scholarly journals COVID-19 restrictions and their influences on ambient air, surface water and plastic waste in a coastal megacity, Chennai, India

2021 ◽  
pp. 112739
Author(s):  
R.S. Robin ◽  
R. Purvaja ◽  
D. Ganguly ◽  
G. Hariharan ◽  
A. Paneerselvam ◽  
...  
Keyword(s):  
Surface Water ◽  
Ambient Air ◽  
Plastic Waste ◽  
Coastal Megacity

scholarly journals High-resolution measurements of elemental mercury in surface water for an improved quantitative understanding of the Baltic Sea as a source of atmospheric mercury

2017 ◽  
Author(s):  
Joachim Kuss ◽  
Siegfried Krüger ◽  
Johann Ruickoldt ◽  
Klaus-Peter Wlost
Keyword(s):  
Surface Water ◽  
High Resolution ◽  
Baltic Sea ◽  
Elemental Mercury ◽  
Ambient Air ◽  
Atmospheric Mercury ◽  
Small Scale ◽  
The Baltic Sea ◽  
Marginal Seas ◽  
The Baltic

Abstract. Marginal seas are directly subjected to anthropogenic and natural influences from land in addition to receiving inputs from the atmosphere and open ocean. Together these lead to pronounced gradients and strong dynamic changes. However, in the case of mercury emissions from these seas, estimates often fail to adequately account for the spatial and temporal variability of the elemental mercury concentration in surface water (Hg0wat). In this study, a method to measure Hg0wat at high resolution was devised and subsequently validated. The better-resolved Hg0wat dataset, consisting of about one measurement per nautical mile, yielded insight into the sea's small-scale variability and thus improved the quantification of the sea's Hg0 emissions, a major source of atmospheric mercury. Research campaigns in the Baltic Sea were carried out between 2011 and 2015 during which Hg0 both in surface water and in ambient air were measured. For the former, two types of equilibrators were used. A membrane equilibrator enabled continuous equilibration and a bottle equilibrator assured that equilibrium was reached for validation. The measurements were combined with data obtained in the Baltic Sea in 2006 from a bottle equilibrator only. The Hg0 sea-air flux was newly calculated with the combined dataset based on current knowledge of the Hg0 Schmidt number, Henry's law constant, and a widely used gas-exchange transfer velocity parameterization. By using a newly developed pump-CTD with increased pumping capability in the Hg0 equilibrator measurements, Hg0wat could also be characterized in deeper water layers. A process study carried out near the Swedish island Øland in August 2015 showed that the upwelling of Hg0-depleted water contributed to Hg0 emissions of the Baltic Sea. However, a delay of a few days after contact between the upwelled water and light was apparently necessary before the biotic and abiotic transformations of ionic to volatile Hg0 produced a distinct sea-air Hg0 concentration gradient. This study clearly showed spatial, seasonal, and interannual variability in the Hg0 sea-air flux of the Baltic Sea. The average annual Hg0 emission was 0.90 ± 0.18 Mg for the Baltic Proper and to 1.73 ± 0.32 Mg for the entire Baltic Sea, which is about half the amount entrained by atmospheric deposition. A comparison of our results with the Hg0 sea-air fluxes determined in the Mediterranean Sea and in marginal seas in East Asia were to some extent similar but they partly differed in terms of the deviations in the amount and seasonality of the flux.

scholarly journals Existence of Microplastics in Indonesia’s Surface Water: A Review

2021 ◽  
Vol 13 (3) ◽  
Author(s):  
Firdaus Ali ◽  
◽  
Khalidah Nurul Azmi ◽  
Madina Rain Firdaus ◽  
◽  
...  
Keyword(s):  
Surface Water ◽  
Management Strategy ◽  
Water Environment ◽  
Short Review ◽  
Plastic Waste ◽  
Emerging Contaminant ◽  
Small Fragment ◽  
The World ◽  
Treatment Technologies ◽  
Living Organisms

Plastic waste is often being an issue that needs to be overcome since mostly plastic waste ends up in the environment. Some studies stated that plastic waste found in the marine environment are mostly sourced from the land which transported along the river systems. It is nearly impossible for nature to completely breakdown plastic waste, regarding its durability and resistance to degradation. Small fragment resulted from the slowly breakdown of plastic waste is an emerging contaminant in water environment called as microplastic. This study is conducted as a short review of microplastics existence on the surface water in Indonesia, particularly on the Citarum River as the most polluted river in the world. Besides, only few papers regarding microplastic occurrence on the surface water in Indonesia that have been published, which mostly focuses on Citarum River. It is known that microplastic tend to persist in water and has possible risks to the living organisms. Hence, managing microplastic pollution is needed which can be in the form of management strategy and treatment technologies used to remove microplastics from water.

Study and Environmental Impact Evaluation on an Expanding Project of Coal Gangue Power Plant

2012 ◽  
Vol 485 ◽  
pp. 596-599 ◽  
Author(s):  
Rong Jun Su
Keyword(s):  
Surface Water ◽  
Power Plant ◽  
Environmental Impact ◽  
Prediction Models ◽  
Environmental Influence ◽  
Water Environment ◽  
Ambient Air ◽  
Coal Gangue ◽  
Operating Period ◽  
Acoustic Environment

To asses environmental feasibility of Expanding Project of Heilongjiang Dadong Coal Gangue Power Plant (EPHDCGPP) and predict it’s influence to ambient, according to government laws, codes and regulations such as 《The Specific Guides to Environmental Impact Assessment》 and technical features of the project, the range, grade, factors and prediction models of influence evaluation were determined. Then predictions and evaluations of ambient air, surface water environment, acoustic environment, waste solids and environmental risk during construction and operating period were undertaken. The results showed that the environmental influence in construction period can meet standard. In operating period, there is no any increased influence on surface water environment, ambient air, acoustic environment and waste solids compared with present plant. The smoke dust and SO2 discharge are still 676.5 t/a and 680 t/a. Moreover, expanding project will reduce 45.8 t/a and 9.9 t/a of chemical oxygen demand (COD) and NH4+-N discharge than before. On occuring accident, discharge concentration of SO2 and smoke dust will exceeds discharge standard 1.5 times and 4.5 times respectively. Therefore, on the condition of eradicating completely accidental discharge this project is feasible from the point of view of environment.

Modelling hydro-climatic suitability of malaria transmission in Africa: new patterns emerge

2020 ◽  
Author(s):  
Mark Smith ◽  
Tom Willis ◽  
Lorenzo Alfieri ◽  
William James ◽  
Mark Trigg ◽  
...  
Keyword(s):  
Surface Water ◽  
Malaria Transmission ◽  
Water Availability ◽  
General Circulation ◽  
Hydrological Model ◽  
Ambient Air ◽  
Breeding Habitat ◽  
Habitat Availability ◽  
Climatic Suitability ◽  
Continental Scale

<p>The availability of water at the ground surface for vector mosquito larval habitats is a critical environmental control of malaria transmission. While ambient air temperature controls the rate of several components of the malaria transmission cycle, extensive laboratory and field studies mean that suitable temperature ranges are well established. In contrast, estimation of surface water availability from current global datasets remains challenging. Instead, monthly rainfall is typically used as a proxy for habitat availability; a threshold of 80 mm per month has gained traction as a proxy for breeding habitat in continental-scale models of malaria climate suitability in Africa and has been applied across the globe. However, since complex and spatially variable hydrological processes (e.g. infiltration, evaporation, soil moisture storage, transfer through and storage in river networks) are omitted, a wide variety of rainfall thresholds are found in the literature that leads to large differences in environmental suitability estimates. Moreover, irrigated areas have been observed to provide suitable year-round habitat for Anopheles mosquitos but are not included in such models.</p><p> </p><p>Here we show that across continental Africa, the estimated geographic range of climatic suitability for malaria transmission is more sensitive to precipitation thresholds than the thermal response curves applied. To address this problem and provide a more physical-basis for larval habitat estimation, we use daily climate predictions from seven downscaled general circulation models to run a continental-scale hydrological model (Lisflood) for a process-based representation of mosquito breeding habitat availability. A more complex pattern of malaria climatic suitability emerges as water is routed through drainage networks and river corridors serve as year-round transmission foci. The area estimated to be hydro-climatically suitable for stable malaria transmission is smaller than previous models suggest; however, more people are found in longer-transmission season areas due to higher-density populations along rivers and in irrigated areas. Hydro-climatic predictions of malaria suitable areas show only a very small increase in state-of-the-art future climate scenarios; however, bigger geographical shifts are observed than with most rainfall threshold models and the pattern of that shift is very different when a hydrological model is used to estimate surface water availability for vector breeding. </p>

scholarly journals High-resolution measurements of elemental mercury in surface water for an improved quantitative understanding of the Baltic Sea as a source of atmospheric mercury

2018 ◽  
Vol 18 (6) ◽  
pp. 4361-4376 ◽  
Author(s):  
Joachim Kuss ◽  
Siegfried Krüger ◽  
Johann Ruickoldt ◽  
Klaus-Peter Wlost
Keyword(s):  
Surface Water ◽  
High Resolution ◽  
Baltic Sea ◽  
Elemental Mercury ◽  
Ambient Air ◽  
Atmospheric Mercury ◽  
Small Scale ◽  
The Baltic Sea ◽  
Marginal Seas ◽  
The Baltic

Abstract. Marginal seas are directly subjected to anthropogenic and natural influences from land in addition to receiving inputs from the atmosphere and open ocean. Together these lead to pronounced gradients and strong dynamic changes. However, in the case of mercury emissions from these seas, estimates often fail to adequately account for the spatial and temporal variability of the elemental mercury concentration in surface water (Hg0wat). In this study, a method to measure Hg0wat at high resolution was devised and subsequently validated. The better-resolved Hg0wat dataset, consisting of about one measurement per nautical mile, yielded insight into the sea's small-scale variability and thus improved the quantification of the sea's Hg0 emission. This is important because global marine Hg0 emissions constitute a major source of atmospheric mercury. Research campaigns in the Baltic Sea were carried out between 2011 and 2015 during which Hg0 both in surface water and in ambient air were measured. For the former, two types of equilibrators were used. A membrane equilibrator enabled continuous equilibration and a bottle equilibrator assured that equilibrium was reached for validation. The measurements were combined with data obtained in the Baltic Sea in 2006 from a bottle equilibrator only. The Hg0 sea–air flux was newly calculated with the combined dataset based on current knowledge of the Hg0 Schmidt number, Henry's law constant, and a widely used gas exchange transfer velocity parameterization. By using a newly developed pump–CTD with increased pumping capability in the Hg0 equilibrator measurements, Hg0wat could also be characterized in deeper water layers. A process study carried out near the Swedish island Øland in August 2015 showed that the upwelling of Hg0-depleted water contributed to Hg0 emissions of the Baltic Sea. However, a delay of a few days after contact between the upwelled water and light was apparently necessary before the biotic and abiotic transformations of ionic to volatile Hg0 produced a distinct sea–air Hg0 concentration gradient. This study clearly showed spatial, seasonal, and interannual variability in the Hg0 sea–air flux of the Baltic Sea. The average annual Hg0 emission was 0.90  ±  0.18 Mg for the Baltic proper and extrapolated to 1.73  ±  0.32 Mg for the entire Baltic Sea, which is about half the amount entrained by atmospheric deposition. A comparison of our results with the Hg0 sea–air fluxes determined in the Mediterranean Sea and in marginal seas in East Asia were to some extent similar but they partly differed in terms of the deviations in the amount and seasonality of the flux.

Application of a Simple Cold Stub to the Direct Observation of Frozen Hydrated Sand

1973 ◽  
Vol 31 ◽  
pp. 212-213
Author(s):  
John M. Wehrung ◽  
Richard J. Harniman
Keyword(s):  
United States ◽  
Surface Water ◽  
Direct Observation ◽  
Controlled Study ◽  
Clay Particles ◽  
Organic Debris ◽  
Rock Formations ◽  
Water Tables ◽  
Permeable Rock ◽  
Natural Means

Water tables in aquifer regions of the southwest United States are dropping off at a rate which is greater than can be replaced by natural means. It is estimated that by 1985 wells will run dry in this region unless adequate artificial recharging can be accomplished. Recharging with surface water is limited by the plugging of permeable rock formations underground by clay particles and organic debris.A controlled study was initiated in which sand grains were used as the rock formation and water with known clay concentrations as the recharge media. The plugging mechanism was investigated by direct observation in the SEM of frozen hydrated sand samples from selected depths.

Development of a Rapid Survey Method of Sampling and Analysis for Asbestos in Ambient Air

1972 ◽  
Vol 30 ◽  
pp. 630-631 ◽  
Author(s):  
R. E. Heffelfinger ◽  
C. W. Melton ◽  
D. L. Kiefer ◽  
W. M. Henry ◽  
R. J. Thompson
Keyword(s):  
Neutron Activation ◽  
Ambient Air ◽  
Survey Method ◽  
Potential Hazard ◽  
Transmission Microscopy ◽  
Comparative Analyses ◽  
Asbestos Fibers ◽  
Controlled Conditions ◽  
Unequivocal Identification ◽  
Identification And Quantification

A methodology has been developed and demonstrated which is capable of determining total amounts of asbestos fibers and fibrils in air ranging from as low as fractional nanograms per cubic meter (ng/m3) of air to several micrograms/m3. The method involves the collection of samples on an absolute filter and provides an unequivocal identification and quantification of the total asbestos contents including fibrils in the collected samples.The developed method depends on the trituration under controlled conditions to reduce the fibers to fibrils, separation of the asbestos fibrils from other collected air particulates (beneficiation), and the use of transmission microscopy for identification and quantification. Its validity has been tested by comparative analyses by neutron activation techniques. It can supply the data needed to set emissions criteria and to serve as a basis for assessing the potential hazard for asbestos pollution to the populace.

Application of Electron Optics to Characterization of Particulate Pollutants

1972 ◽  
Vol 30 ◽  
pp. 364-365
Author(s):  
J. B. Moran ◽  
J. L. Miller
Keyword(s):  
Air Quality ◽  
Quality Standards ◽  
Ambient Air ◽  
Hazardous Substances ◽  
Fuel Additives ◽  
Ambient Air Quality ◽  
Air Quality Standards ◽  
Emission Standards ◽  
Stationary Sources ◽  
Ambient Air Quality Standards

The Clean Air Act Amendments of 1970 provide the basis for a dramatic change in Federal air quality programs. The Act establishes new standards for motor vehicles and requires EPA to establish national ambient air quality standards, standards of performance for new stationary sources of pollution, and standards for stationary sources emitting hazardous substances. Further, it establishes procedures which allow states to set emission standards for existing sources in order to achieve national ambient air quality standards. The Act also permits the Administrator of EPA to register fuels and fuel additives and to regulate the use of motor vehicle fuels or fuel additives which pose a hazard to public health or welfare.National air quality standards for particulate matter have been established. Asbestos, mercury, and beryllium have been designated as hazardous air pollutants for which Federal emission standards have been proposed.

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;

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