Evaluation of Continuous Flow Ultraviolet Light Emitting Diode

[0932116]拟议的研究计划旨在整合实验规模和中试规模的实验和数值技术，以全面表征紫外线发光二极管（UV LED）连续流反应器。这些实验的数据将为开发和验证UV LED消毒系统的计算流体动力学（CFD）模型提供必要的信息。经过验证的CFD模型将与启发式优化程序相结合，根据所需的最优性标准构建高效的连续流UV LED系统（即，在实现所需的污水测井失活的同时最小化总功率输入，或者在给定目标总功率输入的情况下最大化污水测井失活）。总的来说，这项研究将使工程师能够确定基于UV LED的连续流UV反应器系统是否可以实现高消毒系统效率，并提供替代汞蒸气UV灯的替代技术。在过去10年中，接受紫外线作为处理饮用水水源的有效消毒过程及其在水回用应用中的潜在用途导致了相当大的增长。这种增长激发了研究人员提高紫外线反应器设计的有效性，并进行研究，以发现增加低压灯输出功率的新方法，提高中低压灯的效率，增加灯的使用寿命，并开发新的紫外线发射源。然而，大多数紫外线灯技术都含有汞，汞被视为危险废物，如果处置不当或灯具损坏，会对环境和公众健康构成威胁。在处理过程中，灯在运输或安装过程中可能会损坏，也可能在紫外线系统运行时被异物击中。已经出现的其他紫外线技术（即脉冲和准分子灯以及紫外线led）不含汞。然而，很少有研究对UV led进行评估，以评估其作为连续流UV系统中有效的UV发射光源的能力。本研究计划拟通过以下方法检验UV LED连续流反应器的紫外线消毒效率：1)进行准直光束实验测试，确定目标非致病微生物和紫外线敏感荧光微球在多个UV LED波长下的紫外线响应；2)建立数值模型，描述UV LED连续流反应器的UV LED光分布、UV剂量分布和微生物对数失活。3)在紫外LED反应器上进行中试实验，在一定的流量和紫外线透过率范围内验证数值模型；4)基于组合优化程序和CFD模型的输出开发出最优紫外LED反应器。拟议的研究代表了第一个全面和直接的努力来量化连续流UV反应器中分布式点光源的消毒性能，这可能导致没有几何限制的消毒效率的提高，因为合并了圆柱形光源。以前的研究只对UV led进行了实验规模的测试，以评估大肠杆菌的log失活或在过氧化氢的提前氧化条件下苯酚的降解。所提出的研究是评估这种替代UV光源作为当前连续流系统中汞蒸气UV灯的良性替代品的必要的第一步。该项目将为环境工程专业培养一名博士和一名硕士学生。这些学生将从土木、建筑和环境工程（CCEE）系的申请者中挑选出来，并特别考虑来自代表性不足群体的申请者。研究生将广泛参与所有研究领域：1)实验设计，设置和执行，2)数值模拟的开发和执行，3)在国内和国际会议和同行评审出版物上展示研究成果。由于提出的研究方法，研究生将接受许多学科（化学工程，微生物学和计算建模）的培训。鉴于环境问题的复杂性，未来的工程师接受跨学科的培训是至关重要的。这个项目显然需要微生物学、反应工程、参数估计和数值规划方面的知识。与UV LED制造商Sensor Electronic Technologies的合作将有助于确保这项研究中各个阶段的成功。

0932116DucosteThe proposed research plan seeks to integrate bench-scale and pilot-scale experimental and numerical techniques for comprehensive characterization of an ultraviolet light emitting diode (UV LED) continuous flow reactor. Data from these experiments will provide the necessary information to develop and validate a computational fluid dynamics (CFD) model of a UV LED disinfection system. The validated CFD model will be combined with a heuristic optimization routine to construct an efficient continuous flow UV LED system based on desired optimality criteria (i.e., minimize the total power input while achieving the required effluent log inactivation or maximize the effluent log inactivation given a target total power input). Overall, this research will allow engineers to determine whether UV LED based continuous flow UV reactor systems can achieve high disinfection system efficiencies and offer an alternative technology that replaces mercury vapor UV lamps.The acceptance of UV as an effective disinfection process for treating drinking water sources and its potential use in water reuse applications have led to considerable growth over the last 10 years. Such growth has ignited researchers to improve the effectiveness of UV reactor designs and perform research to discover novel ways to increase the power output of low pressure lamps, improve the efficiency of low and medium pressure lamps, increase the lamp operating life, and develop new UV emission sources. However, a majority of the UV lamp technologies contain mercury, which is considered hazardous waste and poses environmental and public health threats if not properly disposed or if lamps are broken. Lamp breakage may occur during the transportation or installation of the lamps within the treatment process as well as by a foreign object strike while the UV system is in operation. Other UV light technologies that have emerged (i.e., pulsed and excimer lamps and UV LEDs) do not contain mercury. However, little research has been performed with UV LEDs to assess their capabilities as an effective UV emission light source within continuous flow UV systems.This research program proposes to examine the UV disinfection efficiency of UV LED continuous flow reactors by 1) performing collimated beam experimental tests that determine the UV response of target non-pathogenic microorganisms and UV sensitive fluorescence microspheres at multiple UV LED wavelengths, 2) developing a numerical model that describes the UV LED light distribution, UV dose distribution, and microbial log inactivation of continuous flow UV LED reactors, 3) performing pilot-scale experiments on a UV LED reactor over a range of flows and UV transmittance to validate numerical models, and 4) developing an optimal UV LED reactor based on the output from a combined optimization routine and CFD model.The proposed research represents one of the first comprehensive and direct efforts to quantify the disinfection performance of a distributed point light source within a continuous flow UV reactor that may lead to improved disinfection efficiencies without geometric constraints due to incorporation of a cylindrical light source. Previous studies have only investigated UV LEDs with bench scale tests to assess either log inactivation of E-coli or the degradation of phenol under advance oxidation conditions with peroxide. The proposed study is a necessary first step to evaluating this alternative UV light source as a benign replacement to current mercury vapor UV lamps in continuous flow systems.This project will contribute to the education of one PhD and one MS student in Environmental Engineering. These students will be selected from the pool of applicants to the Civil, Construction, and Environmental Engineering (CCEE) Department, with special consideration for applicants from under-represented groups. The graduate students will be extensively involved in all areas of research: 1) experimental design, setup, and execution, 2) development and execution of numerical simulations, 3) presentation of research results at national and international conferences and peer reviewed publications. The graduate students will be trained in many disciplines (chemical engineering, microbiology, and computational modeling) due to the proposed research approach. It is essential that future engineers receive interdisciplinary training given the complex nature of environmental problems. This project clearly requires knowledge in microbiology, reaction engineering, parameter estimation, and numerical programming. A partnership involving Sensor Electronic Technologies, a UV LED manufacturer, will help ensure the success of the various phases involved in this research.