Adsorption capacity of bone char for removing fluoride from water solution. Role of hydroxyapatite content, adsorption mechanism and competing anions

2014 ◽  
Vol 20 (6) ◽  
pp. 4014-4021 ◽  
Author(s):  
N.A. Medellin-Castillo ◽  
R. Leyva-Ramos ◽  
E. Padilla-Ortega ◽  
R. Ocampo Perez ◽  
J.V. Flores-Cano ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Water Solution ◽  
Bone Char ◽  
Competing Anions

scholarly journals Adsorption Capacity and Mechanism of Expanded Graphite for Polyethylene Glycol and Oils

2010 ◽  
Vol 7 (4) ◽  
pp. 1258-1265 ◽  
Author(s):  
Xiu-Yan Pang
Keyword(s):  
Polyethylene Glycol ◽  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Water Solution ◽  
Statistical Significance ◽  
Expanded Graphite ◽  
Sem Analysis ◽  
Type I ◽  
Deviation Analysis ◽  
Adsorption Capacities

Expanded graphite (EG) shows higher adsorption capacity for oils such as salad oil and SD300 oil than polyethylene glycol (PEG) with different MW (4000, 10000, 20000). To illustrate their different adsorption mechanism, adsorption capacities of EG for these pollutants are firstly detected. And then stepwise adsorption for oils is carried out with EG which has been saturated first by PEG with different MW. Then difference between stepwise adsorbance of oil is checked with deviation analysis. Scanning electronic microscopy (SEM) analysis is used to show structure difference of EG adsorbed different adsorbates. It is testified adsorption isotherms of PEG are all type I, PEG molecules lay flat on EG surface and equilibrium adsorbance decrease with the increase of PEG MW. Adsorbance for SD 300 oil and salad oil can reach 131.3 g/g and 127.8 g/g respectively. Deviation analysis for stepwise adsorbance of oil shows no statistical significance. EG saturated firstly by PEG, still has an average adsorption capacity of 98 g/g for SD300 oil and 85 g/g for salad oil and it does not change with the initial PEG concentration. SEM photos illustrate the adsorption of oil on EG is mainly filling. In the adsorption of PEG water solution, there is severe breakage of the V-type pore and shrinkage of the particle.

Adsorption mechanism of Chromium(III) from water solution on bone char: effect of operating conditions

Adsorption ◽  
2016 ◽  
Vol 22 (3) ◽  
pp. 297-308 ◽  
Author(s):  
Jose Valente Flores-Cano ◽  
Roberto Leyva-Ramos ◽  
Francisco Carrasco-Marin ◽  
Antonio Aragón-Piña ◽  
Jacob Josafat Salazar-Rabago ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Water Solution ◽  
Operating Conditions ◽  
Bone Char

scholarly journals Single Adsorption of Diclofenac and Ronidazole from Aqueous Solution on Commercial Activated Carbons: Effect of Chemical and Textural Properties

2021 ◽  
Author(s):  
Adriana I. Moral-Rodríguez ◽  
Roberto Leyva-Ramos ◽  
Esmeralda Mendoza-Mendoza ◽  
Paola Elizabeth Díaz-Flores ◽  
Damarys H. Carrales-Alvarado ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Electrostatic Interactions ◽  
Adsorption Mechanism ◽  
Activated Carbons ◽  
Water Solution ◽  
Textural Properties ◽  
Physicochemical Characteristics ◽  
Acidic Site ◽  
Π Stacking ◽  
Acidic Sites

Abstract The importance of the textural and physicochemical characteristics upon the adsorption capacity of the commercial activated carbons (ACs) Coconut, Wood, Merck, Darco and Norit towards ronidazole (RNZ) and diclofenac (DCF) from water solution was investigated thoroughly in this work. At pH = 7, Coconut AC and Wood AC presented the highest adsorption capacity towards RNZ (444 mg/g) and DCF (405 mg/g), correspondingly. The maximum mass of RNZ adsorbed onto Coconut AC was higher in this study than those outlined previously in other works. Besides, the maximum capacity of Wood AC for adsorbing DCF was comparable to those found for other ACs. The findings disclosed that the adsorption capacity of all the ACs was remarkably increased by surface area and was favored by incrementing the acidic site concentration. The π-π stacking interactions were the predominant adsorption mechanism for the RNZ and DCF adsorption on ACs, and the acidic sites favored the adsorption capacity by activating the π-π stacking. Electrostatic interactions did not influence the adsorption of RNZ on Coconut AC, but electrostatic repulsion decreased that of DCF on Wood AC. In the range of 15–25°C, the adsorption of RNZ and DCF on the Coconut and Wood ACs was endothermic, but the capacity remained essentially constant by elevating the temperature from 25 to 35°C.

scholarly journals Investigation of the transport characteristics of Pb(II) in sand-bone char columns

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110236
Author(s):  
Gang Li ◽  
Jinli Zhang ◽  
Jia Liu ◽  
Tao Luo ◽  
Yu Xi
Keyword(s):  
Adsorption Capacity ◽  
Flow Rate ◽  
Dose Response ◽  
Construction Materials ◽  
Column Height ◽  
Maximum Adsorption Capacity ◽  
Complexation Reaction ◽  
Bone Char ◽  
Inlet Flow ◽  
Inlet Flow Rate

Pb(II) leakage from batteries, dyes, construction materials, and gasoline threaten human health and environmental safety, and suitable adsorption materials are vitally important for Pb(II) removal. Bone char is an outstanding adsorbent material for water treatment, and the effectiveness in Pb(II) removing need to be verified. In this paper, the transport characteristics of Pb(II) in columns filled with a sand and bone char mixture were studied at the laboratory scale, and the influences of the initial concentration, column height, inlet flow rate, and competing ion Cu(II) on Pb(II) adsorption and transport were analyzed. The Thomas and Dose-Response models were used to predict the test results, and the mechanisms of Pb(II) adsorption on bone char were investigated. The results showed that the adsorption capacity of the bone char increased with increasing column height and decreased with increasing initial Pb(II) concentration, flow rate, and Cu(II) concentration. The maximum adsorption capacity reached 38.466 mg/g and the saturation rate was 95.8% at an initial Pb(II) concentration of 200 mg/L, inlet flow rate of 4 mL/min, and column height of 30 cm. In the competitive binary system, the higher the Cu(II) concentration was, the greater the decreases in the breakthrough and termination times, and the faster the decrease in the Pb(II) adsorption capacity of the bone char. The predicted results of the Dose-Response model agreed well with the experimental results and were significantly better than those of the Thomas model. The main mechanisms of Pb(II) adsorption on bone char include a surface complexation reaction and the decomposition-replacement-precipitation of calcium hydroxyapatite (CaHA). Based on selectivity, sensitivity, and cost analyses, it can be concluded that bone char is a potential adsorbent for Pb(II)-containing wastewater treatment.

scholarly journals Effects of Electronegativity and Hydration Energy on the Selective Adsorption of Heavy Metal Ions by Synthetic NaX Zeolite

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4066
Author(s):  
Xianyuan Fan ◽  
Hong Liu ◽  
Emmanuella Anang ◽  
Dajun Ren
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Adsorption Capacity ◽  
Heavy Metal Ions ◽  
Binary Systems ◽  
Adsorption Mechanism ◽  
Selective Adsorption ◽  
Hydration Energy ◽  
Nax Zeolite ◽  
High Electronegativity

The adsorption capacity of synthetic NaX zeolite for Pb2+, Cd2+, Cu2+ and Zn2+ in single and multi-component systems were investigated. The effects of electronegativity and hydration energy on the selective adsorption, as well as potential selective adsorption mechanism of the NaX zeolite for Pb2+, Cd2+, Cu2+ and Zn2+ were also discussed. The maximum adsorption capacity order of the heavy metals in the single system was Pb2+ > Cd2+ > Cu2+ > Zn2+, and this could be related to their hydration energy and electronegativity. The values of the separation factors (α) and affinity constant (KEL) in different binary systems indicated that Pb2+ was preferentially adsorbed, and Zn2+ presented the lowest affinity for NaX zeolite. The selective adsorption capacities of the metals were in the order, Pb2+ > Cd2+ ≈ Cu2+ > Zn2+. The trend for the selective adsorption of NaX zeolite in ternary and quaternary systems was consistent with that in the binary systems. Pb2+ and Cu2+ reduced the stability of the Si-O-Al bonds and the double six-membered rings in the NaX framework, due to the high electronegativity of Pb2+ and Cu2+ than that of Al3+. The selective adsorption mechanism of NaX zeolite for the high electronegative metal ions could mainly result from the negatively charged O in the Si-O-Al structure of the NaX zeolite, hence heavy metal ions with high electronegativity display a strong affinity for the electron cloud of the oxygen atoms in the Si-O-Al. This study could evaluate the application and efficiency of zeolite in separating and recovering certain metal ions from industrial wastewater.

Competitive adsorption mechanism of thiophene with benzene in FAU zeolite: The role of displacement

2017 ◽  
Vol 328 ◽  
pp. 172-185 ◽  
Author(s):  
Shanqing Dang ◽  
Liang Zhao ◽  
Qing Yang ◽  
Meng Zheng ◽  
Jingjing Zhang ◽  
...  
Keyword(s):  
Adsorption Mechanism ◽  
Competitive Adsorption ◽  
Fau Zeolite

scholarly journals Efficient removal of Pb(ii) ions using manganese oxides: the role of crystal structure

RSC Advances ◽  
2017 ◽  
Vol 7 (65) ◽  
pp. 41228-41240 ◽  
Author(s):  
Haipeng Zhang ◽  
Anbang Wu ◽  
Heyun Fu ◽  
Ling Zhang ◽  
Hui Liu ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Adsorption Capacity ◽  
Manganese Oxides ◽  
Efficient Removal

The adsorption of Pb(ii) by MnO2 depends on crystal structure; δ-MnO2 exhibited higher adsorption capacity than α-, β-, γ- and λ-MnO2.

Selective Removal of Hg2+ Ions from Water Using New Functionalized Silica Resin: Equilibrium, Thermodynamics and Kinetic Modeling Studies

2021 ◽  
Vol 43 (4) ◽  
pp. 436-436
Author(s):  
Nida Shams Jalbani Nida Shams Jalbani ◽  
Amber R Solangi Amber R Solangi ◽  
Shahabuddin Memon Shahabuddin Memon ◽  
Ranjhan Junejo Ranjhan Junejo ◽  
Asif Ali Bhatti Asif Ali Bhatti
Keyword(s):  
Adsorption Capacity ◽  
Adsorption Mechanism ◽  
Solid Phase ◽  
Maximum Adsorption Capacity ◽  
Adsorption Phenomenon ◽  
Column Adsorption ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Wastewater Samples ◽  
Ft Ir Spectroscopy

In current study, the diphenylaminomethylcalix[4]arene (3) was synthesized and immobilized onto silica surface to prepare a selective, regenerable and stable resin-4. The synthesized resin-4 has been characterized by FT-IR spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX) and Brunauer-Emmett-Teller (BET) techniques. To check the adsorption capacity of resin-4, the batch and column adsorption methodology were applied and it has observed that the resin-4 was selectively removed Hg2+ ions under the optimized parameters. The maximum adsorption capacity was obtained at pH 9 using 25 mg/L of resin-4. Under the optimal conditions, different equilibrium, kinetic and thermodynamic models were applied to experimental data. The results show that adsorption mechanism is chemical in nature following Langmuir model with good correlation coefficient (R2=0.999) and having 712.098 (mmol/g) adsorption capacity. The energy of calculated from D-R model suggests the ion exchange nature of the adsorption phenomenon. Dynamic adsorption experiments were conducted using Thomas model. The maximum solid phase concentration (qo) was 7.5 and rate constant was found to be 0.176 with (R2=0.938) for Hg2+ ions. The kinetic study describes that the adsorption mechanism follows pseudo second order (R2=0.999). The thermodynamic parameters such as ∆H (0.032 KJ/mol) and ∆S (0.127 KJ/mol /K) and ∆G (-5.747,-6.306, -7.027 KJ/mol) shows that the adsorption of Hg2+ ion is endothermic and spontaneous. The reusability of resin-4 was also checked and it has observed that the after 15 cycle only 1.2 % adsorption reduces. Moreover, the resin-4 was applied on real wastewater samples obtained from local industrial zone of Karachi, Sindh-Pakistan.

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