Microscopic investigation into remediation of cadmium and arsenite Co-contamination in aqueous solution by Fe-Mn-incorporated titanosilicate

Abstract The co-contamination of anions and cations with cadmium (Cd) and arsenic (As) as typical pollutants in the water environment has attracted attention. In this study, Fe-Mn-incorporated titanosilicate material (ETFMS-10) with both adsorption and oxidation capacities was prepared by hydrothermal method to treat the Cd and As co-contaminated aqueous solution. SEM-EDS results confirmed the addition of Fe and Mn in the ETFMS-10 structure. The maximum adsorption capacities of ETFMS-10 for Cd (101.86 mg g−1) and As (3.18 mg g−1) were greater than those of ETS-10 for Cd (42.18 mg g−1) and As (0.51 mg g−1) in the single-pollutant system. The removal efficiencies of Cd and As by ETFMS-10 were more than 98% and 70% across pH 4 – 8, respectively. Adsorption kinetics revealed that the capture of Cd and As on ETFMS-10 was mainly controlled by chemical adsorption. XPS analysis showed that Fe mainly served as adsorption sites on ETFMS-10, while Mn was chiefly employed as an oxidant. The main mechanisms for Cd(II) and As(III) removal on ETFMS-10 included electrostatic attraction, ion exchange, and an inner-sphere M−O−As complex formation. These results indicated that the prepared ETFMS-10 had a broad application potential in the treatment of Cd and As co-contamination.