菌藻共生贴壁培养原位生物修复养猪沼液过程中重金属去除机制研究

Developing bioremediation technology of heavy metal for anaerobically digested piggery slurry is important to the utilization of pig manure resources, the pollution problem of pig manure urgently solved now and the development of pig industry and circular economy. In this study, algal-bacterial symbiosis system is constructed by Lactobacillus sp. and Chlorella vulgaris. Attachment cultivation of algal-bacterial symbiosis system is established in a novel photobioreactor. Attachment cultivation of algal-bacterial symbiosis system using simulated slurry under heavy metal stress caused by copper, zinc and arsenic is tested. The interaction between single heavy metal or multiple heavy metals and extracellular functional groups with or without chemically modification, respectively, is investigated. The variation of structure and content of extracellular function groups such as carboxyl, hydroxyl, amino groups and so on are measured by fourier Transform infrared spectroscopy and microbial electrochemical technologies. The extracellular polymeric substances of algal-bacterial symbiosis system induced by single heavy metal or multiple heavy metals are investigated. The extracellular polymeric substances are extracted by sodium hydroxide and their contents are measured. The polysaccharides and proteins in extracellular polymeric substances are separated and identified by high performance liquid chromatography-mass spectrometer. The adsorption mechanism of heavy metal of the extracted polymeric substances is studied by X-ray photoelectron spectroscopy. The adsorption mechanism of heavy metal of attachment cultivation of algal-bacterial symbiosis system is discussed. In order to achieve the methodology for the removal of heavy metals in the complicated wastewater, in situ bioremediation of heavy metals in real anaerobically digested piggery slurry using attachment cultivation of algal-bacterial symbiosis system is established.

发展沼液重金属生物修复技术对于养猪粪污资源化利用，当前亟待解决的养猪粪污环境污染问题，推动养猪产业和循环经济发展具有重要意义。本课题以乳杆菌和小球藻为对象构建菌藻共生体系，通过设计开发新型光生物反应器，建立菌藻共生贴壁培养技术。利用模拟沼液研究养猪沼液中严重超标的重金属铜、锌、砷胁迫条件下菌藻共生贴壁培养，研究单一及多种重金属共存与有无化学修饰菌藻胞外功能基团的相互作用，建立傅里叶红外光谱和微生物电化学表征胞外羧基、羟基、氨基等功能基团结构和数量变化；研究单一及多种重金属共存诱导菌藻胞外聚合物，NaOH法提取胞外聚合物及研究含量变化，分离纯化其多糖和蛋白质，并用液质联用仪表征；建立X射线光电子能谱等方法研究提取的胞外聚合物吸附重金属；阐明菌藻共生贴壁培养去除重金属机制。最终建立菌藻共生贴壁培养原位生物修复真实养猪沼液中重金属；为成分复杂废水重金属菌藻共生贴壁培养去除提供方法学借鉴。

发展沼液重金属生物修复技术对于养猪粪污资源化利用，当前亟待解决的养猪粪污环境污染问题，推动养猪产业和循环经济发展具有重要意义。本课题以乳杆菌和小球藻为对象成功构建了菌藻共生体系，设计开发出新型光生物反应器，建立了菌藻共生贴壁培养技术。利用模拟沼液研究了养猪沼液中严重超标的重金属铜、锌、砷胁迫条件下菌藻共生贴壁培养，研究了单一及多种重金属共存与有无化学修饰菌藻胞外功能基团的相互作用，建立了傅里叶红外光谱和微生物电化学表征胞外羧基、羟基、氨基等功能基团结构和数量变化；研究了单一及多种重金属共存诱导菌藻胞外聚合物，NaOH法提取胞外聚合物及研究含量变化，分离纯化其多糖和蛋白质，并用液质联用仪表征；建立了X射线光电子能谱等方法研究提取的胞外聚合物吸附重金属；阐明了菌藻共生贴壁培养去除重金属机制。最终建立了菌藻共生贴壁培养原位生物修复真实养猪沼液中重金属；为成分复杂废水重金属菌藻共生贴壁培养去除提供方法学借鉴。