ABSTRACT

We studied the speciation of arsenic and antimony in the rhizosphere of 6 pioneer plants grown in zinc smelting slag to understand the main affecting factors of phytoremediation. Compared with the control slag, the pH of rhizosphere decreased significantly (p < 0.05) and the DOC content increased significantly (p < 0.05). Overall, the contents of arsenic (except Photinia serrulata and Lolium perenne) and antimony in the rhizosphere were lower than those of control slag. The proportions of residual arsenic and antimony in the rhizosphere were the highest and significantly higher than control slag. Exchangeable state, aluminum-bound state and calcium-bound state were lower than control slag. The contents of arsenic and antimony in plants were normal and followed the order of roots > leaves > stems. Arsenic and antimony were significantly positively correlated with Free iron and aluminum oxides and negatively correlated with DOC. After 7 years of phytoremediation, the content and bioavailability of arsenic and antimony in the rhizosphere were significantly reduced and have a normal contents in plants. It is speculated that phytoremediation increases the migration of arsenic and antimony to the surrounding area, and Photinia serrulata and Lolium perenne exhibited the best performance on stabilise arsenic in slag.

摘要

我们研究了生长在锌冶炼渣中的 6 种先锋植物根际中砷和锑的形态，以了解植物修复的主要影响因素。与对照渣相比，根际pH值显着降低（p  < 0.05），DOC含量显着增加（p  < 0.05）。总体而言，砷的含量（除了Photinia serrulata和Lolium perenne) 和根际锑低于对照渣。根际残留砷和锑的比例最高，明显高于对照渣。交换态、铝结合态和钙结合态均低于对照渣。植物体内砷、锑含量正常，呈根>叶>茎的顺序。砷和锑与游离铁和氧化铝呈显着正相关，与 DOC 呈负相关。经过7年的植物修复，根际砷和锑的含量和生物利用度显着降低，植物体内含量正常。据推测，植物修复会增加砷和锑向周边地区的迁移，并且Photinia serrulata和Lolium perenne在稳定渣中的砷方面表现出最好的性能。