Adsorption characteristics, isotherm, kinetics, and diffusion of modified natural bentonite for removing diazo dye

Heavy metal pollution has adversely affected the ecological environment. As an eco-friendly and renewable material, biochar has a positive effect on environmental restoration. For study the feasibility of removing lead using corn straw biochar, the adsorption characteristics and mechanism were studied. This work prepared corn straw biochar at 300 °C, and its surface properties were characterized. The adsorption kinetics, isotherm, thermodynamics were determined. The result indicated the mechanism belonged ion exchange and complexation, and the experiment were controlled by comprehensive process, which included reaction rate and diffusion. The Langmuir model had better fitting results for the adsorption data, which indicated that adsorption was chemical adsorption and single molecular layer adsorption, and the maximum adsorption amount of corn straw biochar at 25 °C, 35 °C and 45 °C were 81.63 mg/g, 83.89 mg/g and 89.21 mg/g respectively. The thermodynamic analysis showed that increasing temperature was helpful to adsorption, and the adsorption was spontaneous. The results can be used for comprehensive utilization of straw and treatment of lead pollution.

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Molecular simulation of gas adsorption characteristics and diffusion in micropores of lignite

Fuel ◽

10.1016/j.fuel.2020.117443 ◽

2020 ◽

Vol 269 ◽

pp. 117443 ◽

Cited By ~ 7

Author(s):

Dameng Gao ◽

Lin Hong ◽

Jiren Wang ◽

Dan Zheng

Keyword(s):

Molecular Simulation ◽

Gas Adsorption ◽

Adsorption Characteristics ◽

And Diffusion

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Adsorption characteristics, isotherm, kinetics, and diffusion of modified natural bentonite for removing the 2,4,5-trichlorophenol

Applied Clay Science ◽

10.1016/j.clay.2013.12.030 ◽

2014 ◽

Vol 90 ◽

pp. 81-87 ◽

Cited By ~ 40

Author(s):

H. Zaghouane-Boudiaf ◽

Mokhtar Boutahala ◽

Sousna Sahnoun ◽

Chafia Tiar ◽

Fatima Gomri

Keyword(s):

Adsorption Characteristics ◽

And Diffusion

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Meridional Circulation, Turbulence, and Diffusion Processes in Stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100080477 ◽

1976 ◽

Vol 32 ◽

pp. 109-116 ◽

Cited By ~ 1

Author(s):

S. Vauclair

Keyword(s):

Convection Zone ◽

Diffusion Processes ◽

Meridional Circulation ◽

Diffusion Time ◽

Work In Progress ◽

First Results ◽

Stellar Envelopes ◽

And Diffusion ◽

Turbulence And Diffusion ◽

Hr Diagram

This paper gives the first results of a work in progress, in collaboration with G. Michaud and G. Vauclair. It is a first attempt to compute the effects of meridional circulation and turbulence on diffusion processes in stellar envelopes. Computations have been made for a 2 Mʘstar, which lies in the Am - δ Scuti region of the HR diagram.Let us recall that in Am stars diffusion cannot occur between the two outer convection zones, contrary to what was assumed by Watson (1970, 1971) and Smith (1971), since they are linked by overshooting (Latour, 1972; Toomre et al., 1975). But diffusion may occur at the bottom of the second convection zone. According to Vauclair et al. (1974), the second convection zone, due to He II ionization, disappears after a time equal to the helium diffusion time, and then diffusion may happen at the bottom of the first convection zone, so that the arguments by Watson and Smith are preserved.

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