Adsorptive removal and recovery of organic pollutants from wastewater using waste paper-derived carbon-based aerogel

In this study, carbon-based aerogels derived from waste paper (CWP) were explored as an efficent adsorbent to remove organic pollutants including phenol (Ph) and 2-chlorophenol (2CP) from wastewater. CWP exhibited a highly porous structure and large specific surface area of 892 m² g^-1, which facilitated the adsorption of Ph and 2CP in wastewater. The adsorption behavior of Ph and 2CP on CWP could be well described by the pseudo-second-order kinetics and Langmuir isotherm models. Based on the Langmuir isotherm, the maximum adsorption capacities of CWP for Ph and 2CP were 238 and 278 mg g^-1, respectively, and these values were much higher than those of other adsorbents. The removal of the organic pollutants mainly occurred through electrostatic attraction, pore-filling, hydrogen bonding, and π-π interactions. The CWP can be directly applied for the removal of Ph and 2CP at low concentration (<200 mg L^-1) in the wastewater, while they can be used with additional pre-treatment for wastewater containing high concentration of organic pollutants. The adsorptive recovery of organic compounds and potential reuse of treated wastewater were also discussed. This work provides an efficient approach to produce effective adsorbent for the removal and recovery of chemicals from wastewater.