Effects of environmental materials on maize growth and soil remediation of Pb and Cd contaminated soils

Application of environmental materials is a vital remedial measure of heavy metal lead (Pb) and cadmium (Cd)) contaminated soils. To explore the effects of environmental materials on plant growth and quality and to enhance remediation of Pb and Cd contaminated soils, a pot experiment was setup in greenhouse conditions. The experiment analyzed soil properties, growth and quality as well as Pb and Cd contents of maize (Zea mays L.) in Pb-Cd contaminated soils. Different environmental treatments, including single environmental materials treatments e.g., humus (HA), polymers (SAP), coal-derived composites (FM) and powder minerals (FS), and composite treatments of environmental materials were selected in heavy metal Pb and Cd contaminated soils. The results indicated that F22 (FM+SAP), F23 (FS+SAP) and F32 (HA+SAP+FS) composite treatments promoted stronger maize growth at seedling stage than that of the control. Maize crude ash in all the treatments with environmental materials was less than that of the control. Also maize crude starch in single environmental material treatments was higher than that in composite environmental material and control treatments. By comparison, single FM and combined F33 (SAP+FM+FS) and F4 (HA+SAP+FM+FS) treatments had a significant inhibition effect on maize Pb uptake in Pb-Cd contaminated soils. Similarly, single FM and FS and composite F33 (SAP+FM+FS) environmental materials treatments had a significant prohibition effect on maize Cd uptake in Pb-Cd contaminated soils. Thus the application of environmental materials could improve soil physical and chemical properties and inhibited crop heavy metal uptake.