Every year, about 300,000 tons of human hair is treated as waste and is being discarded as such. Although human hair is biodegradable, its accumulation in waste streams due to uncontrolled disposal leads to clogging and poses serious environmental problems. Scientists from Central Salt and Marine Chemicals Research Institute (CSMCRI) have come up with a solution to fix this problem. They have developed an integrated process through which they have extracted biofertilizer from waste human hair. They have also isolated melanin and keratin from it.
The market value of keratin is Rs 15000-20000 per kilogram, while melanin is more expensive than gold and sold around Rs 4000-5000 per gram. Melanin has been used for various cancer therapies whereas keratin is used in the cosmetic industry.
They have used a hydrated ionic liquid to isolate melanin and keratin. This liquid can completely solubilize human hair. It is basically a 60 percent aqueous solution and 40 percent liquid salt at room temperature. “The common salt we use is solid at room temperature, but this is a different kind of salt that is liquid at normal room temperature. This is been used to solubilize solids,” told Dr. Kamlesh Prasad, CSMCRI, Bhavnagar, Gujarat.
For lab purposes, 50 grams of human hair samples were taken. To remove shampoo, dirt and oil traces, the hair was thoroughly washed with a specialized solution. These were then stirred for nine hours in hydrated ionic liquid to dissolve human hair in it, leaving behind a black solution. When hydrochloric acid was added to this solution, black melanin emerged as a precipitate. After extracting melanin, the addition of acetone to the left-over solution led to the extraction of keratin. “The hydrated ionic liquid is found to completely solubilize 20-25% of waste human hair. Melanin and keratin with 10-22% and 36-38% yield, respectively, were isolated from the solution” said Dr. Prasad.
Subsequent to the extraction of melanin and keratin, the remaining waste liquid can be used as fertilizer, with seaweed fertilizer in the proportion of 50:50. Dr. Prasad estimated that 1 kilogram of human hair can give 200 grams of melanin, 360 grams of keratin, and 300 milliliters of ionic liquid, which can be used as fertilizer.
“We have extracted the crude form of melanin. If we further refine it to make it free of Sulphur, it can be more expensive and valuable” said Dr Prasad.
India is one of the major exporters of human hair and during 2011-12, the Tirumala temple alone has auctioned human hair worth the US $2 billion. Dr. Prasad told that considering the abundance, easy resourcing, excellent biocompatibility, immune-friendly nature upon transplantation, favorable cellular interaction activity, and biodegradability, etc., keratin from human hair may emerge as an alternative biomaterial for several applications. (India Science Wire)