Study of the dynamic adsorption and the effect of the presence of different cations and anions on the adsorption of As(V) on GUT‐3

Abstract

This study is aimed at understanding the dynamic adsorption and the effect of the presence of different cations and anions on the adsorption of As(V) on GUT-3 (a new metal-organic framework). The study showed that Zn 2+ , Ni 2+ , Cu 2+ , CO 3 2À , and NO 3 À promoted the adsorption of As(V) on GUT-3 at all concentrations and Fe 3+ and Cr 3+ promoted the adsorption only at 0.5 and 2 mmol/L, respectively, and PO 4 3À and SO 4 2À at 0.5 mmol/L. Fe 3+ , Cr 3+ , PO 4 3À , and SO 4 2À inhibited the adsorption at other concentrations. And Zn 2+ , Ni 2+ , Cu 2+ , CO 3 2À , and NO 3 promote the adsorption of As(V) on GUT-3. Fe 3+and Cr 3+ at 0.5, 2 mmol/L promote the adsorption of As(V) on GUT-3. PO 4 3Àand SO 4 2À at 0.5 mmol/L promoted the adsorption of As(V) on GUT-3, whereas PO 4 3À and SO 4 2À at other concentrations inhibited the adsorption of As(V) on GUT-3. However, K + , irrespective of the concentration, was seen to inhibit the adsorption of As(V) on GUT-3. The dynamic adsorption study showed that the penetration process of As(V) on GUT-3 was more in line with the bed depth service time (BDST) model. Dynamic adsorption was mainly chemical in nature and was observed to occur on the surface of the adsorbent.

Zn Metal–Organic Framework with High Stability and Sorption Selectivity for CO2

“…All mentioned bond angles and distances are comparable with the values found in reported compounds. 51 The pyromellitic acid ligand serves as a μ 4 -bridge to link four Zn 2+ ions, resulting in a 3,4 -connect 3D fry net with the point symbol {4 × 8 2 }{4 2 × 6 × 8 3 }. This open framework exhibits rectangular channels along the c and b axes (Figure 1b,c), and the size of rectangular channels is 10.33 × 9.84 and 9.37 × 7.55 Å 2 , respectively.…”

“…Metal–organic frameworks (MOFs) are a class of functional materials with open framework structures containing potential voids, which have great potential for use across a broad range of applications, such as gas sorption/separation, − catalysis, − chemical sensing, , magnetism, , and fluorescence. − In recent years, plenty of research studies have focused on selectively capturing CO 2 from flue gas, natural gas, and other greenhouse gas sources, − involving CO 2 /N 2 and CO 2 /CH 4 separation, which aim to alleviate the damage caused by global warming. There are many advantages of MOFs for CO 2 sorption and separation from gas mixtures, including their chemical stability, large surface areas, and tunable void volumes and binding sites.…”

“…Compared with the conventional experimental method, simulation calculation could provide a lot of information from a mechanism point of view. For this reason, more and more research studies have been performed for exploring the attractive electrostatic interactions between CO 2 molecules and organic linkers in the MOFs; 34−37 GUPT-1 exhibits a 3D 3,4 -connect fry net with two rectangular channels along the c and b axis, which presents a high adsorption selectivity of CO 2 /N 2 (118) under ambient conditions. It is praiseworthy that abundant Lewis basic amino functional groups are situated on the channel surface, leading to the possibility of strong interactions with CO 2 molecules.…”

“…Fourier transform infrared (FT-IR) spectra were recorded from KBr pellets in the range of 4000−400 cm −1 using a Bio-Rad FTS-7 spectrometer. The powder Xray diffraction (PXRD) patterns were determined using a PANalytical X'Pert3 powder diffractometer (operating at 40 kV and 40 mA) with graphite-monochromatized Cu Kα radiation (λ = 1.54056 Å). TGA measurements were carried out by heating the crystalline sample from 25 to 900 °C at a rate of 10 °C•min −1 under nitrogen flow on a Netzsch STA-449C thermal analyzer.…”

“…3,4 -connect fry network (GUPT-1) with Lewis basic −NH 2 groups inside the channels was isolated in the hydrothermal reaction. The high adsorption selectivity CO 2 /N 2 (118) of activated GUPT-1 could be ascribed to the electrostatic interactions between CO 2 molecules and −NH 2 groups and C•••O interactions, which is confirmed by GCMC simulation and the DFT-D calculation.…”