Applicability of alkaline hydrolysis for remediation of TNT-contaminated water

Abstract

This study was conducted to assess the applicability of alkaline hydrolysis as an alternative ex situ technology for remediating 2,4,6-trinitrotoluene (TNT)-contaminated water. TNT reactivity had a strong dependence on the reaction pH (11–12) and initial TNT (5–25 mg L −1) in batch systems, resulting in pseudo first-order transformation rate, k ranging between 1.9×10 −3 and 9.3×10 −5 min −1. In continuous flow stirred-tank reactor (CFSTR) systems with initial TNT of 1 mg L −1, the highest 74% of TNT reduction was achieved at the reaction pH of 11.9 and 2-day hydraulic retention time under steady-state condition. Oxalate was produced as the major hydrolysate in the CFSTRs, indicating a ring cleavage during alkaline hydrolysis. It was also believed that TNT alkaline hydrolysis occurred through the production of color-forming intermediates via dimerization. It is concluded that alkaline hydrolysis can be an alternative treatment technology for remediation of TNT-contaminated water.