UNS: Class-Specific Transformations of Antibiotics in UV-Based Water/Wastewater Treatment Processes

1510420 Blaney拟议的工作集中在三类抗生素的紫外线转化反应：氟喹诺酮类，四环素类和磺胺类。重磅炸弹药物（例如，环丙沙星、四环素、磺胺甲恶唑）已经被广泛研究;然而，这些化合物在紫外驱动的水/废水处理过程中的行为不一定延伸到同一类别内的其它化合物。此外，存在将抗生素转化为其他抗生素的潜力。该项目的总体目标是提供对来自三个关键抗生素类别的40种化合物的紫外光反应的全面了解。该项目将包括关注的抗生素，包括15种氟喹诺酮类，10种四环素类和15种磺胺类。假设是在基于紫外线的过程中存在抗生素到抗生素转化的显著潜力。在水/废水处理过程中产生抗生素的这种途径对于降低成品水和废水中抗生素浓度相关的风险至关重要。 这一假设将通过以下具体目标进行检验：1.建立40种抗生素的在线固相萃取液相色谱电喷雾串联质谱分析方法。2.用253.7 nm的紫外光和合成溶液、成品水和废水中的羟基自由基测量反应动力学和抗生素转化。3.确定每个类别中的抗菌药物到抗生素的转化，并构建反应途径，以证明紫外线处理后残留抗菌活性的潜力。4.为了表征经处理的溶液的残余抗微生物活性（即，合成的、饮用水和废水）中含有紫外线转化产物。该方法是一种多管齐下的研究战略，将增加对水和废水中一类日益重要的化学品的命运的了解。对特定类别中抗生素转化为抗生素的认识仅限于自然系统，而不是工程紫外线过程。这项拟议的研究代表了变革性的研究，挑战了围绕紫外线过程中抗生素转化的传统智慧。该项目的另一个变革性的质量来自于强调以类为基础的方法来研究药物和个人护理产品，而不是对化学多样性分子的大规模调查。拟议的研究的预期效益包括比摩尔吸光系数，量子产率和基于通量的伪一级速率常数的测量;确定抗生素与羟基自由基反应的二级速率常数;确定抗生素的光转化产物/途径;和转化产物的毒性表征。为了更好地了解国家处方药回收日计划对防止药物进入水生环境的影响，PI将与DEA特别代理合作，收集未来收集的定量数据。特别是，PI建议每年确定和收集存放在UMBC和霍华德县警察局的所有处方药。

1510420BlaneyThe proposed work focuses on ultraviolet-based transformation reactions for three classes of antibiotics: fluoroquinolones, tetracyclines, and sulfonamides. The blockbuster drugs (e.g., ciprofloxacin, tetracycline, sulfamethoxazole) in these classes have been extensively studied; however, the behavior of these compounds during ultraviolet -driven water/wastewater treatment processes does not necessarily extend to other compounds within the same class. Furthermore, a potential for antibiotic transformation into other antibiotics exists. The overall objective of this project is to provide a comprehensive understanding of ultraviolet-based reactions of 40 compounds from three critical antibiotic classes.The project will include antibiotics of concern including 15 fluoroquinolones, 10 tetracyclines, and 15 sulfonamides. The hypothesis is that a significant potential for antibiotic-to-antibiotic transformation exists during ultraviolet -based processes. This avenue for antibiotic generation during water/wastewater treatment is critical to lowering the risks associated with antibiotic concentrations in finished water and wastewater effluent. This hypothesis will be tested by the following Specific Aims: 1. To develop an online solid-phase extraction liquid chromatography electrospray ionization tandem mass spectrometry analytical method for 40 antibiotics. 2. To measure reaction kinetics and antibiotic transformation with ultraviolet light at 253.7 nm and hydroxyl radicals in synthetic solutions, finished water, and wastewater effluent. 3. To identify antibiotic-to-antibiotic transformations within each class and construct reaction pathways to demonstrate potential for residual antimicrobial activity after ultraviolet treatment. 4. To characterize the residual antimicrobial activity of treated solutions (i.e., synthetic, drinking water, and wastewater) containing ultraviolet transformation products. The approach is a multi-pronged research strategy which will increase understanding of the fate of an increasingly important class of chemicals in water and wastewater. Awareness of antibiotic-to-antibiotic transformations within specific classes has been confined to natural systems, not engineered ultraviolet processes. The proposed study represents transformative research that challenges conventional wisdom surrounding transformation of antibiotics in ultraviolet processes. Another transformative quality of this project derives from the emphasis on a class-based approach to study of pharmaceutical and personal care products, rather than a large investigation of chemically-diverse molecules. The expected benefits of the proposed research include measurement of specific molar absorptivity, quantum yield, and fluence-based pseudo-first order rate constants; determination of second-order rate constants for antibiotic reaction with hydroxyl radicals; identification of phototransformation products/pathways for antibiotics; and characterization of the toxicity of transformation products. To better understand the impact of the national prescription drug take-back day program on preventing pharmaceuticals from entering the aquatic environment, the PI will be working with a DEA Special Agent to gather quantitative data on future collections. In particular, the PI proposes identifying and massing all prescription drugs deposited at the UMBC and Howard County Police Departments each year.