Availability of Trace Elements in Soil with Simulated Cadmium, Lead and Zinc Pollution

Elżbieta Rolka,Mirosław Wyszkowski

doi:10.3390/min11080879

Abstract

The research was based on a pot experiment in which the impact of increasing Cd, Zn and Pb doses on the content of available trace elements in soil was compared. Seven series of trials were designed: 1 (Cd), 2 (Pb), 3 (Zn), 4 (Cd + Pb), 5 (Cd + Zn), 6 (Pb + Zn), 7 (Cd + Pb + Zn). Aside from the control one (without the metals), three increasing levels of contamination were considered within each series. Mobile forms of trace elements (Cd, Pb, Zn, Fe, Mn, Cu, Ni, Co, and Cr) in soil were determined, in addition to which selected physicochemical soil properties—reaction (pH), salinity (EC), hydrolytic acidity (HAC), total exchange bases (TEB)—were identified while cation exchange capacity (CEC), base saturation (BS) and availability factor (AF) were calculated. The application of Cd and Pb to soil resulted in an increase in the share of potentially available forms of these metals in their total content. The availability factor (AF) in the pots polluted with these metals was higher than in the control, in the range 17.5–20.0% for Cd, and 62.8–71.5% for Pb. In turn, the share of Zn mobile forms was comparable in most experimental objects, oscillating around 30%. Moreover, addition to soil of Cd, Pb and Zn usually caused a significant decrease in the content of available forms of Fe, Mn and Cu, and resulted in significantly higher content of available forms of Cr in the soil.

Highlights

IntroductionCd and Pb to soil resulted in an increase in the share of potentially available forms of these metals in their total content
The significant increase in the available forms of these metals was evidenced by the high correlation coefficient (r), which ranged from 0.994** to 1.000** for Cd, from 0.971** to 0.997** for Pb and from 0.999** to 1.000** for Zn
According to the assumed hypothesis, the application to the soil of increasing doses of Cd, Pb and Zn significantly stimulated a rise in the content of mobile forms of these elements

Summary

Introduction

Cd and Pb to soil resulted in an increase in the share of potentially available forms of these metals in their total content. Heavy metals are among the most persistent soil pollutants, demonstrating lasting effects and toxicity [1,2]. This negative impact of trace elements is compounded by their continuous emissions into the natural environment from many anthropogenic sources [3,4,5,6]. According to Wierzbowska et al [13] and Jaafar et al [14], an elevated content of heavy metals in soil may not pose a threat depending on soil conditions.

Objectives

Methods

Results

Conclusion