  We investigate, both analytically and by computer simulation, the kinetics of
a microscopic model of hard rods adsorbing on a linear substrate. For a small,
but finite desorption rate, the system reaches the equilibrium state very
slowly, and the long-time kinetics display three successive regimes: an
algebraic one where the density varies as $1/t$, a logarithmic one where the
density varies as $1/ln(t)$, followed by a terminal exponential approach. A
mean-field approach fails to predict the relaxation rate associated with the
latter. We show that the correct answer can only be provided by using a
systematic description based on a gap-distribution approach.
