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是导致新冠肺炎全球大流行的原因。随着疫情的蔓延，用来杀死表面上的SARS-CoV-2和洗手的消毒方法急剧增加。大量消毒剂已被批准用作SARS-CoV-2消毒剂，其中许多含有季铵化合物(QAC)。QAC将不可避免地被送往废水处理厂，其中一些将最终进入接受水的地方。这些消毒剂对污水处理厂和接受水的运行的影响在很大程度上是未知的。这些化合物还可能导致抗生素耐药性微生物的传播，这是一个对全球健康具有重要意义的问题。这个项目的目标是解决我们在QAC知识上的这些主要差距，以提供信息来帮助限制对环境的任何影响。这一目标将通过评估污水处理厂的QAC来实现，并确定它们在不同的工厂流程和接收水中发生了什么。拟议研究的成功完成将为评估QAC的风险提供所需的信息，以保护公众健康，同时将环境持久性和影响降至最低。该项目将导致与废水处理系统运营商合作，改善操作，并为中学生开发环境科学教育视频，以提高国家的科学素养。季铵化合物(QAC)是目前推荐用于杀灭新冠肺炎病毒的200多种消毒剂的有效成分。这些消毒剂用于洗手和表面清洁的使用继续增加，废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。这项工作的目标是评估QAC负荷增加对废水处理厂以及随后的水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QAC的降解速率常数并预测QAC在地表水中的持久性；以及3)了解厌氧消化器和水环境中增加的QAC负荷如何影响抗生素耐药性。12个采用不同生物和化学处理工艺的废水处理厂将按季节抽样，为期三年，以评估进水、液体流出和生物固体流出的QAC负荷。此外，我们亦会抽取排污口附近的沉积物样本。将在两个处理厂对各个单元操作的QAC进行质量平衡。将进行实验室规模的生物降解和光解实验，以产生速率去除常数来预测环境水域中的持久性。将进行实验室规模的厌氧消化器实验，以确定特定QAC类别浓度增加对抗生素耐药性的影响。来自大规模工厂的样本也将被分析抗生素耐药性的变化。SARS-CoV-2大流行带来了关于将使用的QAC数量及其具体环境影响的巨大不确定性。通过结合实验室规模和全面研究，我们将生成关于QAC类别和单个QAC的数据，这些数据可用于风险评估和评估它们对抗生素耐药性的影响。考虑到新冠肺炎疫情以及消费者和企业对含有QAC的产品的长期购买发生的变化，预计QAC的负载将会增加，这项研究是及时和具有变革性的。该奖项反映了美国国家科学基金会的法定使命，并已通过使用基金会的智力优势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.