Cadmium, arsenic, and molybdenum removal from water using a tantalum MOF

Abstract Access to clean water is increasingly threatened by rapid industrialization, population growth, and the discharge of heavy metals into aquatic systems, posing serious risks to human health and ecological balance. The development of advanced materials with high adsorption efficiency and multifunctionality is therefore essential for sustainable water treatment. In this study, a novel tantalum-based metal–organic framework (Ta-MOF) was synthesized via conventional and ultrasound-assisted methods and evaluated for the removal of cadmium (Cd), arsenic (As), and molybdenum (Mo) from aqueous solutions. The ultrasound-assisted route produced materials with improved crystallinity, particle dispersion, and structural uniformity, as confirmed by FTIR, SEM, EDS, XRD, and BET analyses. The adsorption process was systematically optimized using Response Surface Methodology (RSM), considering key operational parameters including pH, initial metal concentration, adsorbent dosage, and contact time. Maximum removal efficiencies of 89.76% (As), 94.32% (Mo), and 88.94% (Cd) were achieved under optimized conditions, with pH values around neutral and contact times of 39.77–46.25 min. Kinetic studies followed the pseudo-second-order model, indicating that the adsorption rate is strongly dependent on active site availability and suggesting a surface interaction-controlled process. Isotherm analyses showed good agreement with the Langmuir model, indicating monolayer adsorption on a relatively homogeneous surface. In addition, Ta-MOF exhibited moderate antibacterial activity against Escherichia coli and Staphylococcus aureus. Overall, the findings highlight the potential of Ta-MOF as a dual-functional material for heavy metal removal and microbial control, offering a promising approach for integrated water treatment in contaminated environments.