颗粒有机物对活性污泥供碳及絮体结构改善协同作用机制研究

The shortage of carbon source is the main bottleneck for the success operation of biological nutrient removal(BNR) process. A large portion of the organic material within municipal wastewater is in the particulate state. Due to the complex composition and large size span of particulate organics, the study on its hydrolysis and biological uptake is still a weak link. The majority of the research on the particulate organic hydrolysis is based on its average hydrolysis rate, without taking into account the vast difference among particle of different sizes and characteristics. Besides being a carbon source, the particulate organics can also provides the surface area for the attachment of microorganism within activated sludge flocs. The floc structure is more compact within less filaments bacteria and better settling property after the addition of particle organics of a certain sizes. The literature analysis and results we have so far have suggested that the particulate organic can provide the carbon source and attachment surface simultaneously for the microorganisms. In this project, we will study the mechanism of particulate organics being the carbon source and attachment surface to investigate th effect particle size and other characteristics on providing carbon source and improving floc structure for activated sludge. The results can help for the better use of particulate organics within municipal wastewater.

随着对城市污水脱氮除磷要求的提高，污水中碳源不足的问题日益显现。颗粒有机物是污水碳源的一个主要组成部分。由于颗粒的组成复杂，尺寸分布跨度较大，目前对颗粒有机物如何水解，再被生物吸收利用的研究仍然是一个薄弱环节。大部分有关颗粒有机物水解的研究都是基于颗粒的"平均"水解特性，没有考虑到尺寸和性质的差异而导致的水解速率的差异。除了提供碳源之外，颗粒有机物也可以通过为微生物提供附着表面，来改善活性污泥絮体结构特征。在添加一定尺寸的颗粒有机物活性污泥系统中，絮体结构更加密实、丝状菌含量低，从而使活性污泥具有较好的沉降性能。文献分析和申请者现有的研究结果表明，颗粒有机物具有为活性污泥微生物提供碳源和附着表面的协同作用。本项目申请将通过对此协同作用的机理研究，分析不同尺寸，不同性质的颗粒有机物对活性污泥微生物的供碳和絮体结构改善的作用，为颗粒有机物的高效利用提供理论基础。

污水中很大一部分碳源是以颗粒的形式存在，由于污水脱氮除磷对污水中碳源要求的提高，对污水颗粒有机碳源的研究也很重要。本研究开发了一种可以快速界定污水中颗粒碳源分布的方法，通过物理过滤絮凝沉淀等物化方法可以可以快速检测颗粒碳源的生物降解特性。另外颗粒有机物对活性污泥的絮体结构也有重要的影响。本研究通过比较不同进水颗粒特性条件下，活性污泥絮体特性的差别，研究颗粒碳源对絮体稳定性的影响。研究表明，缺少颗粒有机物条件下，絮体比较密实，但是会有较多的丝状菌；而颗粒有机物较多时，可以抑制丝状菌的生长。