Enhancing biodegradation of quaternary ammonium compounds (QAC)

增强季铵化合物 (QAC) 的生物降解

• 批准号: 1702445
• 负责人: Bruce Rittmann
• 金额: $ 32.97万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1702445&HistoricalAwards=false
• 关键词: Enhancing; biodegradation; quaternary; ammonium; compounds

PI Name: Bruce E. RittmannProposal Number: 1702445 Quaternary ammonium compounds (QACs) are widely used as surfactants and disinfectants in human and animal healthcare, agriculture, and industry. Discharge of QACs can be harmful to biological wastewater treatment and aquatic habitats. Most QACs are biodegradable in the presence of oxygen, and delivery of oxygen is a key to good biodegradation; however, the common practice of bubbling air does not work because the QACs, being surfactants, cause serious foaming. The PIs will study and develop a novel biotechnology to efficiently biodegrade QACs: the oxygen-based membrane biofilm reactor (O2-MBfR). Oxygen is delivered without bubbling to bacteria that grow on the outer surface of hollow-fiber membranes. Thus, an O2-MBfR can sustain QAC biodegradation without foaming and with excellent retention of the QAC-biodegrading bacteria. The PIs will develop the science and engineering foundations for a new environmental-biotechnology system able to bring about QAC biodegradation. The educational component will involve community-college students through a summer internship. The PIs will initiate a program to disseminate sustainability and green-chemistry principles in high school science laboratories, and they will stimulate public interest by participating in the NSF-sponsored website "Ask a Biologist". In the O2-MBfR, oxygen is delivered by diffusion to a biofilm accumulating on the outer surface of hollow-fiber membranes, thereby eliminating the foaming problem and providing excellent resistance to toxicity. Thus, an O2-MBfR should sustain QAC degradation even at the high QAC concentrations found in QAC-bearing wastewater from industrial facilities. The project's over-arching goal is to achieve high-efficiency biodegradation of QACs without incurring foaming and toxicity problems. This goal will be attained by (a) understanding the mechanistic principles of QAC biodegradation in the O2-based MBfR; (b) identifying the conditions leading to optimized performance of a two-stage O2-based MBfR to optimize QAC biodegradation; and (c) developing a mathematical model that integrates the kinetics of QACs biodegradation, mass-transfer kinetics, and biofilm accumulation and detachment. On the practical side, results of the work will demonstrate QAC biodegradation by using efficient O2 delivery by bubbleless diffusion. At the same time, the PIs will develop mechanistic and quantitative understanding of QAC biodegradation, including the microbial ecology and physiology of membrane-bound biofilms.

PI姓名：布鲁斯E. Rittmann提案编号：1702445季铵化合物（QAC）广泛用作人和动物保健、农业和工业中的表面活性剂和消毒剂。 QAC的排放可能对生物废水处理和水生生境有害。 大多数QAC在氧气存在下是可生物降解的，并且氧气的输送是良好生物降解的关键;然而，鼓泡空气的常见做法不起作用，因为QAC是表面活性剂，会引起严重的起泡。 研究所将研究和开发一种新的生物技术，以有效地生物降解QAC：氧基膜生物膜反应器（O2-MBfR）。 氧气在没有气泡的情况下输送到生长在中空纤维膜外表面的细菌。 因此，O2-MBfR可以维持QAC生物降解而不起泡，并且具有对QAC生物降解细菌的优异保留。 研究所将为能够实现QAC生物降解的新环境生物技术系统奠定科学和工程基础。 教育部分将通过暑期实习让社区学院的学生参与。 PI将发起一项计划，在高中科学实验室传播可持续性和绿色化学原则，他们将通过参与NSF赞助的网站“问生物学家”来激发公众的兴趣。 在O2-MBfR中，氧气通过扩散传递到中空纤维膜外表面上积聚的生物膜，从而消除了起泡问题并提供了优异的抗毒性。 因此，O2-MBfR应维持QAC降解，即使在高QAC浓度中发现的QAC轴承废水从工业设施。 该项目的最终目标是实现QAC的高效生物降解，而不会产生泡沫和毒性问题。 这一目标将通过以下方式实现：（a）理解QAC生物降解在O2-基MBfR中的机械原理;（B）确定导致两阶段O2-基MBfR优化QAC生物降解的优化性能的条件;以及（c）开发集成QAC生物降解动力学、传质动力学和生物膜积累和分离的数学模型。 在实践方面，工作的结果将证明QAC生物降解通过使用有效的O2输送无泡扩散。 同时，PI将开发QAC生物降解的机制和定量的理解，包括膜结合生物膜的微生物生态学和生理学。

项目成果

Increased expression of antibiotic-resistance genes in biofilm communities upon exposure to cetyltrimethylammonium bromide (CTAB) and other stress conditions

• DOI: 10.1016/j.scitotenv.2020.144264
• 发表时间: 2021-01-05
• 期刊: SCIENCE OF THE TOTAL ENVIRONMENT
• 影响因子: 9.8
• 作者: Luo, Yi-Hao;Lai, YenJung Sean;Rittmann, Bruce E.
• 通讯作者: Rittmann, Bruce E.