Hardness Removal from Groundwater by Ion-Exchange Mechanism Using Sulfonated Waste Plastics - A Review

2021 ◽  
Author(s):  
Thinojah Thiruchchelvam
Keyword(s):  
Ion Exchange ◽  
Exchange Mechanism ◽  
Waste Plastics ◽  
Hardness Removal

Effectiveness of Calcium Deficiency in Nanosized Hydroxyapatite for Removal of Fe(II), Cu(II), Ni(II) and Cr(VI) Ions from Aqueous Solutions

2019 ◽  
Vol 56 ◽  
pp. 17-27
Author(s):  
Van Dat Doan ◽  
Van Thuan Le ◽  
Hoang Sinh Le ◽  
Dinh Hien Ta ◽  
Hoai Thuong Nguyen
Keyword(s):  
Electron Microscopy ◽  
Ion Exchange ◽  
Aqueous Solutions ◽  
Calcium Deficiency ◽  
Exchange Mechanism ◽  
Precipitation Method ◽  
X Ray ◽  
Transmission Electron ◽  
Bet Method ◽  
Langmuir Isotherm Model

In this work, nanosized calcium deficient hydroxyapatite (nCDHA) was synthesized by the precipitation method, and then utilized as an adsorbent for removal of Fe (II), Cu (II), Ni (II) and Cr (VI) ions from aqueous solutions after characterizing it by various techniques as scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and BET method. A possible structure of synthesized nCDHA was proposed. The adsorption study indicated that the adsorption equilibrium is well fitted with Langmuir isotherm model with the maximum adsorption capacities followed the order of Fe (II) > Cu (II) > Ni (II) > Cr (VI) with the values of 137.23, 128.02, 83.19 and 2.92 mg/g, respectively. The ion-exchange mechanism was dominant for the adsorption of metal ions onto nCDHA at initial metal concentrations lower than 0.01 mol/L. Along with the ion-exchange mechanism, there was an additional precipitation occurred on the surface of nCDHA in the case of Fe (II) and Cu (II) at initial concentrations higher than 0.01 mol/L.

Zinc Oxide/ Silver Sulfide (ZnO/Ag2S) Core-Shell Type Composite for Wide Range Absorption of Visible Spectra: Synthesis and Characterization

2019 ◽  
Vol 25 ◽  
pp. 84-89 ◽  
Author(s):  
Afaf Mohammad Babeer ◽  
Lubna Aamir
Keyword(s):  
Zinc Oxide ◽  
Ion Exchange ◽  
Zno Nanoparticles ◽  
Silver Sulfide ◽  
Exchange Mechanism ◽  
Core Shell ◽  
Sem Image ◽  
Wide Range ◽  
Visible Spectra ◽  
Type Composite

This work presents the synthesis of zinc oxide /silver sulfide (ZnO/Ag2S) core/shell type composite; using combined wet chemical precipitation method and ion exchange mechanism; for wide range absorption of visible spectra by the composite. Synthesis is performed in three steps. In the first step; ZnO nanoparticles (nanocores) are produced, in the second step; ZnS layer is deposited over ZnO nanocores and in the third step; Zn from ZnS is replaced by Ag to form Ag2S shell over ZnO; using ion exchange mechanism. The presence of reflection peaks of ZnO and Ag2S in XRD spectra confirms the formation of ZnO/Ag2S composite. SEM image of ZnO shows the formation of near spherical ZnO nanoparticles of diameter in range 256nm to 584nm with a smooth surface, while SEM image of ZnO/Ag2S composite shows the formation of Ag2S layer over ZnO cores as indicated by rougher and contrasted surface as compared to bare ZnO cores. Also, the size of composite particles became larger than ZnO nanocores (100µm-200µm), which further confirms the formation of Ag2S shell over ZnO nanocores. The optical absorption spectrums of both ZnO and ZnO/Ag2S composite clearly indicate that synthesized composite absorb strongly in UV to IR region of the electromagnetic spectrum as compared to ZnO nanocores; which absorb only in UV region. Therefore, the synthesized composite could be used as a photovoltaic material.

Ion Exchange Mechanism and Isotherms from Deep Bed Performance

1952 ◽  
Vol 20 (12) ◽  
pp. 1842-1846 ◽  
Author(s):  
C. Neale Merriam ◽  
Raymond W. Southworth ◽  
Henry C. Thomas
Keyword(s):  
Ion Exchange ◽  
Exchange Mechanism

ESCA and Vibrational Spectroscopy of Alkali Cation Exchanged Manganic Acids with the 2×2 type Tunnel Structure Synthesized via Different Chemical Routes

2000 ◽  
Vol 658 ◽  
Author(s):  
Masamichi Tsuji ◽  
Hirofumi Kanoh ◽  
Kenta Ooi
Keyword(s):  
Ion Exchange ◽  
Vibrational Spectroscopy ◽  
Mixed Valence ◽  
Redox Process ◽  
Alkali Cation ◽  
Exchange Mechanism ◽  
Uptake Mechanism ◽  
Alkali Cations ◽  
Xrd Patterns ◽  
Mixed Valence Compounds

ABSTRACTManganese dioxides have received much attention over the last two decades as ion exchangers. Actually these are typically mixed-valence compounds and the terminology of ‘dioxide’ is not appropriate. The mechanisms for their variety of chemical reactivities are still open for study. On the cation uptake mechanism there are strong claims that a redox process is involved in cation uptakes by manganic acids synthesized by substituting H+ for alkali cations incorporated in ‘hydrous manganese dioxides’. The present work was carried out to physically demonstrate the alkali cation exchange mechanism on tunnel-structured manganic acids and to study the ion exchange with lattice vibrational spectroscopy. Manganic acids were prepared through the redox process using KMnO4 and MnSO4, and thermal decomposition of (CH3)3COK and MnCO3 at 530°C. ESCA spectra of their alkali cation exchanged forms indicated no evidence of redox process and supported the ion exchange mechanism on these materials. Their infrared absorption spectra strongly depended on their preparation routes and are closely related to their ion-exchange selectivity of each material. Thus, the vibrational spectra of manganic acids take an important role as a synthesis index together with XRD patterns.

Concerted Ion-Exchange Mechanism for Sodium Diffusion and Its Promotion in Na3V2(PO4)3 Framework

2018 ◽  
Vol 122 (29) ◽  
pp. 16649-16654 ◽  
Author(s):  
Qiang Wang ◽  
Mingying Zhang ◽  
Chenggang Zhou ◽  
Yanling Chen
Keyword(s):  
Ion Exchange ◽  
Exchange Mechanism ◽  
Sodium Diffusion
Sign in / Sign up

Export Citation Format

Share Document