Removing 2,4,6-trinitrotoluene from water by macroporous resins
大孔树脂吸附去除水中的2,4,6-三硝基甲苯

Adsorption of 2,4,6-trinitrotoluene onto two kinds of macroporous resin including XAD-4 and NDA-804 was studied. The adsorption isotherms of TNT onto resins were measured. Raising the temperature was advantageous to adsorption. The maximum equilibrium adsorption capacities of XAD-4 and of NDA-804 at 35 degrees were 82.86 mg/g and 94.26 mg/g, respectively. The TNT adsorption behaviors could be better described using the Langmuir adsorption model than the Freundlich adsorption model, and the correlation coefficient was greater than 0.99. The kinetics of TNT adsorption onto resins obeyed pseudo-second order kinetic model. The lower the initial TNT solution concentration, the shorter time of the adsorption equilibrium was. The time until equilibrium was 1 hour. The NDA-804 was applied to treat TNT manufacturing wastewater. The TNT concentration in the wastewater decreased from 103.58 mg/L to 0.4 mg/L after adsorption by NDA-804, indicating a high removal efficiency of 99.6%. The NDA-804 could be regenerated by a mixed solution of HCl and methanol with pH of 2. The TNT would be subsequently recovered from the high concentrated regenerant solution by distillation.