Senna multijuga and peat in phytostabilization of copper in contaminated soil

ABSTRACT Phytoremediation is a technique that uses plants, whether associated or not to ameliorating agents, for phytostabilization of contaminated soil. The aim of this study was to evaluate the use of Senna multijuga associated with peat in the phytostabilization of copper contaminated soil. The experiment was carried out in a greenhouse for 120 days, using an entirely randomized design in a factorial arrangement (2 x 6), with and without peat (200 mL L-1 soil) and six doses of copper (0, 60, 120, 180, 240, 300 mg kg-1), with six repetitions of each treatment. At 120 days after seedling, the plants were evaluated for height, stem diameter, root and aerial dry matter, contents and accumulated amount of copper in the root system and aerial part. Also, the Dickson quality indexes, as well as tolerance and translocation indexes were analyzed. The results showed that the use of 200 mL of peat L-1 of soil was inefficient as an ameliorating agent for copper-contaminated soil, but it acted as a soil conditioner, increasing the morphological parameters of S. multijuga. In its initial development period, the S. multijuga species presented low copper phytostabilization potential in contaminated soil.

摘要 植物修复（Phytoremediation）是一类利用植物（无论是否与改良剂联用）开展污染土壤植物稳定（Phytostabilization）的修复技术。本研究旨在评估多叶决明（Senna multijuga）与泥炭联用对铜污染土壤的植物稳定效果。实验于温室中开展，为期120天，采用2×6因子的完全随机设计，设置添加与不添加泥炭（200 mL·L⁻¹土壤）两个处理水平，以及6个铜剂量梯度（0、60、120、180、240、300 mg·kg⁻¹），每个处理设置6次重复。于幼苗定植120天后，测定植株株高、茎粗、根系与地上部干物质质量，分析根系及地上部的铜含量与铜累积量，同时检测迪克森质量指数（Dickson quality indexes）、耐性指数与转运指数。结果表明，每升土壤施加200 mL泥炭作为铜污染土壤的改良剂效果不佳，但可作为土壤调理剂，提升多叶决明的形态学参数。在初始发育阶段，多叶决明对污染土壤的铜植物稳定潜力较低。