Adsorption performance and response surface optimization of boron in desalinated seawater by UiO-66-NH2

Metal-organic framework UiO-66-NH 2 was studied as an adsorbent for effective boron removal from desalination seawater for the first time. First, UiO-66-NH 2 was synthesized using the solvothermal method and then characterized in terms of N 2 adsorption/desorption isotherms, zeta potential, scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. Based on the experimental design of response surface methodology, the adsorption of boron on UiO-66-NH 2 was optimized using three independent variables: adsorbent dosage (60–80 mg/L), pH (5–7), and temperature (298–318 K). Under the optimized conditions, the maximum adsorption capacity was predicted to reach 24.54 mg/g. Investigation of the kinetics and isotherms revealed that the pseudo-second-order kinetics model and the Langmuir isotherm can well cover the adsorption data of boron. Thermodynamic parameters showed that the adsorption of boron by UiO-66-NH 2 is spontaneous and feasible. UiO-66-NH 2 also exhibits good reproducibility. It is a highly practical sorbent that can be used to remove boron from desalination seawater.