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

加拿大有1221个联邦污染场地。大约三分之一位于魁北克、不列颠哥伦比亚省和安大略省。每个省都有自己的类似数量的地方负责地点。圣劳伦斯航道沿线的港口每年疏浚超过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，从而产生有毒藻类(蓝藻)。在美国、墨西哥和欧洲也发现了类似的情况，这使得受污染的土壤和沉积物成为一个世界性的严重环境问题。出现污染问题的原因是，工业废水、受污染的城市/农业径流和危险废物储存污染了河流/湖泊中的水/沉积物；或受污染地点的土壤/地下水。被认为被土壤/沉积物保留的污染物对生态系统和人类健康构成风险，因为它们的释放机制。在土壤/沉积物中发现的典型污染物是：过量营养物质(P和N)、重金属(铅、镉、铬、锌)、石油碳氢化合物和最近/更受关注的道路除冰盐。这项研究计划的全球目标是从整体上了解污染问题，并提出符合可持续发展原则的减轻、保护和恢复遗址的技术手段。具体地说，将在实验室利用实际案例研究的实地样本研究污染土壤/沉积物修复的三个方面：1)污染物行为研究，重点是常见阴离子污染物在重金属的迁移、物理分布和迁移潜力方面的影响；2)地球化学形态与有效性、转化和老化过程之间的关系；3)用于处理或隔离污染物的地质衬垫的构思和设计；这些屏障将在实验室中进行技术和环境无害/测试，并将模仿流域或水文地质系统中的真实案例研究。

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.