Removal of nitro aromatic compounds and sulfite acid from distillate of 2,4,6‐trinitrotoluene red water using modified porous polystyrene microspheres

Abstract

AbstractTo remove the nitro aromatic compounds (NACs) and SO32− from distillate of 2,4,6‐trinitrotoluene (TNT) red water, the carboxylated and aminated polystyrene (PSt) microspheres were used as adsorbents. GC‐MS and HPLC analysis were used to determine the types and concentrations of NACs before and after adsorption. The carboxylated PSt, which was prepared by modifying PSt with phthlandione (PA), could remove the neutral NACs including 2,6‐dinitrotoluene (2,6‐DNT), 2,4‐dinitrotoluene (2,4‐DNT), 1,3,5‐trinitrobenzene (1,3,5‐TNB), and 2,4,6‐trinitrotoluene (2,4,6‐TNT), with the acid 2,4‐dinitrophenol (2,4‐DNP) and SO32− remained in the distillate. The aminated PSt that was synthesized by activating PSt with chloroacetyl chloride follow by reaction with 1,2‐ethanediamine (EDA) could remove all the NACs and SO32−. The results suggested that EDA‐PSt adsorbed the NACs though multimode interactions, i.e., hydrogen bond and electrostatic attraction. After adsorption using EDA‐PSt, chemical oxygen demand (COD) was reduced from 86.1 to 11.2 mg L−1, and a colorless, transparent, and nontoxic solution with neutral pH value was obtained. Five grams of EDA‐PSt could purify 1600 cm3 of distillate of TNT red water, and the adsorbents could be recycled by elution with methanol to desorb the neutral NACs followed by elution with 0.1 mol L−1 NaOH to wash off 2,4‐DNP and SO32−. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013