TNT Full Form

TNT or Trinitrotoluene is a pale yellow nitrogen containing organic compound. It has a IUPAC name as 2 -methyl-1,3,5 trinitrobenzene. It is produced after step wise nitration of toluene .It is used as an organic reagent in certain reactions but the main purpose or use is as an explosive material .It is also used to make charge transfer salts .

History

It was discovered in the year 1863 by a chemist named Julius Wilbrand . Originally for around three decades it was used as dye ( Yellow in colour ) . It’s true potential as an explosive was realised later on due to difficulty to detonate as it was way less sensitive as compared to other such materials.

It’s explosive nature was discovered by a German chemist named Carl Häusserman in the year  1891 .The lack of sensitivity even led to its non consideration as an explosive under the UK’s Explosive act 1875 . TNT can hence be poured easily into shell case when in liquid state. Germany adopted TNT as filling in artillery shell. The use of TNT by Germany came to be an asset as it explodes post entering the armour unlike the Britain’s lyddite filled shells which explode on contact and hence TNT Shells had an upper hand and caused greater damage 

Later the United States Navy also used TNT in the torpedoes, naval mines etc in two specific forms: a crude grade B TNT and a granular  crystallised A TNT.

Preparation

In industry the preparation is a three step process .The first step is production of mononitrotoluene (MNT) that requires nitration in presence of sulfuric and nitric acid . MNT is separated and nitrated to form Dinitrotoluene post that Trinitrotoluene which requires a anhydrous mixture of oleum and nitric acid for production. The sulfuric acid used is collected and reused while the nitric acid is consumed in the given three stage process. After the final step in order to stabilise the final product TNT another process which is known as sulfitation is performed.

Sulphitation – It is a process in which TNT is passed through  aqueous sodium sulphite solution and the less stable isomers are removed along with other undesirable products .The rinse water post sulphitation is known as red water and is a major pollutant and waste product of the process.

Certain steps like the control of nitrogen dioxide is crucial since it can oxidise the methyl group of toluene. in laboratory the process is two step process wherein a mixture of sulphuric and nitric acid is used against toluene to produce isomers of mono and Dinitrotoluene.

Applications

1. As mentioned above the most common use of TNT is as an explosive in the defence sector , industries and in certain mining applications.
2. Used in a process known as hydraulic fracturing or fracking .This is basically a process wherein oil and gas are extracted from shale formations .Here TNT is used in pelletized form .
3. It is less sensitive as compared to other counter compounds like nitroglycerin and hence wide usage because of better safety in storage and transfer .
4. It can be used in wet environments as it neither aborbs or dissolves in water.
5. Available in a variety of sizes like blocks of 250g, 500g ,1000g etc.
6. It is also available in combination with other ingredients .like in a blended form which includes some amount of TNT along with other ingredients .some examples of these explosive blends are -Amonal which is nothing but ammonium nitrate and powder of aluminium plus charcoal , then cyclotol -RDX ,TNT , picratol ,torpex,octol , minol etc.

Detection

Various methods are used for detection of TNT these are as follows:-

• Optical sensors
• Electrochemical sensors
• Explosive – sniffing dogs 
• An initiative by Indian institute of technology(IIT) in2013 wherein they used a Noble- metals quantum cluster to detect TNT .

Safety

• TNT is poisonous and when it comes in contact with skin, our skin tuna is bright orange or yellow in colour . It causes skin irritation
•  Disease like Anaemia and  abnormal liver functions is a common case in people who are exposed to TNT for a  time 
• In animals who ingest Trinitrotoluene or breath it has problems such as blood and liver dysfunction , spleen enlargement and compromised immune system
• It also has a possible effect on male fertility
• It is possible human  carcinogen
• Ingesting TNT produces red urine due to breakdown of products 
• The munition or testing grounds of TNT generally have contaminated subsurface and surface water 
• TNT has a property of exudation that is the process to leak through pores this can cause denotation

Pink water and red water are the two main harmful waste products of TNT.Pink waster is produced post filing of  ammunition during cleaning process .While red water is produced during the purification of crude TNT 

Ecological impact 

The residual TNT from manufacturer , storage can contaminate soil ,air and water .In the year 2001 the United States environment protection agency declared TNT as. A pollutant and has set a particular standard . According to USPA the TNT in soil should not exceed 17.2 grams per kilogram of soil 0.01 milligrams per litre of water.

TNT till now is not biodegradable by any organism in soil but plants can produce phytoremediate explosive from soil.

Conclusion

TNT as an explosive is most widely used but on coming nyo it’s environment impact and impact on humans and animals that huge. So proper care while using and disposing of waste related to TNT manufacture and post-use in the form of explosives should be taken in order to prevent the impact on the environment, humans and animals.