From black liquor to highly porous carbon adsorbents with tunable microstructure and excellent adsorption of tetracycline from water: Performance and mechanism study

In this work, we reported the successful conversion of the industrial SLS originated from black liquor to low-cost porous carbon with tunable microstructure and ultrahigh adsorption performance of tetracycline (TC) from water via pre-carbonation and KOH activation. Comparatively, LCA-850-4 with a very high specific surface area (2805.8   m 2 /g) and pore volume (1.45   cm 3 /g) showed a maximum adsorption of 1173   mg/g at 298   K, which was far higher than other reported adsorbents. LCA-850-4 exhibited excellent adsorption over a broad pH range. Kinetics and isotherm data was well fitted to the pseudo-second-order rate and Langmuir model, respectively. Thermodynamic parameters indicated a spontaneous and endothermic adsorption. The results are of importance to indicate LCA-850-4 with fast kinetics and excellent reusability possessed the huge potentials in practical pharmaceutical antibiotic wastewater treatment.