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This study investigated the removal of phosphorus (PO4−3-P) from water samples by SnO2 and WO3 nanoparticles (NPs). The effects of adsorbent dosage, pH, contact time and temperature with an initial concentration of 50 mg L−1 of P were investigated. SEM-EDX, FTIR, XRD, and BET analyses were performed to characterize these nanoparticles. The results indicated that the maximum adsorption capacity of SnO2 and WO3 NPs was 21.5 and 19.0 mg g−1, respectively and occurred at pH = 3. Within 40 min of operation, about 47.2% and 45.2% of P ion were removed from the solutions by SnO2 and WO3 NPs, respectively. The kinetics of P adsorption from solutions was analyzed by fitting the experimental data to the pseudo-first and second-order kinetic models. The result showed that the pseudo-second-order kinetics model provided much better R2 values. In the multi-component solutions, in the presence of Cl−, NO3− and Cr2O72− ions, the adsorption rates decreased to (26.2% and 28.5%), (27.2% and 30.0%), and (48.0% and 33.0%) by SnO2 and WO3 NPs, respectively. Thermodynamic data (ΔG°< 0) fitting showed that the reactions of adsorption of P were spontaneous. In general, the nanoparticles of SnO2 had better efficiency in the removal of phosphorous from water. [ABSTRACT FROM AUTHOR]

Amino-functionalized Zr-MOF (amino-Zr-MOF) was synthesized using 2-aminoterephthalic acid as an organic linker. The physicochemical properties of the material were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and N2adsorption to understand its crystalline structure, morphology, thermal stability, and porous structure. CO2adsorption isotherms on amino-Zr-MOF were obtained at 1 atm and at different temperatures. In addition, CO2and CH4adsorption at high pressure (up to 10 atm) was also measured. CO2adsorption capacity on amino-Zr-MOF was 9 mmol/g at 988 kPa, 0°C, while CH4adsorption capacity was 3.7 mmol/g at 900 kPa, 0°C. The heat of CO2adsorption on amino-Zr-MOF was estimated to be 29.4 kJ/mol. Continuous column tests of CO2adsorption were performed at different concentrations of CO2in nitrogen at 20 mL/min and 0.7 g adsorbent and total adsorbed amounts of CO2within the column during the breakthrough time were calculated to be 4.55, 5.26 and 4.37 mmol/g at 10%, 15% and 20%CO2, respectively. [ABSTRACT FROM PUBLISHER]