New Materials for Site Remediation and Pollution Containment: Reactive Polymer Gels and Emulsions

加拿大有超过10，000个地点的土壤、地下水或两者都受到有毒物质的污染，包括有机污染物、重金属和杀虫剂。890万加拿大人的家庭用水是地下水，在加拿大人的血液中检测到饮用水中的污染物。因此，处理土壤和地下水污染至关重要。正在作出重大努力，对受污染场地进行补救。然而，大多数现有的修复技术不允许同时捕获和处理地下污染物。因此，污染物在原地处理时可能迁移，对有效补救构成挑战。此外，补救技术可能涉及使用材料，如纳米颗粒，其命运引起了安全问题。拟议研究的范围是通过同时就地捕获和处理地下污染物，并确保用于处理污染物的反应材料仅在污染区输送和释放（有针对性的输送），以应对这些挑战。有针对性地输送反应材料将确保反应仅在污染区域以受控的方式发生，从而提高补救过程的安全性。在该计划中，将开发含有反应物质的凝胶（反应凝胶），以原位捕获和处理地下污染物，如重金属、生物杀灭剂和杀虫剂以及有机污染物。反应性凝胶的一个重要特性是其可调粘度，在清洁区低，在污染区高。清洁区的低粘度将使凝胶能够流过土壤并到达污染物，而污染区的高粘度凝胶将对污染物迁移形成屏障。通过使用可切换的表面活性剂乳化这些材料，可以实现有针对性的反应材料输送，这些表面活性剂对清洁区和污染区的水化学差异敏感。可切换的表面活性剂将在洁净区产生稳定的乳液，而仅在污染区释放活性物质。该计划的最终目标是开发新的修复技术，以恢复污染场地，减轻或消除对人类和生态受体的风险。虽然新技术的实施是该计划的长期愿景，但推进与这些技术相关的所有方面的基础知识是支持实现这一愿景的核心价值。这些知识将成为新应用的窗口，这些应用将从该计划中流出，但可能远远超出它。根据这一核心价值，该计划的主要范围是培养精通土壤修复的HQP，并拥有适用于不同部门的多学科专业知识。

There are over 10,000 sites in Canada in which the soil, the groundwater or both are contaminated by toxic substances, including organic pollutants, heavy metals, and pesticides. Groundwater is used by 8.9 million Canadians for domestic purposes and pollutants in drinking water have been detected in the blood of Canadians. Treating soil and groundwater pollution is thus of paramount importance. Significant efforts are being made to remediate contaminated sites. However, most of the existing remediation technologies do not allow simultaneously trapping and treating subsurface contaminants. The pollutants may thus migrate while being treated in situ, posing a challenge to their effective remediation. Also, remediation technologies may involve the use of materials, e.g. nanoparticles, the fate of which has raised safety concerns.The scope of the proposed research is to address these challenges by simultaneously trapping and treating subsurface contaminants in situ, and by ensuring that the reactive materials used to treat the contaminants are delivered and released exclusively in the polluted zones (targeted delivery). The targeted delivery of reactive materials will ensure that reactions occur in a controlled manner in the polluted areas only, hence increasing the safety of the remedial process.In this program gels containing reactive species (reactive gels) will be developed to trap and treat in situ subsurface contaminants such as heavy metals, biocides and pesticides, and organic pollutants. An important characteristic of the reactive gels will be their tunable viscosity, low in the clean areas and high in the contaminated zones. The low viscosity in the clean zones will allow gels to flow through the soil and reach the pollutants, while the high gel viscosity in the contaminated zones will create a barrier to contaminant migration.The targeted delivery of reactive materials will be achieved by emulsifying these materials with switchable surfactants, sensitive to differences between the water chemistry of the clean and the polluted zones. Switchable surfactants will produce stable emulsions in the clean zones, while releasing the reactive materials in the contaminated areas only.The ultimate goal of this program is the development of new remediation technologies to restore polluted sites, mitigating or eliminating the risks to human and ecological receptors. While the implementation of new technologies is the long term vision of this program, advancing the fundamental knowledge of all aspects related to these technologies is the core value supporting the realization of this vision. This knowledge will be a window to new applications, which will stream from this program but may stretch well beyond it. In line with this core value, a major scope of the program is to educate HQP well-versed in soil remediation, and possessing a multi-disciplinary expertise applicable in diverse sectors.