亚硝酸盐型混养脱硫反硝化中单质硫的形成与堆积特性研究

The sulfur is easily attached to the biofilm surface and leads to bad diffusion of contaminants to biofilm in wastewater desulfurization denitrification process. The generation and transmission stages of element sulfur particles are considered, while the molecular biology detection methods are utilized. The characteristics of microorganisms generating sulfur, surface properties and accumulation features of element sulfur particles in nitrite-type mixotrophic desulfurization denitrification process are researched. The 454 high flux sequencing method is applied to deep dynamic analysis for biotic community, while the biodiversity and biological distribution features are investigated. The degradation ability of nitrogen and sulfur compounds by microorganisms is tested. And the interaction for sulfur generation between autotrophic bacteria and heterotrophic bacteria under mixotrophic conditions is discussed in combination with 454 sequencing results. The microstructure of sulfur particle attached to biofilm is analyzed, in order to reveal the sulfur accumulation features in combination with sulfur distribution conditons in bioreactor main water. The functional groups and charge properties for substances on sulfur particle surface are detected by Fourier infrared spectroscopy, while the surface properties of sulfur are analyzed. The controlling step of element sulfur particles transmission in nitrite-type mixotrophic desulfurization denitrification process is discussed. This research result will provide theoretical support for effective separation of sulfur and biofilms, and has important scientific significant.

针对废水脱硫反硝化系统中，单质硫附着生物膜不易去除，导致污染物向生物膜扩散受限的难题，综合考虑单质硫颗粒的生成阶段和传递阶段，引入分子生物学研究方法，对亚硝酸盐型脱硫反硝化系统内微生物代谢产硫特性、硫颗粒的表面特性和堆积特点进行研究。采用454高通量测序法对微生物群落进行深层次动态分析，研究微生物的多样性和分布特点；对微生物脱氮除硫相关功能进行测试，确定其脱氮除硫的能力，并结合454测序结果，探讨混养条件下自养菌与异养菌在产硫方面的相互作用；对生物膜上附着的硫颗粒进行显微结构分析，结合单质硫在反应器水体中的分布情况，揭示其堆积特点；采用傅里叶红外光谱测试方法对硫颗粒表面物质进行功能基团和电荷特性的检测，分析硫颗粒表面特性。从而明确亚硝酸盐型混养脱硫反硝化系统中硫颗粒传递的控制步骤，为单质硫的有效分离提供理论支持，具有十分重要的科学意义。

针对废水脱氮除硫系统内单质硫易堆积从而堵塞传质通道的难题，引入分子生物学研究方法，探讨亚硝酸盐型脱硫反硝化系统高效运行的条件，并对其微生物代谢产硫特性和硫颗粒表面特性进行分析。分别对反应器不同部位的生物膜进行检测，观察了微生物的形状、生长情况及相对位置，以了解微生物的分布规律；对主要功能细菌进行分离培养及16S rDNA检测，确定其种属及脱氮除硫功能；基于兼养型和自养型脱硫反硝化两套反应系统，采用16S rDNA克隆文库技术和高通量测序方法对系统微生物进行分子生物学检测，解析微生物的群落结构组成及生物多样性，探讨混养条件下自养菌与异养菌在产硫方面的协同作用；观测分析单质硫表面物质的基本特征和电荷属性，包括电镜扫描、丁达尔效应、粒径分布、Zeta电位和能谱分析等，发现单质硫颗粒粒径为2-30μm，表面包裹着带负电的由碳、氮、氧等元素组成的胶体物质，主要为微生物产出的胞外聚合物，阻碍了硫颗粒的自由沉淀去除。本研究为脱硫反硝化系统的广泛应用提供了科学依据，对废水综合处理和资源化向纵深方向发展具有促进作用。