structure having the ability of secreting EPS (extracellular polymeric substances), functional genes of secreting EPS and their expression level in ANR granular sludge by metagenomes and metatranscriptomics. It would lay a solid theoretical foundation for the application of ANR granular sludge to digested swine wastewater.

猪场粪污经厌氧处理后具有高氮低碳特性，脱氮处理困难，传统硝化-反硝化工艺已无法满足其脱氮需求。申请人前期研发的自养型同步脱氮(ANR)颗粒污泥，在胞外多聚物(EPS)的作用下，将好氧氨氧化和厌氧氨氧化菌群整合于同一颗粒，高效、经济、环保，为猪场粪污的脱氮处理带来了新希望。但本课题组在采用ANR颗粒污泥处理猪场粪污的研究中发现，ANR颗粒污泥处理猪场粪污具有显著的效能障碍，导致ANR颗粒污泥大量解体、脱氮效能大幅下降。基于此，本项目拟采用活性试验等方法，鉴别导致ANR颗粒污泥处理猪场粪污效能障碍的主效因子；采用宏基因组和宏转录组等分子生物学手段，通过研究猪场粪污中主要效能障碍因子对ANR颗粒污泥中EPS分泌菌群群落结构、EPS代谢相关功能基因以及功能基因转录水平的影响，解析ANR颗粒污泥处理猪场粪污效能障碍的微生物学机理，为破除ANR颗粒污泥处理猪场粪污的效能障碍奠定理论基础。

猪场粪污经厌氧处理后具有高氮低碳特性，脱氮处理困难，传统硝化-反硝化工艺已无法满足其脱氮需求。申请人前期研发的自养型同步脱氮(ANR)颗粒污泥，在胞外多聚物(EPS)的作用下，将好氧氨氧化和厌氧氨氧化菌群整合于同一颗粒，高效、经济、环保，为猪场粪污的脱氮处理带来了新希望。但本课题组在采用ANR颗粒污泥处理猪场粪污的研究中发现，ANR颗粒污泥处理猪场粪污具有显著的效能障碍，导致ANR颗粒污泥大量解体、脱氮效能大幅下降。基于此，本项目鉴别了猪场粪污中导致效能障碍的主效因子为COD和Cu，分析了其在畜禽粪污中的浓度、探明了其对ANR工艺的最小抑制浓度，其中COD主要抑制氨氧化细菌的活性，而Cu主要抑制Anammox细菌的活性；采用宏基因组和宏转录组等生物学方法，通过分析猪场废水对ANR颗粒污泥颗粒化特性、ANR颗粒污泥微生物群落结构和功能基因表达水平的影响，揭示了主效因子导致ANR颗粒污泥解体的微生物学机理：猪场粪污中的效能障碍因子会导致除Anammox细菌以外的其他细菌从颗粒污泥上分离，导致Anammox细菌与其他细菌的生态位分离，从而降低脱氮效能，该机理为解除猪场废水厌氧消化液影响ANR工艺的效能障碍和进一步提高ANR工艺效能提供理论基础。另外，尽管ANR工艺处理猪场粪污的效能有所降低，但经过驯化，其仍远高于文献报道的同类工艺，因此本项目开发了自养型同步脱氮工艺处理猪场废水厌氧消化液的高效绿色环保工艺，为猪场废水的脱氮处理提供技术支撑。