Transport of Dioxins and Furans Through Geotextiles During Sediment Dewatering

沉积物脱水过程中二恶英和呋喃通过土工织物的传输

• 批准号: RGPIN-2018-04049
• 负责人: Lake, Craig
• 金额: $ 3.82万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=749155
• 关键词: Transport; Dioxins; Furans; Through; Geotextiles

Dredged marine sediment is often dewatered prior to placement or disposal. Sediments contaminated with polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, commonly known as dioxins and furans (PCDD/Fs), present unique challenges for dewatering and disposal due to their toxicity. This issue is prevalent across Canada; the Treasury Board of Canada (2017) lists 157 federally registered contaminated sites with PCDD/Fs and/or PCB contaminated sediments. PCDD/Fs present at even very small levels (i.e. picogram) in water via particulate matter association are not acceptable in most jurisdictions. Dewatering of sediment using geosynthetic tubes (i.e. geotubes) is becoming common practice, yet the risks associated with PCDD/F transport via geotubes is not well understood or quantified. The long-term objective of this research program is to better understand the transport and fate of PCDD/Fs via particle matter during sediment dewatering using geotubes. It is well established in the literature that PCDD/Fs are strongly associated with particulate organic matter in soil water systems. This research program will use a combination of lab and field studies to assess particulate matter transport, and hence PCDD/F transport, during geotube dewatering. New predictive approaches will be developed for designing geotube dewatering systems involving PCDD/Fs.The initial research will focus on lab experiments to identify the dominant mechanisms responsible for PCDD/F transport via particle matter from geotubes during dewatering. Lab experiments will use contaminated marine sediments and will involve physical testing using bench scale dewatering techniques. The sediment retained during these tests will be physically characterized. The particulate matter in the effluent will also be characterized using similar methods (i.e. to assess particle transport during dewatering). The role of different geotextiles and filter cake development on the transport of particle matter will also be assessed. Key mechanisms will be evaluated with respect to transport of PCDD/Fs from sediment during dewatering. This portion of the work will involve spiking of sediment PCDD/Fs and evaluating PCDD/F transport during dewatering. The work will also involve evaluating existing filtration performance models to predict the transport of PCDD/Fs during geotube dewatering under differing operational conditions. A field dewatering trial of PCDD/F contaminated sediment will provide opportunity for comparison to lab findings and predictive tools developed in the research will be assessed based on these field trials. This research program will also support the training of several HQP including 2 doctoral, 2 masters and 4 undergraduate students.

疏浚的海洋沉积物通常在放置或处置之前脱水。被多氯二苯并对二恶英和多氯二苯并呋喃污染的沉积物，通常被称为二恶英和呋喃（PCDD/Fs），由于其毒性，对脱水和处置提出了独特的挑战。这个问题在加拿大很普遍；加拿大财政部（2017年）列出了157个联邦注册的PCDD/Fs和/或PCB污染沉积物的污染场地。在大多数司法管辖区，通过颗粒物质关联存在于水中的PCDD/Fs即使是非常小的水平（即picogram）也是不可接受的。使用土工合成管（即土工管）对沉积物进行脱水已成为一种普遍做法，但通过土工管运输PCDD/F的风险尚未得到很好的理解或量化。本研究项目的长期目标是更好地了解在土工管降水过程中PCDD/Fs通过颗粒物质的迁移和命运。在文献中，PCDD/Fs与土壤水系统中的颗粒有机物质密切相关。该研究项目将结合实验室和现场研究来评估土工管脱水过程中颗粒物质的输送，以及PCDD/F的输送。将开发新的预测方法来设计涉及PCDD/Fs的土工管脱水系统。最初的研究将集中在实验室实验上，以确定在脱水过程中PCDD/F通过土工管中的颗粒物质传输的主要机制。实验室实验将使用受污染的海洋沉积物，并使用实验规模的脱水技术进行物理测试。在这些试验中保留的沉淀物将被物理表征。出水中的颗粒物质也将使用类似的方法进行表征（即评估脱水过程中的颗粒运输）。还将评估不同土工布和滤饼开发对颗粒物质输运的作用。将评价在脱水期间从沉积物中输移PCDD/Fs的关键机制。这部分工作将涉及沉积物PCDD/F的峰值和评估脱水过程中PCDD/F的输送。该工作还将包括评估现有的过滤性能模型，以预测在不同操作条件下土工管脱水过程中PCDD/Fs的运移。PCDD/F污染沉积物的现场脱水试验将提供与实验室结果进行比较的机会，并将根据这些现场试验评估研究中开发的预测工具。本研究项目还将支持培养若干名HQP，其中博士2名，硕士2名，本科生4名。