The Absorption and Distribution of Heavy Metals of Dominant Plant for Ecological Restoration of Stone Coal Mine

Lu Peng,Hailong Sun,Lizhi Xiong,Shuang Luo,Hai-Bo Qin

doi:10.1155/2021/4694528

Abstract

The exposed slopes formed by stone mining had caused serious problems of environmental pollution. The ecological restoration was a very effective measure to solve it. In this study, the Indigofera amblyantha Craib was the dominant species in the ecorestoration during the first two years of ecological restoration, which was based on analyzing the importance value (IV) and diversity indexes of plant species. Meanwhile, the ecorestoration process helps slow down the increase of the concentrations of some heavy metals in the substrate material; however, the changing trends of these metals were not uniform. The root and leaf were the main parts of heavy metal distribution, respectively, corresponding to Pb, Cr, As, Sb, and Ni in root and Cu, Mn, and V in leaf. It confirmed that Indigofera amblyantha Craib had an advantage ability to enrich and transfer Cd, Cu, and Mn obtained from their biological concentration factor (BCF) and biological transfer factor (BTF). The Sb, Cd, and V were the main factors affecting the IV by the redundancy analysis. These fine characters of Indigofera amblyantha Craib help explain it well adapted to the ecorestoration of stone coal mines. The current results are valuable to evaluate and extend the application in ecorestoration engineering of mining areas and other heavy metal-contaminated sites.

Highlights

Stone coal is a kind of coal resource stored in ancient stratum, with the characteristics of a low-carbon (10-25%), low calorific, high ash (65-80%), and high-sulfur (2-5%) [1, 2], and associated with polymetallic composition, such as V, Mo, Ni, Cu, Pb, Cd, Cr, Fe, and Zn, and their compounds, etc. [3, 4]
Many exposed high escarpments derived from the mining of stone coal were exposed to atmospheric oxygen, which resulted in acidic mine discharge (AMD) formed from rain [8, 9]
We firstly found that the Indigofera amblyantha Craib showed great adaptability based on two years of follow-up investigation on ecorestoration engineering in expose slopes of the stone coal mines

Summary

Introduction

Stone coal is a kind of coal resource stored in ancient stratum, with the characteristics of a low-carbon (10-25%), low calorific, high ash (65-80%), and high-sulfur (2-5%) [1, 2], and associated with polymetallic composition, such as V, Mo, Ni, Cu, Pb, Cd, Cr, Fe, and Zn, and their compounds, etc. [3, 4]. Stone coal is an important V resource [2, 5]. Many exposed high escarpments derived from the mining of stone coal were exposed to atmospheric oxygen, which resulted in acidic mine discharge (AMD) formed from rain [8, 9]. For the fine particle sizes of stone coal, the dissolved rates of As, Pb, V, Cd, and Cr were 2.96%, 0.95%, 0.35%, 0.25%, and 0.01% after 100 days in pH 4.5 solution, respectively [12]. These heavy metals further hazarded surrounding farmland and rivers. It was worthy of close attention and needs an effective measure to solve it

Methods

Findings

Discussion

Conclusion