Human hair has been found to adsorb oils and heavy metals and is capable of cleaning up oil spills in seawater as a cheap and natural alternative to traditional methods. On average 5 g of oil can be adsorbed per gram of human hair [1].
Figure 1. Human hair and oil spill clean-up (Source: [2]).
Synthetic sorbents are traditionally used for oil spill clean-up, which are not biodegradable, thereby, sustainable origin sorbents have been explored by researchers. For example, peat moss was studied to be a biodegradable alternative; however, it did not perform as well compared to hair and fur and has limited availability worldwide [3]. Thus, hair is a very promising alternative due to its studied effectiveness and abundance (the average human loses 50-100 hairs per day and receives 3-5 haircuts per year). This not only applies to clean-ups in water bodies but also among terrestrial environments.
Hair clippings from salons or individuals as well as animal fur from groomers and pet owners are donated to non-profit organizations like the Matter of Trust (matteroftrust.org/clean-wave-program). For example, the Matter of Trust creates hair mats and hair booms to be employed to clean up oil spills in oceans, storm drains, and wastewater contamination, etc. See Figure 2 to get an idea of what hair mats and booms look like. Hair booms are made by stuffing recycled hair or fur into recycled hosiery, making a sausage shape that can ‘sandbag’ and protect beaches from oil spills [4].
Figure 2. Hair mat (left) and hair booms (right). (Source: [9])
Given these amazing properties of hair, is it possible that hair could be used in mine site remediation as well?
As you know from our previous SULTAN blog posts, mining generates large quantities of waste rock, tailings, and wastewater. As a result, for instance, abandoned mines can contaminate water bodies through chemical run-off and particulates that accumulate in water sources [5]. These wastewaters contaminated with heavy metals need to be treated to prevent the discharge of contaminants into the environment. This is where the use of hair mats and booms comes in.
Biosorbents have already been studied by many researchers as a means of heavy metal removal from aqueous solutions [6]. Tan et al. (1985) used human hair as a biosorbent for the removal of different metal ions. For improved attraction of metals, the hair can also undergo an initial chemical treatment to increase the hydrophilicity and specific surface area [8].
Today the use of human hair in the mining sector for metal adsorption has not been widely explored. Thereby, maybe this is something that we will see more of in the future.
References
[1] National Aeronautics and Space Administration (NASA), Space Act Agreement 97001 (BEPS) Results, 1998.
[2] https://www.vice.com/en/article/z3e5b9/human-hair-used-to-soak-up-mauritius-oil-spill, (2020).
[3] M.L. Murray, S.M. Poulsen, B.R. Murray, Decontaminating terrestrial oil spills: A comparative assessment of dog fur, human hair, peat moss and polypropylene sorbents, Environ. – MDPI. 7 (2020) 1–8. https://doi.org/10.3390/environments7070052.
[4] Matter of Trust, Donate – Hair, Fur and Fiber., (n.d.). matteroftrust.org/donate-hair-fur-and-fiber/#:~:text=What happens to my hair, Bean bags to make booms. (accessed July 27, 2021).
[5] A.S. Ayangbenro, O.O. Babalola, A new strategy for heavy metal polluted environments: A review of microbial biosorbents, Int. J. Environ. Res. Public Health. 14 (2017). https://doi.org/10.3390/ijerph14010094.
[6] F.A. Banat, S. Al-Asheh, The use of human hair waste as a phenol biosorbent, Adsorpt. Sci. Technol. 19 (2001) 599–608. https://doi.org/10.1260/0263617011494420.
[7] T.C. Tan, C.K. Chia, C.K. Teo, Uptake of metal ions by chemically treated human hair, Water Res. 19 (1985) 157–162. https://doi.org/10.1016/0043-1354(85)90193-9.
[8] H. Zhang, F. Carrillo-Navarrete, M. López-Mesas, C. Palet, Use of chemically treated human hair wastes for the removal of heavy metal ions from water, Water (Switzerland). 12 (2020) 1–17. https://doi.org/10.3390/W12051263.
[9] https://inhabitat.com/donate-your-dog-and-cat-hair-to-clean-up-the-oil-spill/, (2010).