scholarly journals Non-Negligible Effects of UV Irradiation on Transformation and Environmental Risks of Microplastics in the Water Environment

2021 ◽  
Vol 12 (1) ◽  
pp. 1-12
Author(s):  
Fangyuan Cheng ◽  
Tingting Zhang ◽  
Yue Liu ◽  
Yanan Zhang ◽  
Jiao Qu
Keyword(s):  
Environmental Factors ◽  
Uv Irradiation ◽  
Water Environment ◽  
Oxidative Degradation ◽  
Environmental Risks ◽  
Important Process ◽  
Environmental Behaviors ◽  
Environmental Media ◽  
Different Types ◽  
Harmful Effects

Microplastics (MPs) are ubiquitous in environmental media, and their harmful effects on MPs on the ecosystem have attracted more and more attention. Once released into the environment, MPs can trigger oxidative degradation through ultraviolet (UV) to cause photoaging. Photoaging significantly affects the properties of MPs, which leads to changing their environmental behaviors and increasing environmental risks. In this review, the generation of MPs under UV irradiation and the influence of environmental factors on the photoaging of MPs were discussed. Photoaging of MPs is an important process affecting the migration, transformation and interaction of pollutants in water and soil. In order to fully predict the fate and environmental interaction of MPs, more researches are needed in the future to explore the photoaging behavior of different types of MPs under natural environmental conditions.

scholarly journals Phototransformation of Graphene Oxide on the Removal of Sulfamethazine in a Water Environment

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2134
Author(s):  
Fei-Fei Liu ◽  
Meng-Ru Li ◽  
Su-Chun Wang ◽  
Yu-Xue Zhang ◽  
Guang-Zhou Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Uv Irradiation ◽  
Environmental Fate ◽  
Water Environment ◽  
Environmental Pollutants ◽  
Aquatic Environments ◽  
Environmental Behaviors ◽  
Uv Illumination ◽  
Light Yellow

Graphene oxide (GO) is widely used in various fields and has raised concerns regarding its potential environmental fate and effect. However, there are few studies on its influence on coexisting pollutants. In this study, the phototransformation of GO and coexisting sulfamethazine (SMZ) under UV irradiation was investigated, with a focus on the role of reactive oxygen species. The results demonstrated that GO promoted the degradation of SMZ under UV irradiation. The higher the concentration of GO, the higher the degradation rate of SMZ, and the faster the first-order reaction rate. Two main radicals, ∙OH and 1O2, both contributed greatly in terms of regulating the removal of SMZ. Cl−, SO42−, and pH mainly promoted SMZ degradation by increasing the generation of ∙OH, while humic acid inhibited SMZ degradation due to the reduction of ∙OH. Moreover, after UV illumination, the GO suspension changed from light yellow to dark brown with increasing absorbance at a wavelength of 225 nm. Raman spectra revealed that the ID/IG ratio slightly decreased, indicating that some of the functional groups on the surface of GO were removed under low-intensity UV illumination. This study revealed that GO plays important roles in the photochemical transformation of environmental pollutants, which is helpful for understanding the environmental behaviors and risks of nanoparticles in aquatic environments.

scholarly journals Surface Sediment Diatom Assemblages Response to Water Environment in Dongping Lake, North China

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 339
Author(s):  
Shuangshuang Liu ◽  
Min Yao ◽  
Shiyue Chen ◽  
Xingzhong Yuan
Keyword(s):  
Environmental Factors ◽  
Water Environment ◽  
Oxygen Demand ◽  
Diatom Assemblages ◽  
Multivariate Statistical ◽  
Dongping Lake ◽  
Autumn And Winter ◽  
Response To Water ◽  
The Relationship ◽  
Significant Factors

The relationship between the diatom taxa preserved in surface lake sediments and environmental variables in Dongping Lake was explored using multivariate statistical methods. The statistical analysis showed that the lake was eutrophicated in all seasons. Transparency, chlorophyll a (Chla) and total phosphorus (TP) were the dominant environmental factors in spring and summer, and NH4+-N and chemical oxygen demand (COD) were the dominant environmental factors in autumn and winter. Sixteen genera and 43 species of diatom were found in the surface sediments, and the dominant diatom genera were Aulacoseira, Ulnaria, Cyclotella, Navicula and Fragilaria. A redundancy analysis (RDA) and Monte Carlo permutation 20 test revealed that COD, pH, TP, conductivity and transparency were significant factors influencing diatom assemblage change, meaning that the distribution of the diatom assemblages were mostly influenced by nutrient composition, light intensity and ion concentrations.

scholarly journals EFFECTS OF DIFFERENT TYPES OF CYTOPLASM ON THE KERNEL ROW NUMBER OF MAIZE INBRED LINES

AGROFOR ◽  
2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Snežana JOVANOVIĆ ◽  
Goran TODOROVIĆ ◽  
Nikola GRČIĆ ◽  
Ratibor ŠTRBANOVIĆ ◽  
Rade STANISAVLJEVIĆ ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Block Design ◽  
Inbred Lines ◽  
Mean Values ◽  
Maize Inbred Lines ◽  
Different Types ◽  
Maize Inbreds ◽  
Set Up ◽  
Kernel Row Number

The aim of the present study was to determine effects of both, different types ofcytoplasm (cms-C, cms-S and fertile) and environmental factors on the kernel rownumber of 12 maize inbreds lines. The trial with inbred lines was set up in twolocations (Zemun Polje-Selection field and Zemun Polje-Školsko dobro) in 2013and 2014. Moreover, the three-replicate trials were set up according to therandomised complete block design within each type of cytoplasm. Each plot withinthe replicate consisted of four rows. Fertile versions of inbred lines were sown intwo border rows and they were pollinators for their sterile counterparts. Statisticbiometricdata processing was based on mean values per replicate and included theanalysis of variance. According to this analysis, significant differences in thekernel row number were established among inbred lines in dependence on the typeof cytoplasm, year and the location. The average kernel row number ranged from10.3 (L9) to 15.8 (L5 and L7). The variation of the kernel row number, related to thesource of cytoplasm, was very significant. Differences (Lsd0.01) in the kernel rownumber were not determined in inbred lines L5, L8, L10 and L12 in regard to the typeof cytoplasm: cms-C, cms-S and fertile. The average kernel row numbersignificantly (P1%) varied in regard to the year of investigation. A higher averagevalue (13.75) was established in 2014 than in 2013 (13.31). The kernel row numberper year very significantly varied (Lsd0.01) in all inbreds, but the differences werenot significant in the inbreds L2, L3, L8, L9 and L12. Gained results point out toeffects of different types of cytoplasm on the kernel row number.

scholarly journals Analysis of organismic and population characteristics of the coenopopulations of Dracocephalum nutans L.

2021 ◽  
Vol 31 ◽  
pp. 00003
Author(s):  
Gulnora Denisova ◽  
Alexey Astashenkov
Keyword(s):  
Sustainable Development ◽  
Environmental Factors ◽  
Paper Analysis ◽  
Population Characteristics ◽  
Widespread Species ◽  
Different Types ◽  
Selected Traits

On the study of the mechanisms of sustainable development of populations of the widespread species D. nutans presents the results in the paper. Analysis of organism and population traits showed that in unformed communities, the species has maximum values of all selected traits. As a result, the comparison of points has been found to be associated with environmental and censorship conditions. Depending on the environmental factors, different types of ontogenetic spectrums are formed (left-sided, centered, right- sided).

Unele aspecte a starii sanatatii populatiei în raioanele Orhei si Telenesti

2019 ◽  
Author(s):  
Nicolae Bodrug ◽  
Keyword(s):  
Health Status ◽  
Environmental Factors ◽  
Environmental Pollution ◽  
Population Health ◽  
Ecological Factors ◽  
Environmental Risks ◽  
Economic Situation ◽  
Medical Services ◽  
Human Biology

. Environmental pollution affects population health depending on the extension and the degree of exposure to environmental factors. In most cases it is difficult to obtain an accurate situation of exposure of population to harmful factors. Health status is determined by: human biology, ecological factors, the socio-economic situation of each person, and the quality of medical services. In according to regional peculiarities the interdependence of those factors could vary, but not significantly. The environmental risks are everywhere but diminishing them may improve the health status of the population.

scholarly journals Oxidative degradation of non-recycled and recycled paper

Cellulose ◽  
2020 ◽  
Vol 27 (15) ◽  
pp. 8977-8987
Author(s):  
Floriana Coppola ◽  
Alberto Modelli
Keyword(s):  
Oxidative Degradation ◽  
Carbonyl Groups ◽  
Carbonyl Content ◽  
Potassium Periodate ◽  
Recycled Paper ◽  
Pure Cellulose ◽  
Different Types ◽  
The Difference ◽  
Reported Data ◽  
Linear Correlations

Abstract The degradation of paper-based materials involves several and complex mechanisms, such as hydrolysis and oxidation. The behaviour of different types of pulps can be very variable. In this study, the difference upon oxidation of contemporary non-recycled and recycled papers, which now constitute a considerable fibre source, is investigated. A 0.015 M potassium periodate solution is used to oxidise five types of paper, two non-recycled and three recycled, for 0.5, 1, 2 and 4 h. The effects of such oxidation treatments are evaluated in terms of carbonyl content and degree of polymerisation (DP). A modified procedure of the Szabolcs’s method and viscometry are used to measure the carbonyl content and DP, respectively. The carbonyl groups are found to increase more rapidly in the recycled papers than in the non-recycled ones. On the contrary, oxidation causes a larger decrease of the DP values in the non-recycled papers, the paper made of pure cellulose being the most sensitive in terms of depolymerisation. The DP values measured for pure cellulose paper are in line with previously reported data. Moreover, in accordance with the Ekenstam equation, the plots of the reciprocal of DP as a function of oxidation time show good linear correlations for all types of paper investigated. Pseudo rate constants are thus calculated from the slopes of these plots, those of the non-recycled papers being found to be higher than those of the recycled papers. Graphic abstract

Selective inspection planning with ageing forecast for sewer types

2002 ◽  
Vol 46 (6-7) ◽  
pp. 389-396 ◽  
Author(s):  
R. Baur ◽  
R. Herz
Keyword(s):  
Environmental Risks ◽  
Small Sample ◽  
Storm Water ◽  
Actual Condition ◽  
Inspection Planning ◽  
Transition Functions ◽  
Sewer Network ◽  
Different Types ◽  
Sewer Rehabilitation ◽  
Water Profile

Investments in sewer rehabilitation must be based on inspection and evaluation of sewer conditions with respect to the severity of sewer damage and to environmental risks. This paper deals with the problems of forecasting the condition of sewers in a network from a small sample of inspected sewers. Transition functions from one into the next poorer condition class, which were empirically derived from this sample, are used to forecast the condition of sewers. By the same procedure, transition functions were subsequently calibrated for sub-samples of different types of sewers. With these transition functions, the most probable date of entering a critical condition class can be forecast from sewer characteristics, such as material, period of construction, location, use for waste and/or storm water, profile, diameter and gradient. Results are shown for the estimates about the actual condition of the Dresden sewer network and its deterioration in case of doing nothing about it. A procedure is proposed for scheduling the inspection dates for sewers which have not yet been inspected and for those which have been inspected before.

Gene–environment interactions

2018 ◽  
Author(s):  
Barbara Franke ◽  
Jan K. Buitelaar
Keyword(s):  
Environmental Factors ◽  
Genetic Variant ◽  
Differential Susceptibility ◽  
Gene Environment ◽  
Genome Wide ◽  
Single Genome ◽  
Disease Aetiology ◽  
Different Types ◽  
Postnatal Risk Factors ◽  
Genome Wide Study

ADHD is highly heritable, but environmental factors also play significant roles in disease aetiology and outcome. Genetic and environmental influences are likely to show different types of interplay, with gene–environment interactions (G×E) playing a part. Different models of G×E exist, with the most frequently investigated in ADHD up to the present being the diathesis–stress and differential susceptibility models. The most frequently studied have been monoaminergic genes, often based on a single genetic variant. Only a single genome-wide study has been reported thus far. Environmental factors investigated include prenatal and postnatal risk factors for ADHD, in particular prenatal exposure to smoking or alcohol and aspects of parenting.

Effect of Metallic Poisons. Especially Manganese, on Aging of Vulcanized Natural Rubber

1947 ◽  
Vol 20 (3) ◽  
pp. 821-826
Keyword(s):  
Organic Acids ◽  
Natural Rubber ◽  
Harmful Effect ◽  
Manganese Compound ◽  
Naturally Occurring ◽  
Different Types ◽  
Salts Of Organic Acids ◽  
General Experience ◽  
Manganese Compounds ◽  
Harmful Effects

Abstract 1. Information received from rubber manufacturers on their experience of the effects of manganese and copper on aging is summarized. Although there is evidence that the amounts of these impurities in fillers tended to increase during the early war years (1939–42), it seems to be the general experience that little trouble arose from their effects on the properties of the rubber. Fillers containing as much as 0.05–0.10 per cent of manganese, or 0.005 per cent of copper, have not shown any obvious harmful effects. 2. Experiments with a large number of manganese compounds, including naturally occurring (mineral) forms and salts of organic acids, used in amounts equivalent to 0.01 per cent manganese on the raw rubber, have failed to show any pronounced harmful effect on the aging (oven or oxygen bomb) of a vulcanized natural rubber containing mercaptobenzothiazole, although deterioration was noticeably accelerated in some cases. Probably on account of the smallness of the effects observed, it is not possible as yet to draw any conclusion as to the relative activities of different types of manganese compound. 3. According to results of previous workers, manganese in the amount used in the present experiments can produce a more serious effect than these experiments indicate. The effect of manganese is known to depend on the type of mix used, and this aspect of the problem would thus appear to merit further investigation, as does also the influence of the method and degree of dispersion of the manganese compound in the rubber mix.

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