Fate of Biosolid Derived Organic Contaminants in Soils and Effects on Soil Microbial Communities

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。0854167 gunsch废水处理过程不能有效地去除所有类型的污染物。这些污染物在生物固体中的积累日益受到关注，因为目前美国约有50%的生物固体用于土地利用。因此，在生物固体的土地应用之后，这些污染物有可能在环境中被动员起来，造成不利的环境影响。本提案的主要目的是描述生物固体土地应用后土壤和植物中几种具有不同物理化学性质的有机污染物的化学命运。此外，本项目将探索这一过程中微生物群落动态和反硝化功能的变化。反硝化菌是氮循环的关键，与初级生产力和碳分解有关。因此，反硝化群落动态是土壤微生物功能的良好指标。本研究选择的污染物是：1)三氯生（一种个人护理产品中的杀菌剂）；2)壬基酚（洗涤剂/表面活性剂）；3)萘普生（药物活性化合物，又名Aleve）和；4)两种溴化阻燃剂（BFRs）。本项目的工作假设是，生物固体的施用量不仅会影响污染物的命运，还会影响微生物群落的结构和功能。将在间歇式反应器和专门设计的环境室中进行一系列实验来验证这一假设。在本研究结束时，将计算几个指标来评估生物固体土地应用对环境和土壤健康的影响。这些包括：1)每种污染物的土壤保持因子；2)污染物对土壤中栽培植物的生物利用度；3)植物生物量产量；4)确定导致微生物群落结构显著变化和反硝化率降低10%的每种污染物的阈值浓度。该项目将有助于进一步建立和加强普拉特工程学院和杜克大学尼古拉斯环境学院的青年教师之间的合作。这项研究还将使参与该项目的研究生和本科生在一个跨学科的研究团队中工作，并获得宝贵的训练。此外，ppi将继续制定和实施一项外展计划（“未来的科学家和工程师”），旨在向未被充分代表的少数民族中学生介绍科学和工程，以便他们能够做出明智的职业决定。pi目前正在与几位中学科学教师合作，制定工作计划，将学生的课程与具有代表性的生物科学和环境工程的创新实践活动结合起来。学院希望这个拓展项目能帮助这些学生在科学和工程领域的职业选择方面做出明智的选择。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).0854167GunschWastewater treatment processes do not efficiently remove all types of contaminants. The accumulation of these contaminants in biosolids is a growing concern because approximately 50% of biosolids in the United States are currently land-applied. Thus, there is potential for these pollutants to become mobilized in the environment following land-application of biosolids and cause adverse environmental effects. The principal objective of this proposal is to characterize the chemical fate of several organic contaminants, of various physicochemical properties, in soils and plants following biosolid land application. Furthermore, this project will explore microbial community dynamics and changes in denitrification function resulting from this process. Denitrifiers are key to nitrogen cycling and are linked to primary productivity and carbon decomposition. As such, denitrifying community dynamics are a good indicator of microbial function in soils. The contaminants chosen for this study are: 1) triclosan (a bactericide found in personal care products); 2) nonylphenol (a detergent/surfactant); 3) naproxen (pharmaceutically active compound a.k.a. Aleve) and; 4) two types of brominated flame retardants (BFRs). The working hypothesis of this project is that the rate of biosolid application will affect not only the contaminant fate, but impact microbial community structure and function. A series of experiments will be carried out in batch reactors and specially designed environmental chambers to test this hypothesis. At the conclusion of this study several metrics will be calculated to evaluate biosolid land application on environmental and soil health. These include: 1) soil retention factors of each contaminant ; 2) bioavailability of contaminants to plants cultivated in the soils; 3) the plant biomass production; and 4) by determining the threshold concentrations of each contaminant that is responsible for a significant microbial shift in microbial community structure and a 10% decrease in denitrification rate. This project will serve to further establish and strengthen collaborations between junior Faculty in the Pratt School of Engineering and the Nicholas School of the Environment at Duke University. This research will also enable both graduate and undergraduate students participating in this project to work in an interdisciplinary research team and gain valuable training. In addition, the PIs will continue to develop and implement an outreach program ("Scientists and Engineers for the Future") aimed at introducing underrepresented minority students in middle school to science and engineering so that they may make educated career decisions. The PIs are currently working with several middle school science teachers to develop work plans which integrate the students' curriculum with innovative hands-on activities representative of the biological sciences and environmental engineering. The PIs hope this outreach program will help these students make informed choices about career possibilities in science and engineering.