Biochar: a low-cost adsorbent of Methylene Blue from aqueous solutions

Removal of Methylene Blue (MB) from aqueous solutions by compost-biochar and plant biomass-biochar mixtures is investigated under batch conditions to determine the adsorption capacity of biocarbons under variable parameters (initial Methylene Blue and biochar concentrations, temperature, pH of the solution). The experimental data have been computed using Freundlich adsorption isotherms. The adsorption percentage onto the biocarbons is shown to correlate linearly with the adsorbent quantity and concentration, MB-biochar contact time and pH. The results from the adsorption process are well correlated with the Freundlich model: R2 > 0.989 for compost-biochar and R2 > 0.977 for biomass-biochar. Biocarbons have been shown to be an effective and low-cost material for the removal of dye and colourisation from an aqueous solution.