Lichens (Xanthoria parietina) - Bio-Indicators for Sulphur and Metallic Elements for Pollution Investigation in Riga City

2021 ◽  
Vol 903 ◽  
pp. 106-110
Author(s):  
Viktorija Krjukoviča ◽  
Zenta Balcerbule ◽  
Vitālijs Lazarenko ◽  
Māris Bērtiņš ◽  
Arturs Viksna
Keyword(s):  
Polluted Area ◽  
Dust Particles ◽  
Pollution Level ◽  
Metallic Elements ◽  
Xanthoria Parietina ◽  
Lichen Thallus

The aim of the research was to investigate the pollution level of sulphur and metallic elements in Riga city (Freeport of Riga, Kundziņsala, Mežaparks) by using foliose lichens (Xanthoriaparietina) as a bio-indicators. Obtained results show that the Freeport of Riga is the most polluted area comparing with other neatest places in Riga city, Kundziņsala and Mežaparks. Evaluate a washing effect, obtained results shows that lichen thallus contains about 50 % of total amount of sulphur and investigated elements as dust particles on the surface of lichens.

Changes of air pollutants’ concentrations in selected Romanian cities during the pandemic year 2020

2021 ◽  
Author(s):  
Gabriela Iorga ◽  
George-Bogdan Burghelea
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
European Commission ◽  
Air Pollutants ◽  
Meteorological Parameters ◽  
Dust Particles ◽  
Spatial And Temporal Variation ◽  
Pollution Level ◽  
Data Set ◽  
Air Mass

<p>Present research contributes to scientific knowledge concerning spatial and temporal variation of major air pollutants with high resolution at the country scale bringing statistical information on concentrations of NOx, O<sub>3</sub>, CO, SO<sub>2</sub> and particulate matter with an aerodynamic diameter below 10 μm (PM<sub>10</sub>) and below 2.5 μm (PM<sub>2.5</sub>) during the pandemic year 2020 using an observational data set from the Romanian National Air Quality Network in seven selected cities spread out over the country. These cities have different level of development, play regional roles, might have potential influence at European scale and they are expected to be impacted by different pollution sources. Among them, three cities (Bucharest, Brașov, Iași) appear frequently on the list of the European Commission with reference to the infringement procedure that the European Commission launched against Romania in the period 2007-2020 regarding air quality.</p><p>Air pollutant data was complemented with local meteorological parameters at each site (atmospheric pressure, relative humidity, temperature, global solar radiation, wind speed and direction). Statistics of air pollutants provide us with an overview of air pollution in main Romanian cities.  Correlations between meteorological parameters and ambient pollutant levels were analyzed. Lowest air pollution levels were measured during the lockdown period in spring, as main traffic and non-essential activities were severely restricted. Among exceptions were the construction activities that were not interrupted. During 2020, some of selected cities experienced few pollution episodes which were due to dust transport from Sahara desert. However, in Bucharest metropolitan area, some cases with high pollution level were found correlated with local anthropogenic activity namely, waste incinerations. Air mass origins were investigated for 72 hours back by computing the air mass backward trajectories using the HYSPLIT model. Dust load and spatial distribution of the aerosol optical depth with BSC-DREAM8b v2.0 and NMBM/BSC-Dust models showed the area with dust particles transport during the dust events.</p><p>The obtained results are important for investigations of sources of air pollution and for modeling of air quality.</p><p><strong> </strong></p><p><strong>Acknowledgment:</strong></p><p>The research leading to these results has received funding from the NO Grants 2014-2021, under Project contract no. 31/2020, EEA-RO-NO-2019-0423 project. NOAA Air Resources Laboratory for HYSPLIT transport model, available at READY website https://www.ready.noaa.gov  and the Barcelona dust forecast center for BSC-DREAM8b and NMBM/BSC-Dust models, available at:  https://ess.bsc.es/bsc-dust-daily-forecast are also acknowledged. The data regarding ground-based air pollution and meteorology by site was extracted from the public available Romanian National Air Quality Database, www.calitateaer.ro.</p>

Le développement en cultures pures in vitro des mycosymbiotes des lichens

1985 ◽  
Vol 63 (4) ◽  
pp. 681-703 ◽  
Author(s):  
Richard Lallemant
Keyword(s):  
Hollow Structure ◽  
Lobaria Pulmonaria ◽  
Sabouraud Agar ◽  
Xanthoria Parietina ◽  
Lichen Thallus ◽  
Intense Light

The mycosymbiont of Pertusaria pertusa was cultivated from ascospores or conidiospores. On Sabouraud agar, a nematothallus forms a multilobed, conidia-producing vesicle. Some mycelian filaments grow away from it and initiate "sclerotial structures." On maltea 2%, only a mycelian sheet was obtained. On the Lilly and Barnett medium such a mycelian sheet generates a hollow structure. The mycosymbiont of the Xanthoria parietina was cultivated from one ascospore or from conidiospores. On maltea 2%, a mycelian sheet is formed, then a nematothallian structure, generating a swollen, hollow, conidiogenous formation. On the Lilly and Barnett medium, the hollow structure is progressively filled with new hyphae. On the Sabouraud agar, the vesiculous structure becomes more structured; it can bear young apothecial primordia. It gives rise to small tongue-shaped lobes resembling young thallus lobes. The mycosymbiont ofthe Lecidea parasema could be cultivated on Sabouraud agar. A mycelium is formed which is then transformed into a nematothallus. On it appear concentric crown-shaped protuberances. The cultures of Lobaria pulmonaria and Lobaria laetevirens form a mycelian sheet which is transformed into a nematothallus. On Sabouraud agar this generates a vesiculous structure. Under intense light a sclerotic structure is formed. So, the mycosymbiont of the lichens has a great morphogenic plasticity; the phycosymbiont plays a fundamental role in the symbiotic union, leading to the formation of a pseudocladomian lichen thallus.

scholarly journals Analyzing the impact of dust accumulation and different cleaning mechanism on efficiency of solar photovoltaic panel

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Atul Kumar1 ◽  
Srivastava Manish2
Keyword(s):  
Renewable Energy Sources ◽  
Dust Particles ◽  
Energy Sources ◽  
Pollution Level ◽  
Solar Photovoltaic ◽  
Solar Pv ◽  
Photovoltaic Panel ◽  
Pv Systems ◽  
The Impact ◽  
Rooftop Solar

Electricity generation around the world is mainly produced by using non-renewable energy sources especially in the commercial buildings. However, Rooftop solar Photovoltaic (PV) system produced a significant impact on environmental and economical benefits in comparison to the conventional energy sources, thus contributing to sustainable development. Such PV’s system encourages the production of electricity without greenhouse gas emissions that leads to a clean alternative to fossil fuels and economic prosperity even in less developed areas. However, efficiency of rooftop solar PV systems depends on many factors, the dominant being geographical (latitude, longitude, and solar intensity), environmental (temperature, wind, humidity, pollution, dust, rain, etc.) and the type of PV (from raw material extraction and procurement, to manufacturing, disposal, and/or recycling) used. During the feasibility analysis of the environment, geographical conditions are keep in well consideration, but the pollution level of the city is always overlooked, which significantly influences the performance of the PV installations.           Therefore, this research work focused on the performance of rooftop solar PV installed in one of the most polluted city in India. Here, the loss in power generation of rooftop solar PV has been studied for the effect of deposited dust particles, wind velocity before and after the cleaning of the panels. The actual data has been utilized for the calculation of the energy efficiency and power output of the PV systems. According to the results, it has been concluded that dust deposition, wind speed and pollution level in city significantly reduces the efficiency of solar photovoltaic panel. Hence, an overview of social and environmental impacts of PV technologies is presented in this paper along with potential benefits and pitfalls.

scholarly journals Physiological responses of Xanthoria parietina to longterm copper excess: Role of the extracellular secondary metabolite parietin

2019 ◽  
Vol 43 (2) ◽  
pp. 133-142
Author(s):  
Ivana Biľová ◽  
Michal Goga ◽  
Martin Backor
Keyword(s):  
Secondary Metabolite ◽  
Chlorophyll A ◽  
De Novo ◽  
Physiological Parameters ◽  
Term Experiment ◽  
Xanthoria Parietina ◽  
Long Term Experiment ◽  
Lichen Thallus ◽  
Copper Excess

Xanthoria parietina is a common lichen that is widespread around the world. Tolerance of heavy metal pollution in this lichen is well known. Xanthoria parietina contains the secondary metabolite parietin, which protects the photobiont from high UV- radiation. Secondary metabolites of lichens have been found to form complexes with metal cations. In a long-term experiment (lasting 8 weeks), we tested the resistance of X. parietina with and without the secondary metabolite parietin against two concentrations of Cu (50 ?M and 500 ?M). Removal of parietin did not affect the measured physiological parameters. However, it caused higher accumulation of intracellular Cu. De novo synthesis of parietin in the lichen thallus after removal of the metabolite was not observed. Physiological parameters (chlorophyll a fluorescence, chlorophyll a integrity, content of soluble proteins, ergosterol levels, TBARS production) were affected by the higher dose of Cu during the long-term experiment. It seems that the secondary metabolite parietin does not protect the lichen against Cu excess.

scholarly journals Spatio-temporal changes of AOD in Xinjiang of China from 2000 to 2019: Which factor is more influential, natural factor or human factor?

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0253942
Author(s):  
Jinglong Li ◽  
Qing He ◽  
Xiangyu Ge ◽  
Alim Abbas ◽  
Lili Jin
Keyword(s):  
Atmospheric Correction ◽  
Tianshan Mountains ◽  
Dust Particles ◽  
Pollution Level ◽  
Taklimakan Desert ◽  
Hysplit Model ◽  
Temporal Characteristics ◽  
Northern Xinjiang ◽  
Spatio Temporal ◽  
Southern Xinjiang

Aerosol optical depth (AOD), which represents the optical attenuation, poses a major threat to the production activity, air quality, human health and regional sustainable development of arid and semi-arid areas. To some degree, AOD shows areal air pollution level and possesses obvious spatio-temporal characteristics. However, long-time sequences and detailed AOD information can not be provided due to currently limited monitoring technology. In this paper, a daily AOD product, MODIS-based Multi-angle Implementation of Atmospheric Correction (MAIAC), is deployed to analyze the spatio-temporal characteristics in Xinjiang Uygur Autonomous Region from 2000 to 2019. In addition, the importance of influencing factors for AOD is calculated through Random Forest (RF) Model and the propagation trajectories of pollutants are simulated through Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) Model. Spatio distribution of AOD presents a tendency that AOD value in northern Xinjiang is low while the value in southern Xinjiang is high. Regions with high AOD values are mainly concentrated in Tarim Basin. AOD in southern Xinjiang is the highest, followed by that in eastern Xinjiang and AOD value in northern Xinjiang is the lowest. Seasonal variation of AOD is significant: Spring (0.309) > summer (0.200) > autumn (0.161) > winter (0.158). Average AOD value in Xinjiang is 0.196. AOD appears wavy from 2000 to 2014 with its low inflection point (0.157) appearing in 2005, and then increases, reaching its peak in 2014 (0.223). The obvious downward tendency after 2014 shows that the use of coal to natural gas (NG) conversion project improves the conditions of local environment. According to RF Model, NG contributes most to AOD. HYSPLIT Model reveals that aerosol in southern Xinjiang is related to the short-distant carriage of dust aerosol from the Taklimakan Desert. Aerosol there can affect Inner Mongolia through long-distant transport. Blocked by the Tianshan Mountains, fine dust particles can not cross the Tianshan Mountains to become a factor contributing to AOD in northern Xinjiang.

scholarly journals 2. The Chemical Composition of Cometary Meteoroids

1977 ◽  
Vol 39 ◽  
pp. 127-132 ◽  
Author(s):  
P. M. Millman
Keyword(s):  
Chemical Composition ◽  
Upper Atmosphere ◽  
Dust Particles ◽  
Carbonaceous Chondrites ◽  
Metallic Elements ◽  
Chemical Abundances ◽  
The Earth ◽  
Qualitative Evidence ◽  
E Region

Evidence for the chemical composition of cometary meteoroids is available from the spectra of shower meteors, from the analysis of extra-terrestrial dust particles, from a study of residues in the bottom of microcraters on plates exposed to the interplanetary environment, and from measures of the relative abundances of non-atmospheric ions in the E-region of the earth’s upper atmosphere. Quantitative measures of chemical abundances in meteoroids, based on the four techniques listed, show that in general the cometary meteoroids encountered by the earth conform to the carbonaceous chondrites type 1 in the case of the commonest metallic elements. There is also qualitative evidence of the presence of significant quantities of some of the light volatiles.

scholarly journals Vegetation record around a cement factory and the impact of dust pollution on crop productivity

2013 ◽  
Vol 1 ◽  
pp. 55-62
Author(s):  
Narahari Chapagain ◽  
Min Raj Dhakal
Keyword(s):  
Crop Productivity ◽  
Polluted Area ◽  
Dust Particles ◽  
Vegetable Production ◽  
Cement Dust ◽  
Dust Pollution ◽  
Cement Factory ◽  
Cement Dust Pollution ◽  
The Impact ◽  
Factory Site

Effect of cement dust pollution on crop productivity in the environment of Himal Cement Factory, Kathmandu, Nepal has been studied. The productivity of the crops like wheat, maize and mustard were significantly low in the fields 1.5 km around the factory site in comparison to the fields at 3-4-km distance. Productivity of rice was least affected. Polluted area around the cement factory becomes unsuitable for vegetable production due to deposition of dust particles on the leaves. A list of plants growing around the factory has also been presented. DOI: http://dx.doi.org/10.3126/njbs.v1i0.7472 Nepalese Journal of Biosciences 1: 55-62 (2011)

Saturn's E, G and F rings: modulated by the plasma sheet

1984 ◽  
Vol 75 ◽  
pp. 597
Author(s):  
E. Grün ◽  
G.E. Morfill ◽  
T.V. Johnson ◽  
G.H. Schwehm
Keyword(s):  
Solar Wind ◽  
Direct Contact ◽  
Transport Processes ◽  
Time Variable ◽  
Dust Particles ◽  
Spatial Diffusion ◽  
Drag Forces ◽  
Orbit Perturbation ◽  
Time Variations ◽  
F Ring

ABSTRACTSaturn's broad E ring, the narrow G ring and the structured and apparently time variable F ring(s), contain many micron and sub-micron sized particles, which make up the “visible” component. These rings (or ring systems) are in direct contact with magnetospheric plasma. Fluctuations in the plasma density and/or mean energy, due to magnetospheric and solar wind processes, may induce stochastic charge variations on the dust particles, which in turn lead to an orbit perturbation and spatial diffusion. It is suggested that the extent of the E ring and the braided, kinky structure of certain portions of the F rings as well as possible time variations are a result of plasma induced electromagnetic perturbations and drag forces. The G ring, in this scenario, requires some form of shepherding and should be akin to the F ring in structure. Sputtering of micron-sized dust particles in the E ring by magnetospheric ions yields lifetimes of 102to 104years. This effect as well as the plasma induced transport processes require an active source for the E ring, probably Enceladus.

Analytical Electron Microscopy Characterization of Electric Arc Furnace Dust

1981 ◽  
Vol 39 ◽  
pp. 134-135
Author(s):  
J. R. Porter ◽  
J. I. Goldstein ◽  
D. B. Williams
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Dust Particles ◽  
Particle Analysis ◽  
Arc Furnace ◽  
Analytical Electron ◽  
Residual Elements ◽  
Industry Practice

Alloy scrap metal is increasingly being used in electric arc furnace (EAF) steelmaking and the alloying elements are also found in the resulting dust. A comprehensive characterization program of EAF dust has been undertaken in collaboration with the steel industry and AISI. Samples have been collected from the furnaces of 28 steel companies representing the broad spectrum of industry practice. The program aims to develop an understanding of the mechanisms of formation so that procedures to recover residual elements or recycle the dust can be established. The multi-phase, multi-component dust particles are amenable to individual particle analysis using modern analytical electron microscopy (AEM) methods.Particles are ultrasonically dispersed and subsequently supported on carbon coated formvar films on berylium grids for microscopy. The specimens require careful treatment to prevent agglomeration during preparation which occurs as a result of the combined effects of the fine particle size and particle magnetism. A number of approaches to inhibit agglomeration are currently being evaluated including dispersal in easily sublimable organic solids and size fractioning by centrifugation.

Improving soil remediation through characterization

1995 ◽  
Vol 53 ◽  
pp. 386-387
Author(s):  
E. C. Buck ◽  
N. L. Dietz ◽  
J. K. Bates
Keyword(s):  
Dust Particles ◽  
Radiochemical Analysis ◽  
Solid Product ◽  
Uranium Contamination ◽  
Physical Separation ◽  
X Ray ◽  
Rocky Flats ◽  
Remediation Strategies ◽  
Bearing Materials ◽  
X Ray Absorption

Operations at former weapons processing facilities in the U. S. have resulted in a large volume of radionuclidecontaminated soils and residues. In an effort to improve remediation strategies and meet environmental regulations, radionuclide-bearing particles in contaminant soils from Fernald in Ohio and the Rocky Flats Plant (RFP) in Colorado have been characterized by electron microscopy. The object of these studies was to determine the form of the contaminant radionuclide, so that it properties could be established [1]. Physical separation and radiochemical analysis determined that uranium contamination at Fernald was not present exclusively in any one size/density fraction [2]. The uranium-contamination resulted from aqueous and solid product spills, air-borne dust particles, and from the operation of an incinerator on site. At RFP the contamination was from the incineration of Pu-bearing materials. Further analysis by x-ray absorption spectroscopy indicated that the majority of the uranium was in the 6+ oxidation state [3].

Sign in / Sign up

Export Citation Format

Share Document