EFRI E3P: Engineering Suspension Feeder Systems for Separation and Elimination of Microplastics from Water

环境中的塑料污染是一个普遍存在的全球性问题，没有明显的解决方案。环保塑料主要由长度小于5毫米的小碎片组成。这些所谓的“微塑料”（或“MPs”）现在几乎存在于地球上的每一个环境中，包括人类和动物体内，它们未来对健康的影响和生态后果尚不清楚。本研究项目旨在创造安全、高效、经济的技术，从废水中分离和消除MPs。废水处理厂（WWTPs）的流出物是环境MPs的主要来源。从大自然中汲取灵感，该项目将使用成千上万种在水箱中生长的淡水贻贝来快速有效地过滤大量废水。当贻贝吸收废水为食时，它们会将废水中的MPs与能够分解和破坏塑料的特殊细菌结合起来，将MPs转化为自然产生的小有机分子。将对细菌和MP分解产物进行测试，以确保没有有害物质释放到环境中。在整个项目中，该团队将与污水处理厂运营商和州监管机构合作，以确保正在开发的技术能够实际实施。在实验室和中试规模技术开发的同时，将开发一个数学模型，代表一个包括技术、经济和社会组成部分的全面污水处理厂系统。该模型将用于基准测试和情景探索，为决策者提供清晰、定量的答案，以回答以下问题：如何在考虑传统和新技术的情况下修改我们现有的污水处理厂？预防污染的效益是什么？成本是多少？该项目将重点放在现有的污水处理厂基础设施上，这将使科学家和工程师能够以相对较小的投资产生巨大的影响。该项目由来自两所大学的10名科学家和工程师组成的团队领导，还将培训数十名研究生和本科生学习可持续生物技术，并将积极吸引来自代表性不足和处境不利社区的学生。多种推广和教育活动将吸引数千名K-12学生、教师和公众的支持和想象。该项目的目的是从污水处理厂（WWTP）流出物中分离和消除微塑料（MPs）。污水处理厂的废水是目前环境中大约一半的多聚污染物的来源，污水处理厂可以进行改造，以经济地防止接收水的多聚污染物污染。本项目的方法是采用悬浮饲养水生双壳类来有效地从水中分离和浓缩MPs。此外，通过将MPs与某些降解MP的细菌共浓缩，MP的生物利用度将得到提高。微生物介导的解聚将通过利用该团队现有的1000种微生物培养物来实现，这些微生物培养物是从水生环境中的MPs中分离出来的，其中一些已经被证明可以降解某些塑料。康涅狄格大学（University of Connecticut）的污水处理厂将作为该项目的活体实验室，对这些收集的菌株进行补充。该项目的范围将包括颗粒和纤维形式的聚羟基丁酸酯（PHB），一种更容易降解的聚酯，以及更难降解的聚乙烯（PE）和聚对苯二甲酸乙二醇酯（PET）；他们都是普通的环保议员。为了实现更顽固的MPs的解聚，贻贝的生物沉积物将在微生物驱动的Fenton生物反应器中进一步处理，并使用互补梯度微流控方法来确定最佳反应条件。在开发的每个阶段，性能指标将与基本的物理化学性质一起被量化，以告知全面的污水处理厂系统的技术经济优化，该系统还包含了技术采用的社会技术驱动因素/障碍的成本模型。该项目的预期成果包括：(i)详细了解模型污水处理厂中MPs的命运；（ii）从废水中浓缩和消除多聚物的实用、可扩展的工艺，以及（iii）推动广泛采用这种多聚物分离和消除技术的决策工具。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。

Plastic contamination in the environment is a pervasive global problem with no obvious solutions. Environmental plastics are predominantly comprised of tiny pieces less than five millimeters in length. These so-called “microplastics” (or “MPs”) are now found in nearly every environment on Earth, including inside humans and animals, and their future health impacts and ecological consequences are unknown. This research project aims to create safe, efficient, and cost-effective technology to separate and eliminate MPs from wastewater. Outflows from wastewater treatment plants (WWTPs) are a major source of environmental MPs. Taking inspiration from nature, this project will employ freshwater mussels grown by the thousands in tanks to quickly and efficiently filter large volumes of wastewater. When drawing in wastewater for feeding, the mussels will combine the MPs in the wastewater with special bacteria capable of breaking down and destroying the plastic, transforming MPs back into small, naturally-occurring organic molecules. The bacteria and the MP breakdown products will be tested so that nothing harmful is released into the environment. Throughout the project, the team will engage with WWTP operators and state regulators to make sure the technology being developed is practical to implement. In parallel with lab- and pilot-scale technology development, a mathematical model representing a full-scale WWTP system including technical, economic, and social components will be developed. The model will be used for benchmarking and scenario exploration to give decision-makers clear, quantitative answers to the questions: how can our existing WWTP be modified, considering both traditional and novel technologies? what pollution prevention benefits would be achieved and at what cost? The project's focus on existing WWTP infrastructure will allow scientists and engineers to make a large impact with a relatively small investment. Led by a team of 10 scientists and engineers from two universities, the project will also train dozens of graduate and undergraduate students in sustainable biotechnology and will proactively engage students from underrepresented and disadvantaged communities. Multiple outreach and education activities will engage the support and imagination of thousands of K-12 students, teachers, and members of the public.The objective of this project is to separate and eliminate microplastics (MPs) from wastewater treatment plant (WWTP) effluent. WWTP effluent is the source for approximately half of the MPs now in the environment, and WWTPs can be modified to economically prevent MP pollution of receiving waters. The approach of this project is to employ suspension-feeding aquatic bivalves to efficiently separate and concentrate MPs from water. Further, by co-concentrating MPs with certain MP-degrading bacteria, MP bioavailability will be enhanced. Microbially-mediated depolymerization will be achieved by leveraging the team’s existing collection of 1000 microbial cultures isolated from MPs in aquatic environments, some of which have already been shown to degrade certain plastics. This collection will be augmented by additional strains collected from the WWTP at the University of Connecticut, which will serve as a living laboratory for the project. The scope of the project will encompass both particulate and fibrous forms of polyhydroxybutyrate (PHB), a more readily-degraded polyester, as well as polyethylene (PE) and polyethylene terephthalate (PET), which are more recalcitrant; all are common environmental MPs. To achieve depolymerization of even the more recalcitrant MPs, biodeposits from mussels will be further processed in a microbially-driven Fenton bioreactor, and a complementary gradient microfluidic approach will be used to identify the optimal reaction conditions. At each stage of development, performance metrics will be quantified, alongside fundamental physiochemical properties, to inform a techno-economic optimization of a full-scale WWTP system that also incorporates a cost model for the socio-technical drivers/barriers to technology adoption. The expected outcomes of this project include (i) a detailed understanding of the fate of MPs in a model WWTP; (ii) practical, scalable processes to concentrate and eliminate MPs from wastewater, and (iii) decision tools to drive broad adoption of this MP separation and elimination technology.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.