Mass transfer of adsorption of methylene blue into biomass-based activated carbons: heterogeneous surface diffusion model

Adsorption is still considered as one of the most effective ways for treating liquid waste. Mechanistic mathematical model is useful to give physical insights inside adsorbents during adsorption. In this study, a heterogeneous surface diffusion model is developed and implemented to describe mass transfer of methylene blue into biomass-based activated carbons. The results indicate that the model represents well the mass transfer during adsorption. The model matches well with the pore structure of activated carbons. The concentration profiles on both surface of mesopore and micropore help to analyse the transport phenomena of methylene blue inside the activated carbons. The model can potentially be used for designing new adsorption units and optimising existing adsorption facilities.