Contaminant behaviour applied to the remediation of soils and sediments using an integrated multidisciplinary approach

加拿大有1221个联邦污染地点。大约三分之一位于魁北克、不列颠哥伦比亚省和安大略省。每个省都有类似数量的地方责任地。圣劳伦斯海道沿岸的港口每年要疏浚超过20万吨受污染的沉积物，许多加拿大湖泊遭受早期（人为）富营养化，这与沉积物释放的磷有关，导致有毒藻类（蓝藻）的产生。在美国、墨西哥和欧洲也发现了类似的情况，使受污染的土壤和沉积物成为一个全球性的严重环境问题。工业废水处理不当、城市/农业径流受到污染以及危险废物的储存污染了河流/湖泊中的水/沉积物，从而产生了污染问题；或污染场地的土壤/地下水。被认为被土壤/沉积物保留的污染物由于触发其释放的机制而对生态系统和人类健康构成风险。在土壤/沉积物中发现的典型污染物是：过量的营养物质（P和N）、重金属（Pb、Cd、Cr、Zn）、石油碳氢化合物以及最近/更受关注的道路除冰盐。这项研究计划的总体目标是全面了解污染问题，并提出技术手段来减轻污染；遵循可持续发展原则保护和恢复遗址。具体而言，将在实验室使用来自实际案例研究的现场样本研究受污染土壤/沉积物修复的三个方面：1)研究污染物行为，重点研究常见阴离子污染物对重金属动员、物理分布和运输潜力的影响；2)地球化学物种形成与可利用性、转化和老化过程的关系；3)用于处理或隔离污染物的地质衬垫的概念和设计；这些屏障将在技术上和环境上无害/在实验室中用中/大柱进行测试，它们将模仿流域或水文地质系统内的实际案例研究。

Canada counts with 1221 federal contaminated sites. About one third is located in Quebec, British Columbia and Ontario. Each province has its own similar number of sites of local responsibility. Ports along the St-Lawrence sea way dredge over 200 000 ton/year of contaminated sediments and numerous Canadian lakes suffer from early (anthropogenic) eutrophication associated to phosphorus released from sediments with consequent production of toxic algae (cyanobacteria). Similar situations are found in US, Mexico and Europe making of contaminated soils and sediments a worldwide and serious environmental problem. Pollution problems have arisen from the inadequate disposal of industrial effluents, polluted urban/agricultural runoffs and hazardous waste storage that contaminated water/sediments in rivers/lakes; or soils/groundwater in contaminated sites. Pollutants considered retained by soils/sediments pose risk to ecosystems and human health because of mechanisms that trigger their release. Typical contaminants found in soil/sediments are: excess nutrients (P and N), heavy metals (Pb, Cd, Cr, Zn), petroleum hydrocarbons and of recent/higher concern, road de-icing salts. The global aim of this research program is to understand a pollution problem holistically and to propose technical means to attenuate; protect, and restore sites following sustainable development principles. Specifically, 3 aspects of contaminated soil/sediments remediation will be studied in laboratory using field samples from real case studies: 1) study of contaminant behaviour with emphasis on the influence of common anionic contaminants in the mobilization of heavy metals, physical distribution and potential for transport; 2) relation between geochemical speciation and availability, transformation and aging process; 3) Conception and design of geo-liners for the treatment or isolation of contaminants; the barriers are to be technically and environmentally sound/tested in laboratory at meso/large columns and they will mimic real case studies within watershed or hydrogeological systems.