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的全球性问题，没有明显的解决方案。环境塑料主要由长度小于5毫米的微小碎片组成。这些所谓的“微塑料”（或“MP”）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，其未来的健康影响和生态后果尚不清楚。该研究项目旨在创建安全，高效和具有成本效益的技术，以分离和消除废水中的MP。污水处理厂的出水是环境污染物的主要来源。从大自然中汲取灵感，该项目将利用水箱中成千上万的淡水贻贝来快速有效地过滤大量废水。当吸入废水进行喂养时，贻贝会将废水中的MP与能够分解和破坏塑料的特殊细菌结合起来，将MP转化为天然存在的小有机分子。将对细菌和MP分解产物进行测试，以便不会将有害物质释放到环境中。在整个项目过程中，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切实可行。在实验室和中试规模的技术开发的同时，将开发一个代表全尺寸污水处理系统的数学模型，包括技术，经济和社会组成部分。该模型将用于基准测试和情景探索，为决策者提供清晰的定量答案：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？防止污染的好处是什么，代价是什么？该项目的重点是现有的污水处理厂基础设施将使科学家和工程师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，还将对数十名研究生和本科生进行可持续生物技术培训，并将积极吸引来自代表性不足和弱势社区的学生。多个外展和教育活动将吸引成千上万的K-12学生，教师和公众的支持和想象力。该项目的目标是从污水处理厂（WWTP）的污水中分离和消除微塑料（MP）。污水处理厂流出物是目前环境中大约一半MP的来源，并且可以对污水处理厂进行改造以经济地防止MP对接收沃茨的污染。本计画的方法是利用悬浮投饵的水生双壳贝类来有效地分离与浓缩水中的多金属微粒。此外，通过将MP与某些MP降解细菌共浓缩，MP生物利用度将提高。微生物介导的解聚将通过利用该团队现有的从水生环境中的MP分离的1000种微生物培养物来实现，其中一些已经被证明可以降解某些塑料。该收集将通过从康涅狄格大学的污水处理厂收集的额外菌株来增加，该污水处理厂将作为该项目的活体实验室。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，以及聚乙烯（PE）和聚对苯二甲酸乙二醇酯（PET），这些都是常见的环境MP。为了实现解聚，甚至更多的martcitrant MP，生物沉积物从贻贝将进一步处理在微生物驱动的芬顿生物反应器，和一个互补的梯度微流控方法将用于确定最佳的反应条件。在开发的每个阶段，将量化性能指标以及基本物理化学特性，为全面污水处理厂系统的技术经济优化提供信息，该系统还包含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）详细了解污水处理厂模型中MP的命运;（ii）从废水中浓缩和消除MP的实用的、可扩展的工艺，以及（iii）该奖项反映了NSF的法定使命，并通过利用基金会的智力价值进行评估，更广泛的影响审查标准。

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.