Activated carbon from coal tar pitch and furfural for the removal of p- nitrophenol and m-aminophenol

Adsorption of m-aminophenol and p-nitrophenol from aqueous solution on activated carbon synthesized on the base of industrial by product (coal tar pitch) and furfural was investigated. The adsorption capacity of the activated carbon and its oxidized modification is related to the surface area and composition of the prepared materials, as well as to the nature of the adsorbents. Despite the moderate porosity, the prepared materials display adequate adsorption capacity towards the investigated aromatic compounds. Both adsorbates show higher affinity towards the hydrophobic carbon, confirming that the retention mechanism occurs via nonspecific interactions between the electronic density of the adsorbent and the aromatic pollutants. Electrostatic interactions may also appear depending on the solution pH and the charge distribution of the carbons; we have observed that this parameter has a strong influence on the final performance of the oxidized carbon, where repulsive interactions that reduced the uptake of the carbon were found to appear within a larger pH range.