Assessing Soil Metal Levels in an Industrial Environment of Northwestern China and the Phytoremediation Potential of Its Native Plants

Yuan Liu,Changxiao Li,Yujing Yang,Wenchao Ma,Hong Wei,Xilu Ni

doi:10.3390/su10082686

Yuan Liu, Changxiao Li + Show 4 more

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https://doi.org/10.3390/su10082686

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Abstract

Various industrial activities contribute heavy metals to terrestrial ecosystems. In order to evaluate the soil quality of industrial areas and to identify the potential phytoremediator from the native plant species, we collected 45 surface soil samples and 21 plant species in a typical industrial area of northwestern China. The results showed that the average values of the Cd, Cr, As, Pb, Cu, and Zn in the soils were 36.91, 1.67, 7.20, 1.38, 1.27, and 6.66 times, respectively, compared with the corresponding background values. The average single factor pollution index for heavy metals decreased in the order of Cd > As > Zn > Cr > Cu > Pb. The study area was seriously polluted by Cd and As, slightly polluted by Zn, and had relatively little contamination by Cr, Pb, and Cu. In terms of the average Nemerow synthetic pollution index in every sampling site, 97.78% of the samples were seriously polluted and 2.22% of the samples were moderately polluted, which indicated that almost all of the samples in the industrial area were seriously polluted. The results of the biomass, heavy metal concentrations, bioconcentration factors (BCF), and translocation factors (TF) for the native plants showed that Achnatherum splendens for metal Cr presented a phytostabilization potential, Artemisia scoparia and Echinochloa crusgalli for metal Cu and Halogeton arachnoideus for metal Zn presented a phytoextraction potential, and all of the studied plants were limited as phytoremediators for Cd or Pb contaminated soil.

Highlights

Heavy metal pollution has become a worldwide environmental concern because of its latency, toxicity, and contamination within soils over time [1]
The discharge of heavy metals through various industrial activities is an important cause of soil contamination by heavy metals
The results suggest that the study area was seriously polluted by Cd and As, slightly polluted by Zn, and was relatively clean for Cr, Pb, and Cu contamination

Summary

Introduction

Heavy metal pollution has become a worldwide environmental concern because of its latency, toxicity, and contamination within soils over time [1]. Industrial activities are regarded as the principal contributor for heavy metal pollution [4]. With the rapid industrialization and urbanization of China over the last decades, various industrial activities have contributed a large amount of heavy metals to the soil, directly and indirectly [5]. The urban soil around electronics manufacturing has been subject to multiple heavy metal contaminations in the Hebei province of China [6]. It has been found that about 50% of the soil samples are contaminated by heavy metals in the gold-mining region of Shanxi province, China [8]. Exposure to multiple heavy metals may induce more severe diseases such as immune system damage, skin cancer, skeletal damage, vascular disease, and so on [12,13]

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