Performance evaluation and application of oxygen enriched waste rubber tire adsorbent for the removal of hazardous aniline derivatives from waste water

Liquid-phase adsorption of aniline, p-Cl-aniline, p-toluidine and p-anisidine onto rubber tire activated carbons with different textural and surface chemistry was conducted to explore not only the influence of the surface chemical characteristics on the adsorption capacity but also in designing and analyzing the specific studied system for waste water treatment. Rubber tire activated carbons having high surface area and favorable textural properties with oxygen enriched functional groups (RTAC_ox) and without (RTAC) were developed and their adsorption capacity compared with a purely microporous commercial carbon. The pore structure and the adsorbate size played an influencing role in the adsorption of RTAC and CAC, the trend followed being: aniline>p-toluidine>p-anisidine>p-chloro aniline. Superior performance of RTAC_ox was attributed to the oxygen functional groups along with larger mesopore volume. Uptake trend of p-anisidine>p-toluidine>aniline>p-chloro aniline by RTAC_ox correlated well with the basicity of the studied adsorbates. Such results were corroborated by the batch equilibrium and thermodynamic studies. Column experiments with real waste water established the practicality of the developed system. The regeneration and reuse without significant loss in efficiency showed an important criterion of advanced adsorbent in RTAC_ox for waste water treatment.