Antimony release in PET bottled natural water in Lebanon

2012 ◽  
Vol 12 (2) ◽  
pp. 193-199 ◽  
Author(s):  
Lina Hureiki ◽  
Youssef Mouneimne
Keyword(s):  
Natural Water ◽  
Contact Time ◽  
Calcium Concentration ◽  
Volume Ratio ◽  
Exponential Model ◽  
Maximum Temperature ◽  
Spectroscopy Analysis ◽  
Antimony Concentration ◽  
Physico Chemical ◽  
Calcium Magnesium

Antimony (Sb) leaching from polyethylene terephthalate (PET) bottling material was assessed in eight registered Lebanese brands of bottled natural water as a function of contact time. The study was performed indoors at 22 °C in the dark and outdoors at a maximum temperature of 45 °C under sunlight. The leached antimony concentration increased with contact time for all of the studied brands except one. The antimony concentration reached 5.5 μg/L after 544 days of contact time with PET packaging. Small bottles with large contact surface area had higher antimony concentration. However, outdoor storage under sunlight at temperatures below 45 °C did not reveal a significant effect on antimony release. Among some physico-chemical parameters studied (pH, calcium, magnesium and bicarbonate), only calcium concentration showed a significant effect on antimony release. The rate of antimony leaching, normalized to the surface to volume ratio of the water bottle, fits the exponential model Sb/(S/V) = 0.562e0.0041t, with R2 = 0.87. Atomic absorption spectroscopy analysis of the different PET packaging material showed an antimony concentration between 80.6 and 352.7 mg Sb/kg PET.

Magnesium requirement for somatostatin inhibition of insulin secretion

1984 ◽  
Vol 105 (1) ◽  
pp. 83-86 ◽  
Author(s):  
Donald L. Curry ◽  
Leslie L. Bennett
Keyword(s):  
Insulin Secretion ◽  
Calcium Concentration ◽  
Inhibitory Effect ◽  
Secretory Process ◽  
Magnesium Ion ◽  
Second Phase ◽  
Intracellular Membrane ◽  
Calcium Magnesium ◽  
First Phase Insulin Secretion ◽  
Insulin Secretory Response

Abstract. Rat pancreas perfusions were performed using a perfusate with a fixed calcium concentration of 5 mEq/l and magnesium varying from 0 to 0.6 mEq/dl. Insulin secretion was stimulated by a constant glucose infusion of 300 mg/dl. This glucose concentration produces the typical biphasic insulin secretory response. We observed that in the absence of magnesium, somatostatin concentrations of 0.5 and 2.0 ng/ml were without effect on first phase insulin secretion. However, these same somatostatin levels produced 50% or more inhibition of insulin secretion in the presence of magnesium at 0.3 or 0.6 mEq/l. Similarly, in the absence of magnesium, somatostatin at 50 ng/ml failed to inhibit second phase insulin secretion, whereas this same somatostatin level produced about 50% inhibition of insulin secretion in the presence of magnesium at 0.3 mEq/l. Thus, altering perfusate magnesium concentrations without changing calcium is an important determinant of the degree of inhibition of secretion produced by somatostatin. In particular, in the absence of magnesium ion, somatostatin concentrations which would 'normally' produce 50% inhibition of secretion (ID50) are without effect. Therefore, magnesium ion is necessary for the full inhibitory effect of somatostatin to occur. These results suggest that inhibitors, as well as potentiators, of the insulin secretory process may act by altering intracellular/membrane calcium-magnesium ratios, but in opposite directions.

scholarly journals ASSESSMENT OF WATER QUALITY AND POLLUTION LOAD IN TEJASWINI RIVER NEAR THE MALAVETTUVAN TRIBAL SETTLEMENT, CHERUPUZHA PANCHAYATH, KERALA, INDIA

2017 ◽  
Vol 4 (3) ◽  
pp. 71-74
Author(s):  
Sangeeth Thekkan ◽  
Renjini Haridas ◽  
Paulsamy S
Keyword(s):  
Water Quality ◽  
River Water ◽  
Forest Canopy ◽  
Water Quality Assessment ◽  
Primary Sources ◽  
Human Consumption ◽  
Physico Chemical ◽  
Calcium Magnesium ◽  
Domestic Use ◽  
Canopy Water

Rivers are one of the primary sources of water for drinking, irrigation and other domestic purposes.The present study deals with the water quality assessment of Tejaswini river of Cherupuzha Panchayath, Kannur district, Kerala. The water samples collected from five different sites were analyzed for parameters such as temperature, color, pH, BOD, DO, calcium, magnesium and Escherichia coli. The analysis of the physico– chemical and microbiological characters of the river water indicated that the water quality study of site I was affected severely because the study site is very near to the tribal settlements and also the tribes use thisarea mainly for sewage disposal. Study site II, III, IV and V, which are away from the tribal settlement, the river water is not polluted as it is very far away from the tribal settlement and also nearer to forest canopy. Water from study site I which not suitable for drinking and other domestic use. Therefore, source protectionis suggested for the site I water bodies for the benefit of mankind because it is not safe for human consumption.

scholarly journals Physico-Chemical Analysis of Culture Pond for Induced Pearl Production in Lamellidens marginalis

2020 ◽  
Vol 26 (2) ◽  
Author(s):  
Vijiyata Singh Rathour ◽  
Vijay Kumar Yadav
Keyword(s):  
Chemical Analysis ◽  
Pond Water ◽  
Botanical Garden ◽  
Total Alkalinity ◽  
Total Hardness ◽  
Chemical Parameters ◽  
Colour Temperature ◽  
Physico Chemical ◽  
Calcium Magnesium ◽  
Healthy Growth

Bioassay experiments were carried out in order to evaluate values of physico-chemical parameters of the cultured pond water for induced pearl production in Lamellidens marginalis. The pond was located at Botanical garden of Bipin Bihari P.G. College, Jhansi. The parameters included for this study were Colour, Temperature, Transparency, pH, Free CO2 , DO, Total Hardness, Calcium, Magnesium and Total Alkalinity of cultured pond water and to maintain them for the healthy growth of mussels during the whole culture period for obtaining designer pearls.

scholarly journals Bioremoval of chromium from wastewater of tannery factory in Iraq

2008 ◽  
Vol 5 (3) ◽  
pp. 399-405
Author(s):  
Baghdad Science Journal
Keyword(s):  
Waste Water ◽  
Contact Time ◽  
Chemical Process ◽  
Physiological State ◽  
Living Cells ◽  
Electrostatic Attraction ◽  
Optimum Conditions ◽  
Proteus Vulgaris ◽  
Insignificant Effect ◽  
Physico Chemical

Bioremoval of chromium from wastewater of tannery factory in Iraq was studied. The bacteria Proteus vulgaris 7E showed an enhanced capability in biosorping chromium when its concentration increased in the solution, reaching a maximum of 476,7 mg/ ml out of 492 mg/ ml under optimum conditions at pH 6 and 50°C at one hour contact time and biomass of 1 mg/ml. The present results showed that dead cells of P. vulgaris 7E biosorbed 87.41 mg/ml of chromium in comparison with91.18 mg/ml of chromium biosorbed by living cells, this indicates the insignificant effect of physiological state of cells. It was found that the above biosorption is physico-chemical process depends upon electrostatic attraction forces. The results has illustrated that the most efficient eluting solution was 0.1M HCL which recovered 85% of biosorbed chromium. P. vulgaris 7E was able to remove completely all chromium from the waste water taken from tannery factory.

scholarly journals Influence of Physico-Chemical Parameters on the Fabrication of Silver Nanoparticles Using Petrea volubilis L. Stem Broth and Its Anti-Microbial Efficacy

2017 ◽  
Vol 9 (2) ◽  
Author(s):  
N. I. Hulkoti ◽  
T. C. Taranath
Keyword(s):  
Silver Nanoparticles ◽  
Zeta Potential ◽  
Silver Nitrate ◽  
Microbial Activity ◽  
Contact Time ◽  
Nitrate Concentration ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Vis Spectroscopy ◽  
Silver Nitrate Concentration

In this study we describe the phytofabrication of AgNps through a green route as a cost-effective, instantaneous and an eco-friendly approach using Petrea volubilis L. stem broth. The influence of physico-chemical parameters - contact time, stem broth quantity, pH, temperature, and silver nitrate concentration were studied and optimised to engineer, nanoparticles of diverse sizes. Nanoparticles were characterized by UV-Vis spectroscopy, FTIR, XRD, Zeta potential, EDS, and HRTEM. The characterization using HRTEM showed that, the nanoparticles were spherical and with increase in contact time, stem broth quantity, pH, and temperature, the NPs size minimised whereas escalation in silver nitrate concentration, increased their size. Capping molecules were negatively charged and the NPs were passably stable according to zeta potential readings and they were crystalline as per XRD data. According to FTIR analysis, the bio reduction was attributed to alcohol, ethers, carboxylic acids, and esters. The highest anti-bacterial activity was observed against S. aureus and S. typhi whose ZOI diameter was 13 mm at 100?l in both bacteria. The highest anti-fungal activity of silver nanoparticles was observed against A. flavus whose ZOI diameter was 9 mm at 100?l compared to P. chrysogenum which is 3 mm at 100?l. The stem broth did not show any anti-microbial activity for the microbes. Anti-microbial activity of AgNPs is due to its small size and high surface area. Our findings clearly discloses that sizes of silver nanoparticles can be varied by varying the physico-chemical parameters and the small sized nanoparticles so formed are promising antimicrobial agents and has a great potential in various medical applications.

scholarly journals Environmental structure and relationships in the setting of natural water springs in a Lower Highland Seasonal Forest in Brazilian South

2018 ◽  
Vol 48 (11) ◽  
Author(s):  
Paulo Alfonso Floss ◽  
Solon Jonas Longhi ◽  
Malcon do Prado Costa ◽  
Elzira Cecília Serafini Floss
Keyword(s):  
Natural Water ◽  
Riparian Forest ◽  
Forest Recovery ◽  
Physical Analysis ◽  
Soil Variables ◽  
Environmental Structure ◽  
Calcium Magnesium ◽  
Initial Recovery ◽  
Edaphic Variables ◽  
Water Springs

ABSTRACT: The aim of this research was to characterize an environmental structure in the setting of tree natural water springs in a Lower Highland Seasonal Forest, and to verify the relationship between community demography and soil variables as subsidies for species identification in riparian forest recovery programs in similar environments. The research was carried out in the National Forest of Chapecó, located in the west of the state of Santa Catarina in the southern region of Brazil. For this, three water springs were demarcated, where 26 plots of 200m² in each were allocated. All individuals with diameter at 1.30m of soil height ≥5.0cm were measured. Soil samples (0 to 20cm depth) were collected in the plots for chemical and physical analysis. To relate the abundance of the species to the edaphic variables, the Canonical Correspondence Analysis (CCA) was used. A total of 76 species belonging to 64 genera of 36 botanical families were reported in the study area. The families Fabaceae and Myrtaceae presented greater floristic richness. The edaphic variables that most influenced the distribution of the species were aluminum saturation and calcium, magnesium and potassium contents. Specific groups of indicator species were formed for each water spring. The species designated as generalists are the most recommended for the initial filling and recovery of degraded springs. Further rare species and with low density must be included after the initial recovery to increase diversity.

scholarly journals Aluminum Inserts for Enhancing Heat Transfer in PCM Accumulator

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 415 ◽  
Author(s):  
Anna Dmitruk ◽  
Krzysztof Naplocha ◽  
Jakub Grzęda ◽  
Jacek W. Kaczmar
Keyword(s):  
Phase Change Materials ◽  
Heat Storage ◽  
Storage System ◽  
Volume Ratio ◽  
Energy Storage System ◽  
Heat Fluxes ◽  
Heat Of Fusion ◽  
Maximum Temperature ◽  
Release Time ◽  
Storage Unit

Phase change materials (PCMs) are applied in heat storage units, as they are able to accumulate the energy in the form of the latent heat of fusion. Thus, they can be used in recovering the excess of heat from various industrial processes. Their main weakness is their low thermal conductivity coefficient, which strongly limits their usage. In this paper, the benefits of the application of metallic inserts in heat storage PCM-based units were elaborated. Two kinds of Al–Si spatial elements (foams and honeycomb structures) were produced with the use of means of the investment casting method. Key factors influencing the technological process were established. The surface’s roughness was measured in order to compare the obtained structures with their patterns in terms of the casting’s accuracy. The compressive strength of the samples was tested, and their fatigue resistance was considered. The thermal performance of manufactured inserts in the PCM (paraffin)-based accumulator, supported by the calculation of heat fluxes, was analyzed and adjusted. Finally, further optimization was conducted in terms of the volume ratio of the metal insert to the PCM. Metallic inserts were found to significantly affect the performance of the entire energy storage system, as their use results in reduced charging time, a longer heat release time, increased maximum temperature, and a significant reduction in the temperature gradient in the heat storage unit.

scholarly journals Multisensory System Used for the Analysis of the Water in the Lower Area of River Danube

Nanomaterials ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 891 ◽  
Author(s):  
Constantin Apetrei ◽  
Catalina Iticescu ◽  
Lucian Puiu Georgescu
Keyword(s):  
Data Analysis ◽  
Natural Water ◽  
Water Samples ◽  
Multivariate Data Analysis ◽  
Multivariate Data ◽  
Principal Component ◽  
Cyclic Voltammograms ◽  
Physico Chemical ◽  
Multisensory System ◽  
Collection Point

The present paper describes the development of a multisensory system for the analysis of the natural water in the Danube, water collected in the neighboring area of Galati City. The multisensory system consists of a sensor array made up of six screen-printed sensors based on electroactive compounds (Cobalt phthalocyanine, Meldola’s Blue, Prussian Blue) and nanomaterials (Multi-Walled Carbon Nanotubes, Multi-Walled Graphene, Gold Nanoparticles). The measurements with the sensors array were performed by using cyclic voltammetry. The cyclic voltammograms recorded in the Danube natural water show redox processes related to the electrochemical activity of the compounds in the water samples or of the electro-active compounds in the sensors detector element. These processes are strongly influenced by the composition and physico-chemical properties of the water samples, such as the ionic strength or the pH. The multivariate data analysis was performed by using the principal component analysis (PCA) and the discriminant factor analysis (DFA), the water samples being discriminated according to the collection point. In order to confirm the observed classes, the partial least squares discriminant analysis (PLS-DA) method was used. The classification of the samples according to the collection point could be made accurately and with very few errors. The correlations established between the voltammetric data and the results of the physico-chemical analyses by using the PLS1 method were very good, the correlation coefficients exceeding 0.9. Moreover, the predictive capacity of the multisensory system is very good, the differences between the measured and the predicted values being less than 3%. The multisensory system based on voltammetric sensors and on multivariate data analysis methods is a viable and useful tool for natural water analysis.

Mordanting of mercury on styrene-divinylbenzene copolymer beads from aqueous solutions

2007 ◽  
Vol 95 (5) ◽  
Author(s):  
Nasir Khalid ◽  
Saqib Ali ◽  
Arif Iqbal ◽  
Shujaat Ahmad
Keyword(s):  
Aqueous Solutions ◽  
Contact Time ◽  
Aqueous Media ◽  
Mercury Ions ◽  
Chemical Parameters ◽  
Radiotracer Technique ◽  
Physico Chemical ◽  
Styrene Divinylbenzene ◽  
Selection Of

The sorption of mercury ions from aqueous solutions on styrene-divinylbenzene copolymer beads (St-DVB) has been investigated for the decontamination of mercury from aqueous media. Various physico-chemical parameters, such as selection of appropriate electrolyte, contact time, amount of adsorbent, concentration of adsorbate, effect of diverse ions and temperature were optimized to simulate the best conditions which can be used to decontaminate mercury from aqueous media using St-DVB beads as an adsorbent. The radiotracer technique was used to determine the distribution of mercury. The highest adsorption was observed at 0.001 mol L

scholarly journals Enhanced Bactericidal Efficacy of NaOCl at pH 12 Followed by Acidified NaOCl at pH 6.5 on Enterococcus faecalis Biofilm

2020 ◽  
Vol 10 (17) ◽  
pp. 6096
Author(s):  
Ronald Wigler ◽  
Shlomo Matalon ◽  
Tomer Goldberger ◽  
Anat Or Lerner ◽  
Anda Kfir
Keyword(s):  
Contact Time ◽  
Laser Scanning ◽  
Saline Solution ◽  
Volume Ratio ◽  
Bactericidal Effect ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Red Fluorescence ◽  
Bactericidal Efficacy ◽  
Significant Difference

This study aimed to determine the bactericidal efficacy of sequential use of NaOCl pH 12 followed by acidified NaOCl pH 6.5, and compare it to that of either of these NaOCl solutions alone. E. faecalis biofilm was grown on standardized dentine specimens for four weeks. The specimens were randomly divided into four groups: (A) 4 min exposure to 0.9% saline solution (control); (B) 4 min exposure to 4% NaOCl pH 12; (C) 4 min exposure to 4% NaOCl pH 6.5; and (D) 2 min exposure to 4% NaOCl pH 12 followed by 2 min exposure to 4% NaOCl pH 6.5. The bactericidal activity was evaluated after the 4 min of contact time using confocal laser scanning microscopy. The volume ratio of red fluorescence to green and red fluorescence indicated the proportion of dead cells in the biofilm. The percent of dead cells in the saline solution group was significantly lower than those in the other groups. There was no significant difference between NaOCl pH 12 compared to NaOCl pH 6.5. The sequential use of NaOCl pH 12 followed by pH 6.5 significantly increased the percent of dead cells compared to both the samples exposed to either NaOCl pH 12 or pH 6.5. These results show that sequential irrigation protocol had a stronger bactericidal effect than the commonly used NaOCl pH 12.

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