  We address via numerical simulation the two-dimensional bimolecular
annihilation reaction $A + A \to \emptyset$ in the presence of quenched, random
impurities. Renormalization group calculations have suggested that this
reaction displays anomalous kinetics at long times, $c_{A}(t) \sim at^{\delta
-1}$, for certain types of topological or charged reactants and impurities.
Both the exponent and the prefactor depend on the strength of disorder. The
decay exponents determined from our simulations agree well with the values
predicted by theory. The observed renormalization of the prefactor also agrees
well with the values predicted by theory.
