Evaluation of phytoextraction and biochar as a remedial approach for treating agricultural soils impacted with metals

农业土壤金属污染是一个世界性的问题。由于工业加工和/或不适当的处理金属污染废物的做法，加拿大和海外的许多可耕地基本上已无法使用。传统的修复方法包括挖掘和填埋、焚烧、土壤冲洗、固化/稳定化和玻璃化。这些方法虽然有效，但费用昂贵，可能对土壤质量产生负面影响或导致土壤完全破坏。该研究项目评估了应用两种互补的基于植物的方法（即植物技术）来修复中国和加拿大大片农田的可行性。在这两种情况下，土壤覆盖面积很大，主要受到镉污染，但也受到其他污染。 金属包括镍、铜、锌和铅。植物提取是指使用维管植物将土壤污染物提取到植物根部并将其转移到芽中，然后收获，堆肥和处理。这项技术将与使用生物炭固定土壤基质中的金属形成对比，生物炭是一种非常稳定的有机物质，也可以改善土壤质量。通过同时探索使用这两种植物技术修复中国广西河池和加拿大安大略Bolon附近农业区金属污染土壤的有效性，Malroz工程公司希望识别最重要的特定地点变量，并能够将研究结果应用于 其他商业网站。这种替代性的“绿色技术”将是一种方便和具有成本效益的工具，可以添加到Malroz的修复技术“工具箱”中。

Contamination of agricultural soils with metals is a word wide problem. As a result of industrial processes and/or inappropriate disposal practices of metal-contaminated wastes, much of the arable land both in Canada and overseas has become essentially unusable. Traditional remediation methods to deal with metal contamination include excavation and landfilling, incineration, soil washing, solidification/stabilization, and vitrification. Although effective, these methods are costly and can negatively affect soil quality or result in its complete destruction. This research project assesses the feasibility of applying two complementary plant-based approaches (i.e. phytotechnologies) to remediate large tracts of agricultural land in China and Canada. In both cases, the soils cover a large area and are contaminated predominantly with cadmium, but also with other metals including nickel, copper, zinc, and lead. Phytoextraction refers to the use of vascular plants to extract soil contaminants into plant roots and translocate them to the shoots, which are then harvested, composted, and disposed of. This technology will be contrasted with the immobilization of metals in the soil matrix using biochar, a very stable form of organic matter, which also improves the soil quality. By simultaneously exploring the efficacy of using these two phytotechnologies to remediate metal-contaminated soils from agricultural areas near Hechi, Guanxi Province, China and Bolon, Ontario, Canada, Malroz Engineering Incorporated hope to discern the most important site-specific variables, and be able to apply the findings to other commercial sites. This alternative 'green technology' will be a convenient and cost-effective tool to add to Malroz's 'toolbox' of remediation technologies.