Long-term sorption of halogenated organic chemicals by aquifer material. 2. Intraparticle diffusion

Sandy aquifer material was used in studies of the rate of sorption uptake of tetrachloroethene and 1,2,4,5-tetrachlorobenzene during long equilibration periods. An intraparticle diffusion model was used to interpret the measured uptake rates. Diffusive rate constants for use with the model were obtained for different size fractions of the aquifer solids and for pulverized material. Rate constants were inversely correlated with equilibrium distribution coefficients, in accordance with a concept of retarded intraparticle diffusion. Model results suggested that sorption occurred throughout the grain volume and that the particle radius was the appropriate length scale for diffusion. There are 57 references.