Fate and Effects of Silver Nanoparticle Additions in a Lake Ecosystem

Fate and Effects of Silver Nanoparticle Additions in a Lake Ecosystem PDF Author: Daniel Clyde Rearick
Publisher:
ISBN:
Category :
Languages : en
Pages : 308

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Book Description
The potential release of nanoparticles into aquatic environments is raising global concerns. As antimicrobials, silver nanoparticles (AgNPs) are among the most prominent form in use. Despite this, their fate, long-term toxicity, and ecological relevance have yet to be investigated largely under natural settings with seasonality and environmental complexity. To better understand the environmental significance, we released AgNPs into Lake 222 at the Experimental Lakes Area over two years. AgNPs remained suspended in the water column and were detected throughout the lake and in the lower food web. Total Ag concentrations ranged from below 0.07 to 18.9 ?g L-1 in lake water, and were highly dynamic seasonally both in the epilimnion and hypolimnion depending on the physical, chemical and biological conditions of the lake. Approximately 60% of the measured Ag mass in October was present in the sediment in 2014 and 50% in 2015 demonstrating relatively high sedimentation and removal from the water column. During winter months, Ag was largely absent in the water column under the ice. After ice melt and before summer stratification, Ag concentrations increased in the lake suggesting AgNPs may not be tightly bound to the sediment and are able re-enter the water column during spring mixing events. Despite temporal variation, total Ag was highly synchronous across spatial locations for both years, indicating rapid dispersal upon lake entry. When investigating AgNP sizes using spICPMS, size distributions were similar across spatial locations, with the 40-60 nm size class constituting approximately 60% of all particles iii identified. Large aggregates (>100 nm) and dissolved Ag were infrequently detected within the lake. Ag accumulated in the lower food web ranging from 0.27-16.82 ?g Ag mg C-1 in the bacterioplankton and 0.17-6.45 ?g Ag mg C-1 in algae (particulate fraction). Partial least squares models revealed the highest predictors of Ag accumulation were dissolved nutrients including DOC, TDN, TDP in bacterioplankton. Major predictors for particulate Ag included temperature, dissolved oxygen, and sampling date. The diversity of predictors among biological compartments emphasizes the importance of understanding the role of environmental complexity within the lower food web. Despite Ag accumulation we did not detect strong negative effects on the lake food web. An increase in particulate and bacterioplankton chlorophyll-a occurred after addition in contrast to reference lakes, which may indicate a hormetic response to low dose AgNP concentrations. Our findings provide the first whole-lake perspective regarding Ag fate and toxicity, suggesting small scale experiments may overestimate environmental responses. Keywords: Silver nanoparticles, ecotoxicity, whole-lake experiment, lower food web fate.

Fate and Effects of Silver Nanoparticle Additions in a Lake Ecosystem

Fate and Effects of Silver Nanoparticle Additions in a Lake Ecosystem PDF Author: Daniel Clyde Rearick
Publisher:
ISBN:
Category :
Languages : en
Pages : 308

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Book Description
The potential release of nanoparticles into aquatic environments is raising global concerns. As antimicrobials, silver nanoparticles (AgNPs) are among the most prominent form in use. Despite this, their fate, long-term toxicity, and ecological relevance have yet to be investigated largely under natural settings with seasonality and environmental complexity. To better understand the environmental significance, we released AgNPs into Lake 222 at the Experimental Lakes Area over two years. AgNPs remained suspended in the water column and were detected throughout the lake and in the lower food web. Total Ag concentrations ranged from below 0.07 to 18.9 ?g L-1 in lake water, and were highly dynamic seasonally both in the epilimnion and hypolimnion depending on the physical, chemical and biological conditions of the lake. Approximately 60% of the measured Ag mass in October was present in the sediment in 2014 and 50% in 2015 demonstrating relatively high sedimentation and removal from the water column. During winter months, Ag was largely absent in the water column under the ice. After ice melt and before summer stratification, Ag concentrations increased in the lake suggesting AgNPs may not be tightly bound to the sediment and are able re-enter the water column during spring mixing events. Despite temporal variation, total Ag was highly synchronous across spatial locations for both years, indicating rapid dispersal upon lake entry. When investigating AgNP sizes using spICPMS, size distributions were similar across spatial locations, with the 40-60 nm size class constituting approximately 60% of all particles iii identified. Large aggregates (>100 nm) and dissolved Ag were infrequently detected within the lake. Ag accumulated in the lower food web ranging from 0.27-16.82 ?g Ag mg C-1 in the bacterioplankton and 0.17-6.45 ?g Ag mg C-1 in algae (particulate fraction). Partial least squares models revealed the highest predictors of Ag accumulation were dissolved nutrients including DOC, TDN, TDP in bacterioplankton. Major predictors for particulate Ag included temperature, dissolved oxygen, and sampling date. The diversity of predictors among biological compartments emphasizes the importance of understanding the role of environmental complexity within the lower food web. Despite Ag accumulation we did not detect strong negative effects on the lake food web. An increase in particulate and bacterioplankton chlorophyll-a occurred after addition in contrast to reference lakes, which may indicate a hormetic response to low dose AgNP concentrations. Our findings provide the first whole-lake perspective regarding Ag fate and toxicity, suggesting small scale experiments may overestimate environmental responses. Keywords: Silver nanoparticles, ecotoxicity, whole-lake experiment, lower food web fate.

Abiotic and Biotic Influences on Silver Nanoparticle Fate and Effects in Aquatic Model Ecosystems

Abiotic and Biotic Influences on Silver Nanoparticle Fate and Effects in Aquatic Model Ecosystems PDF Author: Yvonne Sakka
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description


The Effects of Particulate Matter on the Fate and Toxicity of Silver Nanoparticles

The Effects of Particulate Matter on the Fate and Toxicity of Silver Nanoparticles PDF Author: Andrea Conine
Publisher:
ISBN:
Category :
Languages : en
Pages : 288

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Book Description
As anemerging contaminant,the antimicrobial agent silver nanoparticles (AgNPs) havebeen receiving considerable attention to determine theirpotential effects to aquatic ecosystems. However, estimates of aquatic consumer survivorship and other toxicological endpoints vary considerably amongexperiments, largely due to the environment in which the test takes place. Throughout this thesis I aim to understand whichnatural environmental variables impact toxicity to the common aquatic consumer Daphnia. I focus on the effectsof particulate matter as it mayplay a role in animal nutrition as well as interact with AgNPs. I exploreparticulate matter?seffect on survival in the complex matrices including other natural variables that could impact toxicity. I conduct a series of complimentary field and laboratorystudies to understand how particles impact AgNP toxicity and how those interactions vary within whole lake ecosystems. Using laboratory studies, I establish that algal particles mitigatethe toxic effects of AgNPs on Daphniasurvival through removing Ag from the water column and that phosphorusincreases this effect. Using wild Daphniaand lake water, I demonstratethe ability of particulate matterto mitigate toxicity in complex natural settings. It was also one of the major predictors of AgNP toxicity to Daphniaalong with dissolved organic carbon and daphnid seasonal health. Finally,usinga whole lake AgNP addition experiment, Idemonstrate that particles and AgNPs interact variably inthe lake. Silver from AgNPs binds to particles and is removed to the sediments through the actions of settling particleswithout impacting the dynamics of living communities. Overall,I amable to demonstrate that the natural components of lake ecosystems, especially particulate matter, are able to mitigate the effects of AgNPs in lake ecosystems to a point where they likely will be never pose a threat to the survivorship of aquatic consumers such as Daphnia. Keywords: Silver nanoparticles, Daphnia, ecotoxicity, whole lake experiment, phytoplankton communities, particulate matter, sedimentation.

The Effects of Silver Nanoparticles on Lower Trophic Levels in Aquatic Ecosystems

The Effects of Silver Nanoparticles on Lower Trophic Levels in Aquatic Ecosystems PDF Author: Katarina Ana Cetinic
Publisher:
ISBN:
Category :
Languages : en
Pages : 384

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Book Description
Due to their effective antibacterial and antifungal properties, silver nanoparticles (AgNPs) have quickly become the most commonly used nanomaterial, with applications in industry, medicine and consumer products. This increased use of AgNPs over the past decade will inevitably result in an elevated release of nanoparticles into the environment, highlighting the importance of assessing the environmental impacts of these nanomaterials on aquatic ecosystems. Although numerous laboratory studies have already reported on the negative effects of AgNPs to freshwater organisms, only a handful of studies have investigated the impacts of environmentally relevant levels of AgNPs on whole communities under natural conditions. This thesis examines the effects of chronic AgNP exposure on natural freshwater littoral microcrustacean, benthic macroinvertebrate and pelagic zooplankton communities. To assess the responses of these communities to AgNPs, I focused on a solely field-based approach, combining a six-week mesocosm study with a three-year whole lake experiment at the IISD ?Experimental Lakes Area (Ontario, Canada). Our mesocosm study tested the effects of AgNP concentration (low, medium and high dose), surface coating (citrate-and polyvinylpyrrolidone [PVP]-coated AgNPs), and type of exposure (chronic and pulsed addition) on benthic macroinvertebrates in fine and stony sediments. Relative abundances of metal-tolerant Chironomidae in fine sediments were highest in high dose PVP-AgNP treatments;however, no negative effects of AgNP exposure were seen on biodiversity metrics or overall community structure throughout the study. I observed similar results within the whole lake study that incorporated a long-term addition of low levels of AgNPs to an experimental lake. Mixed-effects models and multivariate methods revealeda decline in all species of the littoral microcrustacean family Chydoridae in the final year of the study within our experimental lake, suggesting that this taxon may be sensitive to AgNP exposure;however, these effectswere fairly subtle and were not reflected in the overall composition of littoral communities. No other negative effects of AgNPs were observed on the pelagic zooplankton or benthic macroinvertebrate communities. My results demonstrate that environmentally relevant levels of AgNPs have little impact on natural freshwater microcrustacean and benthic macroinvertebrate communities. Instead, biodiversity metrics and community structure are primarily influenced by seasonal dynamics and nutrient concentrations across both lakes. This thesis highlights the importance of incorporating environmental conditions and the natural variability of communities when examining the potential risks posed by the release of AgNPs into the environment, as simplistic laboratory bioassays may not provide an adequate assessment of the long-term impacts of AgNPs on freshwater systems. Keywords: Silver nanoparticles, zooplankton, benthic macroinvertebrates, littoral microcrustaceans, whole lake experiment, IISD ?Experimental Lakes Area.

Silver Nanoparticles in the Environment

Silver Nanoparticles in the Environment PDF Author: Jingfu Liu
Publisher: Springer
ISBN: 366246070X
Category : Science
Languages : en
Pages : 161

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Book Description
This comprehensive book covers the environmental issues concerning silver nanoparticles (AgNPs). Following an introduction to the history, properties and applications, the environmental concerns of AgNPs is discussed. In the second chapter, the separation, characterization and quantification of AgNPs in environment samples are described in detail. In the remaining parts of the book, the authors focus on the environmental processes and effects of AgNPs, with chapters on the pathway into environment, fate and transport, toxicological effects and mechanisms, as well as the environmental bioeffects and safety-assessment of AgNPs in the environment. This book is designed to describe current understanding of the environmental aspects of AgNPs. It provides a valuable resource to students and researchers in environmental science and technology, nanotechnology, toxicology, materials science and ecology; as well as to professionals involved in the production and consumption of AgNPs in various areas including catalysis, food products, textiles/fabrics, and medical products and devices. Jingfu Liu and Guibin Jiang are professors at State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences.

Green Synthesis of Silver Nanomaterials

Green Synthesis of Silver Nanomaterials PDF Author: Kamel A. Abd-Elsalam
Publisher: Elsevier
ISBN: 0128245093
Category : Technology & Engineering
Languages : en
Pages : 798

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Book Description
Green Synthesis of Silver Nanomaterials illustrates how to biologically scale up silver nanoparticle synthesis. This book covers green synthesis of silver nanomaterials, via plants, agricultural waste, fungi, and microorganisms. Sections cover the synthesis and characterization of chemical and green synthesis, various types of silver nanomaterialism, the ability of different fungal species, such as filamentous fungi, to produce silver nanoparticles, the microbial synthesis of silver NMs, biosynthesis mechanisms, toxicity, fate and commercialization. As examples, greener pathways and mechanisms, toxicity of silver nanoparticles in aquatic life and in natural eco-systems, and strategies for the scaling up of green-synthesized nanomaterials are discussed. With the extended work in enhancing nanomaterials synthesis performance, and discovering their biomedical, environmental, and agricultural applications, it is hoped that the execution of these methods on a large scale and their industrial applications in different fields will take place in the near future. Assesses the impact of a large variety of silver-based nanostructures in the biomedical, environmental and agri-food sectors Discusses the major synthesis methods used for effectively processing plant-based silver nanoparticles Outlines the potential and major challenges for adopting green synthesis methods on a mass scale

Nanoparticles in the Water Cycle

Nanoparticles in the Water Cycle PDF Author: Fritz H. Frimmel
Publisher: Springer Science & Business Media
ISBN: 3642103189
Category : Science
Languages : en
Pages : 243

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Book Description
As nanotechnology enters everyday life, engineered nanoparticles (ENP) will find their way into nature, including surface and groundwater. Here, distinguished experts of water chemistry present dedicated methods for the analysis of nanoparticles in the aquatic environment, their distribution and fate. This includes the influence of complex matrices such as wastewater, brown water with natural organic matter (NOM), and high salt concentrations as well as available and future standardized methods. The background of geogenic, natural nanoparticles is considered in a discussion of known environmental effects, including strategies to test for potential effects on human and environmental health.

A Practitioner's Guide to Freshwater Biodiversity Conservation

A Practitioner's Guide to Freshwater Biodiversity Conservation PDF Author: Nicole Silk
Publisher: Island Press
ISBN: 1597266191
Category : Nature
Languages : en
Pages : 404

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Book Description
A Practitioner's Guide to Freshwater Biodiversity Conservation brings together knowledge and experience from conservation practitioners and experts around the world to help readers understand the global challenge of conserving biodiversity in freshwater ecosystems. More importantly, it offers specific strategies and suggestions for managers to use in establishing new conservation initiatives or improving the effectiveness of existing initiatives. The book: offers an understanding of fundamental issues by explaining how ecosystems are structured and how they support biodiversity; provides specific information and approaches for identifying areas most in need of protection; examines promising strategies that can help reduce biodiversity loss; and describes design considerations and methods for measuring success within an adaptive management framework. The book draws on experience and knowledge gained during a five-year project of The Nature Conservancy known as the Freshwater Initiative, which brought together a range of practitioners to create a learning laboratory for testing ideas, approaches, tools, strategies, and methods. For professionals involved with land or water management-including state and federal agency staff, scientists and researchers working with conservation organizations, students and faculty involved with freshwater issues or biodiversity conservation, and policymakers concerned with environmental issues-the book represents an important new source of information, ideas, and approaches.

Marine Anthropogenic Litter

Marine Anthropogenic Litter PDF Author: Melanie Bergmann
Publisher: Springer
ISBN: 3319165100
Category : Science
Languages : en
Pages : 456

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Book Description
This book describes how man-made litter, primarily plastic, has spread into the remotest parts of the oceans and covers all aspects of this pollution problem from the impacts on wildlife and human health to socio-economic and political issues. Marine litter is a prime threat to marine wildlife, habitats and food webs worldwide. The book illustrates how advanced technologies from deep-sea research, microbiology and mathematic modelling as well as classic beach litter counts by volunteers contributed to the broad awareness of marine litter as a problem of global significance. The authors summarise more than five decades of marine litter research, which receives growing attention after the recent discovery of great oceanic garbage patches and the ubiquity of microscopic plastic particles in marine organisms and habitats. In 16 chapters, authors from all over the world have created a universal view on the diverse field of marine litter pollution, the biological impacts, dedicated research activities, and the various national and international legislative efforts to combat this environmental problem. They recommend future research directions necessary for a comprehensive understanding of this environmental issue and the development of efficient management strategies. This book addresses scientists, and it provides a solid knowledge base for policy makers, NGOs, and the broader public.

Transport, Fate and Effects of Silver in the Environment

Transport, Fate and Effects of Silver in the Environment PDF Author:
Publisher:
ISBN:
Category : Silver
Languages : en
Pages : 328

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Book Description