The processes of formation of zinc hydroxide and the processes of oxidation-reduction of Cr6+ under action on water solutions of a direct current discharge of atmospheric pressure in air are analyzed. It is shown that the formation of active particles is localized in thin surface layers of the liquid cathode and anode. The solution in the cathode part is acidified, and in the anode one becomes alkaline. As a result, the process of formation of zinc hydroxide and the reduction of Cr6+ begins with the surface of the liquid anode, gradually capturing the entire volume of the solution. The possible role of active particles (OH, H2O2, H, solvated electrons) in the observed phenomena is discussed. Because of the heterogeneity of the solution, the experimentally measured process characteristics (rate constants, reaction rates, energy efficiency, etc.), which are average in volume, should depend not only on the discharge parameters, but also on the geometry of the reactor.