Data on the fluoride adsorption from aqueous solutions by metal-organic frameworks (ZIF-8 and Uio-66)

Abstract

The variables examined were initial fluoride concentration, ZIF-8 and Uio-66 dosage, pH, and contact time. The residual concentration of fluoride was measured by a spectrophotometer. According to BET, the specific surface area of the ZIF-8 and Uio-66 was 1050 m2/g and 800 m2/g, respectively. Total pore volume and average pore diameter of the ZIF-8 and Uio-66 were 0.57 cm3/g, 0.45 cm3/g and 4.5 nm, 3.2 nm, respectively. The best pH for fluoride adsorption was neutral conditions. By increasing the ZIF-8 and Uio-66 dose, the fluoride uptake increased at first, but then decreased. Also, the maximum adsorption for ZIF-8 and Uio-66 was observed in adsorbent dose 0.2 and 0.6 g/L, respectively. The best model for describing kinetic and isotherms of fluoride adsorption were the pseudo-second-order model and Langmuir isotherm model, respectively. Based on the Langmuir model, the adsorption capacity of fluoride by ZIF-8 and Uio-66 was reported to be 25 mg/g and 20 mg/g, respectively.

Template-Free Synthesis of Magnetic La-Mn-Fe Tri-Metal Oxide Nanofibers for Efficient Fluoride Remediation: Kinetics, Isotherms, Thermodynamics and Reusability

“…As portrayed in Figure 8a-d, the order of the fitted determination coefficients (R 2 ) at 15 to 45 • C is Langmuir (0.9997, 0.9990, 0.9987 and 0.9976) > Temkin (0.8708, 0.8358, 0.6854 and 0.6161) > D-R (0.8402, 0.7725, 0.5981 and 0.4976) > Freundlich (0.7863, 0.7252, 0.5627 and 0.4791), illustrating that the homogeneous and single-layer adsorbed on LMF11 NFs dominates the defluoridation process [29,58]. The evaluated Q m values range from 173.30-199.60 mg F − /g at 15 to 45 • C, exceedingly higher than many reported adsorbents including MOFs such as La-BTC (105.2 mg/g), La-BPDC (125.9 mg/g), La-BHTA (145.5 mg/g), La-PMA (158.9 mg/g) and La-BDC (171.7 mg/g) [29], Uio-66 (20 mg/g) [59], Amine functionalized electrospun cellulose nanofibers (5.31 mg/g) [60], electrospun alumina nanofibers (1.2 mg/g) [61] and double (Ce-Fe bimetal oxides, 60.97 mg/g [62]) or tri-metal oxide-based materials (SA-CMAZ, 31.72 mg/g [63]; Mg/Ce/Mn, 12.99 mg/g [64]). Table 2 lists the fluoride adsorption capacities of the LMF11 NFs and other adsorbents based on rare earth elements for comparison.…”

Performance of metal–organic frameworks for the adsorptive removal of potentially toxic elements in a water system: a critical review

“…153 The ZIF-8 and Uio-66 MOFs, with high surface areas (1050 m 2 g À1 and 800 m 2 g À1 respectively), high total pore volume (0.57 cm 3 g À1 , 0.45 cm 3 g À1 respectively), and average pore diameter (4.5 nm, 3.2 nm respectively) exhibited maximum adsorption capacities of 25 mg g À1 and 20 mg g À1 , respectively for uoride removal. 154 Another novel MOF, Ce-1,1 0 -biphenyl-4,4 0 -dicarboxylic acid (Ce-bpdc), demonstrated a maximum adsorption capacity of 45.5 mg g À1 for uoride at 298 K and a pH of 7. This represented a PC value of 1.54 L g À1 and a removal efficiency greater than 80%.…”