Phenol degradation and Sb(V) adsorption by superparamagnetic CTAB-modified iron calcium composite

Abstract

The heavy metal ions and organic dyes in textile wastewater treatment pose a significant environmental burden and are challenging to effectively manage. A magnetic cationic surfactant hexadecyltrimethylammonium bromide (CTAB), modified iron-calcium composite (referred to as CIC), was prepared using a straightforward method from iron-calcium composites as raw materials. The simultaneous catalytic degradation and adsorption efficiency of phenol and Sb(V) from textile wastewater were evaluated using this material. The results indicate that under conditions of pH 5.0 and a duration of 180 min, both phenol and Sb(V) removal rates exceed 90%. Characterization and experimental findings reveal that CIC possesses magnetic properties, facilitating easy separation, and offers a large surface area, ensuring abundant adsorption sites and stability. Additionally, CIC can assist in the enhanced degradation of phenol by H2O2. Pseudo-second-order kinetics describe the adsorption of Sb(V) by CIC, while oxidative kinetics explain the degradation of phenol. The primary removal mechanisms involve the oxidation and degradation of phenol through the generation of hydroxyl radicals by H2O2 and the formation of Fe-O-Sb complexes between Sb(V) and the iron sites on CIC, as well as the precipitation of Ca-O-Sb compounds between Sb(V) and the calcium sites on CIC. Therefore, the synergistic effect of CIC and H2O2 offers an efficient and environmentally friendly method for the simultaneous removal of Sb(V) and phenol in coupled wastewater, presenting broad prospects for application in wastewater treatment.