Effect of Soil Chemical and Physical Properties on Sorption and Desorption Behavior of Lead in Different Soils of India

Abstract

Lead (Pb) is a non-biodegradable contaminant, present in the environment, especially near lead-based industrial sites, agricultural lands, and roadside soils. Bioavailability of Pb in the soil is controlled by the sorption and desorption behavior of Pb, which are further controlled by the soil chemical and physical properties. In this study, sorption and desorption amounts of Pb in soil were compared with soil physical (sand, silt, clay content) and chemical (pH; electrical conductivity, EC; percent organic carbon, (%OC); cation exchange capacity, CEC) properties. Twenty-six surface soils (0–5cm), expected to vary in physical and chemical properties, were collected from different parts of India and were treated with known concentration of Pb solution (40 μg/L). The amount of Pb sorbed and desorbed were measured and correlated with soil properties using simple linear regressions. Sorption was significantly (p ≤ 0.05) and positively correlated with pH, and %OC; desorption was significantly (p ≤ 0.05) negatively correlated with the same two factors. Stepwise multiple regressions were performed for better correlations. Predicted sorption and desorption amounts, based on multiple regression equations, showed reasonably good fit (R² = 0.79 and 0.83, respectively) with observed values. This regression model can be used for estimation of sorption and desorption amounts at contaminated sites.

Keywords:

• lead
• sorption
• desorption
• soil properties
• multiple regression

Acknowledgments

The authors gratefully acknowledge H. S. Hundal (PhD), Department of Soil, Punjab Agricultural University, and Pritha Dey (M.Sc.), Department of Bioinformatics, Sikkim Manipal University, for their overall support. Grateful acknowledgement is also extended to Punjab Agricultural University, India, for providing a laboratory facility. Indian Council of Agriculture Research provided fellowship to the graduate student (Sudarshan Dutta) to complete the research. We also thank the editors and anonymous reviewers whose comments and suggestions were very constructive and helped further to strengthen this manuscript.