scholarly journals Spectroscopic Assessment of Platinum Group Elements of PM10 Particles Sampled in Three Different Areas in Jeddah, Saudi Arabia

2020 ◽  
Vol 17 (9) ◽  
pp. 3339 ◽  
Author(s):  
Mohammad W. Kadi ◽  
Iqbal Ismail ◽  
Nadeem Ali ◽  
Abdallah A. Shaltout
Keyword(s):  
Saudi Arabia ◽  
Inductively Coupled Plasma ◽  
Heavy Traffic ◽  
Platinum Group Elements ◽  
Catalytic Converters ◽  
High Concentration ◽  
Light Traffic ◽  
Traffic Site ◽  
Platinum Group ◽  
High Concentrations

Platinum group elements (PGE) including Ru, Rh, Pt and Pd have been quantified in air particulate matter with an aerodynamic diameter equal or less than 10 microns (PM10) using inductively coupled plasma mass spectrometry (ICP-MS). PM10 aerosols have been collected from three sites representing various activities in Jeddah city, Saudi Arabia. These locations are residential site with heavy traffic, industrial site and heavy traffic and a light traffic site outside the city. To obtain reasonable data of the PGE concentrations, a group from 10 to 15 PM10 samples were collected every month. The annual and seasonal variation of the mass concentration of the PGE were demonstrated. In all locations, Pt and Pd were relatively higher than Ru and Rh possibly because their main use is in automobile catalytic converters. Concentrations of observed PGE in PM10 could be arranged in ascending order as: Rh < Ru < Pd < Pt. In case of Ru and Pt, there are clear similarities in terms of the overall mean concentrations at the sampling locations. Due to the high concentration of Ru, Rh and Pd at low traffic site, there are certainly other sources of these elements rather than vehicle catalytic converters. However, at the industrial/heavy traffic location, high concentrations of Ru were detected during February 2015. In addition, high Pt concentrations were also detected at the light traffic site during May 2015. Results indicate that Pt source in PM10 is mainly the automobile catalytic converters.

scholarly journals Crystallization of CaCO3 in Aqueous Solutions with Extremely High Concentrations of NaCl

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 647
Author(s):  
Mengqi Qian ◽  
Yuwei Zuo ◽  
Zhihao Chen ◽  
Xiaoshuang Yin ◽  
Ying Liu ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
High Concentration ◽  
Retention Efficiency ◽  
Static Test ◽  
Inductively Coupled ◽  
High Concentrations ◽  
The One ◽  
Phosphate Inhibitors

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.

scholarly journals Platinum Group Elements Recovery from Used Catalytic Converters by Acidic Fusion and Leaching

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 485 ◽  
Author(s):  
Erik Prasetyo ◽  
Corby Anderson
Keyword(s):  
Platinum Group Elements ◽  
Raw Material ◽  
Catalytic Converters ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Chloro Complexes ◽  
Soluble Species ◽  
Platinum Group ◽  
Pre Treatment ◽  
Hcl Concentration

The recovery of platinum group elements (PGE (platinum group element coating); Pd, Pt, and Rh) from used catalytic converters, using low energy and fewer chemicals, was developed using potassium bisulfate fusion pretreatment, and subsequently leached using hydrochloric acid. In the fusion pre-treatment, potassium bisulfate alone (without the addition of an oxidant) proved to be an effective and selective fusing agent. It altered PGE into a more soluble species and did not react with the cordierite support, based on X-Ray Diffraction (XRD) and metallographic characterization results. The fusion efficacy was due to the transformation of bisulfate into pyrosulfate, which is capable of oxidizing PGE. However, the introduction of potassium through the fusing agent proved to be detrimental, in general, since potassium formed insoluble potassium PGE chloro-complexes during leaching (decreasing the recovery) and required higher HCl concentration and a higher leaching temperature to restore the solubility. Optimization on the fusion and leaching parameter resulted in 106% ± 1.7%, 93.3% ± 0.6%, and 94.3% ± 3.9% recovery for Pd, Pt, and Rh, respectively. These results were achieved at fusion conditions: temperature 550 °C, potassium bisulfate/raw material mass ratio 2.5, and fusion time within 30 min. The leaching conditions were: HCl concentration 5 M, temperature 80 °C, and time within 20 min.

scholarly journals Physicochemical Parameters and Toxic Heavy Metals Concentration in Coffee

2019 ◽  
pp. 1-8
Author(s):  
Eltigani Osman Musa Omer ◽  
Osama Ahmed Labib ◽  
Mubashir Zafar
Keyword(s):  
Saudi Arabia ◽  
Toxic Metals ◽  
Inductively Coupled Plasma ◽  
Middle Eastern ◽  
Public Health Problem ◽  
Major Public Health Problem ◽  
Toxic Heavy Metals ◽  
High Concentration ◽  
Limit Values ◽  
Coffee Powder

Background and Objective: Coffee is one of the common drinks in Middle Eastern countries including Saudi Arabia due to its desirable aroma, taste and putative positive physiological functions. The concentration of metals is commonly present in coffee powder. The presence of heavy metal concentration in different brands of coffee powder available in Saudi Arabia market has been analyzed. Methods: Thirteen different coffee brands were selected in different markets, all assessment was carried out in advanced instruments such as Inductively Coupled Plasma and Atomic Absorption Spectroscopy. There are 14 metals which divide into seven non toxic and seven toxic metals were analyzed. Non toxic metals are calcium (Ca), iron (Fe),magnesium (Mg), Magnese (Mn), Potassium (K), phosphorus (P), sodium (Na), and toxic metals are arsenic (Ar), zinc (Zn), chromium (Cr), nickel (Ni), lead (Pb), antimony and cadmium (Cd). Results: The mean and standard deviation of non-toxic and toxic metals concentration in different samples of coffee were as follows: Ca, Fe, K, Mg, Mn, P and Na were 24.87±6.76, 6.670±4.88, 235.98±100.05, 407.02±22.56, 8.63±10.14, 0.01±0.01, 333.86±247.35 respectively. Toxic metals concentration were as Al, Cd, Cu, Ni, Pb, Si, Zn were   11.04±10.03, 0.80 ±2.52, 2.43±3.02, 0.07±0.11, 7.57±9.26,  23.48±27.32  and 1.853±1.66 respectively. These concentration values were high compared to threshold limit values (TLVs) of metals. Conclusion: It was concluded from the study that coffee powder had high concentration of heavy toxic metals which is the major public health problem. Thus, quality control for food safety recommended during production of coffee.

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