新型细管流紫外反应器的研制及水中光化学与光生物反应基础研究

Ultraviolet radiation has been extensively used for microorganisms inactivation and pollutants degradation in water. The quasi-collimated beam apparatus (qCBA), relying on which the fundamental research about UV photoreactions is carried out at present, has a few limitations that impact the test accuracy. This project, based on the idea of microfluidic device, aims to develop a high-performance mini-tubular reactor through modifying the optical structure. Under the premise of ensuring a higher accuracy of UV fluence measurement, this new reactor can increase the maximum fluence rate (FR) by about 500 times (i.e., similar to the practical fluence adopted in engineering applications) and have unique advantages of no sample evaporation and fluidic measurement, in comparison to the qCBA. The fluence will be measured by using our independently developed micro-fluorescent silica detector and conventional chemical actinometers as well. Thereafter, the mini-tubular reactor will be applied to investigate the photodegradation of typical emerging contaminants (e.g. antibiotics) and the inactivation of representative microorganisms in water. The basic parameters, such as the rate constants and quantum yields of photoreactions of interest, will be determined more accurately. Furthermore, this study will reveal the answer to an intricate problem as limited by the conventional reactors: will different FRs impact the inactivation efficiency of microorganisms under UV radiation with a fixed fluence? This project, upon implementation, is expected to provide an advanced experimental apparatus, valuable basic parameters, and quantified microorganism response characteristics for the fundamental research of photochemical and photobiological reactions in water.

紫外线被广泛应用于水中污染物降解和微生物灭活，但目前用于紫外光反应基础研究的准平行光束仪还存在一定缺陷，影响了测试的准确性。本项目基于微流反应器的思想，通过光学结构改进，拟开发一种性能更优的细管流反应器。与准平行光束仪相比，其在确保紫外剂量测定更为准确的前提下，将最大辐照强度提高约500倍（接近工程应用的紫外强度），且具有无样品蒸发、流动式测试的优点。其剂量测定将采用自主开发的荧光微探头以及常规的化学感光剂进行。之后，应用细管流反应器，对水中典型新型污染物（如抗生素）光降解和代表性微生物光灭活过程进行研究，提高光化学反应速率常数、光量子产率等基本参数测定的准确性。重点解决一个因受传统反应器限制而长期没有统一结论的问题：即在相同紫外剂量下，不同辐照强度是否影响微生物的灭活效率？该项目的成果将为水中光化学与光生物反应基础研究提供先进的测试装置、有价值的基本参数、以及量化的微生物响应特性。

紫外线（UV）广泛应用于水消毒和污染物降解。目前实验室小试常用的准平行光束仪还存在一定缺陷，影响了光反应参数测定的准确性。本项目通过光学结构改进，开发了一种性能更优的细管流反应器。与准平行光束仪相比，其在确保UV剂量测定更为准确的前提下，将最大辐照强度提高约500倍（接近工程应用的UV强度），且具有无样品蒸发、流动式测试的优点。此外，该反应器还可以输出剂量准确的真空紫外（185nm）及紫外（254nm）同步辐照(即VUV/UV)，便于开展VUV/UV在消毒和高级氧化应用的研究。开展了水中典型新型污染物（如抗生素）直接光解和UV高级氧化去除、以及代表性微生物光灭活的研究。开发了细管流反应器测定光化学反应速率常数、光量子产率等基本参数的方法。通过尝试应用VUV/UV于多个传统的UV高级氧化过程，发现相对于传统UV辐射，VUV/UV/chlorine和VUV/UV-Fenton对于污染物降解具有明显的强化作用。由于输出VUV/UV和UV的灯管具有相近的生产和运行费用，因此,VUV/UV/chlorine和VUV/UV-Fenton在水中微量有机污染物和高浓度废水处理上将具有很好的应用前景。本项目提供了一个更为先进的实验室UV反应器，为准确测定UV消毒和高级氧化反应中的各光反应参数提供了一个有力的工具。