Adsorption of H2S, NH3 and TMA from indoor air using porous corncob activated carbon: Isotherm and kinetics study

In this study, a corncob-derived activated carbon was prepared via chemical activation using potassium hydroxide as a chemical activating agent for the adsorption of H2S, NH3 and trimethylamine. The activated carbon was impregnated with copper to improve its H2S, NH3 and TMA adsorption performance. SEM, EDX, nitrogen adsorption-desorption, TGA/DTA, proximate and elemental analysis tests were employed to characterize the activated carbon samples. Removal efficiencies of the activated carbon samples for H2S, NH3 and TMA were conducted through batch experiments. The H2S, NH3 and TMA adsorption potentials of the CAC were 164.54, 190.68 and 323.56 mg g−1 respectively. The isotherm analysis results showed that the Langmuir adsorption isotherm model was the most suitable to describe the adsorption isotherm of H2S, NH3 and TMA. Similarly, pseudo-second order kinetic model well explained the adsorption kinetics of NH3 and TMA while pseudo-first order showed better fit towards the adsorption of H2S. The findings revealed that the copper-catalyzed corncob activated carbon is a promising and sustainable adsorbent for the removal of toxic gases from indoor areas.