Abstract <p>2,4,6-Trinitrotoluene (TNT) is a widely used nitroaromatic explosive that poses significant environmental and biological risks due to its toxicity, particularly critical in regions experiencing armed conflict. The remediation of TNT-contaminated sites through adsorption and immobilization using biochar is proposed as a safe and cost-effective strategy. This study evaluated the potential of biochar derived from four different waste sources for TNT adsorption. Biochars derived from plant biomass (wood and coconut shell) exhibited high organic carbon contents (68.72%–69.42%), specific surface areas (535.09–578.99 m²/g), and total pore volumes (0.65–0.69 cm³/g). Their TNT adsorption capacities (240.0–257.2&#xa0;mg/g) were significantly higher than those of bone- and sludge-derived biochars. TNT adsorption kinetics followed the pseudo-second-order model (R² &gt; 0.97), indicating that chemisorption was the dominant mechanism. Adsorption isotherms were well fitted by the Freundlich model (R² &gt; 0.99), suggesting a heterogeneous multilayer adsorption process. The primary mechanisms underlying TNT adsorption were likely π–π interactions and pore filling. Additionally, the biochars showed strong adaptability across a range of temperatures (5–45&#xa0;°C), pH levels (3–11), and coexisting substances (natural organic matter, metal ions). Notably, the addition of 2% biochar effectively immobilized 1000&#xa0;mg/kg of TNT in loamy soil. This research highlighted the promising potential of biochar as an effective adsorbent for TNT and underscored the practical applications of biochar in the remediation of TNT-contaminated soils.</p> Graphical Abstract <p></p>