Clays as Dual-Function Materials for TNT Adsorption and Catalytic Degradation: An Experimental Approach

This study explores the adsorption and catalytic degradation of 2,4,6-trinitrotoluene (TNT) from aqueous solutions, using montmorillonite-based catalysts. Commercially, montmorillonite K10 was modified through aluminum pillaring (K10-Al-PILC), followed by vanadium intercalation (K10-Al-PILC-V) and ozone activation. A novel aspect of this work is the use of naturally contaminated water as the TNT source. The selected sample, collected from the Plaiul Arșiței-Cireșu-Leșunț region (Oituz, Bacau, Romania), originated from an area historically exposed to explosive residues, where TNT traces were previously identified. The adsorption performance of the materials was evaluated by varying adsorbent dosage, contact time, and solution pH. Catalytic ozonation experiments were conducted under different catalyst masses, ozone concentrations, and reaction times to assess degradation efficiency. The results demonstrated that aluminum pillaring significantly enhanced the adsorption capacity of the clay, while vanadium incorporation further improved both adsorption and catalytic activity. The vanadium-modified material exhibited superior performance in TNT removal, both through adsorption and oxidative degradation. Additionally, the catalytic ozonation process led to the formation of degradation products with reduced toxicity, confirming the potential of these materials for environmental remediation of nitroaromatic pollutants in real water systems.