A process for removal of gaseous contaminants from a gas stream, the process comprising: contacting the gas stream with an amine-based wash solution in an amine based wash solution section of an absorption unit to remove gaseous acidic components from the gas stream by absorption into the amine-based wash solution to form a first spent wash solution; contacting the gas stream with one or more aqueous wash solutions in a water wash section of the absorption unit to remove water soluble contaminants and form an additional spent wash solution, wherein at least a portion of the additional spent wash solution is fed to a separation device for separating and removing the water soluble contaminants from the portion of the additional spent wash solution; contacting a chemical agent with the additional spent wash solution in the separation device to form heat stable salts of the water soluble contaminants; and wherein after removal of the volatile water soluble contaminants from the additional spent wash solution, the treated additional spent wash solution is recycled to the absorption unit, wherein the treated additional spent wash solution is recycled to the water wash section of the absorption unit and/or the treated additional spent wash solution is recycled to the amine based wash solution section; comprising regenerating the first and additional spent wash solutions from the bottom of the absorption unit in a regeneration unit having a lower and an upper portion to form a regenerated wash solution and a gas stream of the acidic components, wherein the regeneration unit has a temperature profile and configuration with the upper portion having a lower temperature than the lower portion such that the water soluble contaminants remain in the regenerated wash solution. contacting the gas stream with an amine-based wash solution in an amine based wash solution section of an absorption unit to remove gaseous acidic components from the gas stream by absorption into the amine-based wash solution to form a first spent wash solution; contacting the gas stream with one or more aqueous wash solutions in a water wash section of the absorption unit to remove water soluble contaminants and form an additional spent wash solution, wherein at least a portion of the additional spent wash solution is fed to a separation device for separating and removing the water soluble contaminants from the portion of the additional spent wash solution; contacting a chemical agent with the additional spent wash solution in the separation device to form heat stable salts of the water soluble contaminants; and wherein after removal of the volatile water soluble contaminants from the additional spent wash solution, the treated additional spent wash solution is recycled to the absorption unit, wherein the treated additional spent wash solution is recycled to the water wash section of the absorption unit and/or the treated additional spent wash solution is recycled to the amine based wash solution section; comprising regenerating the first and additional spent wash solutions from the bottom of the absorption unit in a regeneration unit having a lower and an upper portion to form a regenerated wash solution and a gas stream of the acidic components, wherein the regeneration unit has a temperature profile and configuration with the upper portion having a lower temperature than the lower portion such that the water soluble contaminants remain in the regenerated wash solution.