基于旋转磁场强化的光磁耦合技术除藻机理及反应器优化

In order to improve the quantum efficiency, the magnetic filed was used to enhance photocatalytic performance and a novel combined process of rotating magnetic field and photochemical catalysis process was conducted for algae removal. The aim of this research was to improve the algae removal efficiency of combined process and the controllability of process operation. The research key point was followings: The effects of magnetic, photocatalytic and environmental factors on the removal of algae were discussed to explore kinetics of algae removal. Based on chemical effects of magnetic field and characterization of magnetic photocatalyst, the effects of magnetic field on the lifetime and distribution of free radicals and photogenerated carriers were studied to understand the essence of integrated process of photocatalytic oxidation enhanced by magnetic field. The mechanism of inactivation of algae by combined process was conducted through comparative analyses on the changes of morphology, physiology, biochemistry and protein expression of algae cells. The finite volume method was used to simulate the solid-liquid two-phase flow in the photocatalytic reactor to understand the effects of different magnetic factors on particle motion and with MPSS model and UDF function, intensity distribution calculation model was used to study the ultraviolet intensity and light dose distribution combined with the assignment of function, which helped to present a strategy of optimization of control parameters.

针对光催化除藻技术中光生载流子易复合，光量子效率低的问题，课题提出磁技术（磁化学/磁生物/磁物理）强化光催化性能的策略，形成基于旋转磁场强化的光磁耦合除藻技术，目标在于提高耦合除藻技术的高效性与工艺运行的可控性。研究内容：探讨磁作用、光催化和环境等因素对藻类去除影响，明晰耦合技术的除藻动力学规律；从磁致化学方面，研究磁场对自由基和光生载流子寿命及分布的影响规律，结合磁性光催化剂的表征分析，阐明磁场与光催化反应协同效应的本质；对比分析藻细胞表观形态、生理生化、蛋白质表达的变化，从分子水平阐述磁-光催化灭活藻类的过程和相应机理。在反应器优化方面，利用有限体积法模拟光催化反应器内的固液两相流动过程，明晰不同磁作用因素对颗粒运动的影响；以MPSS model为基础，结合UDF赋值功能，研究紫外光的强度和光剂量分布特性，构建可测量参量的机理模型计算光强的分布，提出工艺系统的优化参数与调控对策。

为解决光催化除藻技术中光生载流子易复合，光量子效率低的问题，课题基于磁技术增强光催化性能的策略，提出“旋转磁场-可见光催化”耦合除藻技术。本研究通过设计新型可见光光催剂，利用仪器分析和微生物学手段探究磁特性与光催化等因素对除藻效能的影响，解析光催化除藻效能与机理；利用分子生物学快速准确诊断的特点，结合藻类代谢过程中多种生理指标测定，揭示了磁-光催化中藻类灭活过程和机理。研究内容：以元素掺杂和构建异质结手段制备两种新型可见光光催化剂，将其应用于光催化除藻，进行藻类去除动力学特性分析，探究不同因素对光催化灭活铜绿微囊藻的影响，明晰光催化技术对藻类的表观形态、微观结构、生理生化、蛋白质表达等方面的影响，从细胞和分子水平揭示藻类在光催化灭活过程及相应机理。构建磁场-光催化耦合除藻技术，研究不同磁场作用方式、磁场强度和磁作用时间等对光催化除藻效能的影响，并结合磁场对藻生长特性和磁场对光催化过程中活性自由基的影响，从藻细胞形态等微观方面研究，揭示了在磁-光催化中藻类灭活过程和机理。以上研究成果为光催化除藻技术在实际工程应用奠定了良好的理论基础。研究成果发表SCI学术论文9篇、中文核心期刊2篇；授权中国发明专利1项，申请中国发明专利2项；已培养3名硕士毕业生和在读1名博士。