镍污染土壤植物采矿技术关键过程及其研究进展

Key processes and progress in phytomining of nickel contaminated soils: a review

摘要:

植物采矿是利用超积累植物高量吸收土壤中的重金属，并从中提取、冶炼金属产品，在修复污染土壤的同时实现金属的资源化。全世界广泛分布着自然风化的镍污染土壤，植物采矿因其重要的环境、生态及资源价值，被作为一种环境友好且具备经济效益的土壤修复技术，在此类地区具有广阔的应用前景。该植物采矿技术关键过程主要包括超积累植物镍高选择性根际环境响应、植物镍高效吸收转运以及生物质中镍高附加值资源化等过程。近30年，污染土壤中镍的植物采矿已经在美国、阿尔巴尼亚、马来西亚等多个国家进行了野外实践，取得了良好效果。然而，相关技术在我国的研究与应用仍然处于起步阶段。文中通过综述植物采矿技术的关键过程的研究进展，发现其中的瓶颈，为接下来植物采矿的科学研究和技术在全世界推广提供理论基础和技术指导。

Abstract:

Phytomining technology cultivates hyperaccumulator plants on heavy metal contaminated soils, followed by biomass harvesting and incineration to recover valuable metals, offering an opportunity for resource recycling and soil remediation. Large areas of ultramafic soils, naturally rich in nickel (Ni), are present in numerous places around the world. As an environmentally friendly and cost-effective soil remediation technology, phytomining has a broad application prospect in such areas and thus has attracted great attention from global researchers. The key processes of phytomining include: (1) high-selectivity response of hyperaccumulator plants to Ni the underlying mechanisms involved in the rhizosphere; (2) underlying mechanisms of high-efficiency uptake and translocation of Ni in hyperaccumulators; and (3) resource recycling of high-added value Ni products from the Ni-rich bio-ore of hyperaccumulators. In recent 30 years, phytomining practices have successfully carried out in United States, Albania and Malaysia. However, the research and application of this technology in China are still in the fledging stage. This paper reviews the key processes and research progress of phytomining, and points out the bottleneck, to provide theoretical basis and technical guidance for phytomining.