Heavy metals and arsenic soil contamination resulting from wastewater sludge urban landfill disposal

Abstract

The purpose of the study is to assess the soil contamination of a sewage sludge landfill, bordering specially protected natural areas. The content of heavy metals and arsenic in the landfill soil was assessed based on national soil quality standards in terms of monitoring landfills for priority pollutants (Cd, Cu, Pb, Zn, Ni, As), and in comparison with background concentrations for sod-podzolic soils in the European part of Russia. Soil samples were taken at 9 observation points from depths of 5-20 cm. The concentrations of heavy metals and arsenic were studied through mass spectrometry with ionization in inductively coupled argon plasma and atomic absorption spectrometry. The results of the study showed a significant increase in Cd, Cu, Ni, Pb, and Zn in 2017 compared to 2011. The concentrations of As decreased slightly, but the concentration range remained stable. The concentrations of heavy metals and arsenic had the following maximum range: Cd1083 >Cu45 >Pb16 >Zn5 >Ni4 >As3 in comparison with background concentrations of these elements in the European part of Russia. In general, the degree of the landfill soil contamination can be described as dangerous and very dangerous according to national soil quality standards.