基于污泥结构与形态控制的初级调控-多级耦合脱水过程研究

The unstable and bulk sludge generated in sewage disposal plant has become serious environmental problems. Sludge dewatering is the key to the treatment, which directly affecting the efficient of the sludge post-disposal Therefore, sludge dewatering has became the important issue for sludge treatment. However, the change laws of sludge structure forms in the dewatering process are still unclear, the interconvert in various components of water forms are not in detail, and the impacts of sludge conditioning on the micro-structure of filter cake during dewatering process are lack of research. In the light of the above problems, this project proposed the issue named "Research on the primary-conditioning multi-coupled dewatering process based on the regulation of sludge structure and morphlogy". This study systematically analyzed the inner correlations among the sludge inner properties, primary-conditioning and dewatering, and therefore clarified the mechanisms of multi-stage coupled sludge dewatering process. The impacts and related controlled conditions of sludge properities and structure changes on dewatering process were investigated. The impacts and mechanisms of primary conditioning on the dewaterability were studied, and the optimal kinetically controlled conditions were determined. The micro-structure characteristics of filter cake during sludge dewatering process were analyzed. The resistance characteristics of sludge filter cake were studied for determined the proper energy input of sludge dewatering. The interconvert in sludge water forms and the micro-structure and homogenization of dewatered sludge cake during dewatering process were studied. This research results can further improve the mechanisms of sludge dewatering process, and provide theoretical support for enhancing the sludge dewaterability and achieving the energy-saving and consumption-reducing during sludge dewatering process.

污水处理厂污泥由于其性质不稳定、体积庞大，已成为影响环境的重要问题。污泥脱水是处理的关键环节，直接影响后续处理处置的效能，是污泥处理的重点与难点。针对在脱水过程中污泥结构形态变化规律不清、各组成水分的相互转化机制不详、脱水前期行为对脱水过程中泥饼微观结构特性的影响研究不足等问题，提出"基于颗粒结构与形态调控的污泥多级耦合脱水过程研究"。本课题系统分析污泥性质、前期调理与后期脱水污泥特性的内在关联，研究多级耦合脱水过程机理。研究污泥及其形态变化特性对污泥脱水性能的影响及控制；研究初级调控对污泥脱水性能的影响，阐述该过程的最佳动力学控制条件；分析污泥多级耦合脱水过程中泥饼分层微观结构特性，能量输入与阻力性能的关系，研究多级耦合脱水过程中污泥水分的相互转化机制。课题研究成果可进一步完善污泥脱水过程控制机理，为提高污泥脱水效率、实现污泥脱水过程节能降耗提供理论支撑。

随着我国经济增长，污水处理产生的剩余污泥所带来的环境问题日益突出。污泥脱水是实现污泥减量化的关键环节，目前与之相关的研究多集中在污泥调理对脱水性能提高上，而对脱水过程的机理研究不足，效率难有突破性提高。因此，开展脱水控制机理研究对提高污泥脱水性能、降低能耗有重要的现实意义。. 首先，课题研究了污泥性质及其形态变化对脱水性能的影响。分析了污泥组分、理化性质与形态特性，通过试验探究原污泥的内在性质与脱水指标间的相关关系，分析浓缩时间对污泥理化性质及浓缩效能的影响，通过沉降柱试验探究污泥形态特性与脱水性能指标间的关联关系。. 然后，研究了初级调控对污泥脱水性能的影响及动力学控制。探究PAC、FeCl3和PAM调理过程中不同调理条件对污泥絮体结构、理化性质、脱水性能和沉降性能的影响及相互关联关系；依据最佳投药量，基于正交试验和RSM对初级调控过程中动力学搅拌参数进行优化，确定最佳能量输入梯级、强度、时间等；扩展性研究溶菌酶、复合酶和超声耦合生物质等手段对污泥调理效果的影响作用；研究初级调控过程中水分形态的迁移转化，解析初级调控对污泥脱水过程的作用机制。值得指出的是，详尽研究污泥自絮凝现象，首次确定基于自絮凝条件下的最佳储存时间范围，可节省调理药耗15-20%。. 最后，研究了污泥多级耦合脱水过程中泥饼微观结构特性对脱水性能的影响及其作用机制。分析多级耦合过程泥饼的阻力特性，研究过滤阻塞机制；通过对多级耦合脱水过程泥饼微观结构动态变化特性研究，分析影响多级耦合脱水泥饼微观性能的作用机制；依据泥饼阻力参数计算，建立泥饼过滤参数与孔隙的关系，并结合水分迁移规律的研究，阐明多级耦合脱水过程水分运移机制。. 课题研究建立初级调控-多级耦合脱水体系，阐明初级调控对污泥脱水过程的宏观、微观性能影响及其作用机制和多级耦合脱水过程泥饼微观特性变化规律及主要影响因素和作用机制，丰富污泥脱水作用机制研究，为脱水效率进一步提高及应用提供理论依据。.