原位剩余污泥减量的多孔载体生物膜时空演化规律研究

Excess sludge produced within the wastewater treatment processes is creating environmental challenges such as air, surface water, soil and grounder water pollutions due to much more viruses lived in the untreated excess microbes. In situ excess biomass decrement, removal of more organic loading by enriching the activated biomass and meanwhile reducing the production of excess biomass, is becoming the ultimate goal of the innovative wastewater treatment techniques eager to achieved. The gravel contact oxidation reactor filled with crushed stone globular aggregates (CSGA) as carriers, has been demonstrated capable of reducing the excess sludge effectively in some pilot engineering studies. In order to evaluate the variation and structure of the microbial community survived in the biofilm of CSGA and their functions to excess sludge reduction in CSGA, some biological indexes in the biofilm of CSGA and water indexes in reactor will be sensed in several moments and places during the CSGA reactor running. These biological indexes are composed of biofilm's thickness, pH, extracellular polymeric substances (EPS), biofacies, microbial diversity, dominated microbial community, biomass and microbial activity. The data of the experiment will be analyzed with correlations for determining those biological, physical and chemical indexes both of the biofilm and wastewater responding to excess sludge reduction. Information gained from this study will have direct impacts on our understanding of the role of microbial processes in excess sludge reduction. The mathematic model made in this study will provide new ways of calculating process parameters and finally, the theory deduced from this study will guide new techniques invention and old techniques improving.

剩余污泥中含有各类污染物质及治病微生物，如不进行有效的处理直接排放到环境中，将对空气、地表水、土壤和地下水造成严重污染。原位剩余污泥减量，即在污水生物处理过程中，降低剩余微生物的净增长速率。以剩余污泥原位降解的污水处理工艺核心-多孔载体CSGA表面生物膜和孔隙内膜为研究对象，对表达其物化、生物特性指标（厚度，pH，胞外多聚物；生物相，微生物多样性，优势种群，生物量，生物活性）以及水质指标，在反应器运行的不同时间、不同部位进行原位实时检测；并根据检测结果构建相关的数学模型，实施统计学计算与相关性分析，以阐明生物膜形成、动态平衡、衰亡脱落及分解机制，确立载体生物膜功能性指标及其与环境因素的相互关系，揭示该工艺原位剩余污泥减量机理。本项目的研究将为解析固着式载体生物膜上不同类型微生物的相互作用及其与剩余污泥原位减量的相关性，推导工艺设计参数理论计算公式，原有工艺改进及新型工艺开发，奠定理论基础.

剩余污泥中含有各类污染物质及治病微生物，如不进行有效的处理直接排放到环境中，将对空气、地表水、土壤和地下水造成严重污染。原位剩余污泥减量，即从源头上减少剩余污泥的产量，成为新型污水生物处理工艺追逐的目标。以剩余污泥原位减量的污水处理工艺核心—多孔载体CSGA表面生物膜和孔隙内泥为研究对象，对表达其物化、生物特性指标以及水质指标，随时间、空间变化进行实时检测。根据检测结果用克里格法构建数学模型，用回归支持向量机（SVR）构建载体生物膜由形成-分解全过程的数学模型，通过冗余分析（RDA）确立载体生物膜功能性指标及其与环境因素的相互关系，最终揭示该工艺原位剩余污泥减量机理。结果表明，CSGA载体反应器的剩余污泥量是对照组（无载体）的剩余污泥量的1/10，系统污泥真实产率 0.054gSSD/gCOD，污泥表观产率为0.045～0.052 gSS/gCOD之间，真实产率与表观产率基本吻合，说明多孔载体稳定运行期，活性污泥生长代谢良好，剩余污泥原位减量的效果明显。CSGA载体生物膜厚度横向沿水流方向逐渐增大，纵向随着高度的增高厚度减小，生物膜厚度控制在27-28.5μm时有利于反应装置对水中各类有机物去除。载体反应器中，原位检测出54种细菌，其中，载体外部的慢速生长细菌-球衣菌，黄杆菌(Flavobacterium)、芽单胞杆菌(Gemmatimonas)、丝硫细菌(Thiothrix)和鞘氨醇单胞菌（Sphingopyxis）数量与MLSS呈负相关，载体孔隙污泥中，球衣菌、黄杆菌(Flavobacterium)、芽单胞杆菌(Gemmatimonas)和丝硫细菌(Thiothrix)与MLSS呈负相关。微型动物中红斑瓢体虫与MLSS呈负相关。COD、DO、TN、TP、MLSS这5个环境因子共解释了74.5%的载体孔隙內泥功能细菌数量变化信息和80.7%的载体外部功能细菌数量的变化信息。培养成熟期，多孔载体系统中微型动物密度约达 1200 个/ml，较对照系统约多750 个/ml，代表性微型动物多样性指数，下层明显高于上层。细菌间拮抗、生物溶胞、共代谢作用及微型动物捕食是原位剩余污泥减量机理。本项目的研究结果将为解析固着式载体生物膜上不同类型微生物的相互作用及其与污染质的关系，原有工艺改进及新型工艺开发，奠定理论基础。