In recent years, the adverse effects of nanoplastics (NPs) and pyriproxyfen on aquatic environments have attracted widespread attention. However, research on their combined exposure to aquatic ...organisms could be more extensive. This work evaluated the acute and chronic toxic effects of polystyrene NPs (PS-NPs) and pyriproxyfen on Daphnia magna (D. magna) under their combined exposure conditions. The addition of PS-NPs within 24 h reduced the acute toxicity of pyriproxyfen to D. magna, resulting in an increase in the 24-h ECsub.50 values of pyriproxyfen on D. magna from 0.24 mg/L to 0.35, 0.51, and 1.26 mg/L, respectively when 1, 5, and 10 mg/L of PS-NPs were added. Compared with PS-NPs, pyriproxyfen significantly disturbed the growth and reproduction of D. magna in the chronic toxicity test at 21 days. The adverse effects caused by pyriproxyfen were alleviated when PS-NPs and pyriproxyfen were co-exposed. In addition, it was observed that the addition of pyriproxyfen resulted in less PS-NPs uptake by D. magna using a time-gated imaging technique. These findings provide new insight into the combined toxic effects of NPs and pyriproxyfen on the reproduction and growth of D. magna, and it is important to understand the effects of complex pollutants on aquatic systems. Moreover, it has provided an important scientific basis for environmental protection and sustainable development.
Environmental contamination with arsenic (As) is a global environmental, agricultural and health issue due to the highly toxic and carcinogenic nature of As. Exposure of plants to As, even at very ...low concentration, can cause many morphological, physiological, and biochemical changes. The recent research on As in the soil-plant system indicates that As toxicity to plants varies with its speciation in plants (e.g., arsenite, As(III); arsenate, As(V)), with the type of plant species, and with other soil factors controlling As accumulation in plants. Various plant species have different mechanisms of As(III) or As(V) uptake, toxicity, and detoxification. This review briefly describes the sources and global extent of As contamination and As speciation in soil. We discuss different mechanisms responsible for As(III) and As(V) uptake, toxicity, and detoxification in plants, at physiological, biochemical, and molecular levels. This review highlights the importance of the As-induced generation of reactive oxygen species (ROS), as well as their damaging impacts on plants at biochemical, genetic, and molecular levels. The role of different enzymatic (superoxide dismutase, catalase, glutathione reductase, and ascorbate peroxidase) and non-enzymatic (salicylic acid, proline, phytochelatins, glutathione, nitric oxide, and phosphorous) substances under As(III/V) stress have been delineated via conceptual models showing As translocation and toxicity pathways in plant species. Significantly, this review addresses the current, albeit partially understood, emerging aspects on (i) As-induced physiological, biochemical, and genotoxic mechanisms and responses in plants and (ii) the roles of different molecules in modulation of As-induced toxicities in plants. We also provide insight on some important research gaps that need to be filled to advance our scientific understanding in this area of research on As in soil-plant systems.
As a green and sustainable technology to relieve environmental pollution issues, semiconductor photocatalysis attracted great attention. However, most single-component semiconductors suffer from high ...carrier recombination rate and low reaction efficiency. Here, we constructed a novel visible-light-driven Z-scheme g-Csub.3Nsub.4/AgBr-Ag photocatalyst (noted as CN-AA-0.05) using a hydrothermal method with KBr as the bromine source. The CN-AA-0.05 photocatalyst shows an excellent photocatalytic degradation performance, and a rhodamine B (RhB) degradation ratio of 96.3% in 40 min, and 2-mercaptobenzothiazole (MBT) degradation ratio of 99.2% in 18 min are achieved. Mechanistic studies show that the remarkable performance of CN-AA-0.05 is not only attributed to the enhanced light absorption caused by the Ag SPR effect, but also the efficient charge transfer and separation with Ag nanoparticles as the bridge. Our work provides a reference for the design and construction of efficient visible-light-responsive Z-scheme photocatalysts, and an in-depth understanding into the mechanism of Z-scheme photocatalysts.
Microplastic (MP) pollution is a raising global concern in recent years due to its wide distribution. Additionally, most of the MPs have undergone extensive weathering in the environment, and ...weathered MPs may exhibit different physicochemical properties from pristine ones. The review reveals the change in physicochemical properties (e.g. size, color, crystallinity, mechanical property and oxygen-containing groups) and the release of additives and MP-derived intermediates (i.e. oligomers and oxygenated compounds) during weathering processes. Weathering further affects the sorption behavior of MPs for environmental pollutants because of the changed crystallinity, specific surface area and oxygen functional groups. The interaction mechanisms of pristine and weathered MPs with pollutants are summarized, and how weathering processes affect sorption behavior is critically revealed. Because of the changed size, color and surface charges, weathered MPs might be ingested by aquatic organisms in different ways from the pristine ones. The detailed effects of weathering on the ingestion of MPs are discussed, and the potential toxicity of leachates from weathering processes is evaluated. In addition, the environmental components (e.g. natural organic matter and salinity) and biofilm correlated to the sorption behavior of MPs are reviewed. As for the knowledge gap, further studies should focus on the long-term weathering of MPs and the relationships between weathering properties and sorption capacities toward pollutants. The potential risks of weathered MPs and leachates on organisms should be explored.
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•Weathering significantly changes the physicochemical properties of microplastics.•Surface area, oxygen groups and crystallinity critically affect sorption of pollutants.•Effects of weathering on the risks of microplastics and leachates are revealed.•NOM, salinity and biofilms involved in the environmental behavior are reviewed.
The recent advances in nanotechnology and the corresponding increase in the use of nanomaterials in products in every sector of society have resulted in uncertainties regarding environmental impacts. ...The objectives of this review are to introduce the key aspects pertaining to nanomaterials in the environment and to discuss what is known concerning their fate, behavior, disposition, and toxicity, with a particular focus on those that make up manufactured nanomaterials. This review critiques existing nanomaterial research in freshwater, marine, and soil environments. It illustrates the paucity of existing research and demonstrates the need for additional research. Environmental scientists are encouraged to base this research on existing studies on colloidal behavior and toxicology. The need for standard reference and testing materials as well as methodology for suspension preparation and testing is also discussed.
► Research study investigated physico-chemical parameters of road deposited solids. ► Mineralogy and chemical composition can assist in pollutant source characterisation. ► Road deposited solids ...predominantly composed of minerals from surrounding soil. ► About 30% of road deposited solids consists of particles of anthropogenic origin. ► Significant fraction of heavy metals are derived from anthropogenic particles.
Road dust contain potentially toxic pollutants originating from a range of anthropogenic sources common to urban land uses and soil inputs from surrounding areas. The research study analysed the mineralogy and morphology of dust samples from road surfaces from different land uses and background soil samples to characterise the relative source contributions to road dust. The road dust consist primarily of soil derived minerals (60%) with quartz averaging 40–50% and remainder being clay forming minerals of albite, microcline, chlorite and muscovite originating from surrounding soils. About 2% was organic matter primarily originating from plant matter. Potentially toxic pollutants represented about 30% of the build-up. These pollutants consist of brake and tire wear, combustion emissions and fly ash from asphalt. Heavy metals such as Zn, Cu, Pb, Ni, Cr and Cd primarily originate from vehicular traffic while Fe, Al and Mn primarily originate from surrounding soils. The research study confirmed the significant contribution of vehicular traffic to dust deposited on urban road surfaces.
Metal pollution is an important issue worldwide, with various documented cases of metal toxicity in mining areas, industries, coal power plants and agriculture sector. Heavy metal polluted soils pose ...severe problems to plants, water resources, environment and nutrition. Among all non-essential metals, vanadium (V) is becoming a serious matter of discussion for the scientists who deals with heavy metals. Due to its mobility from soil to plants, it causes adverse effects to human beings. This review article illustrates briefly about V, its role and shows the progress about V research so far done globally in the light of the previous work which may assist in inter-disciplinary studies to evaluate the ecological importance of V toxicity.
•Vanadium might be serious pollutant for soil and environment in future.•Vanadium also a factor of food contamination.•Vanadium might be a main cause of many diseases in human beings.•Vanadium affects the plants growth as well as impairs the metabolic system.•Vanadium interacts with nutrients and its bio-availability depends upon various factors.
Regulatory oversight of toxic emissions from industrial plants and understanding about these emissions ' impacts are in their infancy. Applying a research design based on the openings and closings of ...1,600 industrial plants to rich data on housing markets and infant health, we find that: toxic air emissions affect air quality only within 1 mile of the plant; plant openings lead to 11 percent declines in housing values within 0.5 mile or a loss of about $ 4.25 million for these households; and a plant's operation is associated with a roughly 3 percent increase in the probability of low birthweight within 1 mile.
There is now a plethora of polymer-based materials (PBMs) on the market, because of the increasing demand for cheaper consumable goods, and light-weight industrial materials. Each PBM constitutes a ...mixture of their representative polymer/sand their various chemical additives. The major polymer types are polyethylene, polypropylene,and polyvinyl chloride, with natural rubber and biodegradable polymers becoming increasingly more important. The most important additives are those that are biologically active, because to be effective such chemicals often have properties that make them resistant to photo-degradation and biodegradation. During their lifecycle,PBMs can be released into the environment form a variety of sources. The principal introduction routes being general littering, dumping of unwanted waste materials,migration from landfills and emission during refuse collection. Once in the environment,PBMs are primarily broken down by photo-degradation processes, but due to the complex chemical makeup of PBMs, receiving environments are potentially exposed to a mixture of macro-, meso-, and micro-size polymer fragments, leached additives, and subsequent degradation products. In environments where sunlight is absent (i.e., soils and the deep sea) degradation for most PBMs is minimal .The majority of literature to date that has addressed the environmental contamination or disposition of PBMs has focused on the marine environment. This is because the oceans are identified as the major sink for macro PBMs, where they are known to present a hazard to wildlife via entanglement and ingestion. The published literature has established the occurrence of microplastics in marine environment and beach sediments, but is inadequate as regards contamination of soils and freshwater sediments. The uptake of microplastics for a limited range of aquatic organisms has also been established, but there is a lack of information regarding soil organisms, and the long-term effects of microplastic uptake are also less well understood.There is currently a need to establish appropriate degradation test strategies consistent with realistic environmental conditions, because the complexity of environmental systems is lost when only one process (e.g., hydrolysis) is assessed in isolation. Enhanced methodologies are also needed to evaluate the impact of PBMs to soil and freshwater environments.
A graphene oxide-polydopamine-(β-cyclodextrin) (GPC) ultrafiltration membrane was fabricated by using the method of drop-coating combined with vacuum filtration. The prepared GPC membrane was ...characterized with FTIR and XPS spectrophotometry and evaluated for its performances for the rejection of organic molecules (methylene blue) and adsorption of trace heavy metals (Pb
2+
) from aqueous solutions. The membrane exhibited an excellent rejection coefficient of 99.2% for methylene blue and the permeation flux was 12 L m
−2
h
−1
at 0.1 bar. The membrane also exhibited fast adsorption kinetics for Pb
2+
and the adsorption capacity was 101.6 mg g
−1
at a solution pH of 6. The performance of the membrane could almost be completely recovered after a simple clean and regeneration process. These results indicate that the GPC membrane has potential applications in treatment of complex industrial wastewater streams.
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