Column adsorption of 2-naphthol from aqueous solution using carbon nanotube-based composite adsorbent

Abstract

A core-shell structural carbon nanotube (CNT)-based composite adsorbent is constructed and is adopted to remove 2-naphthol from aqueous solution in a fixed-bed column system in this study. The effects of operation parameters including adsorbent mass, influent flow rate and inlet concentration on the adsorption performance of the column are investigated. The breakthrough curves suggest that an efficient retention of 2-naphthol is achieved by the adsorption column packed with CNT-based composite adsorbent. The equilibrium adsorption amount of 2-naphthol on the CNT-based composite adsorbent varies from 122.7 mg/kg to 286.6 mg/kg in this experimental region. Increasing the adsorbent mass prolongs the breakthrough time and enhances the total removal of the adsorption column. A higher influent flow rate or inlet concentration is beneficial to improve the equilibrium adsorption amount of 2-naphthol on the CNT-based adsorbent. The dynamic behavior of the adsorption column packed with CNT-based adsorbent is described fairly well by the Thomas model, the Yoon-Nelson model and Bed Depth Service Time (BDST) model. The service time of the column is found to be linearly relating to the bed depth. Results from this study show that the CNT-based composite adsorbent can be applied in fixed-bed columns to efficiently remove 2-naphthol from water.