Environmentally Friendly and Cheap Removal of Lead (II) and Zinc (II) from Wastewater with Fish Scales Waste Remains

Abstract

In this article, the physical and chemical properties of pulverized, vinegar treated waste from fish scale remains of fish from Lake Ngami in Sehitwa near Maun, Botswana, were investigated for a possibility of being employed as an environmentally friendly and cheap sorbent material for reducing or removing excess, toxic, heavy metal ions from wastewater before different uses. Lead (II) and Zinc (II) ions were selected as model ions to demonstrate the potential of fish scale waste remains in removing excess toxic heavy metal ions. The pulverized size of the waste was found to be 60 µm, with round and smooth morphology, which are excellent characteristics usually associated with superior sorbents. Furthermore, the fourier transform infrared spectrometer spectrum showed multiple functional groups such as amines, carboxylic, hydroxyl, and carbonyls which are well known to bond well with metals through hydrogen and oxygen bonding. The X-ray diffractogram of the fish scales showed the presence of hydroxyapatite, which has an excellent ion-exchange performance, which exchanges calcium ion site with metals. Multivariate methodologies statistical software, Minitab, were employed for the simultaneous optimization factors that affect sorption studies; initial ions concentration which was found to be 24.45 mg/L, the sorbents dose which was found to be 76.99 mg/L, contact time, which were found to be 62.37 min and solution pH 7.52. The fish scales waste also exhibited high percentage removal efficiencies toward Lead (II) and Zinc (II) removal from real wastewater samples at 81.97% and 80.37% with percentage relative standard deviation of 1.34% and 1.02% respectively.