Efficient Removal of Cationic Dye by Biomimetic Amorphous Calcium Carbonate: Behavior and Mechanisms

Abstract

The search for efficient, environmentally friendly adsorbents is critical for purifying dye wastewater. In this study, we produced a first-of-its-kind effective biomimetic amorphous calcium carbonate (BACC) using bacterial processes and evaluated its capacity to adsorb a hazardous organic cationic dye—methylene blue (MB). BACC can adsorb a maximum of 494.86 mg/g of MB, and this excellent adsorption performance was maintained during different solution temperature (10–55 °C) and broad pH (3–12) conditions. The favorable adsorption characteristics of BACC can be attributable to its hydrophobic property, porosity, electronegativity, and perfect dispersity in aqueous solution. During adsorption, MB can form Cl-Ca, S-O, N-Ca, and H-bonds on the surface of BACC. Since BACC has excellent resistance to adsorption interference in different water bodies and in real dye wastewater, and can also be effectively recycled six times, our study is an important step forward in dye wastewater treatment applications.