scholarly journals Adaption of Theoretical Adsorption Model on Coal: Physical Structure

2021 ◽  
Vol 9 ◽  
Author(s):  
Wu Guodai ◽  
Pan Linhua ◽  
Huang Bingxiang ◽  
Luan Jinhua ◽  
Zhang Ye ◽  
...  
Keyword(s):  
Physical Structure ◽  
Langmuir Model ◽  
Structural Deformation ◽  
Adsorption Model ◽  
Rock Composition ◽  
R And D ◽  
Adsorption Performance ◽  
Coal Deformation ◽  
Coal Rock ◽  
Coal Reservoir

With the motivation to investigate the role of coal physical structure on the adsorption performance of coal reservoir, 18 different types of coal samples with different coal structures were collected from six coal profiles of four production mines located at China. The adsorption characteristics of CH4 on coal samples with different coal structures were examined, and then experimental results were fitted and analyzed by the Langmuir model and the adsorption potential model (D-R and D-A). The prominent factors in terms of adsorption capacity of coal with different coal structures and its adaptability to the model were discussed. Results indicate the following: a) under the condition of a similar coal rank, the adsorption performance of coal is governed by coal rock composition and adsorption heat, the effect of structural deformation on the adsorption performance of coal is not obvious; b) the Langmuir model has a certain adaptability to coal samples with different coal structures, while the D-R model is evidently not suitable to describe coal samples with scaly coal, part of broken coal with small vitrinite content; c) the D-A model has a high adaptability to coal samples with various coal structure types, and the stronger the coal deformation is, the higher the accuracy is.

scholarly journals Development of PANI/BN-based absorbents for water remediation

2019 ◽  
Vol 54 (4) ◽  
pp. 290-298
Author(s):  
Muhammad Arsalan ◽  
Azka Awais ◽  
Tingting Chen ◽  
Qinglin Sheng ◽  
Jianbin Zheng
Keyword(s):  
Adsorption Process ◽  
Binding Capacity ◽  
Order Equation ◽  
Langmuir Model ◽  
Water Remediation ◽  
Ionic Bond ◽  
Adsorption Performance ◽  
Optimum Ph ◽  
Pseudo Second Order ◽  
Bond Effect

Abstract In this research, novel PANI/BN-based absorbent was prepared by bonding polyaniline and bentonite for water remediation and their structures were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The effect of pH, concentration of metal, and dosage amount on synthesized novel PANI/BN-based absorbent was investigated in detail. The result indicated that the PANI/BN-based absorbent has an excellent adsorption performance towards Cu, Pb, and Ni, and the highest binding capacity of 130 mg g−1 for Ni was obtained under normal conditions. The adsorption of PANI/BN absorbent was found to depend on pH when pH < 7.0, but the adsorption has been found independent from the ionic bond effect. The adsorption at optimum pH for Cu (pH 6) and Pb (pH 5) was observed as 85 mg g−1 and 105 mg g−1, respectively. The best results collected at those conditions of isotherm data and adsorption kinetics are represented by the Langmuir model and pseudo-second order equation, respectively. Thermodynamic results (ΔH > 0, ΔS > 0, ΔG < 0) showed that the adsorption process of Cu, Ni, and Pb is significantly increased by the synthesized novel PANI/BN-based absorbent.

EXPERIMENTAL INVESTIGATION ON MULTI-FRACTAL CHARACTERISTICS OF ACOUSTIC EMISSION OF COAL SAMPLES SUBJECTED TO TRUE TRIAXIAL LOADING–UNLOADING

Fractals ◽  
2020 ◽  
Vol 28 (05) ◽  
pp. 2050092 ◽  
Author(s):  
RAN ZHANG ◽  
JIE LIU ◽  
ZHANYOU SA ◽  
ZAIQUAN WANG ◽  
SHOUQING LU ◽  
...  
Keyword(s):  
Damage Evolution ◽  
Dynamic Changes ◽  
Deformation And Failure ◽  
True Triaxial ◽  
Coal Deformation ◽  
Coal Rock ◽  
True Triaxial Stress ◽  
Fractal Characteristics ◽  
Loading And Unloading ◽  
Precursory Information

Coal–rock dynamic disasters seriously threaten safe production in coal mines, and an effective early warning is especially important to reduce the losses caused by these disasters. The occurrence of coal–rock dynamic disasters is determined by mining-induced stress loading and unloading. Therefore, it is of great significance to analyze the precursory information of coal deformation and failure during true triaxial stress loading and unloading. In this study, the deformation and failure of coal samples subjected to true triaxial loading and unloading, including fixed axial stress and unloading confining stress (FASUCS), are experimentally investigated. Meanwhile, acoustic emission (AE) during the deformation of coal samples is monitored, and the multi-fractal characteristics of AE are analyzed. Furthermore, combined with the deformation and failure of coal samples, the precursory information of coal deformation and rupture during true triaxial stress loading and unloading is obtained. Finally, the relationship between multi-fractal characteristics and damage evolution of coal samples under FASUCS is discussed. The results show that the multi-fractal spectral widths of AE time series under the conditions of FASUCS with different initial confining stresses or unloading rates are quite different, but the dynamic changes of multi-fractal parameters [Formula: see text] and [Formula: see text] are similar. This indicates that the microscopic complexity of AE events of coal samples under different conditions of FASUCS differs, but the macroscopic generation mechanism of AE events has inherent uniformity. The dynamic changes of [Formula: see text] and [Formula: see text] can reflect the stress and damage degree of coal samples. The dynamic change process of [Formula: see text] well accords with the damage evolution process of coal samples. A gradual decrease of [Formula: see text] corresponds to a slow increase of damage, while a sharp increase of it corresponds to a rapid growth of damage. At the same time, the mutation point of damage curve at distinct stress difference levels shares the same variation trend with the [Formula: see text] mutation point. The change of [Formula: see text] can reflect the damage process of coal samples, which can be used as precursor information for predicting coal–rock rupture. The finding is of great significance for the early warning of coal–rock dynamic disasters.

Effect of Anionic Surfactant on Adsorption Properties of Nano Calcium Carbonate

2018 ◽  
Vol 281 ◽  
pp. 830-835 ◽  
Author(s):  
Qing Li Ren ◽  
Qiang Luo ◽  
Feng Lei Wang
Keyword(s):  
Calcium Carbonate ◽  
Sodium Dodecyl Sulfate ◽  
High Surface ◽  
Sodium Dodecyl ◽  
Langmuir Model ◽  
Phase Method ◽  
Adsorption Performance ◽  
Dodecyl Sulfate ◽  
Superior Surface ◽  
Surface Modified

Because of its superior surface properties, nanocalcium carbonate can be applied to the adsorption of heavy metals in wastewater. However, because of the easy aggregation of nanocalcium carbonate, high surface energy and poor dispersibility in water, it is not conducive to the process of adsorption. Therefore, surface modification of nanocalcium carbonate is needed. In this paper, nanocalcium carbonate was prepared by liquid phase method. And the nanocalcium carbonate was surface modified by sodium dodecyl sulfate. The effects of modifier amount, modification temperature, and modification time on the activation and absorbance of nanocalcium carbonate were investigated. And the morphology and particle size of modified nanocalcium carbonate were tested by SEM and XRD patterns.The results show that the dispersion and surface activity of the modified nanocalcium carbonate have been improved remarkably. Moreover, the Cu2+ was adsorbed by sodium dodecyl sulfate modified nanocalcium carbonate and unmodified nanocalcium carbonate under the optimum modification conditions. And the effects of nanocalcium carbonate initial concentration on the adsorption performance were studied. The results show that the adsorption performance of modified calcium carbonate is better than that of the unmodified. Moreover, the adsorption process is studied by adsorption isotherm. By drawing the adsorption isotherms lines and by comparing the fitting result of the experimental data based on the Langmuir model and that of Freundlich model, it is found that the adsorption of Cu2+ by modified nanocalcium carbonate meets the Langmuir model.

Simple Fabrication of PEG Modified W18O49 for Enhanced Adsorption Performance towards Methylene Blue

2021 ◽  
Vol 67 ◽  
pp. 81-87
Author(s):  
Hai Yang Fu ◽  
Xue Jiao Li ◽  
Wei Sun ◽  
Dong Yue Liu ◽  
Xiao Fei Gao ◽  
...  
Keyword(s):  
Methylene Blue ◽  
High Surface ◽  
Raw Material ◽  
Adsorption Model ◽  
Polyethylene Glycol 400 ◽  
Adsorption Performance ◽  
Peg 400 ◽  
Colored Wastewater ◽  
Enhanced Adsorption ◽  
Tungsten Chloride

The W18O49 nanoparticles were synthesized by solvothermal method with tungsten chloride as raw material and n-propanol as solvent. Polyethylene glycol 400 (PEG-400) was modified for W18O49 nanoparticles (W18O49@PEG). The structure and morphology of W18O49 and W18O49@PEG were characterized by XRD and SEM. Methylene blue aqueous solution was used as wastewater adsorption model. And the comparative experiments with other absorbent materials, such as artificial zeolite and activated carbon were also conducted. The results revealed that after modifying by PEG-400, W18O49 has a better adsorption performance than other materials due to its large specific surface area and high surface energy. Finally adsorption circulation experiment was performed，the results indicate that the W18O49@PEG nanoparticles show great potential in the treatment of colored wastewater.

Adsorption performance of magnetic aminated lignin for the removal of Cu(II) and Cd(II)

TAPPI Journal ◽  
2019 ◽  
Vol 18 (01) ◽  
pp. 9-18
Author(s):  
Dafeng Zheng ◽  
Yingzhi Ma ◽  
Xueqing Qiu ◽  
Xuejun Pan
Keyword(s):  
Heavy Metals ◽  
Entropy Change ◽  
Enthalpy Change ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Order Model ◽  
Adsorption Performance ◽  
Monolayer Adsorption ◽  
Removal Of Heavy Metals ◽  
Pseudo Second Order

The adsorption behavior of Cu(II) and Cd(II) onto a magnetic lignin-based nanomaterial (MLN) was investigated in detail. The results showed that the adsorption isotherm was better described by the Langmuir model, showing monolayer adsorption with a maximum adsorption capacity of 135.7 and 156.5 mg/g. The kinetics fit the pseudo-second-order model. The thermodynamics showed the enthalpy change of the adsorption for Cu(II) and Cd(II) was 24.12 and 36.49 kJ/mol, with entropy change of 85.12 and 130.3 J/mol·K, respectively; thus, the adsorption was endothermic and spontaneous in the range of 25°C–45°C. Additionally, the adsorbent was easy to regenerate. This study shows that MLN is a capable, sustainable absorbent for the removal of heavy metals.

Studi Komparasi Model Langmuir, Freundlich dan Emzha untuk Biosorpsi Beberapa Ion Logam

2019 ◽  
Vol 4 (2) ◽  
pp. 141
Author(s):  
Rahmiana Zein ◽  
Zulfi Zulfi ◽  
Riza Nurafni
Keyword(s):  
Experimental Data ◽  
Metal Ions ◽  
Research Method ◽  
Langmuir Model ◽  
Coefficient Of Determination ◽  
Original Form ◽  
Adsorption Model ◽  
Average Coefficient ◽  
Two Stages

<p><em>Telah dilakukan studi komparasi untuk menguji keandalan model EMZHA dibandingkan model Langmuir dan Freunlich dalam penyerapan ion logam Cu(II), Cd(II) dan Pb(II) oleh beberapa biosorben. Model EMZHA adalah model adsorbsi baru yang diusulkan oleh peneliti Indonesia sebagai upaya mendapatkan model yang lebih bersifat universal (berlaku untuk semua tipe data) sehingga dapat digunakan untuk mengungkap mekanisme adsorbsi secara lebih lengkap dan mendasar. Model Langmuir dan Freunlich dipillih sebagai pembanding karena kedua model ini paling banyak digunakan dan memiliki karakter yang cenderung berlawanan. Penelitian ini digunakan data ekperimen dalam bentuk aslinya,  tidak diubah kedalam bentuk linier terlebih dahulu, dengan tujuan untuk menghindari error yang timbul akibat proses linierisasi. Regresi yang digunakan adalah regresi non linier. Metode penelitian ini dibagi dalam dua tahapan yaitu tahap pengumpulan data eksperimen yang berasal dari berbagai penelitian adsorbsi ion logam berat oleh berbagai biosorben dan pengolahan data komparasi model. Pengusul model EMZHA telah melaporkan keandalan prediksi model ini untuk penyerapan beberapa ion logam tapi hanya menggunakan satu jenis biosorben, yaitu kulit buah atap, sedangkan penelitian ini menggunakan 11 biosorben yang berbeda. Pada penelitian ini berhasil dibuktikan bahwa model EMZHA memiliki koefisien determinasi rata-rata 0,9034 yang lebih tinggi dari rata-rata koefisien determinasi model Langmuir (0,8485) dan Freundlich (0,8483).</em></p><p><em><br /></em></p><p><em><em>Comparative studies have been conducted to test the reliability of the EMZHA model compared to the Langmuir and Freunlich models in the absorption of Cu (II), Cd (II) and Pb (II) metal ions by several biosorbents. The EMZHA model is a new adsorption model proposed by Indonesian researchers in an effort to obtain a more universal model (applicable to all types of data) so that it can be used to uncover the mechanism of adsorption more fully and fundamentally. Langmuir and Freunlich's models are chosen as a comparison because these two models are the most widely used and have opposing characters. This study used experimental data in its original form, not converted into linear form first, with the aim of avoiding errors arising from the linearization process. The regression used is non linear regression. This research method is divided into two stages, namely the stage of collecting experimental data derived from various studies of adsorption of heavy metal ions by various biosorbents and the processing of comparative data models. Proponents of the EMZHA model have reported the reliability of the prediction of this model for the absorption of several metal ions but only use one type of biosorbent, namely the skin of the roof, while this study uses 11 different biosorbents. In this study successfully proved that the EMZHA model has an average determination coefficient of 0.9034 which is higher than the average coefficient of determination of the Langmuir model (0.8485) and Freundlich (0.8483).</em></em></p>

Synthesis of Spherical Assembly Composed of Mn3O4 Nanoparticles and its Adsorption Behavior for Alizarin Red in Water

2011 ◽  
Vol 694 ◽  
pp. 165-169 ◽  
Author(s):  
Ming Yang ◽  
Qian Sun ◽  
Chen Fei Zhao ◽  
Xin Xin Sheng
Keyword(s):  
High Efficiency ◽  
Average Diameter ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Alizarin Red ◽  
X Ray ◽  
Adsorption Performance ◽  
Adsorption Data ◽  
Isotherm Adsorption ◽  
Mn3o4 Nanoparticles

Spherical assembly composed of Mn3O4 nanoparticles with an average diameter of 400-600 nm have been prepared by a simple reactions between Ba(MnO4)2, H2SO4 and MnSO4 and thermal decomposition at 580 °C. The product was characterized by X-ray powder diffraction and scanning electron microscope. The adsorption performance of spherical assembly composed of Mn3O4 for alizarin red was investigated. The adsorbent showed high efficiency for the removal of alizarin red in water. The equilibrium of adsorption was achieved within 8 min. The isotherm adsorption data obeyed the Langmuir model, with a maximum adsorption capacity of 32.8 mg g-1.

Synthesis of Spherical Assembly Composed of MnO2 Nanoparticles Using Spent Zn-Mn Batteries

2012 ◽  
Vol 178-181 ◽  
pp. 1012-1015 ◽  
Author(s):  
Ming Yang ◽  
Guan Liu Zhang ◽  
Peng Fei Li ◽  
Xiao Ying Li ◽  
Cheng Chen
Keyword(s):  
High Efficiency ◽  
Average Diameter ◽  
Langmuir Model ◽  
Maximum Adsorption Capacity ◽  
Methyl Red ◽  
X Ray ◽  
Adsorption Performance ◽  
Mno2 Nanoparticles ◽  
Adsorption Data ◽  
Isotherm Adsorption

Spherical assembly composed of MnO2 nanoparticles with an average diameter of 0.8-2.0 μm have been prepared using spent Zn-Mn batteries. The product was characterized by X-ray powder diffraction and scanning electron microscope. The adsorption performance of spherical assembly composed of MnO2 for methyl red was investigated. The adsorbent showed high efficiency for the removal of methyl red in water. The equilibrium of adsorption was achieved within 30 min. The isotherm adsorption data obeyed the Langmuir model, with a maximum adsorption capacity of 92.6 mg g-1.

scholarly journals Removal of methylene blue in water by electrospun PAN/β-CD nanofibre membrane

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 398-410
Author(s):  
Zhaoying Sun ◽  
Tao Feng ◽  
Zhihui Zhou ◽  
Hongdan Wu
Keyword(s):  
Methylene Blue ◽  
Adsorption Capacity ◽  
Ion Concentration ◽  
Maximum Adsorption Capacity ◽  
Nanofiber Membrane ◽  
Adsorption Model ◽  
Adsorption Performance ◽  
The Matrix ◽  
Isotherm Adsorption ◽  
Hydrophobic Binding

Abstract The polyacrylonitrile (PAN) nanofiber membrane prepared by the electrospinning technology was used as the matrix, and β-cyclodextrin (β-CD) was introduced into it to synthesize the composite nanofiber membrane. Taking methylene blue as the object, the adsorption performance of nanofiber membranes for dyes in the aqueous solution was studied. The structure, morphology, and specific surface area of the nanofiber membrane were characterized using FTIR, SEM, BET, XRD, and EDS. Meantime, the adsorption equilibrium was also explored. After being modified by cyclodextrin, a large number of cavity structures and hydrophobic binding sites were provided for the nanofiber membrane, and the adsorption performance was significantly improved. The results showed that the maximum adsorption capacity of the PAN/β-CD blend nanofiber membrane (at 25℃) for methylene blue was 108.66 mg g−1. The effects of pH, adsorption time, ion concentration, and adsorbent dosage on the adsorption capacity were also investigated. In addition, by fitting with the adsorption model, the adsorption process was more complex with the quasi-secondary adsorption kinetics and Langmuir isotherm adsorption model.

scholarly journals Research status and development direction of controlling factors of graphite mineralization in coal measures

2021 ◽  
pp. 31
Author(s):  
Keyword(s):  
Research Direction ◽  
Rock Composition ◽  
Control Factors ◽  
Influence Mechanism ◽  
Development Direction ◽  
Forming Temperature ◽  
Coal Rock ◽  
Coal Grade ◽  
Coal Measures ◽  
Degree Of Graphitization

Coal-measure graphite mineralization control is affected by many factors. In order to explore the ore-forming control factors and influence mechanism, the paper comprehensively analyzes the influence and mechanism of each factor from five aspects of coal rock composition, coal grade, temperature, pressure and mineralizer, combined with geological examples. The results show that in the process of graphite mineralization in coal measures, the components of coal and rock have the ability of graphitization, but the higher the degree of metamorphism of coal as carbon source, the higher the degree of graphitization of products, the higher the ore-forming temperature, and the higher the degree of graphitization. The development of tectonic movement promotes the graphitization, but the degree of graphitization is different and complicated due to the stress dissipation. Different minerals in coal have different effects on graphite mineralization in coal measures, and its mechanism needs to be further explored. Finally, it is pointed out that the research direction of coal series graphite lies in the different graphitization mechanism of the same rank coal and the different influence mechanism of different minerals in coal.

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