The effect of HS- ions in 1-mol/l NaOH solutions on the ion diffusion in wood calculated as the steady state diffusion and the drift speed

Diffusion tests in pine, birch and spruce were done with different Na2S fractions of 1-mol/l NaOH solutions. The steady state diffusion was found to be dependent on the original moisture content present in the wood samples and the concentration of the electrolyte, but not the HS- ions. The drift speed was dependent on the mobility of the HS- ions, reducing the flux as compared to the OH- flux in pure NaOH solutions. The moisture content originally present inside the wood samples affected the migration, especially in the longitudinal direction due to structural effects.