The relative performance of microwave regenerated activated carbons on the removal of phenolic pollutants

Abstract

The adsorption of reagent on the surface of porous material and the regeneration of porous material are significant processes that are widely used in chemical industries. The performance of a granular commercial activated carbon and two activated carbons synthesised from the factory waste tea and demineralised waste tea, were tested during a series of adsorption and regeneration cycles. Phenol and p-nitrophenol (PNP, 4-nitrophenol) were used as the reagents to represent water pollutants. The activated carbon samples were regenerated by the application of a short period of microwave energy (30 s). The influence of the microwave regeneration process on the surface area and pore volumes were investigated with laboratory characterisation techniques. Several cycles of adsorption and regeneration processes were conducted to determine the variation in the adsorption capacity and the characteristics of each porous material. The adsorption and regeneration processes were interpreted in terms of the amount of adsorbed reagent and surface characteristic of the porous material. The materials were found to be good adsorbents for phenol and PNP and the regeneration process worked effectively; broadly maintaining the adsorption capacity over multiple adsorption – regeneration cycles.