Natural Melanin as a Potential Biomaterial for Elimination of Heavy Metals and Bacteria from Aqueous
Development of materials for treatment of heavy metals and bacteria in aqueous
solution is still on the way. Although there are many materials developed, there is limit material
which could be practical applied to eliminate a wide range of heavy metal ions and bacteria in
drinking water. In this study, we investigated the adsorption capacity of melanin extracted from the
ink sacs of squids toward heavy metals (chromium and manganese), which normally presented at
high concentrations in water sources originated from mining, metal plating and steel making
industries, as well as bacteria in aqueous solution. Our results showed that melanin could remove
Cr6+ and Mn2+ effectively (> 97%) with the adsorption capacities to be 5.78 mg/gam and 31.8
mg/gam for Cr6+ and Mn2+, respectively. More interestingly, it indicated that melanin could not
only eliminate heavy metals but also effectively removed vibrio parahaemolyticus bacteria
with
efficiency more than 90%. The obtained results suggested that melanin, a natural material with
high level of biosafety, might be a good adsorbent for removal of heavy metal ions and bacteria in
aqueous solution and could be used for advantage treatment of drinking water.