Sorption of perfluorooctane sulfonate on organo-montmorillonites

Zhou, Qin; Deng, Shubo; Yu, Qiang; Zhang, Qiaoying; Yu, Gang; Huang, Jun; He, Hongping

doi:10.1016/j.chemosphere.2009.12.005

Cited by 132 publications

(62 citation statements)

References 30 publications

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“…7, a broad peak at a d-spacing of 1.19 nm for the wet paste of montmorillonite without PFOS adsorption indicated the existence of interlayer hydration with monolayer of water molecules [44,45]. Upon PFOS adsorption, a slight increase in d(0 0 1) spacing from 1.19 to 1.24 nm was observed, which is consistent with a previous report on expansion from 1.34 to 1.46 nm [46]. The magnitude of the d-spacing increase (0.05 nm) was significant less than the molecular sectional size of PFOS (OD: ≈0.40 nm [9]), which indicated that PFOS may partially insert into interlayers of montmorillonite during the adsorption.…”

Section: Xrd Analysissupporting

confidence: 82%

Mechanistic study of PFOS adsorption on kaolinite and montmorillonite

Zhang

Yan

Jing

2014

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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h i g h l i g h t s• The mechanisms of PFOS adsorption on clay minerals are examined at molecular level.• XANEFS analysis provides direct evidence for chemical adsorption.• FTIR spectra in situ monitors the interaction process of PFOS with clay minerals.• PFOS could insert into the interlayers of montmorillonite.• The HA coating decreased PFOS adsorption on kaolinite and montmorillonite. Adsorption of perfluorooctane sulfonate (PFOS) on clay minerals is pivotal in the fate and transport of PFOS in the environment. Understanding the PFOS adsorption mechanisms, however, presents challenges, especially in the presence of natural organic substances. In this study, the adsorption mechanism of PFOS on kaolinite and montmorillonite, with and without humic acids (HA), were investigated using batch experiments, ATR-FTIR spectroscopy, zeta potential, NEXAFS, and XRD. The results showed that PFOS had a higher adsorption capacity on kaolinite than on montmorillonite, both with a rapid formation of an outer-sphere complex followed by a slow ligand exchange reaction with the elimination of adsorbed H 2 O molecules. In addition to nonspecific hydrophobic and electrostatic interactions, specific chemisorption also exists between sulfonate group of PFOS and hydroxyl group on surfaces of clay minerals. The HA coating on clay materials inhibited PFOS adsorption due to its occupation of adsorption sites and increased electrostatic repulsion. The insights gained from this study improve our understanding on the mechanism of multilateral forces on PFOS adsorption at the molecular level.

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Section: Xrd Analysissupporting

confidence: 82%

Mechanistic study of PFOS adsorption on kaolinite and montmorillonite

Zhang

Yan

Jing

2014

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…Since the pH at point of zero charge (pHpzc) of CDSS is about 4.4, the CDSS has a positive edge below pH 4.4, and a negative edge and basal surfaces above pH 4.4. Contrasted with the previous research, [34] the zeta potentials of the CMCDSS were all positive in the pH range studied. The zeta potentials of the CMCDSS increased gradually at a pH ranging from 6.0 to 9.0.…”

Section: Characterization Of Cdss and Cmcdsscontrasting

confidence: 52%

“…[34] In our previous study, co-combustion ash was derived to synthesize zeolite-based adsorbent for heavy metal removal, [35] and moreover, a special functional material, namely ceramsite-zeolite composite, was successfully prepared using construction and demolition (C&D) waste as raw material, [36] elucidating that C&D waste possesses the potential to be converted into zeolitelike materials.…”

Section: Introductionmentioning

confidence: 99%

Characterization of a cetyltrimethyl ammonium bromide-modified sorbent for removal of perfluorooctane sulphonate from water

Zhang

2014

Environmental Technology

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This study was carried out to develop a cost-effective and practicable sorbent for application in abrupt perfluorooctane sulphonate (PFOS) pollution accidents. The main merit of this work was that a waste material, namely construction and demolition (C&D) waste, was employed as a raw base material for the sorbent synthesis. The waste material underwent alkaline fusion-hydrothermal synthesis and a cationic surfactant cetyltrimethyl ammonium bromide (CTAB) modification process to form a CTAB-modified sorbent (CMCDSS). Experimental results showed that PFOS concentrations and solution pH had significant effect on the PFOS sorption on construction and demolition waste synthesized sorbent (CDSS) and CMCDSS (using 0.2CMCDSS as representative). PFOS could be effectively and rapidly adsorbed on CMCDSS, and sorption equilibrium was achieved within 2.5 h. The sorption amounts of PFOS on CMCDSSs enhanced along with the increase in CTAB loading amounts. Moreover, the CMCDSS can be applied effectively under acidic condition at pH 2-6 and various removal mechanisms were clarified at different sorption conditions. Accordingly, this work developed a novel and applicable material for dealing with abrupt environmental PFOS contamination accidents.

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“…In this study, the pseudosecond-order adsorption kinetic model was adopted to evaluate and calculate the solute uptake rate and the corresponding thermal dynamical parameters. The pseudo-second-order adsorption kinetic equation can be written as follows [20]:…”

Section: Resultsmentioning

confidence: 99%