Comparison of simple ozonation and direct hydrogen
peroxide processes in TNT removal from aqueous solution
Mohammad Mehdi Amin and Fahimeh Teimouri
ABSTRACT
Oxidation of 2,4,6-trinitrotoluene (TNT) using simple ozonation and direct hydrogen peroxide was
studied. An analytical method based on the HPLC (high performance liquid chromatography) system
was used for TNT detection. The influence of parameters such as pH of the solution (3–10), initial TNT
concentration (10–100 mg/L), dosage of ozone (0.2–1 g/hr), H
2
O
2
/TNT molar ratio (250–1,000), and
reaction time (15–60 min) on TNT degradation ratio were investigated. Maximum TNT degradation
efficiency occurred at pH ¼ 10, initial TNT concentration ¼ 20 mg/L, dosage of ozone ¼ 1 g/hr in
simple ozonation (90%), while this amount was obtained in H
2
O
2
oxidation process with pH ¼ 3, initial
TNT concentration of 10 mg/L and H
2
O
2
/TNT molar ratio ¼ 1,000/L. The results of kinetic experiments
were shown to follow pseudo-second reaction. It can be recommended that simple ozonation seems
to be the best at TNT degradation from aqueous solution. However, low TNT concentration could be
reduced by performance of the hydrogen peroxide process, in which case, a longer reaction time is
also required.
Mohammad Mehdi Amin
Environment Research Center,
Research Institute for Primordial Prevention of
Non-communicable Disease, Isfahan University
of Medical Sciences,
Isfahan, Iran
and
Department of Environmental Health Engineering,
School of Health, Isfahan University of Medical
Sciences,
Isfahan, Iran
Fahimeh Teimouri (corresponding author)
Environment Research Center,
Isfahan University of Medical Sciences,
Isfahan, Iran
and
Department of Environmental Health Engineering,
Student Research Committee, School of Health,
Isfahan University of Medical Sciences,
Isfahan, Iran
E-mail: f_teimouri@hlth.mui.ac.ir
Key words | 2,4,6-trinitrotoluene, advanced oxidation process, H
2
O
2
oxidation, simple ozonation
INTRODUCTION
The most widely used explosive is 2,4,6-trinitrotoluene
(TNT), also known as trinitrotoluol, trotyl, and tilite
(C
̌
e ˙ nas et al. ; Ayoub et al. ; Singh ). Several
methods are available for TNT production. The most fre-
quently used method for TNT production is nitration of
toluene that leads to the production of a benzene ring
with nitro groups on positions 2,4,6 and a methyl
group. It has been estimated that during the First
World War, the Germans produced 2,500 tons of TNT
a week. TNT enters the environment through wastewater
and solid waste from manufacture of the processing of
compounds and destruction of bombs (King ). Inha-
lation of TNT in micro-levels can cause liver disease,
anemia, and cataracts. TNT has potential impacts on
the environment because of the adsorption to soil (Liu
et al. ).
TNT moves from surface water and soil to groundwater.
When TNT enters the human body, it spreads to the liver,
breaks down and changes to several substances. Exposure to
TNT in high concentrations has many effects, including such
blood disorders as anemia and abnormal liver function. The
United States Environmental Protection Agency (US EPA)
has classified TNT under group C, a possible human carcinogen
(Richter-Torres et al. ). TNT is a known mutagen and can
cause pancytopenia as a result of bone marrow failure. Oral
LD
50
in rats is near 1 g/kg.day. The US EPA has regulated
TNT contamination in soil to 17.2 ppm and in water to 2 ppb
(King ). TNT has been discharged into the aqueous effluents
of explosive manufacturing facilities assembling, packing, etc.
Studies have reported TNT concentrations between 20 and
120 mg/L in manufacturing plant effluents (Richter-Torres
et al. ). The Department of Defense (DoD) and Department
564 © IWA Publishing 2016 Journal of Water Supply: Research and Technology—AQUA | 65.7 | 2016
doi: 10.2166/aqua.2016.044
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