Every year, about 300,000 tons of human hair is treated as wasteand is being discarded as such. Although human hair is biodegradable, itsaccumulation in waste streams due to uncontrolled disposal leads to clogging,and poses serious environmental problem. Scientists from Central Salt andMarine Chemicals Research Institute (CSMCRI) have come up with a solution tofix this problem. They have developed an integrated process through which theyhave extracted bio fertilizer from waste human hair. They have also isolatedmelanin and keratin from it. 

The market value of keratin is Rs 15000-20000per kilogram, while melanin is more expensive than gold and sold around Rs4000-5000 per gram. Melanin has been used for various cancer therapies whereaskeratin is used in cosmetic industry. 

They have used a hydrated ionic liquid toisolate melanin and keratin. This liquid can completely solubilise human hair.It is basically 60 per cent aqueous solution and 40 per cent liquid salt atroom temperature. “The common salt we use is solid at room temperature but thisis a different kind of salt that is liquid at normal room temperature. This isbeen used to solubilise solids,” told Dr Kamlesh Prasad, CSMCRI, Bhavnagar, Gujarat. 

For lab purpose, 50 grams of human hairsamples were taken. To remove shampoo, dirt and oil traces, the hair wasthoroughly washed with a specialized solution. These were then stirred for ninehours in hydrated ionic liquid to dissolve human hair in it, leaving behind ablack solution. When hydrochloric acid was added to this solution, blackmelanin emerged as precipitate. After extracting melanin, addition of acetone tothe left-over solution led to the extraction of keratin. “The hydrated ionicliquid is found to completely solubilise 20-25% of waste human hair. Melaninand keratin with 10-22% and 36-38% yield, respectively, were isolated from thesolution” said Dr Prasad.  

Subsequent to the extraction of melanin andkeratin, the remaining waste liquid can be used as fertilizer, with withseaweed fertilizer in the proportion of 50:50. Dr Prasad estimated that 1kilogram of human hair can give 200 gram of melanin, 360 gram of keratin, and300 millilitres of ionic liquid, which can be used as a fertilizer.  

 “We have extracted the crude form ofmelanin. If we further refine it to make it free of sulphur, it can be moreexpensive and valuable” said Dr Prasad.

India is one of the majorexporters of human hair and during 2011-12, the Tirumala temple alone hasauctioned human hair worth US $2 billion. Dr Prasad told that considering theabundance, easy resourcing, excellent biocompatibility, immune-friendly natureupon transplantation, favourable cellular interaction activity andbiodegradability, etc., keratin from human hair may emerge as an alternativebiomaterial for a number of applications.

(India Science Wire)

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