Collaborative Research: WERF: Determining the role of organic matter quality on PFAS leaching from sewage sludge and biosolids

聚全氟烷基和全氟烷基物质（PFAS）是一类合成化合物，50多年来已广泛用于各种工业应用和消费品。 全氟辛烷磺酸是一个国家的关注，由于这些化合物对人类健康和生态系统的负面影响。 最近，在污水处理厂的固体（污水污泥）中发现了PFASs，实验室和现场研究表明PFASs可以从这些固体中浸出。 由于这些固体（也称为生物固体）的土地应用是施肥和改善土壤条件的常见做法，因此了解固体管理和处理做法如何影响生物固体中PFASs的存在非常重要。 此外，人们对暴露于自然环境如何影响PFAS在施用于土壤后从生物固体中沥滤的可能性知之甚少。 该研究项目将与污水处理厂合作，通过实验确定污水污泥管理实践对最终进入生物固体的PFAS数量和类型的影响。该项目还将研究温度、降雨量和生物分解等环境因素，这些因素可能会影响在土地上施用生物固体后PFAS向环境中的释放。除了更好地了解PFAS在生物固体中的命运外，该项目的成果可能会导致更好的污泥管理实践，最大限度地减少PFAS对土壤生态系统的可能暴露。该项目将包括推广工作，以提高理解PFAS和土地应用的生物固体的初中，高中，大学的学生。这个合作研究项目的主要目标是了解固体特性和水质如何影响PFAS解吸从污水衍生的固体。 拟议的研究将是第一次努力，系统地确定固相特性和水质因素，管理PFASs的吸附能力，在污水固体。 对污水来源的污泥，即二级和厌氧消化器污泥和生物固体的关注，提供了一种相同来源的固体，其性质在其生产和使用过程中发生了重大变化。该提案将结合联合收割机PFASs吸附等温线和边缘实验，与污水衍生固体和渗滤液表征和微生物评估一起进行，以确定控制PFASs吸附的关键因素。 本研究的主要假设如下：1）污水中的固体蛋白质含量是影响PFAS吸附能力的关键固相特性，微生物处理后PFAS的吸附能力会降低; 2）溶解态多价阳离子浓度的增加会增加PFAS的吸附能力，尤其是对长链化合物的吸附能力;以及3）非生物连续沥滤风化过程将耗尽生物固体的亲水组分，使剩余的生物固体具有更疏水的特性，从而增加PFASs吸附能力。如果成功的话，这个项目将提供有价值的信息，这将有助于安全使用从回收污水废物中产生的生物固体，使国家的废水处理过程中的资源回收的可持续方法成为可能。这个奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为是值得支持的。

Poly- and perfluoroalkyl substances (PFASs) are a class of synthetic compounds that have been widely used in a variety of industrial applications and consumer products for over 50 years. PFASs are a national concern due to the negative effects of these compounds on human health and ecosystems. Recently, PFASs were found in wastewater treatment plant solids (sewage sludge), and laboratory and field studies indicate that PFASs can leach from these solids. Since land application of these solids, also known as biosolids, is a common practice to fertilize and improve soil conditions, it is important to understand how solids management and treatment practices affect the presence of PFASs in biosolids. Additionally, little is known about how exposure to natural environments may affect the potential leaching of PFASs from biosolids once they are applied to soil. This research project will work with wastewater treatment plants to experimentally determine the effects of sewage sludge management practices on the amount and types of PFASs that end up in the biosolids. This project will also study environmental factors, such as temperature, rainfall, and biological decomposition, that may impact the release of PFASs into the environment following land application of biosolids. In addition to better understanding the fate of PFAS in biosolids, the outcomes of the project will likely lead to better sludge management practices that minimize possible PFAS exposure to soil ecosystems. The project will include outreach efforts to improve the understanding of PFASs and land-application of biosolids for middle school, high school, and university students.The main objective of this collaborative research project is to understand how solid characteristics and water quality affect PFAS desorption from sewage-derived solids. The proposed research will be the first effort to systematically identify solid phase characteristics and water quality factors that govern PFASs sorption capacity in sewage solids. The focus on sewage-derived sludge, namely secondary and anaerobic digester sludges and biosolids, provides a same-sourced solid that substantially changes in character over its production and its use. This proposal will combine PFASs sorption isotherm and edge experiments, conducted in concert with sewage-derived solid and leachate characterization and microbial assessments, to identify the critical factors governing PFASs sorption. The central hypotheses in this study are as follows: 1) sewage-derived solids protein contents will be the key solid phase characteristics that affects PFASs sorption capacity, and that sorption capacity will generally decrease with microbiological processing; 2) the presence of increased dissolved polyvalent cation concentration will increase PFASs sorption capacity, particularly for the longer chain length compounds; and 3) the abiotic sequential leaching weathering process will deplete the hydrophilic components of the biosolids, rendering the remaining biosolids with a more hydrophobic character and thus increased PFASs sorption capacity. If successful, this project will provide valuable information that will aid in the safe use of biosolids produced from recycling sewage waste, enabling a sustainable method of resource recovery from the Nation's wastewater treatment processes.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.