Heavy Metals Behavior in Soil/Plant System after Sewage Sludge Application

Urszula Wydro,Elżbieta Wołejko,Andrzej Butarewicz,Eliza Hawrylik,Joanna Rodziewicz,Agata Jabłońska-Trypuć,Wojciech Janczukowicz

doi:10.3390/en14061584

Urszula Wydro, Elżbieta Wołejko + Show 5 more

Open Access

https://doi.org/10.3390/en14061584

Copy DOI

Abstract

One of the possibilities of removing heavy metals (HMs) from soil is the use of phytoremediation techniques supported with biosolids, which also allow for their disposal. Therefore, the objective of the research was the determination of the sewage sludge suitability after its application to urban soil in order to increase the phytoremediation efficiency of contaminated soil. A field experiment was established on lawns in Białystok (Poland) in two locations with different traffic. The research plots were fertilized with sludge in doses of 14.5 t DM/ha and 29 t DM/ha. A mixture of lawn grasses was sown on the prepared plots. During two years of experiment soil/plant samples were collected, and pH, organic matter, dehydrogenase and catalase activity (soil), the total content of Cd, Cr, Cu, Mo, Ni, Pb, Zn, and Hg (soil/plant), and their fractions (soil) were determined. The HMs in soil were present mainly in residual and reducible fractions. Zn had the highest share in acid-soluble fractions (17–45%). The efficiency of urban soil phytoremediation was determined by the calculation of bioconcentration (BCF) and translocation (TF) factors. The highest values for BCF and TF were obtained for Mo (1.97 and 1.99, respectively). In the presented study, sludge amendment caused an immobilization of heavy metals.

Highlights

Urban soils are an integral part of the urban ecosystem, which directly and indirectly determines the quality of life of its inhabitants
heavy metals (HMs) are introduced into soils from the air in the form of industrial dust, or they are released from vehicles when fuels are burned
Similar values were recorded in T2, with the clay content in soil from 5% to 6%

Summary

Introduction

Urban soils are an integral part of the urban ecosystem, which directly and indirectly determines the quality of life of its inhabitants. More than any other type of soil, they are exposed to pollution, both from point and diffuse sources [1,2]. One of the most important aspects determining the chemical properties of soil and land in urban space is the content of heavy metals (HMs). According to Chen et al [4] and Hong et al [5], the main source of chemical pollution of urban soils with trace elements is primarily an exposition to pollution from the atmosphere. In the case of their high concentrations in soil, there is a risk of their incorporation in the trophic circulation, which may pose a threat to living organisms, including humans. Too high concentrations of metals in soil reduces the rate of decomposition of organic matter and disrupts the biogeochemical cycle [1,6]

Objectives

Methods

Results

Discussion

Conclusion