Synthesis, characterisation, and adsorption evaluation of carbon-natural-zeolite composites

Natural zeolite is well known for the removal of heavy metals and has wide spread applications, however it has a negligible adsorption capacity for organic contaminants from aqueous solution. Several composites of carbon and natural zeolite with varying amounts of carbon were synthesised as prospective adsorbents to adsorb organic contaminants from waste water. The composites were prepared by saturating a natural zeolite with carbon precursor (furfural alcohol) and then carbonised at 800 °C in inert atmosphere. The structure and properties of the composites were characterised using various techniques such as XRD, FT-IR, FT-Raman, SEM and TEM. In phenol adsorption tests, adsorption isotherm indicated an enhanced adsorption of phenol on the composites as compared with the natural zeolite. It was also showed that the adsorption increased with increase in carbon content of the composite. The equilibrium data were modelled with the Langmuir, Freundlich, Temkin and Smith models.