ERI: Dynamic membranes in anaerobic wastewater treatment systems: Enhancing mitigation of emerging microbial threats to promote safe water reuse

厌氧膜生物反应器(ANMBR)为设计、建造和部署新一代处理工艺提供了新的机会，这些工艺可以从废水中回收清洁的水，同时产生能源(沼气)和/或有价值的产品，如中等羧酸。ANMBR在专门设计的生物反应器中将膜过滤(微滤或超滤)与厌氧消化结合在一起。厌氧动态膜生物反应器(AnDMBR)是一种很有发展前途的新型膜生物反应器，它具有通量低、投资和运行费用高、易造成膜污染等缺点。在ANDMBR中，在孔径从5-200微米的不锈钢网(或机织/非织造布)上原位形成的生物膜提供过滤介质，从而避免了使用商业微滤膜或超滤膜的需要。该ERI项目的首要目标是评估ANDMBR去除与抗生素耐药性传播相关的病原菌、基因和其他生物标记物的有效性，目的是产生安全的农业回用废水。该项目的成功完成将使社会受益，因为它促进了关于使用ANDMBR的基本知识，从而使农村废水能够可持续和安全地用于作物灌溉。通过学生教育和培训将为社会带来更多好处，包括指导新墨西哥州采矿与技术学院的一名研究生和两名本科生。厌氧膜生物反应器(ANMBR)将膜分离和厌氧消化相结合，产生适合农业重复使用的高质量污水。在厌氧动态膜生物反应器(ANDMBR)中，在低成本的多孔基质(如不锈钢网或机织/非织造布)上原位形成的生物膜作为动态膜和过滤介质。最近的研究表明，在膜生物反应器的膜表面形成的生物膜可以提高出水水质，并有助于去除病原菌和新出现的生物污染物。然而，目前尚不清楚AnDMBRs的生物膜是否能在去除致病菌、基因或其他与抗生素耐药性相关的标记方面保持类似的益处。该ERI项目将解决这一关键的知识差距。这项研究的具体目标是1)量化ANMBR系统出水中抗生素耐药细菌(ARB)、抗生素耐药基因(ARGs)和其他相关基因转移元件的浓度和丰度；2)建立评估ANMBR系统出水中细胞内和细胞外ARGs丰度的基线；以及3)评估ANDMBR在农村废水处理过程中去除ARB和ARGs的有效性。这一项目的成功完成有可能产生变革性的影响，通过发展新的基本知识，推动设计和部署更有效、更具成本效益的技术，为农村社区的农业和农业可持续和安全地再利用废水。为实施该项目的教育和外联活动，首席调查员(PI)计划利用新墨西哥州矿业和技术学院的现有方案，如K-12外联方案、高中生STE2M暑期体验、该项目由CBET环境工程计划和既定的激励竞争研究计划(EPSCoR)共同资助。该奖项反映了NSF的法定使命，并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。

Anerobic membrane bioreactors (AnMBRs) are providing new opportunities to design, build, and deploy a new generation of treatment processes that can recover clean water from wastewater while generating energy (biogas) and/or valuable products such as medium-carboxylic acids. AnMBRs combine membrane filtration (microfiltration or ultrafiltration) with anaerobic digestion in specially designed bioreactors. Anaerobic dynamic membrane bioreactors (AnDMBRs) have emerged as promising alternatives to address the shortcomings of current AnMBRs including low flux, high capital and operating costs, and high propensity for membrane fouling. In AnDMBRs, in-situ formed biofilms on stainless-steel meshes (or woven/nonwoven fabrics) with pore sizes ranging from 5-200 microns provide the filtration media thereby circumventing the need to use commercial microfiltration or ultrafiltration membranes. The overarching goal of this ERI project is to evaluate the effectiveness of AnDMBRs to remove pathogenic bacteria, genes, and other biomarkers associated with the spread of antibiotic resistance with the goal of producing water effluents that are safe for agricultural reuse. The successful completion of this project will benefit society by advancing fundamental knowledge on the use of AnDMBRs to enable the sustainable and safe reuse of rural wastewater for crop irrigation. Additional benefits to society will be achieved through student education and training including the mentoring of one graduate student and two undergraduate students at the New Mexico Institute of Mining and Technology.Anaerobic membrane bioreactors (AnMBRs) combine membrane separation with anaerobic digestion to produce a high-quality effluent suitable for agricultural reuse. In anerobic dynamic membrane bioreactors (AnDMBRs), in-situ formed biofilms on low-cost porous substrates (e.g., stainless-steel meshes or woven/nonwoven fabrics) serve as dynamic membranes and filtration media. Recent studies have shown that the biofilms that form on membrane surfaces in AnMBRs can enhance effluent water quality and aid in the removal of pathogenic bacteria and emerging biological contaminants. However, it is still unclear if the biofilms of AnDMBRs can maintain similar benefits for the removal of pathogenic bacteria, genes or other markers associated with antibiotic resistance. This ERI project will address this critical knowledge gap. The specific objectives of the research are to 1) Quantify the concentration and abundance of antibiotic-resistant bacteria (ARBs), antibiotic resistance genes (ARGs), and other relevant gene transfer elements in AnMBR system effluents; 2) Establish a baseline for assessing the abundances of both intracellular and extracellular ARGs in AnMBR system effluents during the treatment of real and representative rural wastewaters; and 3) Evaluate the effectiveness of AnDMBRs to remove ARBs and ARGs during the treatment of rural wastewaters. The successful completion of this project has the potential for transformative impact through the development of new fundamental knowledge to advance the design and deployment of more efficient and cost-effective technologies for the sustainable and safe reuse of wastewater for agriculture and farming in rural communities. To implement the education and outreach activities of the project, the Principal Investigator (PI) plans to leverage existing programs at the New Mexico Institute of Mining and Technology such as the K-12 outreach program, the STE2M summer experience for high school students, and the Upward Bound Math and Science program for local high school students to communicate the outcomes of the proposed research and engage the local community on water management and reuse.This project is jointly funded by the CBET Environmental Engineering program and the Established Program to Stimulate Competitive Research (EPSCoR).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.