Collaborative Research: Fundamental Understanding of the Environmental Fate of Disinfection By-Products Arising from Desalination Plants

该奖项由化学部的环境化学科学计划和化学，生物工程，环境和运输系统部门的环境工程计划共同支持。马里兰州大学环境科学中心的Michael Gonsior博士及其同事与南卡罗来纳州大学的Susan Richardson博士合作。他们研究在海水消毒过程中产生的化合物的形成，这是在美国和澳大利亚的主要海水淡化厂使用水之前所必需的。在世界上许多地方，海水淡化是将盐水转化为饮用水的重要方法。随着淡水供应越来越少，它正成为一种越来越重要的处理技术。然而，目前在消毒处理过程中产生的潜在有害的有机化合物在废水流中被排放到水生环境中。这些有机化合物对水生生物的影响在很大程度上是未知的。这项研究提供了新的知识，形成以前未知的消毒副产品（DBPs）在海水淡化过程中产生的。水环境中的有机化合物的新的定量方法也被开发。本科生通过实习接触到这项研究，如通过马里兰州海洋赠款REU计划和南加州大学。CBL游客中心展示了海水DBPs，它们是如何形成的，以及它们对沿海海洋的影响。与切萨皮克生物实验室游客中心合作，研究小组为7 - 12年级的学生/教师举办夏季研讨会。研究人员还与美国、澳大利亚和德国的同事合作，包括来自主要海水淡化厂的行业合作伙伴。预计未来全球都将依赖海水淡化和水再利用来提供合适的饮用水。 在脱盐过程中，需要对水进行氯化，以限制膜的生物污染并杀死潜在的有害细菌。饮用水氯化消毒过程中消毒副产物（DBPs）的形成以及不同淡水来源所呈现的复合因素（如高水平的溶解性有机物（DOM））是公认的。然而，在海水的氯化过程中，会形成数百种溴化和碘化化合物，其中很少有被表征的，并且其中一些已知具有高度毒性。研究人员利用新的分析技术来调查沿海环境中DBPs的产生、归宿和毒性。超高分辨率质谱已被用于在分子水平上描述复杂的有机基质，并已成功地证明了船舶压载水氯化后形成的DBPS的复杂性以及表征天然沃茨中的DOM。所有这些研究都表明，高精度的质量测量与软电离相结合，能够分配明确和准确的分子式。结合传统的气相色谱法与质谱法相结合，以支持化合物子集的定量，该团队在脱盐过程的不同步骤表征了DBP，并评估了释放到环境中的DBP的命运。学生和教师结合联合收割机海水淡化厂测量与控制实验室研究，以更好地了解机制和因素的生产，命运和已知的和新发现的消毒副产物的毒性在海水中形成的预氯化和积累在废水沃茨排放到沿海生态系统。

This award is supported jointly by the Chemistry Division's Environmental Chemical Sciences Program and the Environmental Engineering Program in the Division of Chemical, Bioengineering, Environmental, and Transport Systems. Dr. Michael Gonsior and colleagues at the University of Maryland Center for Environmental Science collaborate with Dr. Susan Richardson at the University of South Carolina. They study the formation of chemical compounds that arise during disinfection of seawater, which is required before water can be used in major desalination plants in the U.S. and Australia. Desalination is an important method for turning salt water into drinkable (potable) water in many parts of the world. It is becoming an increasingly important treatment technology as freshwater supplies are becoming scarcer. However, currently potentially harmful organic compounds produced during disinfection treatments are discharged into the aquatic environment in the waste water stream. The consequences of these organic compounds to aquatic organisms are largely unknown. This study provides new knowledge regarding the formation of previously unknown disinfection by-products (DBPs) produced during desalination. New quantification methods for organic compounds in aqueous environments are also developed. Undergraduate students are exposed to this research through internships, such as through the Maryland Sea Grant REU program and at USC. The CBL Visitor Center host displays about seawater DBPs, how they are formed and what impact they may have on the coastal ocean. In partnership with the Chesapeake Biological Laboratory Visitor Center, the research team hosts a summer workshop for 7-12th grade school students/teachers. The investigators also collaborate with colleagues in the U.S, Australia, and Germany, including industry partners from major desalination plants.Future reliance on desalination and water reuse to provide suitable drinking water is expected globally. During the desalination process, chlorination of water is required to limit biofouling of membranes and to kill potentially harmful bacteria. The formation of Disinfection Byproducts (DBPs) during drinking water chlorination and the compounding factors presented by different sources of fresh water, such as high levels of dissolved organic matter (DOM), is well recognized. However, during the chlorination of seawater, hundreds of brominated and iodinated compounds are formed, few of which have been characterized, and some of which are already known to be highly toxic. The researchers utilize new analytical techniques to investigate the production, fate and toxicity of DBPs in the coastal environment. Ultrahigh resolution mass spectrometry has been utilized to describe complex organic matrices at the molecular level, and has successfully demonstrated the complexity of DBPS formed after chlorination of ship ballast water as well as characterizing DOM in natural waters. All of these studies have shown that highly precise mass measurements combined with soft ionization are capable of assigning unambiguous and exact molecular formulas. In combination with traditional gas chromatography interfaced with mass spectrometry methods to support quantification of a subset of compounds, the team characterizes DBPs at different steps of the desalination process and evaluates the fate of produced DBPs released into the environment. The students and faculty combine desalination plant measurements with controlled laboratory studies to better understand the mechanisms and factors contributing to the production, fate and the toxicity of known and newly discovered DBPs formed in seawater during pre-chlorination and accumulated in waste waters discharged into coastal ecosystems.