Adsorptive Behavior of [3H] 2,3,7,8-TeCDD on Seven Japanese Soils using a Batch Equilibrium Method

The adsorption behavior of [1, 6-3H] 2, 3, 7, 8-TeCDD from water on seven Japanese soils has been evaluated by a batch equilibrium experiment. The experimental conditions of the soil/solution ratio and the equilibrium time were optimized to be 1: 5000 (50 mg/250 ml) and 72 hours, respectively. The Freundlich adsorption isotherm experiment was conducted at four initial concentrations ranging from 0.005 to 0.06 μg/l in the aqueous phase. The adsorption isotherms followed the Freundlich equation with good correlation coefficients. The Freundlich exponents (1/n) were close to one. The Freundlich adsorption coefficients (KadsF) ranged from 9, 887 to 97, 248. The organic-carbon-normalized Freundlich adsorption coefficients (log KadsFoc) ranged from 5.58 to 6.77. No positive relation was found between soil parameters (such as organic carbon content, clay content and cation exchange capacity) and adsorption parameters.