Impedance spectroscopy as a tool to monitor the adsorption and removal of nitrate ions from aqueous solution using zinc aluminum chloride anionic clay

Abstract

In this study, Zn3AlCl ionic clay was used to investigate the adsorption mechanism of the nitrate ions in solutions containing nitrate ions at different contact time. The clay was synthesized by coprecipitation method at room temperature, and this sample was characterized by XRD, Fourier transform-infrared (FT-IR) and inductively coupled plasma (ICP). This sample was crystallized in a rhombohedral symmetry (Space group: R-3 m). Impedance spectroscopy was used as a tool to evaluate and monitor the adsorption process at different contact time 5; 10; 20; 30; 60 min and the clay alone. The impedance measurement was well analyzed and fitted with an equivalent circuit containing both (R//CPE) connected in series. Furthermore, the σac conductivity was also investigated as a function of frequency. It was analyzed and fitted using double power law: σac(ω)=σdc+Aωs1+Bωs2,(0≤s1≤1and0≤s2≤1).This study reveals the existence of two relaxation processes with different relaxation times, which could be attributed to the grain and grain boundaries, and exhibit high values of dielectric constant at low frequencies.

Experimental and Theoretical Study of the Adsorption Behavior of Nitrate Ions by Layered Double Hydroxide Using Impedance Spectroscopy

“…exponent decreases with increasing surface adsorption. This result is in clear agreement with the correlated barrier hopping (CBH) model, so the frequency dependence of σ'ac can be explained in terms of this model [47][48][49][50][51][52][53].…”

Preparation and in-vitro evaluation of β-CD/HA nanocomposite as a potential carrier for hydrophobic drugs

“…15 The peak observed at 1252 cm −1 in the case of Figure 3(a), (b) and (d) revealed the presence of C-H vibration. 16 In Figure 3(c), the absorption peaks at 567, 956, 1034 cm −1 could be related to PO 4 −3 groups, at 1635 cm −1 to adsorbed water molecules and at 1385 cm −1 to nitrates 17 or ammonium ions in HA structure.…”

“…groups, at 1635 cm À1 to adsorbed water molecules and at 1385 cm À1 to nitrates 17 or ammonium ions in HA structure.…”

Facile Synthesis of Hydrogel-Based Ion-Exchange Resins for Nitrite/Nitrate Removal and Studies of Adsorption Behavior

“…The peaks at 1466 cm −1 and 1266 cm −1 were due to the C–H bending and C–N stretching respectively in PEGDA-MTAC/AMHC respectively. The peak at 1387 cm −1 was attributed to the N–O stretching of the nitrate adsorbed PEGDA-MTAC/AMHC [ 55 , 56 ]. According to the results of the above analysis, the characteristic signals of PEGDA, MTAC, and AMHC can be found on the FT-IR spectrum of PEGDA-MTAC and PEGDA-AMHC modified hydrogels, confirming that the hydrogels were successfully modified and synthesized.…”