Use of chicken feather char and egg shell for removal of heavy metal ions from aqueous solutions

Water is a vital material for living things. Therefore, water security is very important for countries. With the development of industry and agriculture, large amounts of heavy metal ions are discharged into water, especially in developing countries. Uptake of heavy metal ions into the human body due to their toxicity and persistence; damage to the central nervous system, kidney and liver. Therefore, studies on heavy metal ions have received special attention in the scientific community in recent years, and great efforts have been made to find effective methods to control and remove heavy metal ions. Due to its low cost and environmental friendliness, wide material selection and reusability, the adsorption method is widely used, but it is also an important method in wastewater treatment research. In this study, the pyrolysis product of chicken feathers and egg shells, which are among the animal waste products with high adsorption potential due to their porosity and functional groups in their structures, which are abundant in our country and in the world, were used as adsorbent. Chemical activation process with phosphoric acid was applied to regulate the pore structures and increase the surface area of the crayfish obtained from chicken feathers. Studies were carried out on the removal of Al3+, Cr3+, Mn2+, Fe3+, Ni2+, Cu2+, Zn2+, As3+, Cd2+ and Pb2+ heavy metal ions and methylene blue dyestuff from aqueous solutions with the obtained 3 different adsorbents. Heavy metal analyzes were made with a high-sensitivity Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and the effects of pH and contact time were examined and optimum conditions for adsorption and the effectiveness of the adsorbents used were determined. Functional group analysis of czar and egg shells obtained from chicken feathers were performed with Fourier Transform Infrared Spectroscopy (FT-IR) device, and morphological analyzes were performed with Scanning Electron Microscope (SEM) device. The Brunauer-Emmett-Teller (BET) technique was used for surface area and porosity analyses. In order to determine the kinetic model of the adsorption process, pseudo-first-order kinetic model and pseudo-second-order kinetic model constants and correlation coefficients were examined. Adsorption experiments were carried out at 22 °C temperature, 300 rpm stirring speed, 2 g/L adsorbent amount and up to 24 hours. Three different adsorbents were used in the studies, and different pH values were selected by considering the studies in the literature. In studies examining the removal of Cu2+, Zn2+, Fe3+, Cd2+, Cr3+, Pb2+, Al3+, As3+, Ni2+ and Mn2+ heavy metal ions from aqueous solution, firstly the char obtained by pyrolysis of chicken feathers, then the char prepared by chemically activating this czar with phosphoric acid is used as an adsorbent. used. However, heavy metal adsorption did not occur under the specified conditions with the use of these adsorbents. After the heavy metal adsorption experiments, a study was conducted on the adsorption of char and methylene blue dyestuff activated at different rates with phosphoric acid, and no adsorption was observed in this study. Finally, the use of egg shells, which is an important waste material obtained from chicken, in the adsorption of 10 different heavy metal ions was investigated. In the adsorption experiments performed with eggshell adsorbent at pH 2,8 and 4,8, no decrease was observed in the initial concentrations of Fe3+, As3+, Mn2+, Ni2+, Zn2+ and Cd2+ heavy metal ions over time. Adsorption of heavy metal ions Al3+, Cr3+, Cu2+ and Pb2+ was achieved by using egg shells as adsorbent, and the best adsorption capacities were found as 2,44, 2,49, 1,78 and 2,41 mg/g, respectively. As a result, it has been demonstrated that the use of egg shell, which is an animal waste product, as an effective and low-cost adsorbent can be provided in the removal of heavy metal ions from aqueous solutions.