scholarly journals Chemical and Isotope Studies of Zakher Lake and Its Possible Risk on the Geoenvironment, Al Ain, United Arab Emirates

2019 ◽  
Vol 2 (2) ◽  
pp. 78-82
Author(s):  
Saber Hussein ◽  
Hasan Arman ◽  
Dalal Al Shamsi ◽  
Ahmed Murad ◽  
Ala Aldahan

This study concerns the occurrence of pollutants in Zakher Lake, Al Ain, UAE, which are relevant to the water supply and impact on ecosystem. Lake water and sediment samples were collected from the lake and were analyzed for different chemical and physical properties. In-situ measurements of temperature, pH, EC and TDS and Rn-222 activity were carried out using a WTW-COND-330I and RAD7 instrument with errors of < 5%. The analyses of trace and major elements were performed using inductively coupled plasma optical emission spectroscopy (ICP-OES) Varian 715 with errors < 5%. The results reveal high concentrations of Na, K, Mg and Ca, Fe, Mn, Al, Sr, Ba and Pb in water samples of the lake, which are higher than permissible limits for drinking and irrigation. Variable concentrations of these elements were found in the sediment samples. In addition, radon isotope (Rn-222) data in the lake water indicate activity values below the detection limit of the instrument. The high concentrations of major and trace elements support the idea that the water is polluted. The sources of water to the lake are considered mainly anthropogenic due to the relatively high activity of Rn-222 in surrounding groundwater wells that is not detected in the lake water. Consequently, the lake water is not suitable for drinking, domestic or irrigation purposes and may be considered as a source of environmental hazard in the area.

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 647
Author(s):  
Mengqi Qian ◽  
Yuwei Zuo ◽  
Zhihao Chen ◽  
Xiaoshuang Yin ◽  
Ying Liu ◽  
...  

The effect of NaCl at extremely high concentrations from 3.5 to 14 wt. % on the crystallization of CaCO3 was investigated in depth. The static test experiment verified that the Ca2+ retention efficiency (η) of NaCl on CaCO3 scale increased from 31.06% (3.5 wt. %) to 41.56% (14 wt. %). Based on the calculation of supersaturation rations, the high concentration of NaCl could reduce the activity coefficients of [Ca2+] and [CO32−], thus reducing the actual concentration of CaCO3. The CaCO3 deposition rate constants (k) showed that NaCl slowed down the rate of CaCO3 crystallization. The X–ray diffraction (XRD) testing disclosed that the growth of (1 0 4) and (1 1 0) faces from calcite was impeded, while the formation of (1 1 1) face from aragonite was induced by the increasing concentration of NaCl. The inductively coupled plasma optical emission spectrometry (ICP–OES) results indicated that Na+ could be doped into CaCO3, leading to the one–dimensional crystal growth. It was further proved that NaCl heightens the efficiency of the typical phosphate inhibitors (2–phosphonobutane–1,2,4–tricarboxylic acid (PBTCA) and 1–hydroxyethane–1,1–diphosphonic acid (HEDP)) on prohibiting the scale of CaCO3.


2019 ◽  
Vol 12 ◽  
pp. 117862211986900 ◽  
Author(s):  
Joan Nyika ◽  
Ednah Onyari ◽  
Megersa Olumana Dinka ◽  
Shivani Bhardwaj Mishra

Precise estimation of metals in samples remains a challenge as a result of analytical biases and errors, which occur at sample collection, preparation, and measurement stages. A poor understanding of the nature and occurrence of these errors further aggravates this challenge. This study aimed at comparing the effectiveness of inductively coupled plasma (ICP) mass spectrometry (MS) and optical emission spectrometry (OES) techniques in quantifying metals from contaminated soils of Roundhill landfill vicinity. Using statistical tools, the study evaluated biases of the 2 methods. High coefficients of variation were realized for V, Cr, and Pb concentrations varied at various sampling sites. Concentrations of elements obtained using the 2 methods had no significant differences using t-test analysis. Definitive agreement for the 2 methods was observed for V, Cr, Co, Ni, Cu, Zn, Sr, and Pb concentrations, whereas the concentrations of Mg, Ca, Ti, Mn, and Fe showed some deviations in their regression lines. Spectral, systematic, memory, and carry over errors could be attributable to these deviations. The errors promote chelation and adsorption of ions in samples to form insoluble compounds that cannot be quantified. Overall, ICP-MS had greater sensitivity than ICP-OES in trace elements analysis compared with major elements.


Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 724-730 ◽  
Author(s):  
Qing Ge ◽  
Paul A. Cobine ◽  
Leonardo De La Fuente

Xylella fastidiosa is a xylem-limited plant pathogenic bacterium that causes disease in many crops worldwide. Copper (Cu) is an antimicrobial agent widely used on X. fastidiosa hosts to control other diseases. Although the effects of Cu for control of foliar pathogens are well known, it is less studied on xylem-colonizing pathogens. Previous results from our group showed that low concentrations of CuSO4 increased biofilm formation, whereas high concentrations inhibited biofilm formation and growth in vitro. In this study, we conducted in planta experiments to determine the influence of Cu in X. fastidiosa infection using tobacco as a model. X. fastidiosa-infected and noninfected plants were watered with tap water or with water supplemented with 4 mM or 8 mM of CuSO4. Symptom progression was assessed, and sap and leaf ionome analysis was performed by inductively coupled plasma with optical emission spectroscopy. Cu uptake was confirmed by increased concentrations of Cu in the sap of plants treated with CuSO4-amended water. Leaf scorch symptoms in Cu-supplemented plants showed a trend toward more severe at later time points. Quantification of total and viable X. fastidiosa in planta indicated that CuSO4-amended treatments did not inhibit but slightly increased the growth of X. fastidiosa. Cu in sap was in the range of concentrations that promote X. fastidiosa biofilm formation according to our previous in vitro study. Based on these results, we proposed that the plant Cu homeostasis machinery controls the level of Cu in the xylem, preventing it from becoming elevated to a level that would lead to bacterial inhibition.


2017 ◽  
Vol 32 (1) ◽  
pp. 66-72
Author(s):  
Katarzyna Szczepańska ◽  
Grażyna Dembska ◽  
Łukasz Zegarowski ◽  
Grażyna Pazikowska-Sapota ◽  
Katarzyna Galer-Tatarowicz ◽  
...  

This paper describes the methodology of inductively coupled plasma optical emission spectrometry for determining the total phosphorus content in bottom sediment samples. Homogenized samples subjected to a microwave-assisted aqua regia digestion, and next analyzed for total phosphorus content using the inductively coupled plasma optical emission spectrometer. The method was optimized and its validation parameters were determined. Assessing the selectivity of the method, found the spectral interferences of other elements (especially copper) on P can be partially eliminated by using the optimal operating conditions. The method exhibited excellent linearity (r>0.999) in the entire measurement range (25-5000 mg Pkg-1) and very good recovery (99%). It was also characterized by high repeatability (relative standard deviation of 1%) and reproducibility (reproducibility standard deviation of 10%). The relative expanded uncertainty of the method was estimated at 21.2%.


2017 ◽  
Vol 3 (3) ◽  
Author(s):  
Magal Saphier ◽  
Oron Zamir ◽  
Polina Berzansky ◽  
Oshra Saphier ◽  
Dan Meyerstein

The reaction of fluoride ions with alumina was found to strongly depend on the concentration of fluoride ions in the aqueous solution. At low concentrations ([fluoride ions] < 0.1 mol/l in the case of potassium fluoride), the aqueous concentration of aluminum ions is relatively high as measured by using inductively coupled plasma optical emission spectroscopy (ICP-OES), and the aluminum oxide dissolves as a fluoride complex. At high concentrations of fluoride ([fluoride ions] > 0.5 mol/l in the case of potassium fluoride), a new structure is formed on the alumina surface involving fluoride, aluminum, potassium, and oxygen (in the case of potassium fluoride). The structure was characterized by using X-ray powder diffraction (XRD), scanning electron microscope (SEM), and energy-dispersive X-ray spectroscopy (EDS). The resulting structure improved the passivation of alumina, the solubility of aluminum ions decreasing compared to the untreated alumina. Aluminum surfaces that were fluoride-treated showed a better resistance to dissolution in both acidic and basic media.


2005 ◽  
Vol 72 (3) ◽  
pp. 362-368 ◽  
Author(s):  
John E Hermansen ◽  
Jens H Badsberg ◽  
Troels Kristensen ◽  
Vagn Gundersen

A total of 480 samples of milk from 10 organically and 10 conventionally producing dairy farms in Denmark and covering 8 sampling periods over 1 year (triplicate samplings) were analysed for 45 trace elements and 6 major elements by high-resolution inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry. Sampling, sample preparation, and analysis of the samples were performed under carefully controlled contamination-free conditions. The dairy cattle breeds were Danish-Holstein or Jersey. Sources of variance were quantified, and differences between production systems and breeds were tested. The major source of variation for most elements was week of sampling. Concentrations of Al, Cu, Fe, Mo, Rb, Se, and Zn were within published ranges. Concentrations of As, Cd, Cr, Mn and Pb were lower, and concentrations of Co and Sr were higher than published ranges. Compared with Holsteins, Jerseys produced milk with higher concentrations of Ba, Ca, Cu, Fe, Mg, Mn, Mo, P, Rh, and Zn and with a lower concentration of Bi. The organically produced milk, compared with conventionally produced milk, contained a significantly higher concentration of Mo (48 v. 37 ng/g) and a lower concentration of Ba (43 v. 62 ng/g), Eu (4 v. 7 ng/g), Mn (16 v. 20 ng/g) and Zn (4400 v. 5150 ng/g respectively). The investigation yielded typical concentrations for the following trace elements in milk, for which no or very few data are available: Ba, Bi, Ce, Cs, Eu, Ga, Gd, In, La, Nb, Nd, Pd, Pr, Rh, Sb, Sm, Tb, Te, Th, Ti, Tl, U, V, Y, and Zr.


2020 ◽  
Vol 35 (4) ◽  
pp. 679-692 ◽  
Author(s):  
Jake A. Carter ◽  
John T. Sloop ◽  
Tina Harville ◽  
Bradley T. Jones ◽  
George L. Donati

Plasma species of Ar, H and O are monitored and used for modeling and for correcting signal bias caused by high concentrations of easily ionizable elements in ICP OES.


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