A novel remediation method of cadmium (Cd) contaminated soil: Dynamic equilibrium of Cd2+ rapid release from soil to water and selective adsorption by PP-g-AA fibers-ball at low concentration

2021 ◽  
Vol 416 ◽  
pp. 125884
Author(s):  
Kaijian Zou ◽  
Junfu Wei ◽  
Di Wang ◽  
Zhiyun Kong ◽  
Huan Zhang ◽  
...  
Keyword(s):  
Contaminated Soil ◽  
Dynamic Equilibrium ◽  
Selective Adsorption ◽  
Low Concentration ◽  
Rapid Release ◽  
Soil Dynamic

Desorption of Anthracene from Soil in Presence of Surfactant and Nanomaterial

2013 ◽  
Vol 800 ◽  
pp. 159-161
Author(s):  
Ai Fang Ding ◽  
Chang Yun Chen ◽  
Qin Pu Liu
Keyword(s):  
Contaminated Soil ◽  
Desorption Process ◽  
Low Concentration

Surfactant LAS and nanomaterial taxoite were used to study their effects on anthracene desorption from artificially contaminated soil. The results show that the desoption of anthracene from soil is affected by the type and concentration of materials. Two type of materials with low concentration dont improve anthracene desorption from soil. While, they could enhance the desorption process with the concentrations increasing, especially surfactant LAS. The desorption and solubility ratios of anthracene from soil are 18.55% and 17.11% with the concentrations of surfactant LAS being0.2g/g. However, their ratios are only 3.91% and 2.21% with nanomaterial taxoite.

Zeolites for the selective adsorption of sulfur hexafluoride

2015 ◽  
Vol 17 (27) ◽  
pp. 18121-18130 ◽  
Author(s):  
I. Matito-Martos ◽  
J. Álvarez-Ossorio ◽  
J. J. Gutiérrez-Sevillano ◽  
M. Doblaré ◽  
A. Martin-Calvo ◽  
...  
Keyword(s):  
Sulfur Hexafluoride ◽  
Molecular Level ◽  
Selective Adsorption ◽  
Molecular Simulations ◽  
Low Concentration

Molecular simulations have been used to investigate at the molecular level the suitability of zeolites with different topology on the adsorption, diffusion and separation of a nitrogen–sulfur hexafluoride mixture containing the latter at low concentration.

scholarly journals Comparative Activation Process of Pb, Cd and Tl Using Chelating Agents from Contaminated Red Soils

2020 ◽  
Vol 17 (2) ◽  
pp. 497 ◽  
Author(s):  
Lirong Liu ◽  
Dinggui Luo ◽  
Guangchao Yao ◽  
Xuexia Huang ◽  
Lezhang Wei ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Chelating Agents ◽  
Dynamic Equilibrium ◽  
Ethylenediaminetetraacetic Acid ◽  
Speciation Analysis ◽  
Activation Process ◽  
Activation Effect ◽  
Red Soils

Adding chelating agents is a critical technique of heavy metal activation for enhancing phytoextraction through the formation of soluble metal complexes which will be more readily available for extraction. The preliminary, dynamic, equilibrium activation experiments and speciation analysis of Pb, Cd and Tl in contaminated red soils were used to select six chelates with relatively good activation performance from nine chelates, and the effects of dosage and pH on the heavy metals activation were studied systematically. Results showed that the activation of Pb, Cd and Tl by chelates reached equilibrium within 2 h, and the activation process showed three stages. Under neutral conditions, chelates had better activation performance on Pb- and Cd-contaminated soils. Except for S,S-ethylenediamine disuccinic acid (S,S-EDDS) and citric acid (CA), the maximum equilibrium activation effect (MEAE) of ethylenediaminetetraacetic acid (EDTA), N,N-bis (carboxymethyl) glutamic acid (GLDA), diethylenetriaminepentaacetic acid (DTPA) and aminotriacetic acid (NTA) was over 81%. The MEAE of Tl-contaminated soil was less than 15%. The decreasing order of the dosage of chelating agents corresponding to MEAE for three types of contaminated soils was Pb-, Cd- and Tl-contaminated soil, relating to the forms of heavy metals, the stability constants of metal–chelates and the activation of non-target elements Fe in red soil. Under acidic conditions, the activation efficiencies of chelates decreased to differing degrees in Pb- and Cd-contaminated soils, whereas the activation efficiencies of chelating agents in Tl-contaminated soils were slightly enhanced.

Surfactant-Enhanced Washing of Aged PAH Contaminated Soils: Comparison between Nonionic Surfactant and Anionic Surfactant

2014 ◽  
Vol 522-524 ◽  
pp. 316-321 ◽  
Author(s):  
He Lian Li ◽  
Rong Hui Qu ◽  
Xue Mei Han ◽  
Jia Jun Chen
Keyword(s):  
Critical Micelle Concentration ◽  
Aqueous Solutions ◽  
Anionic Surfactant ◽  
Contaminated Soil ◽  
Contaminated Soils ◽  
Surfactant Concentration ◽  
Nonionic Surfactants ◽  
Low Concentration ◽  
Removal Efficiencies ◽  
Triton X

Nonionic surfactants Triton X-100 (TX100), Triton X-305 and anionic surfactant SDS were used to desorb PAHs from contaminated soil. The surfactant loss due to sorption/ precipitation and PAH removal efficiency by each surfactant were evaluated. Due to sorption/precipitation, the apparent critical micelle concentration (CMCsoil) values for the 3 surfactants are 1.3-3.8 times their corresponding CMC values in aqueous solutions. The maximal surfactant loss follows the order of SDS>>TX100>TX305. The anionic surfactant SDS is quite different from nonionic surfactants TX100 and TX305 in PAH removal. SDS can effectively remove 3-ring PAHs at very low concentration, but is not so efficient for 5 or 6-ring PAHs. While for nonionic surfactants TX100 and TX305, the removal efficiencies of PAHs increased with increasing surfactant concentration. Nonionic surfactants at low concentration cannot facilitate PAH desorption, but enhance the retardation of PAHs in soil. While anionic surfactant SDS enhanced PAH desorption at all the concentrations.

Microtubule nucleation sequence studied by time-resolved x-ray scattering and electron microscopy

1983 ◽  
Vol 41 ◽  
pp. 766-767
Author(s):  
Eva-Maria Mandelkow ◽  
Eckhard Mandelkow ◽  
Joan Bordas
Keyword(s):  
Electron Microscopy ◽  
Dynamic Equilibrium ◽  
Time Resolved ◽  
X Ray ◽  
Additional Information ◽  
X Ray Scattering ◽  
Low Concentrations ◽  
Microtubule Growth ◽  
Ray Patterns ◽  
Ray Scattering

When a solution of microtubule protein is changed from non-polymerising to polymerising conditions (e.g. by temperature jump or mixing with GTP) there is a series of structural transitions preceding microtubule growth. These have been detected by time-resolved X-ray scattering using synchrotron radiation, and they may be classified into pre-nucleation and nucleation events. X-ray patterns are good indicators for the average behavior of the particles in solution, but they are difficult to interpret unless additional information on their structure is available. We therefore studied the assembly process by electron microscopy under conditions approaching those of the X-ray experiment. There are two difficulties in the EM approach: One is that the particles important for assembly are usually small and not very regular and therefore tend to be overlooked. Secondly EM specimens require low concentrations which favor disassembly of the particles one wants to observe since there is a dynamic equilibrium between polymers and subunits.

Atom-probe analysis of the solid-liquid interface

1995 ◽  
Vol 53 ◽  
pp. 676-677
Author(s):  
J.A. Panitz
Keyword(s):  
Molecular Level ◽  
Selective Adsorption ◽  
Electronic Devices ◽  
Atom Probe ◽  
Chemical Agent ◽  
Hostile Environment ◽  
Solid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Chemically Selective

The first few atomic layers of a solid can form a barrier between its interior and an often hostile environment. Although adsorption at the vacuum-solid interface has been studied in great detail, little is known about adsorption at the liquid-solid interface. Adsorption at a liquid-solid interface is of intrinsic interest, and is of technological importance because it provides a way to coat a surface with monolayer or multilayer structures. A pinhole free monolayer (with a reasonable dielectric constant) could lead to the development of nanoscale capacitors with unique characteristics and lithographic resists that surpass the resolution of their conventional counterparts. Chemically selective adsorption is of particular interest because it can be used to passivate a surface from external modification or change the wear and the lubrication properties of a surface to reflect new and useful properties. Immunochemical adsorption could be used to fabricate novel molecular electronic devices or to construct small, “smart”, unobtrusive sensors with the potential to detect a wide variety of preselected species at the molecular level. These might include a particular carcinogen in the environment, a specific type of explosive, a chemical agent, a virus, or even a tumor in the human body.

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