Supercritical fluid extraction for the remediation of soils contaminated with heavy metals and organics

近年来，越来越多的土地受到石油、汽油、农药、多氯联苯和爆炸物等有机化合物以及重金属和放射性化合物等无机化合物的污染。这些被污染的土地对环境和公众健康构成威胁。 污染物可以进入我们呼吸的空气。它们还可以进入我们饮用和用于娱乐目的的水中。土壤中的污染物也可能通过暴露于受污染土壤的植物或动物进入食物链。这些场地还造成了经济负担，因为受污染的场地一直未被使用，因此，通过财产税等可能造成收入损失。 加拿大有数千个受污染的地点，世界各地还有更多的地方必须清理。要做到这一点，我们需要能够清理受污染场地的创新技术。迄今为止，大多数研究工作都集中在开发清理受有机化合物污染的场地的技术。一些研究涉及被无机化合物污染的场地。很少有技术能够清理被有机和无机化合物污染的土壤。 超临界流体萃取是一种有潜力处理这些类型污染土壤的技术。这是一个使用二氧化碳从污染土壤中提取化合物的过程。以下提案概述了一个研究方案，其中将确定重要的初步设计参数，并将对受有机化合物（石油烃）和重金属（铜、镉、铬、汞和/或铅）污染的土壤进行独特的实验。该研究计划的结果将是设计用于修复污染土壤的超临界流体萃取系统所必需的重要参数。 这些信息将导致设计一种商业上可行和有效的创新处理技术，可以处理加拿大许多具有挑战性的污染场地。

In recent years, more land has become contaminated with organic compounds such as oil, gasoline, pesticides, PCBs and explosives as well as inorganic compounds such as heavy metals and radioactive compounds. These contaminated lands pose a threat to the environment and to public health.  The contaminants can move into the air we breathe. They can also move into the water we drink and use for recreational purposes. Contaminants in soil may also find their way into the food chain through plants or animals that have been exposed to the contaminated soil. These sites also pose an economic burden since contaminated sites remain unused and therefore represent a loss in potential revenue through property taxes, etc.    There are thousands of contaminated sites in Canada and many more around the world that must be cleaned up. To do this, we need new and innovative technologies that can clean up contaminated sites. Most research efforts to date have concentrated on developing technologies to clean up sites contaminated with organic compounds. Some research has address sites contaminated with inorganic compounds. Very few technologies can clean up soils contaminated with both organic and inorganic compounds.    Supercritical fluid extraction is a technology that could potentially deal with these types of contaminated soils. It is a process that uses carbon dioxide to extract the compounds from the contaminated soils. The following proposal outlines a research program in which important preliminary design parameters will be determine and  unique experiments will be performed with soils contaminated with both organic compounds (petroleum hydrocarbons) and heavy metals (copper, cadmium, chromium, mercury and/or lead). The outcome of the research program will be important parameters necessary for the design of a supercritical fluid extraction system for the remediation of contaminated soils.  This information will lead to the design of a commercially feasible and effective innovative treatment technology that can deal with many of the challenging contaminated sites in Canada.