One-step hydrothermal synthesis of CTAB-modified SiO2 for removal of bisphenol A

A stable SiO2 material marked as CTAB-Ms(x) was synthesized by a novel sol-gel method. It was modified with hexadecyl trimethyl ammonium bromide (CTAB), which resulted in high adsorption capacity. Its microstructure and surface functional groups were characterized by scanning electron microscope, transmission electron microscope and Fourier transform infrared. The results showed that CTAB-Ms(x) had a core/shell structure in which the core was a CTAB micelle and the shell was SiO2. The prepared material was applied to adsorb bisphenol A (BPA). Pseudo-first-order kinetics equation, pseudo-second-order kinetics equation, Langmuir adsorption isotherm model, Temkin adsorption isotherm model, and thermodynamic equations were used to fit and analyze the experiment results. The theoretical maximum adsorption capacities calculated according to linear and non-linear forms of the Langmuir isotherm were 370.37 mg·g−1 and 198.80 mg·g−1, and the adsorption equilibrium time was 120 min. A mechanism study showed that the high adsorption capacity was attributed to the solubilization effect of the CTAB micelle.

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Competitive adsorption of organic solvents using modified and unmodified calcium bentonite clay mineral

10.31221/osf.io/w9dj6 ◽

2019 ◽

Author(s):

Chem Int

Keyword(s):

Adsorption Isotherm ◽

Adsorption Capacity ◽

Organic Solvents ◽

Competitive Adsorption ◽

Correlation Factor ◽

Isotherm Model ◽

Isotherm Models ◽

High Concentration ◽

Dual Purpose ◽

Calcium Bentonite

Dodecyltrimethylammonium bromide (DTAB)–modified and unmodified calcium bentonite were both used for the competitive adsorption of aromatics (xylene, ethylbenzene and toluene) and petroleum products (gasoline, dual purpose kerosene and diesel) from their aqueous solution. Infrared spectroscopy (IR) and expansion tests (adsorption capacity and Foster swelling) measurement were performed in order to evaluate the performance of the adsorbents. The Foster swelling index and adsorption capacity of the DTAB modified calcium bentonite in the organic solvents follow the trend: xylene > ethylbenzene > toluene > gasoline > dual purpose kerosene (DPK) > diesel > water. However, the adsorption capacity of the adsorbent in diesel outweighed the adsorption capacity in DPK at high concentration of DTAB indicating that diesel has higher affinity for high DTAB concentration than DPK. The percentage removal of the solvent is directly proportional to the concentration of DTAB used in modifying the bentonite as well as the contact time between the adsorbent and the solvent, hence modified calcium bentonite adsorbed a higher percentage of organic solvents than the unmodified calcium bentonite. The adsorption characteristics of both adsorbents improved remarkably after proper agitation of the organic solvents, the unmodified calcium bentonite however adsorbed more water than the modified bentonite. Data obtained from adsorption isotherm models confirms that Freundlich adsorption isotherm model was favored more than Langmuir adsorption isotherm model with the correlation factor (R2) of the former tending more towards unity. The adsorption of ethylbenzene using DTAB modified and unmodified calcium bentonites follow a pseudo second order kinetics mechanism, suggesting that the rate determining step of adsorption involves both the adsorbent and the organic solvent.

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Mercury Removal from Wastewater by Steamed Hoof Powder

Water Science & Technology ◽

10.2166/wst.1999.0340 ◽

1999 ◽

Vol 40 (7) ◽

pp. 109-116 ◽

Cited By ~ 4

Author(s):

M. H. Ansari ◽

A. M. Deshkar ◽

P. S. Kelkar ◽

D. M. Dharmadhikari ◽

M. Z. Hasan ◽

...

Keyword(s):

Heavy Metals ◽

Adsorption Capacity ◽

Adsorption Process ◽

Adsorption Equilibrium ◽

Light Metal ◽

Mercury Removal ◽

High Adsorption ◽

Surface Sites ◽

Ph Values ◽

High Adsorption Capacity

Steamed Hoof Powder (SHP), size < 53μ, was observed to have high adsorption capacity for Hg(II) with >95% removal from a solution containing 100 mg/L of Hg(II) with only 0.1% (W/V) concentration of SHP. The SHP has good settling properties and gives clear and odour free effluent. Studies indicate that pH values between 2 and 10 have no effect on the adsorption of Hg(II) on SHP. Light metal ions like Na+, K+, Ca2+ and Mg2+ up to concentrations of 500 mg/L and heavy metals like Cu2+, Zn2+, Cd2+, Co2+, Pb2+, Ni2+, Mn2+, Cr3+, Cr6+, Fe2+ and Fe3+ up to concentrations of 100 mg/L do not interfere with the adsorption process. Anions like sulphate, acetate and phosphate up to concentrations of 200 mg/L do not interfere. Chloride interferes in the adsorption process when Hg(II) concentration is above 9.7 mg/L. The adsorption equilibrium was established within two hours. Studies indicate that adsorption occurs on the surface sites of the adsorbent.

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Bimetallic Metal‐Organic Framework with High Adsorption Capacity toward Lithium Polysulfides for Lithium‐sulfur Batteries

Energy & Environmental Materials ◽

10.1002/eem2.12196 ◽

2021 ◽

Author(s):

Pengbiao Geng ◽

Meng Du ◽

Xiaotian Guo ◽

Huan Pang ◽

Ziqi Tian ◽

...

Keyword(s):

Adsorption Capacity ◽

Metal Organic Framework ◽

High Adsorption ◽

Lithium Sulfur Batteries ◽

Metal Organic ◽

High Adsorption Capacity ◽

Lithium Sulfur ◽

Organic Framework

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One-pot synthesis of hematite-alumina hollow sphere composite by ultrasonic spray pyrolysis technique with high adsorption capacity toward PAHs

Advanced Powder Technology ◽

10.1016/j.apt.2021.02.015 ◽

2021 ◽

Vol 32 (4) ◽

pp. 1060-1069

Author(s):

Hossein Vojoudi ◽

Jahan B. Ghasemi ◽

Ahmadreza Hajihosseinloo ◽

Bahareh Bastan ◽

Alireza Badiei

Keyword(s):

Spray Pyrolysis ◽

Adsorption Capacity ◽

Hollow Sphere ◽

Spray Pyrolysis Technique ◽

Ultrasonic Spray Pyrolysis ◽

High Adsorption ◽

One Pot ◽

Ultrasonic Spray Pyrolysis Technique ◽

Ultrasonic Spray ◽

High Adsorption Capacity

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Effective Poly (Cyclotriphosphazene-Co-4,4′-Sulfonyldiphenol)@rGO Sheets for Tetracycline Adsorption: Fabrication, Characterization, Adsorption Kinetics and Thermodynamics

Nanomaterials ◽

10.3390/nano11061540 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1540

Author(s):

Muhammad Ahmad ◽

Tehseen Nawaz ◽

Mohammad Mujahid Alam ◽

Yasir Abbas ◽

Shafqat Ali ◽

...

Keyword(s):

Adsorption Capacity ◽

Surface Area ◽

High Surface ◽

High Surface Area ◽

High Adsorption ◽

Clean Environment ◽

Equilibrium Data ◽

Langmuir Isotherm Model ◽

High Adsorption Capacity ◽

Adsorption Equilibrium Data

The development of excellent drug adsorbents and clarifying the interaction mechanisms between adsorbents and adsorbates are greatly desired for a clean environment. Herein, we report that a reduced graphene oxide modified sheeted polyphosphazene (rGO/poly (cyclotriphosphazene-co-4,4′-sulfonyldiphenol)) defined as PZS on rGO was used to remove the tetracycline (TC) drug from an aqueous solution. Compared to PZS microspheres, the adsorption capacity of sheeted PZS@rGO exhibited a high adsorption capacity of 496 mg/g. The adsorption equilibrium data well obeyed the Langmuir isotherm model, and the kinetics isotherm was fitted to the pseudo-second-order model. Thermodynamic analysis showed that the adsorption of TC was an exothermic, spontaneous process. Furthermore, we highlighted the importance of the surface modification of PZS by the introduction of rGO, which tremendously increased the surface area necessary for high adsorption. Along with high surface area, electrostatic attractions, H-bonding, π-π stacking and Lewis acid-base interactions were involved in the high adsorption capacity of PZS@rGO. Furthermore, we also proposed the mechanism of TC adsorption via PZS@rGO.

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