Preparation and application of novel catalytic-ceramic-filler in a coupled system for TNT manufacturing wastewater treatment

Abstract

2,4,6-Trinitrotoluene (TNT) has been widely used in military and civilian blasting all over the world, causing great concern with regard to its toxicity to environment and human health. Our research investigated preparation and application of the catalytic-ceramic-filler in the catalytic micro-electrolysis coupled with a biological aerated filter for TNT manufacturing wastewater treatment. As a possible pretreatment process of TNT manufacturing wastewater, catalytic micro-electrolysis packed with the catalytic-ceramic-filler had higher TNT and chemical oxygen demand removal (98.73% and 65.49%, respectively) than traditional micro-electrolysis at the optimum hydraulic retention time of 4.0h and slight aeration (dissolved oxygen of about 2.0mgL−1). Subsequently, biological aerated filter applied as the secondary biological treatment removed 81.68% of the influent chemical oxygen demand at the optimum hydraulic retention time of 16.0h. Moreover, the coupled catalytic micro-electrolysis and biological aerated filter system could remove chroma values by 95.21%. The residual TNT (1.5–1.6mgL−1), chemical oxygen demand (57.0–84.6mgL−1) and chroma (7.9–17.2) in the effluent met the national discharge standard (GB 14470.1-2002, TNT concentration ⩽5.0mgL−1, chemical oxygen demand ⩽100mgL−1, chroma ⩽50).