Removal of 2,4,6-Trinitrotoluene from Pink Water Using Molecularly-Imprinted Absorbent

Molecularly-Imprinted Polymers (MIPs) were designed, prepared, and tested for the removal of TNT from pink water, which contains 2,4,6-trinitrotoluene (TNT) and other nitrobenzene compounds (NBCs) produced in army ammunition plants. We have investigated the interactions between TNT template and different monomers using molecular modeling and spectrometric methods, which enables us to optimize the MIP compositions. A suspension polymerization method was utilized to prepare MIP beads with an average diameter of 25 mu m, and an imprinting effect of 4.3 was achieved. Furthermore, we have constructed a model absorbance reactor using a flash chromatography system, which was successfully used to monitor the removal of TNT and other NBCs on-line, and the MIP absorbent was regenerated in-situ. Compared with granular activated carbon, the capacity of the MIP absorbent is 65-fold higher. In addition, the MIP absorbent can be regenerated easily, and the capacity only decreases by 7% after four rounds of regeneration. Besides pink water, the MIP absorbent can also be used to remove NBCs in the waste stream from TNT production.