Biocarbon nanoadsorbents derived from walnut shell and their excellent adsorption of trinitrotoluene from wastewater

Abstract A new reusable biomass derived adsorbent biocarbon material was prepared by charring ball-milled walnut shell powders under an inert gas atmosphere and treating with sodium hydroxide (NaOH) solution (the formed biochar is named as WS). WS was able to achieve a rapid adsorption of trinitrotoluene (TNT) from waste streams, reaching an equilibrium within 30 min. The maximum adsorption capacity reached 107.0 mg·g-1. The TNT adsorption from waste streams by WS followed the Langmuir isotherm model and the proposed second order kinetic model. The WS prepared in this study was able to achieve an efficient removal of TNT waste streams through the synergistic effect of electrostatic attraction and chemisorption.