Synthesis And Characterization of Nanoparticles Using Keratin Extracted From Sheep Hooves for Industrial Applications

Abstract

Environmental degradation is a concern in developing countries due to industrial development, constantly rising population which practice agriculture, industrial development, urbanisation and poor waste management. The waste disposed to the environment contributes to environmental pollution. Industrial effluents and water runoff from urban regions and farms contribute to water pollution in rivers and other water bodies. In various parts of the world persons lack access to clean water for drinking, due to pollutants from industries and residential waste. Some of the pollutants in water include: Dyes from industries such as the textile and leather industries, steroids and antibiotics from industries and hospital waste water. Wastes from slaughter houses are source pollution and landfills occupy space which could have been used for farming and other purposes. The aim of this research was to extract keratin from sheep hooves using NaOH and use it as a reducing and capping agent in synthesis of nanoparticles for use in adsorption of selected organic dyes in water. Sheep hooves were collected from a slaughter house in Litein, cleaned with detergent and distilled water and 70 % ethanol before drying. The optimum conditions for Keratin hydrolysis were: A time of 9 hours, temperature of 70 °C, NaOH concentration of 1 % (w/v) and a pH of 12. The pH of Keratin solution was adjusted to 3.2 to obtain keratin precipitate which was used as a reducing and stabilizing agent in synthesis of Cu, Ag, ZnO and Fe3O4 nanoparticles. The optimum conditions for synthesis of copper and silver nanoparticles were: A time of 90 minutes, temperature of 80 °C and a concentration of 0.01 mol/dm3

of the salt containing the metal ions. Characterisation of the synthesized nanoparticles was done using UV-VIS to determine optical properties, FT-IR to determine functional groups on nanoparticles, SEM to determine shape and particle size distribution and XRD to determine crystallinity of the nanoparticles. UV-VIS analysis confirmed the formation of nanoparticles. FT-IR results indicated the involvement of keratin in formation of nanoparticles. Efficiency of adsorption of methylene blue using copper nanoparticles and adsorption of crystal violet dyes using AgNps and Fe3O4 was investigated. Residual dye concentrations were determined by UV-VIS. Adsorption of CV using silver nanoparticles attained equilibrium after 60 minutes at room temperature with 97.9 % efficiency of the dye removal. Copper nanoparticles were used in removal of methylene blue with equilibrium attained after 330 minutes at room temperature with 95% efficiency. Adsorption of crystal violet using Fe3O4 attained equilibrium after 8 minutes with 99.2 % efficiency. Influences of preliminary concentration, pH and temperature on dye removal were investigated. Optimum conditions for removal of crystal violet by silver were pH of 5-6, 60 minutes of contact time and a temperature of 45 °C. The optimum conditions for the removal methylene blue dye by copper nanoparticles were a pH range of 2-5 and a dosage of 8 mg/10 ml of the colorant. The optimum conditions for adsorption of CV using Fe3O4 nanoparticles were a time of 8 minutes and a dosage of 6 mg/10 ml. Adsorption kinetics were investigated using Pseudo first order and second order kinetics. Adsorption isotherms were investigated by plotting Langmuir and Freundlich isotherms. The results followed Langmuir and Freundlich isotherms and Pseudo second order kinetics. The findings of this research will add knowledge on the probable use of CuNps, AgNps and Fe3O4 in removal of organic dyes in waste water. These results demonstrate that keratin capped nanoparticles are effective, eco-friendly and low-cost adsorbent material for removal of dyes from aqueous solutions and industrial effluents.