Preparation of peanut shell-like calcium carbonate from biowaste chicken eggshell and its application for aqueous Victoria Blue B removal

Abstract Chicken eggshell, a by-product of food processing, has been considered as natural waste and causes a major waste disposal problem. Recently, eggshell wastes have attracted great attention because of their rich calcium sources, and they can turn trash into treasure by rational use. In this work, peanut shell-like calcium carbonate (CaCO3) materials were synthesized with chicken eggshell biowastes as starting materials via coprecipitation method. CaCO3 materials were characterized by using XRD, SEM, XPS, and FTIR, respectively. The adsorption behavior of CaCO3 materials for Victoria blue B (VB) from aqueous solution was systematically investigated. The as-prepared hydrophilic CaCO3 materials show excellent adsorption performance for VB. The maximum adsorption capacity of CaCO3 at 35 °C is 1387 mg g−1. The kinetics and isotherm studies indicate that the absorption process follows the pseudo-second-order model and Langmuir isotherm model well. The thermodynamic parameters such as ΔG0, ΔH0 and ΔS0 show that the adsorption of VB onto CaCO3 materials is a spontaneous, endothermic and chemisorption process accompanied with an increase in entropy. The adsorption of VB onto CaCO3 materials is mainly controlled by electrostatic interaction. Thus, CaCO3 nanomaterial, as a hopeful adsorbent, can be used to efficiently remove VB in aqueous solution.