Study on Yangzonghai runoff areas rainfall and lake body capacity for increase of arsenic concentration in the lake

2014 ◽  
Author(s):  
Zhihui Liu ◽  
Xiaoming Li ◽  
Juan Wang ◽  
Shu Zhang ◽  
Genlin Zhang ◽  
...  
Keyword(s):  
Arsenic Concentration ◽  
Capacity For Increase

Morphometric Analysis of the Hepatocytes from Fish Exposed to Arsenic

1976 ◽  
Vol 34 ◽  
pp. 282-283
Author(s):  
Elsie M. B. Sorensen
Keyword(s):  
Morphometric Analysis ◽  
Arsenic Concentration ◽  
Ultrastructural Changes ◽  
Sodium Arsenate ◽  
Lepomis Cyanellus ◽  
Mammalian Counterpart ◽  
Intracellular Changes ◽  
Green Sunfish ◽  
Organic Pesticides

The detoxification capacity of the liver is well documented for a variety of substances including ethanol, organic pesticides, drugs, and metals. The piscean liver, although less enzymatically active than the mammalian counterpart (1), contains endoplasmic reticulum with an impressive repertoire of oxidizing, reducing, and conjugating abilities (2). Histopathologic changes are kncwn to occur in fish hepatocytes following in vivo exposure to arsenic (3); however, ultrastructural changes have not been reported. This study involved the morphometric analysis of intracellular changes in fish parynchymal hepatocytes and correlation with arsenic concentration in the liver.Green sunfish (Lepomis cyanellus, R.) were exposed to 0, 30, or 60 ppm arsenic (as sodium arsenate) at 20°C for 1, 2, or 3 week intervals before removal of livers for quantification of the arsenic burden (using neutron activation analysis) and morphometric analysis of ultrastructural alterations. Livers were cut into 1 mm cubes for fixation, dehydration, and embedding.

Study of dislocation loops in Arsenic-Rich as-grown GaAs

1987 ◽  
Vol 45 ◽  
pp. 350-351
Author(s):  
Byung-Teak Lee
Keyword(s):  
Point Defects ◽  
Electronic Devices ◽  
Arsenic Concentration ◽  
Stoichiometric Compound ◽  
Dislocation Loops ◽  
Gaas Crystal ◽  
Ion Milling ◽  
Transmission Electron ◽  
Arsenic Source ◽  
High Arsenic

Grown-in dislocations in GaAs have been a major obstacle in utilizing this material for the potential electronic devices. Although it has been proposed in many reports that supersaturation of point defects can generate dislocation loops in growing crystals and can be a main formation mechanism of grown-in dislocations, there are very few reports on either the observation or the structural analysis of the stoichiometry-generated loops. In this work, dislocation loops in an arsenic-rich GaAs crystal have been studied by transmission electron microscopy.The single crystal with high arsenic concentration was grown using the Horizontal Bridgman method. The arsenic source temperature during the crystal growth was about 630°C whereas 617±1°C is normally believed to be optimum one to grow a stoichiometric compound. Samples with various orientations were prepared either by chemical thinning or ion milling and examined in both a JEOL JEM 200CX and a Siemens Elmiskop 102.

As(III) Removal by Dynamic Adsorption onto Amberlite XAD7 Functionalized with Crown Ether and Doped with Fe(III) Ions

2019 ◽  
Vol 70 (7) ◽  
pp. 2330-2334
Author(s):  
Mihaela Ciopec ◽  
Adina Negrea ◽  
Narcis Duteanu ◽  
Corneliu Mircea Davidescu ◽  
Iosif Hulka ◽  
...  
Keyword(s):  
Adsorption Process ◽  
Arsenic Removal ◽  
Arsenic Concentration ◽  
Fixed Bed ◽  
World Health ◽  
Arsenic Content ◽  
Arsenic Adsorption ◽  
Stage Of Development ◽  
Wide Range ◽  
Health Organization

Arsenic content in groundwater�s present a wide range of concentration, ranging from hundreds of micrograms to thousands of micrograms of arsenic per litter, while the maximum permitted arsenic concentration established by World Health Organization (WHO) is 10 mg L-1. According to the WHO all people, regardless of their stage of development and their social economic condition, have the right to have access to adequate drinking water. The most efficient and economic technique used for arsenic removal is represented by adsorption. In order to make this remediation technique more affordable and environmentally friendly is important to new materials with advance adsorbent properties. Novelty of present paper is represented by the usage of a new adsorbent material obtained by physical - chemical modification of Amberlite XAD polymers using crown ethers followed by iron doping, due to well-known affinity of arsenic for iron ions. Present paper aims to test the obtained modified Amberlite polymer for arsenic removal from real groundwater by using adsorption in a fixed bed column, establishing in this way a mechanism for the adsorption process. During experimental work was studied the influence of competing ions from real water into the arsenic adsorption process.

STIMULATING MICROBIAL SULFATE REDUCTION TO LOWER ARSENIC CONCENTRATION IN GROUNDWATER

2016 ◽  
Author(s):  
Ben R. Haller ◽  
◽  
Janet M. Paper ◽  
Michael Vega ◽  
Saugata Datta ◽  
...  
Keyword(s):  
Sulfate Reduction ◽  
Arsenic Concentration ◽  
Microbial Sulfate Reduction

ARSENIC CONCENTRATION VARIABILITY IN NEWLY CONSTRUCTED DRINKING WATER WELLS IN MINNESOTA, USA

2018 ◽  
Author(s):  
Emily Berquist ◽  
◽  
Helen Fitzgerald Malenda ◽  
Melinda L. Erickson
Keyword(s):  
Drinking Water ◽  
Arsenic Concentration ◽  
Water Wells

scholarly journals Synonymous single nucleotide polymorphism in arsenic (+3) methyltransferase of the Western mosquitofish (Gambusia affinis) and its gene expression among field populations

Ecotoxicology ◽  
2021 ◽  
Author(s):  
Daesik Park ◽  
Catherine R. Propper ◽  
Guangning Wang ◽  
Matthew C. Salanga
Keyword(s):  
Gene Expression ◽  
Sequence Variation ◽  
Allelic Variation ◽  
Arsenic Concentration ◽  
Gambusia Affinis ◽  
Contamination Level ◽  
Water Medium ◽  
Single Nucleotide ◽  
Wide Range ◽  
High Arsenic

AbstractNaturally occurring arsenic is toxic at extremely low concentrations, yet some species persist even in high arsenic environments. We wanted to test if these species show evidence of evolution associated with arsenic exposure. To do this, we compared allelic variation across 872 coding nucleotides of arsenic (+3) methyltransferase (as3mt) and whole fish as3mt gene expression from three field populations of Gambusia affinis, from water sources containing low (1.9 ppb), medium-low (3.3 ppb), and high (15.7 ppb) levels of arsenic. The high arsenic site exceeds the US EPA’s Maximum Contamination Level for drinking water. Medium-low and high populations exhibited homozygosity, and no sequence variation across all animals sampled. Eleven of 24 fish examined (45.8%) in the low arsenic population harbored synonymous single nucleotide polymorphisms (SNPs) in exons 4 and/or 10. SNP presence in the low arsenic population was not associated with differences in as3mt transcript levels compared to fish from the medium-low site, where SNPs were noted; however, as3mt expression in fish from the high arsenic concentration site was significantly lower than the other two sites. Low sequence variation in fish populations from sites with medium-low and high arsenic concentrations suggests greater selective pressure on this allele, while higher variation in the low population suggests a relaxed selection. Our results suggest gene regulation associated with arsenic detoxification may play a more crucial role in influencing responses to arsenic than polymorphic gene sequence. Understanding microevolutionary processes to various contaminants require the evaluation of multiple populations across a wide range of pollution exposures.

scholarly journals Evaluation of Fe-Mg Binary Oxide for As (III) Adsorption—Synthesis, Characterization and Kinetic Modelling

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 805
Author(s):  
Saif Ullah Khan ◽  
Rumman Zaidi ◽  
Feroz Shaik ◽  
Izharul Haq Farooqi ◽  
Ameer Azam ◽  
...  
Keyword(s):  
Arsenic Removal ◽  
Kinetic Modelling ◽  
Arsenic Concentration ◽  
Experimental Studies ◽  
Precipitation Method ◽  
Arsenic Adsorption ◽  
Adsorbent Dosage ◽  
X Ray ◽  
Co Precipitation ◽  
Contaminated Waters

Nanotechnology has received much attention in treating contaminated waters. In the present study, a facile co-precipitation method was employed to synthesize a novel iron and magnesium based binary metal oxide using a stoichiometrically fixed amount of FeNO3.9H2O and MgNO3.6H2O in a proportion of molar concentration 1:1 and was later evaluated in removing As (III) from contaminated waters. Characterization of the prepared nanomaterial was done using X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy Dispersive X-Ray Analysis (EDAX) and ultraviolet–visible spectrophotometry (UV-VIS). Experimental studies on batch scale were carried out, examining the effect of varying initial concentrations of metal, adsorbent dosage, application time and initial pH on removal efficiency. Arsenic removal increased on increasing adsorbent dosage (0.1–1 g/L) but trend reversed on increasing initial arsenic concentration attaining qmax of 263.20 mg/g. Adsorption was quite efficient in pH range 4–8. Freundlich fitted better for adsorption isotherm along with following Pseudo-2nd order kinetics. The reusability and effect of co-existing ions on arsenic adsorption, namely SO42−, CO32− and PO43− were also explored with reusability in 1st and 2nd cycles attained adsorptive removal up to 77% and 64% respectively. The prepared nano-adsorbent showed promising results in terms of high arsenic uptake (qmax of 263.20 mg/g) along with facile and cost-effective synthesis. Thus, the co-precipitation technique used in this work is a simple one step procedure without any use of any precursor as compared to most of the other procedures used for synthesis.

Analysis of Arsenic concentration and its speciation in rice of different markets of Pakistan and its associated health risk

2020 ◽  
pp. 101252
Author(s):  
Tasneem Sarwar ◽  
Sardar Khan ◽  
Xinwei Yu ◽  
Shehla Amin ◽  
Muhammad Amjad Khan ◽  
...  
Keyword(s):  
Health Risk ◽  
Arsenic Concentration

SIMULTANEOUS MULTI-ELEMENT (INCLUDING FLUORINE) ANALYSIS OF VARIOUS BIO-MEDICAL SAMPLES

2005 ◽  
Vol 15 (03n04) ◽  
pp. 169-180 ◽  
Author(s):  
K. SERA ◽  
T. TERASAKI ◽  
J. ITOH ◽  
S. FUTATSUGAWA ◽  
Y. SAITOH ◽  
...  
Keyword(s):  
Toxic Elements ◽  
Elemental Concentration ◽  
Urine Analysis ◽  
Arsenic Concentration ◽  
Measuring System ◽  
Clinical Samples ◽  
Fluorine Concentration ◽  
Titanium Concentration ◽  
Quantitative Analyses ◽  
Contaminate Environment

We have measured fluorine concentration in samples taken from humans, such as sweat, saliva, snivel and tear in addition to hair, nail and urine, together with those of other elements by means of a three-detector measuring system. Fluorine has been known as one of the most toxic elements as well as arsenic, lead, mercury and cadmium which contaminate environment over the wide area. This system allowed us to discuss about fluorine concentration related to other elements'. A standard-free method established by us has been applied to quantitative analyses of these samples. By means of these methods, quantitative analysis becomes possible for samples of less than 1mg or 1μl and it is quite suited to tear, snivel and sweat. As one of the conclusion, sweat, snivel and tear give useful information in addition to the samples which have been traditionally analyzed. It is found that titanium concentration in a body is well estimated by analyses of sweat, snivel and saliva, arsenic concentration can be estimated by sweat analysis in addition to urine analysis, and nickel is well evaluated by sweat and tear. In this way, it is required to estimate elemental concentration in a human body by measuring various clinical samples. Especially, correlation between fluorine and arsenic is found in a few bio-medical samples.

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