Today, pollution of soil and groundwater by lead (Pb) is one of the most important concerns in densely populated and industrial areas. Sorption of Pb by soil solid phase determines the mobility, traort and bioavailability of Pb in soils. Parameters of Pb sorption by soils can be determined using sorption isotherms. Sorption isotherms can provide useful information about the capacity and affinity of soils for Pb sorption. Laboratory tests to determine the soil sorption coefficients arecostly, time-consuming and hazardous. The sorption parameters can be easily estimated from soil properties such as clay, silt, sand, organic matter, calcium carbonate, and pH using siutable pedotransfer functions. The purpose of this research was to develop appropriate pedotransfer functions to estimate the sorption coefficients of Pb in soils from Mazandaran province using multiple regression analysis. For this purpose, Pb sorption isotherms were obtained for 100 soil samples and various regression equations were developed for estimating the parameters of Pb sorption parameters based on the physical and chemical characteristics of the soils. Results showed that capacity parameters of Pb sorption (q max and K F ), were significantly correlated with the characteristics of the soil, including clay, organic matter, CEC, CCE, and silt. Freundlich exponent (N) representing the intensity of the sorption of Pb in soils were significantly affected by organic matter content, pH, and CEC of the soils. Various models to estimate the sorption parameters of Pb in the soils were developed. To estimate the sorption capacity parameters (q max and K F ) properties such as organic matter, calcium carbonate, CEC, clay and silt entered the models, but average distribution coefficient ( ), Freundlich N, and Langmuir K L parameters showed non-significant coefficients with soil properties. In general, clay and organic matter content, CEC, CCE and silt were the most important soil properties that entered the predictive models. Keywords : pedotransfer functions, sorption isotherms, multiple regression, lead, Mazandaran province
