Flocculation performance and mechanism of graphene oxide for removal of various contaminants from water

Yang, Zhen; Yan, Han; Yang, Hu; Li, Haibo; Li, Aimin; Cheng, Rongshi

doi:10.1016/j.watres.2013.03.027

Cited by 155 publications

(91 citation statements)

References 38 publications

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“…In this particular study, chemical bonding was found to be more effective than electrostatic interactions at forming heteroaggregates between the two NPs, although equilibrium was reached much slower than observed in electrostatic interactions which are more instantaneous [99,155]. Both hydrogen bonding and Lewis acid-base interactions were proposed by Yang et al [128] to overcome charge repulsion between graphene oxide and clay materials, leading to heteroaggregation.…”

Section: Chemical Bondingmentioning

confidence: 65%

“…Lewis acid-base interactions are a type of chemical bonding that lead to heteroaggregation of NPs (and colloids in general) in aqueous and non-aqueous systems [47]. A heteroaggregation system can also arise from interplay of multiple mechanisms -both physical and chemical interactions [99,128,129]. The common mechanisms of heteroaggregation are shown in Fig.…”

Section: Mechanisms Of Heteroaggregationmentioning

confidence: 99%

“…Heteroaggregation may result from either weak electrostatic repulsion, attractive electrical fields from oppositely charged surfaces, and van der Waals forces, which tend to result in nonspecific spontaneous agglomeration [93,99,103,129,[134][135][136]. Heteroaggregation resulting from electrostatic interactions has been shown in NP-NP [99,127,136], NP-clay [128], NP-natural colloid [93,128,137,138], and NP-microorganism [107,108,116,117] interactions. Hetero(aggregation) due to suppression of electrostatic forces is typically influenced by a change in solution chemistry, and can in general be predicted by Derjaguin-Landau-VerweyOverbeek (DLVO) (or extended DLVO) theory [93,135,139].…”

Section: Electrical Forcementioning

confidence: 99%

“…Hydrogen bonding typically occurs between nanoparticles or colloids with abundant oxygen-containing groups such as functionalized NPs, metallic oxides NPs, clays, and NOM etc. [99,128,129,148]. Sun et al [129] reported that SiO 2 NPs attached to CNT surfaces via both van der Waals forces and hydrogen bonds.…”

Section: Hydrogen Bondingmentioning

confidence: 99%

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Heteroaggregation of nanoparticles with biocolloids and geocolloids

Wang

Adeleye

Huang

et al. 2015

Advances in Colloid and Interface Science

164

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The application of nanoparticles has raised concern over the safety of these materials to human health and the ecosystem. After release into an aquatic environment, nanoparticles are likely to experience heteroaggregation with biocolloids, geocolloids, natural organic matter (NOM) and other types of nanoparticles. Heteroaggregation is of vital importance for determining the fate and transport of nanoparticles in aqueous phase and sediments. In this article, we review the typical cases of heteroaggregation between nanoparticles and biocolloids and/or geocolloids, mechanisms, modeling, and important indicators used to determine heteroaggregation in aqueous phase. The major mechanisms of heteroaggregation include electric force, bridging, hydrogen bonding, and chemical bonding. The modeling of heteroaggregation typically considers DLVO, X-DLVO, and fractal dimension. The major indicators for studying heteroaggregation of nanoparticles include surface charge measurements, size measurements, observation of morphology of particles and aggregates, and heteroaggregation rate determination. In the end, we summarize the research challenges and perspective for the heteroaggregation of nanoparticles, such as the determination of α hetero values and heteroaggregation rates; more accurate analytical methods instead of DLS for heteroaggregation measurements; sensitive analytical techniques to measure low concentrations of nanoparticles in heteroaggregation systems; appropriate characterization of NOM at the molecular level to understand the structures and fractionation of NOM; effects of different types, concentrations, and fractions of NOM on the heteroaggregation of nanoparticles; the quantitative adsorption and desorption of NOM onto the surface of nanoparticles and heteroaggregates; and a better understanding of the fundamental mechanisms and modeling of heteroaggregation in natural water which is a complex system containing NOM, nanoparticles, biocolloids and geocolloids.

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Section: Chemical Bondingmentioning

confidence: 65%

Section: Mechanisms Of Heteroaggregationmentioning

confidence: 99%

Section: Electrical Forcementioning

confidence: 99%

Section: Hydrogen Bondingmentioning

confidence: 99%

See 2 more Smart Citations

Heteroaggregation of nanoparticles with biocolloids and geocolloids

Wang

Adeleye

Huang

et al. 2015

Advances in Colloid and Interface Science

164

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“…Therefore, soil B results in higher ionic strength and contributes to the process of coagulation by condensing the electric double layer [16]. In addition, the absolute values of zeta potentials were determinized to be lower than 5 mv, which indicates that charge neutralization isn't the main mechanism of the soil coagulation [9,19]. Fig.…”

Section: The Effects Of Initial Turbidity and Settling Time On Coagulmentioning

confidence: 98%

Study on natural soil coagulants for point-of-use drinking water treatment

Wang

Getahun

et al. 2017

IOP Conf. Ser.: Earth Environ. Sci.

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Natural soil coagulants were used for domestic drinking water treatment in Ethiopia because of lacking drinking water supply. In this study, two soils were collected from Ethiopia and jar test was used to investigate the optimum working conditions, performance and safety of them. The turbidity removal efficiencies of soil A and soil B are 74.5% and 91.1% (initial turbidity=400 NTU), respectively. The pH of purified water can meet drinking water standards of Ethiopia (pH=6.5-8.5). Both soils contribute to remove TOC when the initial concentration of it is high. A small amount (0.5 mg. L-1 or 1 mg. L-1) of poly-aluminum chloride can improve the performance of soil coagulants for the removal of turbidity. The application of soil coagulants didn't introduce coliforms, although the total bacteria number of treated water increased to 40 CFU (soil A) and 81 CFU (soil B), still meeting the drinking water quality standards (<=100 CFU).

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