scholarly journals Environmental Issues within the Chlor-Alkali Manufacturing Industry -

2012 ◽  
Vol 69 (2) ◽  
Author(s):  
Tania MIHAIESCU ◽  
Radu MIHAIESCU ◽  
Antonia ODAGIU
Keyword(s):  
Manufacturing Industry ◽  
Mercury Contamination ◽  
Mercury Compounds ◽  
Mercury Cell ◽  
Run Off ◽  
Plant Equipment ◽  
Pollutant Source ◽  
Almost All ◽  
A Site ◽  
Diffuse Emissions

At present is estimated that around 12000 tones of mercury are contained in mercury cells used for chlorine production in the EU. Mercury contamination risk, remains active for long periods after the removing of the pollutant source, and is recognized as extremely dangerous for humans and environment due to the toxicity of various mercury compounds that can accumulate in the trophic chains. Almost all facilities using mercury -cell process reports unaccounted for mercury losses. The annual mercury balance for a site is never zero. This is because mercury accumulates in plant equipment and structures during the life of the plant. The majority of mercury losses occur, in the various process wastes. Considerable emissions of mercury can also occur with run-off water. The soil at many sites is contaminated with mercury due to deposition of atmospheric diffuse emissions and/or historical disposal of mercury contaminated wastes. An even greater problem is represented by the decommissioning of obsolete facilities when large quantities of mercury can escape in the environment despite all precaution measures.

Methyl mercury in the dutch rhine delta

1994 ◽  
Vol 30 (10) ◽  
pp. 213-219 ◽  
Author(s):  
Hendrik Pieters ◽  
Victor Geuke
Keyword(s):  
Suspended Matter ◽  
Methyl Mercury ◽  
Mercury Contamination ◽  
Benthic Organisms ◽  
Considerable Decrease ◽  
Continuous Sedimentation ◽  
Highly Correlated ◽  
High Level ◽  
Almost All

Samples of yellow eel from various locations in the Dutch Rhine area have been analyzed for trend monitoring of mercury since 1977. In the western Rhine delta mercury levels in eels have hardly changed since the seventies, whereas in the eastern part of the Dutch Rhine area a considerable decrease of mercury concentrations in eel has occurred. Because of continuous sedimentation of contaminated suspended matter transported from upstream regions, accumulation rates and concentrations of mercury in eel in the western Rhine delta remained at a relatively high level. Analyses of methyl mercury in biota have been performed to elucidate the role of methyl mercury in the mercury contamination of the Dutch Rhine ecosystem. Low percentages of methyl mercury were observed in zooplankton (3 to 35%). In benthic organisms (mussels) percentages of methyl mercury ranged from 30 to 57%, while in fish species and liver of aquatic top predator birds almost all the mercury was present in the form of methyl mercury (> 80%). During the period 1970-1990 mercury concentrations of suspended matter in the eastern Rhine delta have drastically decreased. These concentrations seemed to be highly correlated with mercury concentrations of eel (R = 0.84). The consequences of this relation are discussed.

Tolerance to heavy metals in Littorina saxatilis from a metal contaminated estuary in the Isle of Man

2004 ◽  
Vol 84 (2) ◽  
pp. 393-400 ◽  
Author(s):  
Erema R. Daka ◽  
Stephen J. Hawkins
Keyword(s):  
Littorina Saxatilis ◽  
Co Tolerance ◽  
Isle Of Man ◽  
Run Off ◽  
High Zinc ◽  
Lead Tolerance ◽  
Test Concentration ◽  
A Site ◽  
High Lead ◽  
Tolerance To Copper

Population differences were measured in the tolerance of Littorina saxatilis from sites around the Isle of Man, to acute exposure to zinc, lead, copper and cadmium. Animals from a site influenced by disused mine run-off in Laxey estuary (high zinc) were compared with animals from less contaminated estuaries (Peel-high lead, but lower zinc), and the relatively uncontaminated Castletown and Ramsey estuaries, plus the open coast near Derbyhaven. Median lethal times (LT50) were estimated for each test concentration (5, 10, 20 mg l−1 Zn; 5, 10 mg l−1 Pb; 0·5, 1·0, 2·0 mg l−1 Cu and Cd) except for those that did not produce sufficient mortalities. Individuals from Laxey estuary showed significantly higher tolerances to zinc (10 mg l−1) and lead (5 mg l−1) than animals from the unpolluted sites. No co-tolerance to copper or cadmium was apparent. Population tolerance to zinc was correlated with reduced accumulation rates. Lead tolerance may result from the ability of the tolerant individuals to sequester the metal and detoxify it in their tissues; the littorinids from Laxey had significantly higher rates of lead accumulation.

Elevated mercury exposure and neurochemical alterations in little brown bats (Myotis lucifugus) from a site with historical mercury contamination

Ecotoxicology ◽  
2012 ◽  
Vol 21 (4) ◽  
pp. 1094-1101 ◽  
Author(s):  
Dong-Ha Nam ◽  
David Yates ◽  
Pedro Ardapple ◽  
David C. Evers ◽  
John Schmerfeld ◽  
...  
Keyword(s):  
Mercury Exposure ◽  
Myotis Lucifugus ◽  
Mercury Contamination ◽  
A Site ◽  
Little Brown Bats

scholarly journals The Escherichia coli cysG promoter belongs to the ‘extended −10’ class of bacterial promoters

1993 ◽  
Vol 296 (3) ◽  
pp. 851-857 ◽  
Author(s):  
T Belyaeva ◽  
L Griffiths ◽  
S Minchin ◽  
J Cole ◽  
S Busby
Keyword(s):  
Escherichia Coli ◽  
Point Mutations ◽  
Growth Conditions ◽  
Upstream Region ◽  
E Coli ◽  
Run Off ◽  
A Site ◽  
Specific Sequences

The Escherichia coli cysG promoter has been subcloned and shown to function constitutively in a range of different growth conditions. Point mutations identify the -10 hexamer and an important 5′-TGN-3′ motif immediately upstream. The effects of different deletions suggest that specific sequences in the -35 region are not essential for the activity of this promoter in vivo. This conclusion was confirmed by in vitro run-off transcription assays. The DNAase I footprint of RNA polymerase at the cysG promoter reveals extended protection upstream of the transcript start, and studies with potassium permanganate as a probe suggest that the upstream region is distorted in open complexes. Taken together, the results show that the cysG promoter belongs to the ‘extended -10’ class of promoters, and the base sequence is similar to that of the P1 promoter of the E. coli galactose operon, another promoter in this class. In vivo, messenger initiated at the cysG promoter appears to be processed by cleavage at a site 41 bases downstream from the transcript start point.

scholarly journals Technical note: A time-integrated sediment trap to sample diatoms for hydrological tracing

2020 ◽  
Vol 24 (10) ◽  
pp. 4709-4725
Author(s):  
Jasper Foets ◽  
Carlos E. Wetzel ◽  
Núria Martínez-Carreras ◽  
Adriaan J. Teuling ◽  
Jean-François Iffly ◽  
...  
Keyword(s):  
Water Quality Assessment ◽  
Technical Note ◽  
Sampling Effort ◽  
Terrestrial Environment ◽  
The Third ◽  
Run Off ◽  
Analysis Of Similarity ◽  
Sediment Data ◽  
Almost All ◽  
Diatom Community Composition

Abstract. Diatoms, microscopic single-celled algae, are present in almost all habitats containing water (e.g. streams, lakes, soil and rocks). In the terrestrial environment, their diversified species distributions are mainly controlled by physiographical factors and anthropic disturbances which makes them useful tracers in catchment hydrology. In their use as a tracer, diatoms are generally sampled in streams by means of an automated sampling method; as a result, many samples must be collected to cover a whole storm run-off event. As diatom analysis is labour-intensive, a trade-off has to be made between the number of sites and the number of samples per site. In an attempt to reduce this sampling effort, we explored the potential for the Phillips sampler, a time-integrated mass-flux sampler, to provide a representative sample of the diatom assemblage of a whole storm run-off event. We addressed this by comparing the diatom community composition of the Phillips sampler to the composite community collected by automatic samplers for three events. Non-metric multidimensional scaling (NMDS) showed that, based on the species composition, (1) all three events could be separated from each other, (2) the Phillips sampler was able to sample representative communities for two events and (3) significantly different communities were only collected for the third event. These observations were generally confirmed by analysis of similarity (ANOSIM), permutational multivariate analysis of variance (PERMANOVA), and the comparison of species relative abundances and community-derived indices. However, sediment data from the third event, which was sampled with automatic samplers, showed a large amount of noise; therefore, we could not verify if the Phillips sampler sampled representative communities or not. Nevertheless, we believe that this sampler could not only be applied in hydrological tracing using terrestrial diatoms, but it might also be a useful tool in water quality assessment.

scholarly journals THE RESULTS OF THE MONITORING OF THE MERCURY CONTAMINATION WITHIN A MEGAPOLIS

2018 ◽  
Vol 97 (12) ◽  
pp. 1189-1194 ◽  
Author(s):  
A. M. Malov ◽  
L. V. Lukovnikova ◽  
Liliya A. Alikbayeva ◽  
I. S. Iakubova ◽  
D. K. Shchegolikhin
Keyword(s):  
Soil Layer ◽  
Argon Plasma ◽  
Atomic Emission ◽  
Mercury Content ◽  
Mercury Contamination ◽  
Human Organism ◽  
Professional Activities ◽  
Inductively Coupled ◽  
Mercury Compounds ◽  
Environmental Objects

Introduction. Macromycetes include mercury compounds in their metabolism processes. The method for assessing the contamination of the soil layer (topsoil) by mercury by estimating the mercury content in the mushrooms is accessible and sufficiently informative. Mercury is a persistent inorganic ecotoxicant, it enters the human body from the environment. This process requires constant monitoring of the content of this hazardous metal in the environment and the in biomaterials of the human organism. Material and methods. The object of the study was selected bracket macromycetes growing on open soil areas: lawns, boulevards, parks, squares, etc. There were studied representatives from the fungal families as follows: Agaricacea, Boletaceae, Russu-laceae, Coprinaceae. Mushrooms were collected in the stage of sporulation, in the spring-summer-autumn period from 2002 to 2017. The determination of mercury in fungi was performed by atomic absorption method on specialized mercury analyzers of the “Julia” series (detection limit of 1 ng/g, the error of the method is not more than 15%). Mercury content in hair was determined in 1153 St. Petersburg residents aged from 0 to 80 years using atomic emission and mass spectrometry methods with inductively coupled argon plasma on devices Elan 9000 (Perkin Elmer, USA) and Optima 2000 V (Perkin Elmer, USA). Results. The results of the analysis of mushrooms collected in 2017 on one of the green streets of the industrial district of Saint-Petersburg demonstrate a high degree of mercury contamination of the megapolis. Mushrooms (Cinereus comatus) were collected at three locations of Alameda, separated by approximately 100 m, and were analyzed for the content of mercury in them. The following values of mercury in mushrooms were got is a 0.61 mg/kg, 0.83 mg/kg and 0.35 mg/kg. The hair of 1153 inhabitants of St.-Petersburg has been analyzed for mercury content. The highest concentrations of mercury have been established to be set at working population aged 18-64 years. This fact can be explained by the professional activities associated with the contact with mercury and active way of life, particularly with greater frequency of the use in the diet of mushrooms and other products, being potential sources of mercury. Discussion. The performed studies show the mercury concentration to be not only generalized but also stable. The pollution of the territory of St. Petersburg is little different from the pollution of the territories of other cities, where the mercury content in mushrooms is also found to be high in comparison with the permissible level. Conclusion. The obtained data indicate a high stable contamination of the territory of St. Petersburg and its nearest suburbs with mercury. Mercury and its compounds in environmental objects (mushrooms) can present the real danger to the health of the population, therefore there is a need for non-invasive monitoring of the content of mercury in biomaterials of the human organism and environmental objects.

scholarly journals Virtual worlds as a site of convergence for children’s play

1970 ◽  
Vol 3 (2) ◽  
Author(s):  
Sun Sun Lim ◽  
Lynn Schofield Clark
Keyword(s):  
Conceptual Framework ◽  
Virtual Worlds ◽  
Learning Opportunities ◽  
Children's Play ◽  
Parents And Children ◽  
Children’S Play ◽  
Potential Risks ◽  
Almost All ◽  
A Site ◽  
Convergence Of Cultures

Virtual worlds have made notable inroads into the lives of children, affording online extensions of their offline lives In this article, we propose a conceptual framework for understanding the space that virtual worlds occupy in children’s play and the ways in which children’s participation in them overlap with their everyday play experiences, both offline and mediated. We argue that virtual worlds can be viewed as sites of convergence for children’s play in that virtual worlds allow for almost all aspects of children’s play to converge, primarily manifested in the convergence of social spheres, the convergence of play spaces and playthings, the convergence of cultures and the convergence of learning experiences. we explain how such convergence, while presenting valuable opportunities for children to learn and develop, will not be fully exploited without a corresponding ability on the part of parents and children to recognise potential risks; and for parents and educators to scaffold these learning opportunities.

scholarly journals Application of Special Cause Control Charts to Green Sand Process

2015 ◽  
Vol 15 (4) ◽  
pp. 55-60 ◽  
Author(s):  
M. Perzyk ◽  
A. Rodziewicz
Keyword(s):  
Control Charts ◽  
Manufacturing Industry ◽  
Processing System ◽  
Original Data ◽  
Green Sand ◽  
Statistical Process ◽  
Shewhart Control Charts ◽  
Shewhart Control ◽  
Iron Foundry ◽  
Almost All

Abstract Statistical Process Control (SPC) based on the well known Shewhart control charts, is widely used in contemporary manufacturing industry, including many foundries. However, the classic SPC methods require that the measured quantities, e.g. process or product parameters, are not auto-correlated, i.e. their current values do not depend on the preceding ones. For the processes which do not obey this assumption the Special Cause Control (SCC) charts were proposed, utilizing the residual data obtained from the time-series analysis. In the present paper the results of application of SCC charts to a green sand processing system are presented. The tests, made on real industrial data collected in a big iron foundry, were aimed at the comparison of occurrences of out-of-control signals detected in the original data with those appeared in the residual data. It was found that application of the SCC charts reduces numbers of the signals in almost all cases It is concluded that it can be helpful in avoiding false signals, i.e. resulting from predictable factors.

A Successful Remediation Project

2009 ◽  
Author(s):  
L. Max Scott
Keyword(s):  
Public Relations ◽  
Manufacturing Industry ◽  
Nuclear Regulatory Commission ◽  
Management Plan ◽  
Lessons Learned ◽  
Radioactive Material ◽  
Aircraft Manufacturing ◽  
Molten Magnesium ◽  
Regulatory Commission ◽  
A Site

As part of a program to visit formerly licensed sites to determine if they meet current uncontrolled release conditions, a United States Nuclear Regulatory Commission (USNRC) inspection was conducted in the fall of 1993 at a site that had possessed a radioactive material license from about 1955 to 1970. While the license was in force, the plant processed magnesium scrap containing up to 4 percent thorium. The source of the scrap is believed to be the aircraft manufacturing industry. The scrap was placed in furnaces and heated to the melting point of magnesium, and the molten magnesium was drawn off, leaving the thorium with the residue (dross). Under the regulation in existence at that time, the thorium dross was buried on site in an approximate 14 acre field. In 1993 the inspector found readings up to 900uR/h. Early in 1994 an informal grid survey of most of the 14 acre site was conducted. Based on that survey, it was concluded that the thorium was widespread and extended beyond the property lines. The preliminary findings were reported to the USNRC, and in 1994 the site was designated as a Site Decommissioning Management Plan (SMPD) site. A remediation team was formed which included the following disciplines: remediation health physics, geology, hydrology, engineering, law, public relations, and project management. This remediation team planned, participated in selecting vendors, and provided project over site for all activities from site characterization through the final status survey. In 2006 the site was released for uncontrolled access. A chronology of activities with lessons learned will be presented.

Leucocytes and Platelets in Isolated Lung Perfusion

1975 ◽  
Author(s):  
N. van Zandwijk ◽  
Th. F. J. Lenssen ◽  
Elisabeth M. Prakke ◽  
J. van der Meer ◽  
A. S. Groen ◽  
...  
Keyword(s):  
Whole Blood ◽  
Serotonin Level ◽  
Rabbit Lung ◽  
Isolated Lung Perfusion ◽  
Isolated Lung ◽  
Isolated Lungs ◽  
Almost All ◽  
A Site ◽  
Plasma Serotonin ◽  
Lung Preparation

Removal of leucocytes and platelets from homologous blood prevents early functional and morphologic deterioration of an isolated rabbit lung preparation. Lungs perfused with whole blood have a marked ability for granulocyte sequestration. Control experiments in which the perfusion system was not connected with the lung revealed an increase of plasma serotonin and histamine levels due to platelet injury and/or aggregation generated by the perfusion circuit. When an isolated lung was connected with the circuit, plasma serotonin was largely metabolized. However, the metabolic uptake of serotonin by lungs perfused with whole blood decreased after 30 min while pulmonary vascular resistence (PVR) increased. In contrast, perfusion experiments with blood from which almost all leucocytes had been removed, were characterized by a less pronounced rise of plasma serotonin level and no or little change in PVR.It is concluded that leucocytes particularly granulocytes most likely traumatized by the extracorporeal procedure, have a detrimental effect on the integrity of perfused isolated lungs. Damage of endothelium, which has been recognized as a site of serotonin metabolism, could then be an early symptom. The results of our experiments in which the perfused isolated lung preparation has been used as a model for pulmonary dysfunction after extracorporeal circulation and massive transfusion warrants more attention to be paid to the role granulocytes and platelets play in the genesis of respiratory distress after such procedures.

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