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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=656394
• 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.

疏浚的海洋沉积物往往在放置或处置之前进行脱水。被多氯二苯并对二恶英和多氯二苯并呋喃（俗称二恶英和呋喃）污染的沉积物，由于其毒性，对脱水和处置提出了独特的挑战。这一问题在加拿大普遍存在;加拿大财政委员会（2017年）列出了157个联邦登记的多氯二苯并对二恶英/多氯二苯并呋喃和/或多氯联苯污染沉积物的污染场地。在大多数管辖范围内，通过颗粒物结合在水中的多氯二苯并对二恶英/多氯二苯并呋喃即使含量很低（即皮克）也是不可接受的。* 使用土工合成管（即土工管）对沉积物进行脱水正在成为一种普遍做法，但对通过土工管迁移多氯二苯并对二恶英和多氯二苯并呋喃的相关风险还没有很好的了解或量化。该研究方案的长期目标是更好地了解在使用土工管进行沉积物脱水过程中多氯二苯并对二恶英和多氯二苯并呋喃通过颗粒物质的迁移和归宿。文献中已明确指出，多氯二苯并对二恶英和多氯二苯并呋喃与土壤水系统中的颗粒有机物密切相关。该研究方案将采用实验室和实地研究相结合的方法，评估在土工管脱水过程中颗粒物质的迁移情况，从而评估多氯二苯并对二恶英/多氯二苯并呋喃的迁移情况。将为设计涉及多氯二苯并对二恶英和多氯二苯并呋喃的土工管排水系统开发新的预测方法。初步研究将侧重于实验室实验，以确定脱水过程中多氯二苯并对二恶英和多氯二苯并呋喃通过土工管中的颗粒物质迁移的主要机制。实验室实验将使用受污染的海洋沉积物，并涉及使用实验室规模脱水技术的物理测试。将对这些试验期间保留的沉积物进行物理表征。还将使用类似的方法表征流出物中的颗粒物质（即，评估脱水过程中的颗粒迁移）。还将评估不同土工织物和滤饼发展对颗粒物质运输的作用。将对脱水过程中多氯二苯并对二恶英和多氯二苯并呋喃从沉积物中迁移的主要机制进行评价。这部分工作将涉及沉积物中多氯二苯并对二恶英和多氯二苯并呋喃的掺加，以及评估脱水过程中多氯二苯并对二恶英和多氯二苯并呋喃的迁移情况。这项工作还将涉及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多氯二苯并对二恶英和多氯二苯并呋喃的迁移情况。对多氯二苯并对二恶英/多氯二苯并呋喃污染的沉积物进行的实地脱水试验将提供与实验室研究结果进行比较的机会，并将根据这些实地试验对研究中开发的预测工具进行评估。该研究项目还将支持多名HQP的培训，包括2名博士，2名硕士和4名本科生。