Governing factors affecting the impacts of silver nanoparticles on wastewater treatment

Zhang, Chiqian; Hu, Zhiqiang; Li, Ping; Gajaraj, Shashikanth

doi:10.1016/j.scitotenv.2016.07.145

Cited by 63 publications

(18 citation statements)

References 311 publications

(235 reference statements)

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“…Table 1 indicates that Ag + was not the key determinant that caused the different ecotoxicity between two culturing conditions. The anaerobic condition was supposed to eliminate confounding effects associated with oxidative release of silver ions 13 . However, except oxidative dissolution of AgNPs caused silver ion, the chemisorbed silver ions from the surface of AgNPs is another Ag + release mechanism 17 .…”

Section: Discussionmentioning

confidence: 99%

Aerobic condition enhances bacteriostatic effects of silver nanoparticles in aquatic environment: an antimicrobial study on Pseudomonas aeruginosa

Chen

Yang

Yuan

et al. 2017

Sci Rep

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The intensive applications of silver nanoparticles (AgNPs) inevitably cause continuous release of such materials into environments, as a consequence posing potential risks to microbial communities in engineered or natural ecosystems. However, the magnitude of antibacterial capacity of nanoparticles is still inconclusive, owing to influential factors such as the size of nanoparticle, microbial species, or environmental conditions. To reveal whether the presence of air would alter AgNPs ecotoxicity, Pseudomonas aeruginosa PAO1, a facultative denitrifying bacterium and an opportunity pathogen, was used to study antibacterial assays under both anaerobic and aerobic conditions. The results indicate that the respiration status of P. aeruginosa affect the ecotoxicity of AgNPs. P. aeruginosa cultured under aerobic condition were more susceptible to AgNPs than that under anaerobic condition. Aerobic condition greatly enhanced bacteriostatic effects of AgNPs but not their bactericidal effects, as the ratio of viable but nonculturable (VBNC) bacteria remained above 90% when 5 mg L −1 AgNPs applied. Our findings offer further understanding for the degree of toxicity of nanoparticles on microbial ecosystems and underscore the importance of exposure condition (e.g. oxygen) in the mode of action of AgNPs.Silver nanoparticles (AgNPs) have been widely used in consumer products such as textile, cosmetics, and medical products, due to their excellent antibacterial, optical, and electronic properties [1][2][3] . AgNPs are the most popular nanoparticles in markets, which accounts for about 50% of commercial nanoproducts 4 . It is estimated that approximate 500 tons of AgNPs were produced each year worldwide 5,6 . As being incorporated in fabric and personal care products, the processes of fabrication and consumption thereby can release AgNPs from consumer products to sewage, eventually entering environment. Thus, it represents a potential risk to a great variety of organisms in natural or engineered ecosystems, including wastewater treatment plants (WWTPs).AgNPs have shown great antibacterial activities against various microbes. Choi et al. 7 reported that the respiration of autotrophic nitrifiers in a continuously stirred tank reactor was inhibited by 86% at 1 mg L −1 of AgNPs. Tan et al. 8 documented that AgNPs at 300 µg L −1 decreased nitrifying efficiency from 98% to 15%. In addition, Li et al. 9 showed that a commercial AgNPs at 10 mg L −1 was the miminum inhibitory concentration (MIC) to Escherichia coli, whereas a synthesized AgNPs exhibited 100% killing of E. coli when added at 4.5 mg L −110 . According to these previous studies 7-11 , the concentration of AgNPs that will cause toxic impacts on microbes, ranged from µg L −1 to mg L −1 . Such an inconclusive antibacterial capacity of nanoparticles may be associated with different exposure conditions or microorganism types, which may alter the antibacterial activity of nanoparticles. Some studies [12][13][14][15] suggested that the susceptibility of microbes, microbial adapt...

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Section: Discussionmentioning

confidence: 99%

Aerobic condition enhances bacteriostatic effects of silver nanoparticles in aquatic environment: an antimicrobial study on Pseudomonas aeruginosa

Chen

Yang

Yuan

et al. 2017

Sci Rep

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“…Because of their well-known antibacterial and antifungal properties, they can be used in household products, food packaging, textiles, medical devices, antiseptics in healthcare delivery, and personal healthcare [2,3,4,5,6]. AgNPs can also be used in electronic devices and wastewater treatment because of their good electrical conductivity and photochemical properties [6,7].…”

Section: Introductionmentioning

confidence: 99%

Impacts of Silver Nanoparticles on Plants: A Focus on the Phytotoxicity and Underlying Mechanism

Chen

2019

IJMS

372

177

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Nanotechnology was well developed during past decades and implemented in a broad range of industrial applications, which led to an inevitable release of nanomaterials into the environment and ecosystem. Silver nanoparticles (AgNPs) are one of the most commonly used nanomaterials in various fields, especially in the agricultural sector. Plants are the basic component of the ecosystem and the most important source of food for mankind; therefore, understanding the impacts of AgNPs on plant growth and development is crucial for the evaluation of potential environmental risks on food safety and human health imposed by AgNPs. The present review summarizes uptake, translocation, and accumulation of AgNPs in plants, and exemplifies the phytotoxicity of AgNPs on plants at morphological, physiological, cellular, and molecular levels. It also focuses on the current understanding of phytotoxicity mechanisms via which AgNPs exert their toxicity on plants. In addition, the tolerance mechanisms underlying survival strategy that plants adopt to cope with adverse effects of AgNPs are discussed.

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“…The composition and morphology of ENMs in surface waters is critical to understanding ENM transformations, fate, and toxicity. Currently, there is limited information on the concentration and morphology of ENMs in natural water, and many existing studies rely on artificially high ENM concentrations and lab-synthesized NMs (Scown et al, 2010;Mitrano et al, 2014;Zhang et al, 2016). Thus it is important to clarify the abundance and existence of NMs in natural waters.…”

Section: Introductionmentioning

confidence: 99%

Prospecting nanomaterials in aqueous environments by cloud-point extraction coupled with transmission electron microscopy

Yang

Reed

Schoepf

et al. 2017

Science of The Total Environment

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Increasing application of engineered nanomaterials (ENMs) in industry and consumer products inevitably lead to their release into and impact on aquatic environments. To characterize the NMs efficiently in surface water, a fast and simple method is needed to separate and concentrate nanomaterials from the aqueous matrix without altering their shape and size. Applying cloud-point extraction (CPE) using the surfactant Triton 114 to an array of NMs (titanium dioxide, gold, silver, and silicon dioxide) with different sizes or capping agents in nanopure water resulted in extraction efficiency of 83%-107%. Additional CPE experiments were conducted to extract NMs from surface, potable, and sewage waters, and NMs enriched in the surfactant phase were characterized using transmission electron microscopy coupled with energy dispersive x-ray spectroscopy. The most abundant nanoparticles identified in surface water were silica, titanium dioxide, and iron oxide with 4-99nm diameter. The extraction efficiencies of CPE for silicon, titanium, and iron elements from environmental water samples were 51%, 15%, and 99%, respectively. This study applied CPE with TEM to enrich and analyze popular nanoparticles such as SiO and TiO from natural waters, which has not been well addressed by previous researches. Overall, CPE coupled with transmission electron microscopy (TEM) can be an effective method to characterize NMs in aqueous water samples, and further optimization will increase the extraction efficiency of NMs in complicated surface water matrix.

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Governing factors affecting the impacts of silver nanoparticles on wastewater treatment

Cited by 63 publications

References 311 publications

Aerobic condition enhances bacteriostatic effects of silver nanoparticles in aquatic environment: an antimicrobial study on Pseudomonas aeruginosa

Aerobic condition enhances bacteriostatic effects of silver nanoparticles in aquatic environment: an antimicrobial study on Pseudomonas aeruginosa

Impacts of Silver Nanoparticles on Plants: A Focus on the Phytotoxicity and Underlying Mechanism

Prospecting nanomaterials in aqueous environments by cloud-point extraction coupled with transmission electron microscopy

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