Will adding sodium carbonate to a low pH solution of sodium hydrosulfide have an adverse reaction?

I am managing an HSE project to dispose of an expired NaHS solution. There was approximately 500 gallons of liquid in two tanks. Both tanks have been pumped down, and there is little residual liquid with ~ 100lbs of solid in the bottom of the tanks. The H2S readings in the tank are approaching IDLH conditions. I am assuming that over time, the pH of the NaHS solution decreased due to exposure to air which is causing the high concentration of H2S in the tank.


We want to suppress the H2S vapors so that when the solids are placed in drums for disposal, there won't be any off gassing in the headspace of the drum. Would adding solid sodium carbonate to the solid in the bottom have any adverse reaction? I am assuming that some heat will be generated due to it neutralizing the H2S, but this is taking place outdoors and we would add the carbonate slowly to minimize heat generation.


