Kinetic Model and Ecological Dose Values for the Inhibition of Effects of Cd2+ and Hg2+ on Soil Enzymes
Jinlong Yan and Guixiang Quan
Journal Title:Nature Environment and Pollution Technology
Effects of Hg2+ and Cd2+ on the activities of urease, invertase and amylase in different periods and concentration were studied by indoor soil cultivating method. Results showed that the activities of soil urease, invertase, and amylase by heavy metals were inhibited markedly, but this inhibitory effect differed among enzymes. During the treatment of 45 days, the activities of urease, invertase and amylase were decreased with the increase of the concentrations of Hg2+. There were significant logarithmic correlations between the concentration of heavy metals and the inhibition ratios of the activities of these three enzymes (r2 > 0.902). The inhibitory effect was also characterized in the term of ecological dose value (ED50). It indicated that urease activity was more sensitive than the other two enzymes to heavy metals contamination. So, urease activity may be a suitable early warning index to be used in the characterization the soil pollution condition of heavy metals.