Evaluation of Continuous Flow Ultraviolet Light Emitting Diode

连续流紫外发光二极管的评估

• 批准号: 0932116
• 负责人: Joel Ducoste
• 金额: $ 35.68万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0932116&HistoricalAwards=false
• 关键词: Evaluation; Continuous; Flow; Ultraviolet; Light

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.

0932116DucosteThe拟议的研究计划旨在整合实验室规模和中试规模的实验和数值技术的紫外线发光二极管（UV LED）连续流反应器的综合表征。从这些实验的数据将提供必要的信息，开发和验证的计算流体动力学（CFD）模型的紫外线LED消毒系统。经验证的CFD模型将与启发式优化程序相结合，以根据所需的最优标准（即，最小化总功率输入，同时实现所需的流出物对数灭活，或者在给定目标总功率输入的情况下最大化流出物对数灭活）。总的来说，这项研究将使工程师能够确定是否紫外线LED为基础的连续流紫外线反应器系统可以实现高消毒系统的效率，并提供一种替代技术，取代汞蒸气紫外线lamps.The接受紫外线作为一种有效的消毒过程处理饮用水源和其潜在的使用在水回用应用已经导致了相当大的增长，在过去的10年。这种增长激发了研究人员提高UV反应器设计的有效性，并进行研究以发现增加低压灯的功率输出的新方法，提高低压和中压灯的效率，增加灯的工作寿命，并开发新的UV发射源。 然而，大多数紫外线灯技术都含有汞，汞被认为是危险废物，如果处置不当或灯损坏，会对环境和公众健康构成威胁。灯管破损可能发生在处理过程中灯管的运输或安装过程中，也可能发生在紫外线系统运行时异物撞击时。已经出现的其他UV光技术（即，脉冲灯和准分子灯以及UV LED）不含汞。然而，很少有研究已经进行了与紫外线LED，以评估其作为一个有效的紫外线发射光源在连续流紫外线系统中的能力。本研究计划提出，检查紫外线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，确定目标非病原微生物和紫外线敏感荧光微球在多个紫外线LED波长的紫外线响应，2）开发描述连续流UV LED反应器的UV LED光分布、UV剂量分布和微生物对数灭活的数值模型，3）在一定流量和UV透射率范围内对UV LED反应器进行中试规模实验以验证数值模型，和4）基于优化程序和CFD模型的输出，开发了一种最佳的UV LED反应器。该研究代表了第一个全面的，直接致力于量化连续流UV反应器内的分布式点光源的消毒性能，这可以导致改进的消毒效率，而没有由于圆柱形光源的结合而引起的几何约束。以前的研究只研究了紫外线LED与实验室规模的测试，以评估无论是对数灭活大肠杆菌或苯酚的降解提前氧化条件下与过氧化物。拟议的研究是一个必要的第一步，以评估这种替代紫外线光源作为一个良性的替代目前的汞蒸气紫外线灯在连续流动system.This项目将有助于教育的一个博士和一个MS学生在环境工程。这些学生将从申请人中选择到土木，建筑和环境工程（CCEE）部门，特别考虑来自代表性不足的群体的申请人。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）在国家和国际会议上展示研究成果以及同行评审的出版物。由于所提出的研究方法，研究生将在许多学科（化学工程，微生物学和计算建模）进行培训。鉴于环境问题的复杂性，未来的工程师必须接受跨学科的培训。这个项目显然需要微生物学，反应工程，参数估计和数值编程的知识。 与UV LED制造商Sensor Electronic Technologies的合作将有助于确保这项研究所涉及的各个阶段的成功。