scholarly journals Effect of Bio-Based Surfactant on Wettability of Low-Rank Coal Surface and Its Mechanism

2021 ◽  
Author(s):  
Lin Li ◽  
Mingpu Liu ◽  
Jianqiao Lvu ◽  
Xiaoteng Li ◽  
Zhihao Li ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Water System ◽  
Low Rank ◽  
Order Kinetic ◽  
Low Rank Coal ◽  
Adsorption Model ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
The Stability ◽  
Adhesion Work

Abstract In this study, the effect of a bio-based environment-friendly surfactant, cardanol polyoxyethylene ether (BGF), on the wettability of the surface of low-rank coal (LRC) and its mechanism were studied. The adsorption experiment showed that the adsorption of the surfactant conformed to the Langmuir adsorption model and the pseudo-second-order kinetic model. The adsorption was mainly affected by hydrogen bonding, and the adsorption rate was affected by intraparticle diffusion and liquid film diffusion. The wettability experiment showed that the influence of BGF on the wettability of the surface of LRC followed the given order: BGF-7 > BGF-10 > BGF-15. The investigation of adhesion work showed that the adhesion work and the stability of the coal–water system decreased after adsorption. Fourier transform infrared and X-ray photoelectron spectroscopy analyses showed that after adsorption, the peak strength of vinyl ether, the content of elemental carbon, and the content of C-C/C-H groups increased.

scholarly journals Optimization of cadmium(II) adsorption onto modified and unmodified lignocellulosics (rice husk and egussi peeling)

2015 ◽  
Vol 5 (1) ◽  
pp. 45
Author(s):  
Tchuifon Tchuifon Donald Raoul ◽  
Nche George Ndifor-Angwafor ◽  
Ngakou Sadeu Christian ◽  
Kamgaing Théophile ◽  
Ngomo Horace Manga ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Rice Husk ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Batch Technique ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Adsorbed Quantity ◽  
Minimal Mass ◽  
Modified Adsorbents

<p>The present study is based on the adsorption of cadmium (II) ions on rice husk and egussi peeling, unmodified and modified with nitric acid in aqueous solution, using batch technique. It was carried out as a function of contact time, dosage, pH and initial concentration. The equilibrium time was achieved within 25 minutes for unmodified rice husk (Glu NT) and 20 minutes for unmodified egussi peeling (Cuc NT) with an adsorbed quantity of 13.18 mg/g. In the case of modified materials, we obtained 15 minutes for modified rice husk (Glu HNO3) and 10 minutes for modified egussi peeling (Cuc HNO3) with an adsorbed quantity of 18.77 mg/g. The maximum biosorption occurred at pH 5.5 for all biosorbents. The adsorbent mass for maximum adsorption was 0.4 g giving an adsorption capacity of 62.02 % for unmodified adsorbents. In the case of modified adsorbents, the minimal mass at which maximum adsorption occurred was 0.4 g giving an adsorption capacity of 98.33 % and 0.6 g giving an adsorption capacity of 98.33 % for modified rice husk and egussi peeling respectively. The adsorbent/adsorbate equilibrium was well described by the pseudo-second order kinetic model and by Langmuir’s and Freundlich adsorption model. This models showed that the adsorption of cadmium (II) is a chemisorption process.</p>

Biosorption of hexavalent chromium from aqueous solution by polyethyleneimine-modified ultrasonic-assisted acid hydrochar from Sargassum horneri

2020 ◽  
Vol 81 (6) ◽  
pp. 1114-1129 ◽  
Author(s):  
Jun Wang ◽  
Qinglong Xie ◽  
Ao Li ◽  
Xuejun Liu ◽  
Fengwen Yu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Batch Adsorption ◽  
Crosslinking Reaction ◽  
Order Kinetic ◽  
Adsorption Capacities ◽  
Initial Ph ◽  
Ultrasonic Assisted ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract In this study, an efficient route to synthesizing polyethyleneimine-modified ultrasonic-assisted acid hydrochar (PEI-USAH) is developed and reported. Ultrasonic irradiation technique was used as surface modification method to shorten the crosslinking reaction for hydrochar and polyethyleneimine (PEI). The PEI-USAH showed an excellent adsorption capacity for Cr(VI) from aqueous solution. The physicochemical properties of this PEI-modified adsorbent were comparatively characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analysis and CNHS analysis. The effects of contact time, initial pH, and biosorbent dose on adsorption capacities were investigated. The batch adsorption experiments showed that PEI-USAH possessed the maximum adsorption capacities of 94.38 mg/g and 330.84 mg/g for initial Cr(VI) concentration of 100 mg/L and 500 mg/L, respectively. Furthermore, this adsorption process could be fitted to Langmuir adsorption and described by the pseudo second order kinetic model. Based on the above findings, PEI-USAH could be used as a potential adsorbent for removal of Cr(VI) from wastewater.

Chromate sorption and reduction kinetics onto an aminated biosorbent

2006 ◽  
Vol 54 (10) ◽  
pp. 1-8 ◽  
Author(s):  
S. Deng ◽  
Y.P. Ting ◽  
G. Yu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Penicillium Chrysogenum ◽  
Sorption Process ◽  
Sorption Kinetics ◽  
Order Kinetic ◽  
Chromium Species ◽  
X Ray ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Amine Groups

A novel biosorbent was prepared by chemically grafting of polyethylenimine (PEI) onto the fungal biomass of Penicillium chrysogenum through a two-step reaction. The modified biosorbent is favorable for the removal of anionic Cr(VI) species from aqueous solution due to the protonation of amine groups on the biomass surface. The sorption capacity for Cr(VI) increased by 7.2-fold after surface modification. Sorption kinetics results show that the pseudo-second-order kinetic model described the experimental data well. During the sorption process, X-ray photoelectron spectroscopy (XPS) was used to analyze the chromium species on the biosorbent surface and the results indicate that part of the Cr(VI) ions were reduced to Cr(III) ions which can be chelated with the amine groups on the biomass surface. The reduced Cr(III) ions formed some aggregates on the surface at higher solution pHs.

Adsorption of azo dyes from aqueous solution by the hybrid MOFs/GO

2016 ◽  
Vol 73 (7) ◽  
pp. 1728-1737 ◽  
Author(s):  
Ling Li ◽  
Zhennan Shi ◽  
Hongyang Zhu ◽  
Wei Hong ◽  
Fengwei Xie ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Azo Dyes ◽  
Metal Organic Framework ◽  
Freundlich Isotherm ◽  
Order Kinetic ◽  
Sunset Yellow ◽  
Order Kinetic Model ◽  
Metal Organic ◽  
Pseudo Second Order ◽  
The Stability

In this work, a hybrid of chromium(III) terephthalate metal organic framework (MIL-101) and graphene oxide (GO) was synthesized and its performance in the removal of azo dyes (Amaranth, Sunset Yellow, and Carmine) from water was evaluated. The adsorption for azo dyes on MIL-101/GO was compared with that of MIL-101, and it was found that the addition of GO enhanced the stability of MIL-101 in water and increased the adsorption capacity. The maximum adsorption capacities of MIL-101/GO were 111.01 mg g−1 for Amaranth, 81.28 mg g−1 for Sunset Yellow, and 77.61 mg g−1 for Carmine. The adsorption isotherms and kinetics were investigated, showing that the adsorption fits the Freundlich isotherm and the pseudo-second-order kinetic model. The recyclability of MIL-101/GO was shown by the regeneration by acetone. The high adsorption capability and excellent reusability make MIL-101/GO a competent adsorbent for the removal dyes from aqueous solution.

scholarly journals Adsorption of Co(II) from aqueous solution using municipal sludge biochar modified by HNO3

2021 ◽  
Author(s):  
Chunlian Hu ◽  
Wei Zhang ◽  
Yuantao Chen ◽  
Na Ye ◽  
DaWa YangJi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Photoelectron Spectroscopy ◽  
Order Kinetic ◽  
Adsorption Effect ◽  
Surface Areas ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
Adsorption Of Co

Abstract Herein adsorption studies were proposed on a carboxylated sludge biochar (CSB) material modified by HNO3 to assess its capacity in the removal of cobalt from aqueous solution. The as-prepared sludge biochar material were characterized by Brunaure-Emmett-Teller (BET), Fourier transform infrared (FT-IR), Thermogravimetric analysis (TGA), Energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). The isotherm process could be well described by Langmuir isotherm model. The adsorption kinetics indicated that cobalt adsorption followed pseudo-second-order kinetic model. The mechanism between Co(II) and biochar involved electrostatic interaction, ion exchange, surface complexation and physical function. The adsorption capacity on CSB was as high as 72.27 mg·g−1, surpassing original sludge biochar (SB). This is due to the fact that CSB had abundant oxygen-containing functional groups and many hydroxyls, as well as, the BET surface areas increased when SB was modified by HNO3, which stimulate adsorption effect. Therefore, this work shows that CSB could be used as an efficient adsorbent to remove Co(II) in the wastewater.

scholarly journals Modification of Silica Coated on Iron Sand Magnetic Material with Chitosan for Adsorption of Au(III)

2017 ◽  
Vol 17 (2) ◽  
pp. 264 ◽  
Author(s):  
Muflikhah Muflikhah ◽  
Bambang Rusdiarso ◽  
Edy Giri Rachman Putra ◽  
Nuryono Nuryono
Keyword(s):  
Magnetic Material ◽  
Sol Gel ◽  
Order Kinetic ◽  
External Magnet ◽  
X Ray ◽  
Sol Gel Process ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Ft Ir ◽  
The Stability

Modification of silica coated on magnetic material iron sand with chitosan for adsorption of Au(III) has been carried out. Magnetic material (MM) from iron sand was separated using an external magnet, washed with water and HF solution 10%. MM–silica–chitosan material (MMSC) was synthesized via sol gel process and the product was characterized with Fourier Transform Infrared (FT-IR) spectrophotometer, X–ray diffractometer, scanning electron microscopy and energy dispersive X–ray, thermogravimetric analysis, and vibration sample magnetometer. Additionally, the effect of pH on the stability of MMSC has also been tested. The adsorption of Au(III) on MMSC was proceeded in a batch system with variation of pH, contact time, and concentration of absorbate. Adsorbent was separated using external magnet and concentration of Au(III) not adsorbed was analyzed using Atomic Absorption Spectrometer. Characterization result indicated that MMSC was successfully synthesized. Adsorption of Au(III) on MMSC followed pseudo second-order kinetic model with the value of adsorption rate constant (k) of 4.10 x 10-3 g mg-1 min-1 and adsorption isotherm fixed with Langmuir model with the adsorption capacity (qmax) of 149.25 mg g-1.

scholarly journals Adsorption Properties of Comb-Shaped Polycarboxylate Dispersant onto Different Crystal Pyraclostrobin Particle Surfaces

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5637
Author(s):  
Liying Wang ◽  
Chong Gao ◽  
Jianguo Feng ◽  
Yong Xu ◽  
Danqi Li ◽  
...  
Keyword(s):  
Physical Adsorption ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Adsorption Models ◽  
Crystal Forms ◽  
Adsorption Processes ◽  
Different Temperatures ◽  
Pseudo Second Order ◽  
The Stability ◽  
Crystalline Forms

The stability of the suspension system of the two crystal forms of pyraclostrobin is evaluated using multiple light technology, and the adsorption performance of polycarboxylate dispersant on the surface of two different crystalline pyraclostrobin particles is compared in combination with XRD, FTIR, XPS, and SEM from the microscopic view. The adsorption kinetics and thermodynamics studies of 2700 on the surfaces of different crystalline forms of pyraclostrobin particles show that the adsorption process of 2700 on the surfaces of pyraclostrobin crystal forms II and IV conform to pseudo-second-order kinetic adsorption model. The Ea values for crystal forms II and IV are 12.93 and 14.39 kJ∙mol−1, respectively, which indicates that both adsorption processes are physical adsorption. The adsorption models of 2700 on the surfaces of pyraclostrobin crystal forms II and IV are in accordance with Langmuir adsorption isotherms. The ∆Gad values of crystal forms II and IV are negative and the ∆Sad values are positive at different temperatures. Therefore, the adsorption processes are spontaneous and accompanied by entropy increase. The results of this study provide an important theoretical basis for the selection of polycarboxylate dispersants in the suspension of pyraclostrobin. This study also provides a reference for the research of polycrystalline pesticide suspension concentrate.

scholarly journals Adsorption characteristics of ciprofloxacin on the schorl: kinetics, thermodynamics, effect of metal ion and mechanisms

2017 ◽  
Vol 8 (3) ◽  
pp. 350-359 ◽  
Author(s):  
Danyang Yin ◽  
Zhengwen Xu ◽  
Jing Shi ◽  
Lili Shen ◽  
Zexiang He
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Adsorption Process ◽  
Ph Value ◽  
Physical Adsorption ◽  
Order Kinetic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Order Kinetic Model ◽  
Pseudo Second Order

Abstract In this study, schorl was used as an effective adsorbent for ciprofloxacin removal from wastewater. The adsorption performance, mechanism and effect of metal ion on sorption were investigated. Adsorption capacity reached a maximum (8.49 mg/g) when the pH value was 5.5. The pseudo-second-order kinetic model and Freundlich model could better describe the experimental data. The negative ΔH (–22.96 KJ/mol) value showed that the adsorption process was exothermic. The results also indicated physical adsorption existed on the adsorption process, which was in agreement with the analysis of X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy. The desorption rate could reach 94%, which suggested that schorl had a good desorption and regeneration performance. Coexisting ions, such as Cu2+ and Al3+, could obviously inhibit adsorption, and the inhibition from Al3+ was significantly higher than that from Cu2+. However, the additional Zn2+ could slightly promote the adsorption.

scholarly journals Preparation of Cotton Fibers Modified With Aromatic Heterocyclic Compounds and Study of Cr(VI) Adsorption Performance

2021 ◽  
Author(s):  
Zhiyu Huang ◽  
Peng Wu ◽  
Yankun Yin ◽  
Xiang Zhou ◽  
Lu Fu ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Metal Ion ◽  
Low Cost ◽  
Order Kinetic ◽  
Adsorption Mechanisms ◽  
Adsorption Capacities ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order

Abstract In order to prepare low-cost and environmentally friendly adsorbent materials for adsorption of heavy metal ion, two kinds of novel modified cottons (C-4-APD and C-2-APZ) were obtained by introducing 4-aminopyridin and 2-aminopyrazine into the surface of degreasing cotton, respectively, and used for the removal of Cr(VI) ions from aqueous solution. The two modified cottons were characterized by Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), which confirmed the amino groups, pyridine groups and pyrazine groups grafted onto the surface of modified cottons. The maximum adsorption capacities of C-4-APD and C-2-APZ were 73.78 mg/g and 61.34 mg/g, respectively, at the optimum pH of 6 and an initial concentration of 200 mg/g. Kinetic and isotherm studies were carried out to investigate the adsorption behavior of the modified cottons on Cr(VI) ions. The results showed that the adsorption of Cr(VI) ions by modified cottons followed a pseudo-second-order kinetic model, the equilibrium data were in good agreement with the Langmuir isotherm model, and electrostatic and chemisorption may be the main adsorption mechanisms. The recovery and reuse of modified cotton were achieved by washing with 2 wt% thiourea-hydrochloric acid solution (0.5 mol/L concentration of HCl), and the adsorption capacities of C-4-APD and C-2-APZ were maintained above 90% and 80%, respectively, after six cycles.

scholarly journals Magnetically modified Posidonia oceanica biomass as an adsorbent for organic dyes removal

2016 ◽  
Vol 17 (2) ◽  
pp. 351 ◽  
Author(s):  
I. SAFARIK ◽  
N. ASHOURA ◽  
Z. MADEROVA ◽  
K. POSOIKOVA ◽  
E. BALDIKOVA ◽  
...  
Keyword(s):  
Organic Dyes ◽  
Posidonia Oceanica ◽  
Water Soluble ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Adsorption Model ◽  
Adsorption Processes ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Safranin O

Magnetically modified Posidonia oceanica sea grass dead biomass was employed as an adsorbent of organic dyes. The adsorption of seven water-soluble organic dyes was characterized using Langmuir adsorption model. The highest calculated maximum adsorption capacity was found for Bismarck brown Y (233.5 mg g-1), while the lowest capacity value was obtained for safranin O (88.1 mg g-1). The adsorption processes followed the pseudo-second-order kinetic model and the thermodynamic studies indicated spontaneous and endothermic adsorption.

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