Lead reactions in some calcareous soils of Nineveh Governorate

الملخص EN

The adsorption experiment of three different calcareous soils two loam and oneclay textures) for Nineveh governorate (Tel Aakoub, Ibrahim Al-Khalil, and TelKaif) was classified under Aridsol-Calciorthids with a slight slant to alkaline(7.43), non saline (3.24 dS m-1), Low content of organic matter (17.3 kg-1), cationexchange capacity (42 Cmolc kg-1), high content of carbonate minerals (409 g kg-1).

Lead adsorption was studied by batch equilibrium method at a temperature of (298Kelvin) for lead solutions (5, 10, 20, 40, 80, 100 mg L-1).

For 48 hours, the lead wasmeasured in equilibrium solutions and the adsorption criteria were calculatedaccording to Langmuir, Freundlich and the DR equations.

The results of themathematical description of lead adsorption showed high efficiency in the use ofLangmuir, Freundlich and the DR equations at the concentrations used.

The leadadded to the soil was also distributed between the equilibrium solution and the solidsoil phase in terms of propagation coefficient values (Kd), which ranged from(111.8) to (255.5 l kg-1) with an average of 169 l kg-1.

The exceeded the Langmuirand Freundlich equivalents in the description of lead adsorption to obtain thehighest coefficient of determination (R2) and a lesser standard error (SE).

Theadsorption capacity (qm) of the lead ion in the study of soil (13.63 - 41.48 mol g-1).

The K value associated with the adsorption capacity ranged from (-0.44) to (- 1.24)(mol2 KJ -2).

The value of (E) is the free energy rate of the reaction ranged from thelead adsorption values (0.63 - 1.06 KJmol-1(.