Surface pore tension and adsorption characteristics of polluted sediment

Fang, Hongwei; Chen, Minghong; Chen, Zhihe

doi:10.1007/s11433-008-0104-8

Cited by 26 publications

(5 citation statements)

References 15 publications

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“…In the region of relative pressure from 0 to 0.8, the adsorption of nitrogen by both carbon black and particles increases with the increase of relative pressure, and the adsorption increases sharply after the relative pressure exceeds 0.8. From the shape of the adsorption isotherm, the trend of nitrogen adsorption by carbon black and sample particles classified as type II isotherm adsorption, which is the case of adsorption in multiple layers of porous media, similar to the findings of (Fang et al 2008). The sharp increase in adsorption at relative pressures approaching 1 is primarily attributed to the capillary condensation of nitrogen within the pores of the particles.…”

Section: Resultssupporting

confidence: 75%

Investigation of Adsorption Characteristics and Influencing Factors for Diesel Engine Exhaust Particles

Zhong

Zhang

Liu

et al. 2021

Preprint

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The adsorption process of diesel exhaust particles has a great influence on the particles. A single-cylinder diesel exhaust particle collection system was established to collect particle samples with different adsorption environment conditions, and the adsorption capacity of the samples was analyzed and characterized by an isothermal adsorption test; the change patterns of particle characteristics were investigated by the scanning electron microscope and thermogravimetric analyzer, correlation analysis of the factors influencing the adsorption process was performed. The results show that the particles have adsorption capacity and belong to the type of multilayer adsorption on porous media; the pore diameter is continuously distributed in the range of 8–80 nm with multiple peaks, which is the category of mesoporous and macroporous; the adsorption capacity of the sample particles increase with the increase of engine speed. Compared with the particles at the inlet of the exhaust pipe, the box-counting dimension (DB) of particles at the outlet increased, the content of water and soluble organic fraction (SOF) increased, the activation energy (E) decreased. Among the parameters affecting the adsorption process, the increase of hydrocarbons concentration contribute to the increase of particle adsorption and E reduction; the increase of the average temperature of the exhaust pipe inhibit the increase of the DB, and the increase of the temperature difference between the inlet and outlet facilitate the adsorption of water and SOF by the particles; the decrease of the adsorption time is one of the main reasons for the slowdown of the increase in DB; the average pore diameter had the greatest positive correlation with the amount of variation in the DB; the increase in specific surface area and pore volume of the sample particles was the dominant cause of the increase in adsorption capacity as well as the decrease in E.

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Section: Resultssupporting

confidence: 75%

Investigation of Adsorption Characteristics and Influencing Factors for Diesel Engine Exhaust Particles

Zhong

Zhang

Liu

et al. 2021

Preprint

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“…Xue et al [29] studied multifractal characteristics of pores in soil based on experimental data measured by mercury intrusion methods. Fang et al [30] calculated the fractal dimension according to different model based on nitrogen adsorption and desorption experiments. Zhou et al [31] quantified the complexity of the flow boundary by introducing the fractal dimension of boundary shape.…”

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confidence: 99%

Computation of fractal dimension of rock pores based on gray CT images

et al. 2011

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The characterization of pore structure in rocks is relevant in determining their various mechanical behaviors. Digital image processing methods integrated with fractal theory were applied to analyze images of rock slices obtained from industry CT, elucidating the characteristics of rock pore structure and the relationship between porosity and fractal dimensions. The gray values of pixels in CT images of rocks provide comprehensive results with respect to the attenuation coefficients of various materials in corresponding rock elements, and these values also reflect the effect of rock porosity at various scales. A segmentation threshold can be determined by inverse analysis based on the pore ratios that are measured experimentally, and subsequently binary images of rock pores can be obtained to study their topological structures. The fractal dimension of rock pore structure increases with an increase in rock pore ratio, and fractal dimensions might differ even if pore ratios are the same. The more complex the structure of a rock, the larger the fractal dimension becomes. The experimental studies have validated that fractal dimension calculated directly from gray CT images of rocks can give an effective complementary parameter to use alongside pore ratios and they can suitably represent the fractal characteristics of rock pores. As complex geological materials, rocks have discontinuous, non-homogeneous, multi-phase composite structures. Many irregular pores occur at different scales that affect the physical, mechanical and chemical properties of rock materials; such as strength, elastic modulus, permeability, conductivity, wave velocity, particle surface adsorption, and the capacity of a rock reservoir. A significant problem in petroleum exploration, mining, metallurgy, civil and hydraulic engineering is how to understand and quantitatively characterize the evolution of pore structures in rock materials. Thus far, more than 30 kinds of parameters have been proposed to describe rock pore structures [1,2]; these include density or volume fraction of pores (poreratio), pore size and its distribution, and specific surface area. These parameters mainly characterize the average pore structure from a macroscopic view. Pore ratio is the most readily available basic parameter, the effect of which is far greater than all the other factors; therefore, studies related to pore ratios are the most common. Determining pore ratios involves use of microscopic image analysis, weighing method, immersion method and mercury, which have been discussed in detail elsewhere [1,3]. Because pore structures in rocks are very complex [4][5][6], advanced measurement techniques have gradually been introduced to describe pore structures at different scales [7]. Pore morphology and microstructure in rocks can be observed and analyzed over different magnifications using optical or scanning electron microscopy. X-ray fluoroscopy methods also have been adopted to observe internal rock structures. A more effective method is Computerized Tomography (CT...

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“…However, we had measured the porosity and pore size distributions of the same sediment samples from Guanting Reservoir by the gas adsorption method. The average pore sizes of those samples were in the range of 2 to 50 nm, with the largest pore volume being 3.7 nm in size [ 17 ].…”

Section: Resultsmentioning

confidence: 99%

“…The pores of sediment particles increase the specific surface area, and large specific surface area greatly enhances the physical and chemical effects on the microinterface (solid-liquid interface). We previously reported that the adsorption of phosphorus onto sediments decreases the volume of pores smaller than 10 nm by filling these pores with contaminants [ 17 ]. Luo et al [ 19 ] also found that the fill of Enano-TiO2 particles into the micropores of sediments could significantly reduce t-Plot micropore specific surface area and cause slight decrease in sediment P binding energy.…”

Section: Resultsmentioning

confidence: 99%

Cross-Sectional Information on Pore Structure and Element Distribution of Sediment Particles by SEM and EDS

et al. 2017

Self Cite

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The interaction between pollutants and sediment particles often occurs on the particle surface, so surface properties directly affect surface reaction. The physical and chemical processes occurring on sediment particle surfaces are microscopic processes and as such need to be studied from a microscopic perspective. In this study, field emission scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS) were adopted to observe and analyze the pore structure and element distribution of sediment particles. In particular, a special method of sample preparation was used to achieve the corresponding cross-sectional information of sediment particles. Clear images of a particle profile and pore microstructure were obtained by high-resolution SEM, while element distribution maps of sediment particles were obtained by EDS. The results provide an intuitive understanding of the internal microenvironment and external behavior of sediment particles, in addition to revealing a significant role of pore microstructure in the adsorption and desorption of pollutants. Thus, a combination of different experimental instruments and observation methods can provide real images and information on microscopic pore structure and element distribution of sediment particles. These results should help to improve our understanding of sediment dynamics and its environmental effects.

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Surface pore tension and adsorption characteristics of polluted sediment

Cited by 26 publications

References 15 publications

Investigation of Adsorption Characteristics and Influencing Factors for Diesel Engine Exhaust Particles

Investigation of Adsorption Characteristics and Influencing Factors for Diesel Engine Exhaust Particles

Computation of fractal dimension of rock pores based on gray CT images

Cross-Sectional Information on Pore Structure and Element Distribution of Sediment Particles by SEM and EDS

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