Human hair (50–100mm in diameter) is a natural biosorbent
consisting of the medulla, cortex and dead cells made up of the
cuticle, water, lipids, trace elements and 65–95% proteins, mainly
polymers of amino acids such as keratin and cystine [21,22]. The
cuticle content makes it water repellent and therefore, highly
hydrophobic [21–23]. In addition, it has an abundance of peptide
bonds and CO as well NH groups which form hydrogen bonds