Tracing the sources of PCDD/Fs in Baltic Sea air by using metals as source markers

2018 ◽  
Vol 20 (3) ◽  
pp. 544-552 ◽  
Author(s):  
Anteneh Assefa ◽  
Mats Tysklind ◽  
Jana Klanova ◽  
Karin Wiberg
Keyword(s):  
Baltic Sea ◽  
Ambient Air ◽  
Air Mass ◽  
Back Trajectories ◽  
Air Samples ◽  
Metal Source ◽  
Source Markers

A combination of PCDD/F patterns and metal source markers in ambient air samples together with stable air mass back trajectories can reveal the most significant atmospheric sources of PCDD/Fs.

scholarly journals Ship Based Measurements of Seasonal Atmospheric Mercury Concentrations over the Baltic Sea

2017 ◽  
Author(s):  
Hanna Hoeglind ◽  
Sofia Eriksson ◽  
Katarina Gardfeldt
Keyword(s):  
Baltic Sea ◽  
Background Level ◽  
Ambient Air ◽  
Atmospheric Mercury ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
The Baltic Sea ◽  
Back Trajectories ◽  
Gaseous Mercury ◽  
The Baltic

Mercury is a toxic pollutant emitted from both natural sources and through human activities. A global interest in atmospheric mercury has risen ever since the discovery of the Minamata disease in 1956. Properties of gaseous elemental mercury enable long range transport which can cause pollution even in pristine environments. Total gaseous mercury (TGM) was measured from winter 2016 to spring 2017 over the Baltic Sea. A Tekran 2357A mercury analyser was installed aboard the research and icebreaking vessel Oden for the purpose of continuous measurements of gaseous mercury in ambient air. Measurements were performed during a campaign along the Swedish east coast and in the Bothnian Bay near Lulea during the icebreaking season. Data was evaluated from Gothenburg using a plotting software and back trajectories for air masses were calculated. The TGM average of 1.365 ± 0.054 ng/m3 during winter and 1.288 ± 0.140 ng/m3 during spring was calculated as well as a total average of 1.362 ± 0.158 ng/m3. Back trajectories showed a possible correlation of anthropogenic sources elevating the mercury background level in some areas. There were also indications of depleted air, i.e., air with lower concentrations than average, being transported from the Arctic to northern Sweden resulting in a drop in TGM levels.

Electron Microscopic Characterization and Quantitation of Air Borne Particulate Matter with Special Emphasis on Asbestos

1972 ◽  
Vol 30 ◽  
pp. 356-357
Author(s):  
Peter K. Mueller ◽  
Glenn R. Smith ◽  
Leslie M Carpenter ◽  
Ronald L. Stanley
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Ambient Air ◽  
Quality Standard ◽  
Primary Objective ◽  
Cellulose Ester ◽  
Main Concept ◽  
Electron Microscopic ◽  
Air Samples ◽  
Diffraction Patterns

At the present time the primary objective of the electron microscopy group of the Air and Industrial Hygiene Laboratory is the development of a method suitable for use in establishing an air quality standard for asbestos in ambient air and for use in its surveillance. The main concept and thrust of our approach for the development of this method is to obtain a true picture of fiber occurrence as a function of particle size and asbestos type utilizing light and electron microscopy.We have now available an electron micrographic atlas of all asbestos types including selected area diffraction patterns and examples of fibers isolated from air samples. Several alternative approaches for measuring asbestos in ambient air have been developed and/or evaluated. Our experiences in this regard will be described. The most promising method involves: 1) taking air samples on cellulose ester membrane filters with a nominal pore size of 0.8 micron; 2) ashing in a low temperature oxygen plasma for several hours;

scholarly journals Polybrominated diphenyl ethers (PBDEs) in ambient air samples at the electronic waste (e-waste) reclamation site

2019 ◽  
Vol 1 (1) ◽  
pp. 79-89 ◽  
Author(s):  
Ajit Ghimire ◽  
Albert Leo N. dela Cruz ◽  
Roberto Wong ◽  
Panida Navasumrit ◽  
Stephania Cormier ◽  
...  
Keyword(s):  
Polybrominated Diphenyl Ethers ◽  
Electronic Waste ◽  
Ambient Air ◽  
Air Samples ◽  
Diphenyl Ethers ◽  
Waste Reclamation

scholarly journals Identification of the Aerosol Types over Athens, Greece: The Influence of Air-Mass Transport

2010 ◽  
Vol 2010 ◽  
pp. 1-15 ◽  
Author(s):  
D. G. Kaskaoutis ◽  
P. G. Kosmopoulos ◽  
H. D. Kambezidis ◽  
P. T. Nastos
Keyword(s):  
Winter Season ◽  
Saharan Dust ◽  
Dust Particles ◽  
Hysplit Model ◽  
Air Mass ◽  
Back Trajectories ◽  
Air Masses ◽  
Local Pollution ◽  
Coarse Mode ◽  
Aerosol Types

Aerosol optical depth at 550 nm () and fine-mode (FM) fraction data from Terra-MODIS were obtained over the Greater Athens Area covering the period February 2000–December 2005. Based on both and FM values three main aerosol types have been discriminated corresponding to urban/industrial aerosols, clean maritime conditions, and coarse-mode, probably desert dust, particles. Five main sectors were identified for the classification of the air-mass trajectories, which were further used in the analysis of the ( and FM data for the three aerosol types). The HYSPLIT model was used to compute back trajectories at three altitudes to investigate the relation between -FM and wind sector depending on the altitude. The accumulation of local pollution is favored in spring and corresponds to air masses at lower altitudes originating from Eastern Europe and the Balkan. Clean maritime conditions are rare over Athens, limited in the winter season and associated with air masses from the Western or Northwestern sector. The coarse-mode particles origin seems to be more complicated proportionally to the season. Thus, in summer the Northern sector dominates, while in the other seasons, and especially in spring, the air masses belong to the Southern sector enriched with Saharan dust aerosols.

In the vicinity of a rendering plant it is very difficult to find a really unpolluted place for the olfactometric measurements. Although the most unpolluted site luff of the plant was chosen, another precaution was taken. As adaption of the panelists to the plant odour could cause one of the greatest errors, some minutes before and during the measurement the panelists inhale solely odourless air from the olfactometer. To prevent discomfort by inhaling completely dry air, the olfactometer Modell 1158 is supplied with a moistening device, fig. 1. Fig. 1. Moistening device. In a standard impinger, filled with destillated water, air is moistened close to saturation. An equal flow of moistened air is mixed to the olfactometer outlet, thus delivering to the panelist a rel. moisture content of nearly 50 %. The panel consisted of 4 persons. The samples are prediluted taken into plastic bags, simultaneously at the inlet (raw air) and at the outlet (cleaned air) of the air cleaners. To receive an unfalsified sample from the outlet of the biofilters, undiluted by ambient air, a "tent” of plastic foil, fig. 2, is placed on the filter surface. The cleaned air blows up the tent and escapes through the sample hole, large enough to prevent a significant increase of pressure. The form of the upblown tent indicates, wether a sample area with normal air flow is chosen, and over the space of the covered filter area of 6,25m2 an average sample is received. Fig. 2. Device for cleaned air samples from biofilter outlet.

1986 ◽  
pp. 238-238
Keyword(s):  
Ambient Air ◽  
Air Samples ◽  
Dry Air ◽  
Filter Surface ◽  
Plastic Bags ◽  
Plastic Foil ◽  
Air Cleaners ◽  
Unpolluted Site ◽  
Filter Area ◽  
To Receive

scholarly journals Off-Design Performances of an Organic Rankine Cycle for Waste Heat Recovery from Gas Turbines

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1105 ◽  
Author(s):  
Carlo Carcasci ◽  
Lapo Cheli ◽  
Pietro Lubello ◽  
Lorenzo Winchler
Keyword(s):  
Gas Turbine ◽  
Mass Flow Rate ◽  
Air Temperature ◽  
Mass Flow ◽  
Flow Rate ◽  
Power Output ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Ambient Air ◽  
Air Mass

This paper presents an off-design analysis of a gas turbine Organic Rankine Cycle (ORC) combined cycle. Combustion turbine performances are significantly affected by fluctuations in ambient conditions, leading to relevant variations in the exhaust gases’ mass flow rate and temperature. The effects of the variation of ambient air temperature have been considered in the simulation of the topper cycle and of the condenser in the bottomer one. Analyses have been performed for different working fluids (toluene, benzene and cyclopentane) and control systems have been introduced on critical parameters, such as oil temperature and air mass flow rate at the condenser fan. Results have highlighted similar power outputs for cycles based on benzene and toluene, while differences as high as 34% have been found for cyclopentane. The power output trend with ambient temperature has been found to be influenced by slope discontinuities in gas turbine exhaust mass flow rate and temperature and by the upper limit imposed on the air mass flow rate at the condenser as well, suggesting the importance of a correct sizing of the component in the design phase. Overall, benzene-based cycle power output has been found to vary between 4518 kW and 3346 kW in the ambient air temperature range considered.

scholarly journals Atmospheric Chemistry, Sources, and Sinks of Carbon Suboxide, C<sub>3</sub>O<sub>2</sub>

2017 ◽  
Author(s):  
Stephan Keßel ◽  
David Cabrera-Perez ◽  
Abraham Horowitz ◽  
Patrick R. Veres ◽  
Rolf Sander ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Relative Rate ◽  
Ambient Air ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Carbon Suboxide ◽  
Air Samples ◽  
Sources And Sinks

Abstract. Carbon suboxide, O = C = C = C = O, has been detected in ambient air samples and has the potential to be a noxious pollutant and oxidant precursor; however, its lifetime and fate in the atmosphere is largely unknown. In this work, we collect an extensive set of studies on the atmospheric chemistry of C3O2. Rate coefficients for the reactions of C3O2 with OH radicals and ozone were determined using relative rate techniques as k4 = (2.6 ± 0.5) × 10−12 cm3 molecule−1 s1 at 295 K (independent of pressure between ~ 25 and 1000 mbar) and k6 

scholarly journals Measurement of 14C Concentrations of Stratospheric CO2 by Accelerator Mass Spectrometry

Radiocarbon ◽  
1992 ◽  
Vol 34 (3) ◽  
pp. 745-752 ◽  
Author(s):  
Toshio Nakamura ◽  
Takakiyo Nakazawa ◽  
Nobuyuki Nakai ◽  
Hiroyuki Kitagawa ◽  
Hideyuki Honda ◽  
...  
Keyword(s):  
Transport Mechanism ◽  
Sampling Method ◽  
Lower Stratosphere ◽  
Mass Movement ◽  
Vertical Mixing ◽  
Air Transport ◽  
Air Mass ◽  
Air Masses ◽  
Air Samples ◽  
Accelerator Mass Spectrometer

In order to measure the concentrations of anthropogenically influenced gases in the stratosphere, we have collected air samples from the lower stratosphere since 1985, by a balloon-borne cryogenic sampling method, developed at the Institute of Space and Astronautical Science (ISAS). Air samples of ≃16 liters at STP were collected in the stratosphere at altitudes from 18.6 to 30.4 km, over the northeastern part of Japan (39.5°N, 139–142°E), on 1 September 1989. We conducted 14C analyses to study the vertical and horizontal air-mass movement in the stratosphere, and to investigate the air transport mechanism between troposphere and stratosphere. Carbon dioxide (containing a few mg carbon) was separated cryogenically from the air samples, and the 14C concentration of the CO2 was measured by a Tandetron accelerator mass spectrometer, using Fe-graphite targets prepared by reducing CO2 on Fe-powder with hydrogen in a Vycor tube at 650°. The 14C concentrations, expressed as Δ14C, of CO2 were 267–309‰ at altitudes of 21–30 km, and 134‰ at 19–20 km. The Δ14C values at 21–30 km were higher than those of the current tropospheric CO2, of around 80–200‰. The observed 14C concentrations, higher in the stratosphere than the troposphere, seem to be explained by large bomb-produced 14C inventories and/or high 14C production by cosmic rays, as well as weak vertical mixing of air masses in the stratosphere.

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