Effect of Application of Increasing Concentrations of Contaminated Water on the Different Fractions of Cu and Co in Sandy Loam and Clay Loam Soils

John Volk,Olusegun Yerokun

doi:10.3390/agriculture6040064

Abstract

This study aimed to establish the fate of copper (Cu) and cobalt (Co) in sandy loam and clay loam soils that had been irrigated with increasing concentrations of contaminated water. A sequential extraction procedure was used to determine the fractions of Cu and Co in these soils. The concentration of bioavailable Cu and Co on clay loam was 1.7 times that of sandy loam soil. Cu on sandy loam soil was largely in the organic > residual > exchangeable > water-soluble > carbonate fractions, whereas on clay loam soil the element was largely in organic > exchangeable > residual > carbonate > water-soluble fractions. Co was largely observed in the exchangeable, water-soluble, and carbonate fractions, but with no particular trend observed in both soil types. When crops are grown on sandy soils that have a low capacity to hold heavy metals, the resulting effect would be high uptake of the heavy metals in crop plants. Because the predominant forms of Cu and Co vary in soils, it is expected that the metals will behave differently in the soils.

Highlights

The increased copper mining in Zambia has generally contributed to employment opportunities coupled with improvements in living standards of the population in these new mining areas
The objective of this study was to determine the chemical fractions of Cu and Co in sandy loam and clay loam soils that had been irrigated with contaminated water
The concentration of bioavailable Cu and Co in soil at the end of the pot experiment increased in all treatments where contaminated water was used for irrigating the crops

Summary

Introduction

The increased copper mining in Zambia has generally contributed to employment opportunities coupled with improvements in living standards of the population in these new mining areas. High levels of copper (Cu), cobalt (Co), lead (Pb), and zinc (Zn) have been recorded in the soils and in water on the Copperbelt in Zambia [1,2,3,4,5,6,7,8]. The cause for the elevated levels of Cu on the Copperbelt province of Zambia is due to mining activities and processing of Cu and Co. Copper is mined in all towns of the Copperbelt province. Cobalt is mined only in Kitwe and Chambishi on the Copperbelt province of Zambia

Objectives

Methods

Results

Discussion

Conclusion