污泥旋流处理强化缺氧/好氧过程深度脱氮机理研究

More attention has been commonly paid to the transfer inhibition of containment from industrial wastewater to microbial cells in biological process. The hydrocyclone flow field, as well as its effect on the mass transfer in sludge floc and microbial community structure, will be comprehensively investigated to explore the mechanism of nitrogen removal enhancement in a hydrocyclone-improved anoxic-aerobic (A/O) process. Three-dimensional synchronous high-speed motion analyzer (S-HSMA) will be firstly applied to study the self-rotation of simulated sludge in a hydrocyclone. The action force of hydrocyclone flow field on sludge will also be analyzed. The variation of sludge image, compounds in supernatant, interior microbial aggregates, interfacial mass transfer from wastewater to microbial cell and extracellular polymeric substances (EPS) confirmation will be evaluated after hydrocyclone treatment. Mechanism of interfacial mass transfer improvement by self-rotation in a hydrocyclone will be explored as well as the optimization of hydrocyclone intensity. Finally, the effect of sludge hydrocyclone treatment on path and key enzymes of nitrification and denitrification process, microbial community structure and change of dominant bacterial communities will be studied in the hydrocyclone-improved A/O process. The present research will be certainly contributed to the nitrogen removal enhancement.

针对工业废水生化处理中泥-水界面抑制污染物迁移转化的问题，拟从流场特性、界面传质及生物反应耦合的角度，首先采用同步高速运动分析系统研究旋流场中模拟污泥的自转运动特性，阐释旋流场流动对污泥的作用形式；再通过泥项形貌及水项组分、污泥孔道分布、泥-水界面传质过程、污泥胞外聚合物结合污染物分子构型等指标，研究自转过程对污泥的影响，解析污泥自转过程强化泥-水界面传质过程的机理，并优选旋流处理强化界面污染物脱附的自转强度阈值；最后通过自转强化传质对生化过程脱氮路径、硝化与反硝化过程关键酶活性、微生物群落结构以及脱氮优势菌的影响，并结合旋流改进缺氧/好氧过程的连续脱氮效能变化，系统解析污泥旋流自转强化生物脱氮的机理，为工业污水深度脱氮提供技术支持。

针对环境承载负荷降低引起的全国性污水提标需求，项目从流场特性、传质过程和生物反应等三方面，通过解析旋转湍流流场中的污泥运动特性，探明了污泥旋流处理对泥-水界面传质过程的影响，并从关键酶活性和微生物群落结构阐释了污泥旋流处理强化脱氮机理，由此构建了回流污泥旋流分选强化生化工艺。具体地，基于流场特性的模拟研究结论证实，旋流场自转会产生促进颗粒向边壁移动的压力，且自转速度越大压力越大、活性污泥相较于SS自转速度要偏大，因此会更快向边壁、向底流口迁移，证明旋流器内颗粒自转运动强化了活性污泥向旋流器边壁迁移的趋势，加剧了活性污泥与SS的径向迁移差别，从而有利于活性污泥与SS的分选。进一步从泥水界面传质过程的角度分析了回流污泥旋流处理对污泥孔道结构、污泥EPS分子构型、粘性、沉降性等关键指标的影响，并从溶氧和溶解性污染物的角度分析了阐释了旋流分选过程对传质速率的影响趋势。再通过构建回流污泥旋流处理强化A/O中试装置，长周期考察流场作用引起的传质变化对生化效能的影响，开发了新型生化强化工艺，并依托实际废水工程装置开展长周期稳定运行实验；连续旋流分选工况下，由于旋流分选过程不断外排轻质、低活性SS，优选重质、高活性的活性污泥，从而不断的强化了反应器内污泥的活性，增强了污泥的硝化能力，使生化池对COD、NH4-N去除率分别提高了9.4%和15.8%；此外旋流分选过程中由于流体剪切导致污泥絮体表面多糖、蛋白质脱附，补充了反应器碳源，增强了反硝化使TN去除率提高了10.5%，生化池的降解效能得到提高，由此为污水减污降碳和深度提标奠定技术基础。