Cd(II) Adsorption from Wastewater Using Bi-Metallic MOF Based on CNTs

Heavy metal-contaminated water has been found to present serious hazards to human health. Thus, developing of rapid and safe water-treatment methods is required. Ni: Cu metal organic frameworks @carbon nanotubes (Ni: Cu-MOFs@CNTs1:1) was prepared by a hydrothermal process utilizing N, N-dimethylformamide (DMF), terephthalic acid and cadmium (Cd) was successfully removed. We studied how CNTs affected the properties of the bimetallic MOFs. Nitrogen physisorption analysis, Transmission electron microscopy, Zeta potential, X-ray diffraction and Fourier transform infra-red spectroscopy are used to describe structures of Ni: Cu-MOFs@CNTs1:1 before and after adsorption. The batch technique generated quantitative adsorption under a range of circumstances, including initial concentration of Cd (II), pH, temperature, and contact time. The adsorption kinetics were investigated using two kinetic models, including pseudo-first order and pseudo-second order, and a pseudo-second-order kinetic is the best model suggested to explain the kinetics model with a good agreement with the intra-particle diffusion model. Two common isotherm equations (Langmuir and Freundlich) are that were used to determine the Cd ions adsorption isotherms on adsorbent and showed a good fit with the Langmuir model more than Freundlich's isotherm model (R2= 0.992).The results clarified that a highest adsorption capacities and the optimized conditions where initial concentration of Cd(II) is 80 mg/l, adsorbent mass of 0.25 g/100ml, contact time of 75 min and pH of 5.5 and different temperature, the highest adsorption capacities 17.3, 21.37 and 23.84 mg/g at 298, 308 and 318 K respectively. After calculating the variables thermodynamically and using the Langmuir isotherm and pseudo second-order model, the adsorption process is known to have spontaneous, endothermic, and feasible nature. From these results illustrated that the produced Ni: Cu-MOF@CNTs1:1 material perhaps very good adsorbent of eliminating Cd (II) from water solutions.