The one-sided single-pellet dynamic technique introduced in this artic
le is shown to be a very effective and simple method for the analysis
of adsorption and diffusion in porous solids. Moment expressions are p
resented for reversible and irreversible adsorption processes. Since t
he adsorption equilibrium constant is the only unknown parameter in th
e first moment expression, this parameter can be evaluated from a sing
le set of pulse-response experiments. This technique to evaluate the a
dsorption equilibrium constant is illustrated using ethylbromide as tr
acer. It is also shown that for a very strongly adsorbing tracer, such
as 1,2-dichloroethane in soil, modified moment expressions derived wi
th a semiinfinite boundary condition are necessary unless a criterion
developed in this work is satisfied.