Sustainable Applications Of Chitosan

-Master Soham Shastri – IX

(This article was published in Times NIE, 26th March 2018)

 The Chitosan team, prepared themselves to represent the school at the National Children’s Science Congress. They realized that plastic is one of the major pollutants today ad a lethal threat to the environment, being composed of toxic chemicals and most importantly a non-biodegradable substance. Plastic pollutes soil and also causes air and water pollution. There is so much more to be done in sensitizing people to stop the use of plastic. There is no safe way to dispose plastic waste and this waste causes serious damage to environment during its production, its usage and disposal process.

The team addressed the challenge of making Bio-plastic from prawn shells (organic waste).The significant feature of these bio-plastics is that it is derived from renewable resources and could degrade fast. Bio-plastics don’t generate as much toxic run-off.

Attempts were made to process the prawn shells, the raw material, to extract chitosan and compress it with cellulose to make Bio-plastic sheet out of it.

The first step was deprotienization when all the proteins from the shells were removed. The second step was demineralization when Calcium Carbonate was removed to get the product chitin. This chitin was used to make chitosan by the process of deacetylation. The chitosan thus produced was used to make bio-plastic. Chitosan was mixed with corn starch in the lab and heated, till it became a translucent substance. This was then spread on aluminium foil and kept to dry. The sample thus made was then used to test for its biodegradability, anti microbial and anti mosquito breeding properties.

A portion of the sample was buried in a pot and observations taken everyday till the sample was completely degraded. Another portion was tested of the  bioplastic sample in stagnant water  that was light green in colour. The water sample was left undisturbed overnight. The water appeared colourless and there were no larvae moving, the next day. This result was the impetus needed  to go in for a comparative study of  bio-plastic with plastic. They managed an appointment with a CEO of a bio-plastic Firm, Earthsoul India Pvt Ltd.

While plastic is non biodegradable and causes serious harm to our planet, our bio-plastic is not only bio-degradable, it does not pollute our natural resources, and it also controls mosquito breeding. It could play an important role in the conservation and sustainability of the natural resources.

Due to its heat resistant property, it could be used to make disposable cup and glasses. If thrown in any water body it would prevent mosquito breeding in that area. Due to its antimicrobial property it is also used as a membrane filter in water purifier and  is also used to make bandages, dissolvable sutures, etc.

Waste management, bio-waste management and segregation of waste continue to be vexing problems of the city. It  is imperative  to switch to bio plastic.

( The Research Project reached the National level)