CAS-MNP: Assessing the Controls of Plastic Photochemical Reactivity in the Surface Ocean

在NSF化学部环境化学科学计划的支持下，伍兹霍尔海洋研究所（WHOI）的柯林沃德和泰勒纳尔逊将研究塑料在阳光照射下的海洋表面的命运。尽管利益相关者持续关注，但消费塑料在海洋中的最终命运仍然是一个悬而未决的问题。暴露于阳光是关键的降解过程（即，光降解），但影响海洋中塑料光降解速率和程度的控制措施还没有得到很好的理解。这项研究旨在确定控制消费塑料光化学降解的因素，从而确定它们在海洋中的命运。从这项研究中获得的基本知识将为估计海洋中塑料的数量，位置和持久性及其对生态系统过程的潜在影响的命运和运输模型提供信息。该项目支持参与林肯实验室海狸工程暑期研究所和建立一个立方体卫星挑战赛，为全国各地的高中学生提供了解海洋塑料污染的机会。 此外，许多本科生和研究生将接受培训并参与这项研究项目。众所周知，阳光将海洋中的塑料化学转化为一系列聚合物、溶解物和气相产物。然而，这些光化学过程的管理控制约束不足。这项研究将揭示对海上消费塑料的光化学反应性进行不同控制的相对重要性，包括粒径、塑料配方（即，基础聚合物+无机添加剂如二氧化钛和氧化锌），和日光波长。具体测试措施包括氧化（分子氧消耗）、断链（分子量降低）和溶解有机物的产生。该项目支持高中生的外展活动，以及本科生和研究生的培训。该奖项反映了NSF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。

With support from the Environmental Chemical Sciences Program in the Division of Chemistry at NSF, Collin Ward and Taylor Nelson at the Woods Hole Oceanographic Institution (WHOI) will study the fate of plastics in the sunlit surface ocean. Despite sustained attention from stakeholders, the ultimate fate of consumer plastics in the ocean remains an open question. Exposure to sunlight is a key degradation process (i.e., photo-degradation) for most consumer plastics but the controls that affect the rates and extents of plastic photo-degradation in the ocean are not well understood. This study aims to determine the factors that control photochemical degradation of consumer plastics and thus their fate in the ocean. The basic knowledge gained from this research will inform fate and transport models that estimate the amount, location, and persistence of plastics in the ocean, as well as their potential impacts on ecosystem processes. This project supports engagement with the Lincoln Laboratory Beaver Works Summer Institute and the Build a CubeSat Challenge, opportunities for high school students across the country to learn about marine plastic pollution. Moreover, numerous undergraduate, and graduate students will be trained and participate on this research project.It is widely understood that sunlight chemically transforms plastics in the ocean into a suite of polymer-, dissolved-, and gas-phase products. However, the governing controls of these photochemical processes are poorly constrained. This research will deconvolute the relative importance of varying controls on the photochemical reactivity of consumer plastics at sea, including particle size, plastic formulation (i.e., base polymer + inorganic additives such as titanium dioxide and zinc oxide), and sunlight wavelength. Specific measures to be tested include oxidation (molecular oxygen consumption), chain scission (decrease in molecular weight), and the production of dissolved organics. This project supports outreach activities with high school students, and the training of undergraduate and graduate students.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.