Nanoparticles in wastewater from a science-based industrial park—Coagulation using polyaluminum chloride

“…2c). This indicated that the high removal rate of TiO 2 NPs at intermediate pH (7)(8)(9)(10) is likely attributed to their surface charge. However, TiO 2 NPs removal rate at pH 11 was still near 90% under [NaCl] = 0.03 M or 0.3 M (Fig.…”

Section: Effect Of Ionic Strength On the Removal Of Tio 2 Nps By Feclmentioning

confidence: 96%

“…As a widely used water treatment technology, coagulation can accelerate the aggregation and precipitation of colloids with easier operation and lower cost. Some studies have illustrated the possibility of separating nanomaterials from wastewater by coagulation, but most of the target pollutants have been carbon nanotubes and silicate nanoparticles [10][11][12]. There are few studies on the removal of TiO 2 NPs from aqueous solution by coagulation.…”

Section: Introductionmentioning

confidence: 99%

Effects of pH, ionic strength and humic acid on the removal of TiO2 nanoparticles from aqueous phase by coagulation

Wang

Jing

Keller

et al. 2014

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…The adsorption of AuNPs on EOMI diatoms was studied as a function of time (0-3 h and 1-55 days), pH (3)(4)(5)(6)(7)(8)(9)(10), and AuNPs concentration in solution (1-1000 µg/L). Although this range of concentration exceeded that of real cases found in contaminated environments linked to industrial and hospital waste, the concentration of diatoms used in our experiments was also several orders of magnitude higher than that encountered in freshwater aquatic environments, so that the ligand to metal ratio in the experiments was similar to that in natural settings.…”

Section: Short Term Aunps Adsorptionmentioning

confidence: 99%

“…Together with other nanoparticles in aquatic systems, AuNPs are also investigated for their use as decontamination devices. For example, coagulation or flocculation techniques of nanoparticles by organic molecules have been developed [6][7][8], and the efficiency of gold nanoparticles as low-molecular-weight-chelators in aqueous suspensions has been demonstrated [9]. However, their harmless nature has yet to be proven for living organisms in the natural environment.…”

Section: Introductionmentioning

confidence: 99%

Interaction of Freshwater Diatom with Gold Nanoparticles: Adsorption, Assimilation, and Stabilization by Cell Exometabolites

et al. 2018

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Abstract:The rising concern about the potential toxicity of synthetic gold nanoparticles (AuNPs) in aquatic environments requires a rigorous estimation of physico-chemical parameters of reactions between AuNPs and major freshwater microorganisms. This study addresses the interaction of 10-nm size, positively charged AuNPs with periphytic freshwater diatoms (Eolimna minima). The adsorption experiments on viable cells were performed in 10 mM NaCl and 5 mM NaCl + 5 mM NaHCO 3 solution at a variable pH (3-10), at an AuNPs concentration from 1 µg/L to 10,000 µg/L, and an exposure time from a few minutes to 55 days. Three types of experiments, adsorption as a function of time (kinetics), pH-dependent adsorption edge, and constant-pH "Langmuirian" type isotherms, were conducted. In addition, long-term interactions (days to weeks) of live diatoms (under light and in the darkness) were performed. The adsorption was maximal at a pH from 3 to 6 and sizably decreased at a pH of 6 to 10. Results of adsorption experiments were modeled using a second order kinetic model, a Linear Programming Model, Freundlich isotherm, and a ligand binding equation for one site competition. The adsorption of AuNPs(+) most likely occurred on negatively-charged surface sites of diatom cell walls such as carboxylates or phosphorylates, similar to previously studied metal cations. Under light exposure, the AuNPs were stabilized in aqueous solution in the presence of live cells, probably due to the production of exometabolites by diatoms. The adsorbed amount of AuNPs decreased after several days of reaction, suggesting some AuNPs desorption. In the darkness, the adsorption and assimilation were stronger than under light. Overall, the behavior of positively charged AuNPs at the diatom-aqueous solution interface is similar to that of metal cations, but the affinity of aqueous AuNPs to cell exometabolites is higher, which leads to the stabilization of nanoparticles in solution in the presence of diatoms and their exudates. During photosynthetic activity and the pH rising above 9 in the vicinity of diatom cells, the adsorption of AuNPs strongly decreases, which indicates a decreasing potential toxicity of AuNPs for photosynthesizing cells. The present study demonstrates the efficiency of a thermodynamic and kinetic approach for understanding gold nanoparticles interaction with aquatic freshwater peryphytic microorganisms.

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Nanoparticles in wastewater from a science-based industrial park—Coagulation using polyaluminum chloride

Cited by 49 publications

References 4 publications

Inhibition of total oxygen uptake by silica nanoparticles in activated sludge

Inhibition of total oxygen uptake by silica nanoparticles in activated sludge

Effects of pH, ionic strength and humic acid on the removal of TiO2 nanoparticles from aqueous phase by coagulation

Interaction of Freshwater Diatom with Gold Nanoparticles: Adsorption, Assimilation, and Stabilization by Cell Exometabolites

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