Collaborative Research: Environmental Fate and Impacts of Quaternary Ammonium Compounds Following Increased Use During the SARS-CoV‑2 Pandemic

新型冠状病毒SARS-CoV-2是全球COVID-19大流行的罪魁祸首。为应对大流行，用于杀死表面上的SARS-CoV-2和洗手的消毒使用量急剧增加。大量消毒剂已被批准作为SARS-CoV-2消毒剂使用，其中许多含有季铵化合物（QACs）。质量化学物质将不可避免地被送到污水处理厂，有些将最终进入接收水。这些消毒化学品对污水处理厂的运行和接收水的影响在很大程度上是未知的。这些化合物还可能促进抗生素耐药微生物的传播，这是一个对全球健康具有重要意义的问题。该项目的目标是解决我们在质量保证体系知识方面的这些主要差距，以提供有助于限制任何环境影响的信息。该目标将通过评估废水处理厂的质量化学物质，并确定它们在不同的工厂工艺和接收水中发生的情况来实现。拟议研究的成功完成将提供评估质量保证物质的风险所需的信息，以保护公众健康，同时尽量减少对环境的持久性和影响。该项目将与污水处理系统运营商合作，改善操作，并为中学环境科学学生制作教育视频，以提高国民的科学素养。季铵化合物（QACs）是目前推荐用于杀死SARS-CoV-2 （COVID-19）病毒的200多种消毒剂中的有效成分。这些消毒剂在洗手和表面清洁中的使用仍在增加，而污水处理厂和地表水的化学负荷增加对生物的影响在很大程度上是未知的。这项工作的目的是评估增加的QAC负荷对污水处理厂以及随后的水生和土壤环境的潜在影响。这一目标将通过具体的研究目标来实现：1)评估废水处理设施、地表水和沉积物中的QAC水平；2)量化QACs的降解速率常数并预测其在地表水中的持久性；3)了解厌氧消化池和水环境中QAC负荷的增加如何影响抗生素耐药性。将对采用各种生物和化学处理工艺的12个污水处理厂进行为期三年的季节性采样，以评估进水、液体流出物和生物固体流出物的QAC负荷。还将对排水口附近的沉积物样本进行采样。我们会在两个滤水厂就质素保证谘询服务在个别单位的运作进行质量平衡。实验室规模的生物降解和光解实验将进行，以产生速率去除常数，以预测在环境水域的持久性。将进行实验室规模的厌氧消化实验，以确定特定QAC类浓度增加对抗生素耐药性的影响。来自全尺寸工厂的样本也将被分析抗生素耐药性的变化。SARS-CoV-2大流行给QACs的使用数量及其具体环境影响带来了很大的不确定性。通过结合实验室规模和全面研究，我们将生成QACs类别和个体QACs的数据，这些数据可用于风险评估和评估其对抗生素耐药性的影响。鉴于2019冠状病毒病（COVID-19）大流行以及消费者和企业购买含有QACs的产品的长期变化，预计QACs的负荷将增加，这项研究是及时的和变革性的。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The novel coronavirus SARS-CoV-2 is responsible for the global pandemic of COVID-19. Disinfection use to kill SARS-CoV-2 on surfaces and for handwashing has increased dramatically in response to the pandemic. A large number of disinfectants have been approved for usage as SARS-CoV-2 disinfectants, many of which contain quaternary ammonium compounds (QACs). QACs will inevitably be sent to wastewater treatment plants and some will end up in receiving waters. The effect of these disinfection chemicals on the operation of wastewater treatment plants and receiving waters is largely unknown. These compounds may also contribute to the spread of antibiotic resistance microorganisms, an issue of global health importance. The goal of this project is to address these major gaps in our knowledge on QACs to provide information to help limit any environmental impact. The goal will be achieved by assessing QACs in wastewater treatment plants and determine what happens to them in different plant processes and receiving waters. Successful completion of the proposed research will provide the information needed to assess the risk of QACs to protect public health while minimizing environmental persistence and impacts. The project will lead to collaborations with wastewater treatment systems operators to improve operations and the development of educational videos for middle school environmental science students to enhance scientific literacy of the Nation.Quaternary ammonium compounds (QACs) are active ingredients in over 200 disinfectants currently recommended for use to kill the SARS-CoV-2 (COVID-19) virus. Increased use of these disinfectants for hand washing and surface cleaning continues, and the biological impacts of increasing chemical loadings to wastewater treatment plants and surface waters is largely unknown. The goal of this work is to assess the potential impacts of increased QAC loadings to wastewater treatment plants and subsequently aquatic and soil environments. This goal will be achieved through specific research objectives to: 1) Assess QAC levels in wastewater treatment facilities, surface waters, and sediments; 2) Quantify degradation rate constants for QACs and predict persistence in surface waters; and 3) Understand how increased QAC loadings to anaerobic digesters and water environments affects antibiotic resistance. Twelve wastewater treatment plants employing various biological and chemical treatment processes will be sampled seasonally for three years to assess influent, liquid effluent, and biosolids effluent QAC loadings. Sediment samples near outfalls will also be sampled. A mass balance on QACs across individual unit operations will be conducted at two treatment plants. Lab-scale biodegradation and photolysis experiments will be conducted to generate rate removal constants to predict persistence in environmental waters. Lab-scale anaerobic digester experiments will be conducted to determine the impact of increasing concentrations of specific QAC classes on antibiotic resistance. Samples from full-scale plants will also be analyzed for changes in antibiotic resistance. The SARS-CoV-2 pandemic brings large uncertainty regarding the amount of QACs that will be used and their specific environmental impacts. By combining lab-scale and full-scale studies we will generate data on classes of QACs and individual QACs that can be used for risk assessments and assessing their impacts on antibiotic resistance. This research is timely and transformative given the expectation of increased loadings of QACs due to the COVID-19 pandemic and long-term changes in consumer and business purchasing of products containing QACs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.