Adsorption of organic compounds from solution by activated carbons produced from waste tyre rubber

Activated carbons produced from waste tyre rubber have shown exceptional characteristics for the adsorption of organic species from solution. Adsorption capacities were found to be dependent primarily on the degree of activation and the molecular size of the adsorbate compound. For the purpose of this work, a series of activated carbons were produced by steam activation of waste tyre rubber at 925°C over a period of 80–640 min. The resulting carbons were investigated for their porosity, using nitrogen gas adsorption, and for their aqueous adsorption characteristics, using phenol, methylene blue, and textile dyes Turquoise H-A and Red H-E2B. Two widely used commercial adsorbents were also tested for comparative purposes. Aqueous adsorption data were modeled to the Langmuir equation in order to determine the adsorption capacities (X m) and affinity parameters (b) associated with each sample. Rubber-derived carbons proved superior to the commercial adsorbents for the removal of medium and large molecular weight compounds from solution, which was attributed to their extensive total micropore volume and external surface area.