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. <EOS>