Site Energy Distribution Analysis of Preloaded Adsorbents

Carter, Margaret C.; Kilduff, James E.; Weber, Walter J.

doi:10.1021/es00007a013

Cited by 236 publications

(147 citation statements)

References 9 publications

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“…Because of the dual sorption mechanisms, the sorptive behaviour of glassy polymers is normally described by the nonlinear Freundlich model (q ¼ K f C n e ), where q is the amount of the compound sorbed per unit mass of solid, C e the aqueous-phase concentration at equilibrium, K f the Freundlich constant related to the capacity of the sorbent material to sorb the sorbate and n the Freundlich exponent and an indicator of the site energy distribution of a sorbent (i.e. sorbent heterogeneity increases as n decreases from 1; Carter et al 1995). Absorptive partitioning into an organic matrix is characterized by a linear sorption model (q ¼ K p C e ), where K p is the partition coefficient.…”

Section: Sorption and Desorption Of Anthropogenic Contaminants From Pmentioning

confidence: 99%

Transport and release of chemicals from plastics to the environment and to wildlife

Teuten

Saquing²,

Knappe³

et al. 2009

Phil. Trans. R. Soc. B

2,215

1,200

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Plastics debris in the marine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, petroleum hydrocarbons, organochlorine pesticides (2,2 0 -bis(p-chlorophenyl)-1,1,1-trichloroethane, hexachlorinated hexanes), polybrominated diphenylethers, alkylphenols and bisphenol A, at concentrations from sub ng g -1 to mg g -1. Some of these compounds are added during plastics manufacture, while others adsorb from the surrounding seawater. Concentrations of hydrophobic contaminants adsorbed on plastics showed distinct spatial variations reflecting global pollution patterns. Model calculations and experimental observations consistently show that polyethylene accumulates more organic contaminants than other plastics such as polypropylene and polyvinyl chloride. Both a mathematical model using equilibrium partitioning and experimental data have demonstrated the transfer of * Author for correspondence (shige@cc.tuat.ac.jp).Electronic supplementary material is available at http://dx.doi.org/rstb20080284 or via http://rstb.royalsocietypublishing.org.One contribution of 15 to a Theme Issue 'Plastics, the environment and human health'.

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Section: Sorption and Desorption Of Anthropogenic Contaminants From Pmentioning

confidence: 99%

Transport and release of chemicals from plastics to the environment and to wildlife

Teuten

Saquing²,

Knappe³

et al. 2009

Phil. Trans. R. Soc. B

2,215

1,200

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“…On a theoretical basis, isotherm parameters can thus be related to particular site energy distributions, and their empirically determined values can be interpreted with respect to the energy characteristic of a sorbent. 29 The basic integral equation underlying the theory of heterogeneous surfaces is; Q e C e qhEY C e FEdE where Q e de®nes the total sorption of a solute by a heterogeneous surface as the integral of an energetically homogenous isotherm (qh), multiplied by a site energy frequency distribution [F(E)] over a range of energies, C e the equilibrium concentration of the solute, and E is the difference between the solute and solvent adsorption energies for a given site. 29 While the limits on the integral are most appropriately based on the minimum and maximum adsorption energies RT where E* is the net energy, C e the equilibrium concentration of the solute, C s the maximum solubility of the solute, E the difference between the solute and solvent adsorption energies for a given site, E s that value of the sorption energy corresponding to C e = C s , R the universal gas constant, and T is the absolute temperature.…”

Section: Site Energy Distributionmentioning

confidence: 99%

“…The parameter E s is analogous to E o in that it determines the position of the distribution on the energy axis. 29 The approximate site energy distribution, F(E*), is obtained by differentiating q e (E*), with respect to E*.…”

Section: Site Energy Distributionmentioning

confidence: 99%

Sorption of isoxaflutole by five different soils varying in physical and chemical properties

1999

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“…When the initial concentration of nitrate was 300 mg/L, the adsorption capacity of MSS was 6.165 mg/g, which reached a higher level compared with other adsorbent materials such as halloysite, Comparing the correlation coefficients of the two models, the Freundlich model (R 2 > 0.98) was more suitable for the experimental data of this paper (Table 6, Figure 9). It is generally believed that adsorption is more likely to occur when 1/n is between 0.1 and 1.0, whereas adsorption is more difficult when 1/n is greater than two [47,48]. In this experiment, MSS was favourable for the adsorption of nitrate (1/n = 0.7894).…”

Section: Isothermal Adsorption Modelmentioning

confidence: 73%

Characteristics of Nitrate Removal from Aqueous Solution by Modified Steel Slag

Yang

et al. 2017

Water

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Steel slag, which makes up a gigantic amount of metallurgical industrial solid waste, was in this experiment successfully synthesized an inexpensive adsorbent used to remove nitrate pollution from aqueous solution. This adsorbent was obtained by mixing steel slag, aluminium hydroxide and deionized water, and aging this at a mass ratio of 3:0.45:2, and then activating it at 800 • C. The physicochemical characteristics of the steel slag before and after modification were investigated to compare the effect of their surface properties on the adsorption behaviour of nitrate. The effects of adsorbent dosage, pH, and contact time on the adsorption process were investigated. The results showed that an increase in specific surface area and the formation of a positive surface of the modified steel slag (MSS) compared with the original steel slag (OSS) could effectively increase the number of the active adsorption sites and nitrate removal ability. The optimum parameters for nitrate removal were as follows: the concentration of nitrate was 20 mg/L, the dosage was 1 g/100 mL, the pH was four, and the reaction time was 180 min. The adsorption capacity of the MSS was approximately 1.9 times that of the OSS. The nitrate adsorption of the MSS was in accordance with the pseudo-second-order model and the Freundlich model, which indicated that the adsorption of nitrate on the MSS was mainly single layer chemical adsorption. The mechanism of nitrate removal mainly included ion exchange, hydrogen bonding, electrostatic interactions and intermolecular interactions. In addition, regeneration experiments indicated that the MSS after regeneration still had the capacity to remove nitrate.

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Site Energy Distribution Analysis of Preloaded Adsorbents

Cited by 236 publications

References 9 publications

Transport and release of chemicals from plastics to the environment and to wildlife

Transport and release of chemicals from plastics to the environment and to wildlife

Sorption of isoxaflutole by five different soils varying in physical and chemical properties

Characteristics of Nitrate Removal from Aqueous Solution by Modified Steel Slag

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