Preparation of cobalt-containing spinel oxides as novel adsorbents for efficient phosphate removal

We prepared a series of novel and efficient phosphate removal adsorbents, figured out the adsorption mechanism in depth and revealed the relationship between the properties of adsorbents and their adsorption capacity.

Download Full-text

Treating Disperse Dye Wastewater with Organic Clay

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.977.279 ◽

2014 ◽

Vol 977 ◽

pp. 279-284

Author(s):

Li Xuan Wang ◽

Yan Kun Cheng ◽

Peng Huo ◽

Ya Nan Gao

Keyword(s):

Adsorption Capacity ◽

Adsorption Mechanism ◽

Equilibrium Concentration ◽

Disperse Dye ◽

Dye Wastewater ◽

Effect Of Ph ◽

Static Tests ◽

Ft Ir ◽

Organic Clay ◽

The Relationship

The adsorption of disperse dye wastewater with organic clay by static tests is studied, Meanwhile, the composition of wastewater is analyzed by means of FT-IR,and organic clay is analyzed by means of XRD. The effect of pH , dosing quantity and concentration of wastewater on the efficiency of adsorption has been studied, and the relationship between the equilibrium concentration and adsorption capacity is concluded. In the end, the adsorption mechanism is preliminary discussed.

Download Full-text

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

Materials ◽

10.3390/ma14154066 ◽

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.

Download Full-text

Selective removal of anionic dyes with exceptionally high adsorption capacity and removal of dichromate (Cr2O72-) anion using Ni-Co-S/CTAB nanocomposites and its adsorption mechanism

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2019.121602 ◽

2020 ◽

Vol 385 ◽

pp. 121602 ◽

Cited By ~ 17

Author(s):

Arif Chowdhury ◽

Sunita Kumari ◽

Afaq Ahmad Khan ◽

Sahid Hussain

Keyword(s):

Adsorption Capacity ◽

Adsorption Mechanism ◽

Selective Removal ◽

High Adsorption ◽

Anionic Dyes ◽

High Adsorption Capacity

Download Full-text

Adsorption of Cu(II) Ions from an Aqueous Solution by Cross-Linked Carboxymethyl Konjac Glucomannan

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.239-242.2310 ◽

2011 ◽

Vol 239-242 ◽

pp. 2310-2316 ◽

Cited By ~ 1

Author(s):

Chun Mei Niu ◽

Shao Ying Li ◽

Dong Huang

Keyword(s):

Adsorption Capacity ◽

Copper Nitrate ◽

Konjac Glucomannan ◽

Ion Adsorption ◽

Adsorption Time ◽

Isotherm Equation ◽

Langmuir Isotherm Equation ◽

Effects Of Ph ◽

The Relationship ◽

Carboxymethyl Konjac Glucomannan

Crosslinked Carboxymethyl Konjac Glucomannan(CMKGM) with substitution degrees ofcarboxymethyl group（DS）0.265, 0.457 and 0.586 were prepared through reaction of monochloroacetic acid, konjac glucomannan(KGM) and epichlorohydrin and used to adsorb Cu(II) from the aqueous solutions of copper nitrate. The effects of pH, adsorbent dose, initial concentration of Cu(II), adsorption time and temperature on adsorption capacity were investigated. The results showed that adsorption capacity increased with an increasing DS of the carboxymethyl groups. Equilibrium adsorption time was 20 min or so and was independent on DS. The adsorption followed Langmuir isotherm equation. Ligand ion adsorption between carboxymethyl group and Cu(II) was thought to be predominate in the process of adsorption according to the relationship between DS and thermodynamic parameters. CMKGM can be used as cheaper and more effective adsorbents.

Download Full-text

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

Journal of the chemical society of pakistan ◽

10.52568/000588 ◽

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.

Download Full-text

Enhanced phosphate removal by nano-lanthanum hydroxide embedded silica aerogel composites: superior performance and insights into specific adsorption mechanism

Separation and Purification Technology ◽

10.1016/j.seppur.2021.120365 ◽

2021 ◽

pp. 120365

Author(s):

Bing Zhang ◽

Longqian Xu ◽

Zhenyu Zhao ◽

Shuai Peng ◽

Chao Yu ◽

...

Keyword(s):

Silica Aerogel ◽

Adsorption Mechanism ◽

Phosphate Removal ◽

Specific Adsorption ◽

Superior Performance ◽

Lanthanum Hydroxide

Download Full-text

Selective removal of silicic acid by a gallic-acid modified resin

Journal of Water Reuse and Desalination ◽

10.2166/wrd.2019.030 ◽

2019 ◽

Vol 9 (4) ◽

pp. 431-441

Author(s):

Shuqin Bai ◽

Jue Han ◽

Cong Du ◽

Wei Ding

Keyword(s):

Adsorption Capacity ◽

Gallic Acid ◽

Silicic Acid ◽

Adsorption Mechanism ◽

Adsorption Process ◽

Selective Adsorption ◽

Hydroxyl Groups ◽

Acid Type ◽

The Common ◽

Common Anion

Abstract To remove silicic acid from aqueous solutions, a novel gallic acid-type resin (GA-type resin) was prepared by a grafting method. The effects of the adsorption capacity, pH and presence of NaCl, NaNO3, Na2SO4, and NaCO3 salts on the silicic acid removal were studied. The GA-type resin adsorbs monosilicic acid, silicate ions, and polymeric silicic acid. The adsorption capacity of 4.64–4.94 mg/g was achieved in a short adsorption time (Qm of 8.99 mg/g) and is 30–40 times larger than that of the OH-type resin. The silicic acid removal efficiency was almost unaffected by the pH and common anions when the common anion and silicic acid contents were similar, proving the GA-type resin exhibits an excellent performance for selective adsorption of silicic acid. The Temkin isotherm model can well describe the adsorption process, which is chemical adsorption, and indicates that the adsorption heat decreases with the increasing adsorption amount. The adsorption mechanism of silicic acid on the GA-type resin involves dehydration condensation reactions of the hydroxyl groups in silicic acid and gallic acid. The GA-type resin can be efficiently regenerated and reused after treatment with an HCl solution.

Download Full-text

CH4/N2 Adsorptive Separation on Zeolite X/AC Composites

Journal of Chemistry ◽

10.1155/2019/2078360 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 4

Author(s):

Cai Long Xue ◽

Wen Ping Cheng ◽

Wen Ming Hao ◽

Jing Hong Ma ◽

Rui Feng Li

Keyword(s):

Adsorption Capacity ◽

Micropore Volume ◽

Zeolite X ◽

Adsorption Selectivity ◽

Adsorptive Separation ◽

Capacity Loss ◽

Pressure Swing ◽

Polar Functional Groups ◽

Adsorption Desorption ◽

The Relationship

A series of zeolite X/activated carbon (AC) composites were prepared from the same starting materials at various activation time. The corresponding modified samples were obtained by being treated with diluted NH4Cl solution. The relationship between porosity development, surface properties, and CH4/N2 adsorption performance was investigated. The increase of micropore volume is beneficial to the improvement of CH4 and N2 adsorption capacity, but more sensitive for CH4. In addition, the polar functional groups of zeolite X/AC composites may enhance CH4 adsorption capacity. More importantly, both developing micropore structure and surface modification contributed to enhance the adsorption selectivity αCH4/N2. As the optimum sample of these studies, HZAC(24) showed CH4 adsorption capacity of 17.3 cm3/g and the highest adsorption selectivity αCH4/N2 of 3.4. The CH4 and N2 adsorption isotherms of all samples can be well fitted by the Langmuir–Freundlich model. HZAC(24) showed an excellent cyclability of adsorption/desorption of CH4 with a neglectable capacity loss after subsequent cycles. Moreover, HZAC(24) displayed relatively rapid adsorption kinetics. These properties of zeolite X/AC composites are essential for the adsorptive separation of CH4 from N2 in the pressure swing adsorption (PSA) process.

Download Full-text

Adsorptive removal of phosphate by a Fe–Mn–La tri-metal composite sorbent: Adsorption capacity, influence factors, and mechanism

Adsorption Science & Technology ◽

10.1177/0263617420942709 ◽

2020 ◽

Vol 38 (7-8) ◽

pp. 254-270

Author(s):

Yuanrong Zhu ◽

Xianming Yue ◽

Fazhi Xie

Keyword(s):

Aqueous Solutions ◽

Adsorption Capacity ◽

Photoelectron Spectroscopy ◽

Phosphate Removal ◽

Maximum Adsorption Capacity ◽

Hydroxyl Groups ◽

Metal Composite ◽

Order Kinetic ◽

Composite Sorbent ◽

Composite Adsorbent

Reducing input of phosphorus is the key step for control of eutrophication and algal blooming in freshwater lakes. Adsorption technology is a cost-effective technology for phosphate removal in water for the purpose. Thus, in this study, a novel Fe–Mn–La tri-metal composite sorbent was developed, and then evaluated for phosphate removal. The results showed that the maximum adsorption capacity could be approached to 61.80 mg g−1 at 25°C under pH of 6.03. Adsorption of phosphate by Fe–Mn–La tri-metal composite adsorbent fitted better by pseudo-second-order kinetic equation and Langmuir model, which suggested that the adsorption process was surface chemical reactions and mainly in a monolayer coverage manner. The thermodynamic study indicated that the adsorption reaction was an endothermic process. The phosphate removal gradually decreased with the increasing of pH from 3.02 to 11.00. The sequence of coexisting anions competing with phosphates was that CO32− > Cl− > SO42− > NO3−. Dissolved organic matter, fulvic acid as a representative, would also decrease adsorption capacities of phosphate by Fe–Mn–La tri-metal composite adsorbents. Adsorption capacity would be decreased with increasing addition of adsorbents, while removal efficiency would be increased in this process. The Fe–Mn–La tri-metal composite adsorbent showed a good reusability when applied to removal of dissolved phosphate from aqueous solutions. The Fourier transform infrared spectrometer and X-ray photoelectron spectroscopy analyses indicated that some hydroxyl groups (–OH) on the surface of adsorbent were replaced by the adsorbed PO43−, HPO42−, or H2PO4−. Aggregative results showed that the novel Fe–Mn–La tri-mental composite sorbent is a very promising adsorbent for the removal of phosphate from aqueous solutions.

Download Full-text