Singular potentials and absorption problem in Quantum Mechanics

We discuss a possible approach to the absorption problem in Quantum Mechanics based on using of singular attractive potentials in the corresponding Schr\"{o}dinger equations. Possible criteria for selection of exact solutions of these equations are considered and it is shown that different models of absorption can be realized by a special choice of exact solutions. As an example, the motion of charged particles in the Aharonov-Bohm (AB) and the scalar attractive $\rho^{-2}$ potentials is investigated in detail. Other attractive potentials are briefly considered.