The hazard content of cadmium, lead and other trace elements in some medicinal herbs and their water infusions
Evaluation of allergenic metals and other trace elements in personal care products
Evaluation of Residual Amounts of Persistent Organic Pollutants and Traces of Heavy Metals in King Talal Dam
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Research Summary
In this study, concentrations of different persistent organic pollutants (POP's) and heavy metals in samples from King Talal Dam (KTD) were investigated. The levels of PAH's were in the range from below the detection limit of 1 ng/l to 120 ng/L for water samples and from below the detection limit of
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- key words
King Talal Dam, Heavy metals, POP's, Water pollution
The Correlations between mercury speciation and dissolved organic matter in the sediment of the Red sea
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Research Summary
This study addresses the correlations between Hg and organic matter in recent sediment; samples were
collected from the Gulf of Aqaba, Red Sea coasts (oligotrophic regions) during 2010. In the present study
TOC analyzer was used to determine Total Organic Carbon (TOC) and Total Nitrogen (TN) concentrations
and the total amount of mercury (HgT) in sediment samples were analyzed by Hydra-C mercury analyzer.
The obtained results indicated that, mercury, TOC and TN average concentrations in the Red Sea were
85.42 ng g-1, 5.10 and 4.45 mg L-1, respectively. The results show that the Total Organic Carbon (TOC) in
sediment represents the sum of various organic compounds, which may play a completely different role in
the distribution and accumulation of Hg. slightly correlations between the TOC and the concentration of Hg
in the studied sediment arise mainly from the labile portion of organic matter released. These compounds
primarily consist of easily degradable algal-derived lipids and various pigments, which are petrographically
described as a soluble Organic Matter (OM). The preserved OM in sediment is commonly entrapped within
the cell walls of phytoplankton and also appears as a surface coating on sediment particles. The strong
affinity between Hg and OM is due not only to its chemical reactivity, but also to the physical characteristic
of these labile compounds, which plays the most important role in the distribution of Hg in sediment.
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- key words
Total organic carbon,
total nitrogen,
mercury,
sediment,
gulf of Aqaba-Jordan
The Correlations between mercury speciation and dissolved organic matter in the sediment of the Red sea
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Research Summary
This study addresses the correlations between Hg and organic matter in recent sediment; samples were
collected from the Gulf of Aqaba, Red Sea coasts (oligotrophic regions) during 2010. In the present study
TOC analyzer was used to determine Total Organic Carbon (TOC) and Total Nitrogen (TN) concentrations
and the total amount of mercury (HgT) in sediment samples were analyzed by Hydra-C mercury analyzer.
The obtained results indicated that, mercury, TOC and TN average concentrations in the Red Sea were
85.42 ng g-1, 5.10 and 4.45 mg L-1, respectively. The results show that the Total Organic Carbon (TOC) in
sediment represents the sum of various organic compounds, which may play a completely different role in
the distribution and accumulation of Hg. slightly correlations between the TOC and the concentration of Hg
in the studied sediment arise mainly from the labile portion of organic matter released. These compounds
primarily consist of easily degradable algal-derived lipids and various pigments, which are petrographically
described as a soluble Organic Matter (OM). The preserved OM in sediment is commonly entrapped within
the cell walls of phytoplankton and also appears as a surface coating on sediment particles. The strong
affinity between Hg and OM is due not only to its chemical reactivity, but also to the physical characteristic
of these labile compounds, which plays the most important role in the distribution of Hg in sediment.
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- key words
Total organic carbon,
total nitrogen,
mercury,
sediment,
gulf of Aqaba-Jordan
Stabilization of lead bearing sludge by utilization in fly ash-slag based geopolymer
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Research Summary
The present work demonstrates the utilization of three important industrial by-products; fly ash (FA),
ground blast-furnace slag (GBFS), and lead-bearing sludge (LS) in preparing geopolymer as a replacement
for cement binder. The feasibility of preparing high-performance geopolymers by mixing various ratios of
industrial by-product fractions (FA, GBFS and LS) with alkali activator is examined, the prepared
geopolymers were cured at room temperature up to 90 days. Various parameters such as setting time,
mechanical strength, hydration characteristics and leaching behaviour of lead were evaluated The results
show that at percentages of 70–80 mass% GBFS and 20–30 mass% FA, a reasonable compression strength
compared to the past of ordinary Portland cement (OPC) is obtained. However, the substitution of 40
mass% GBFS or more with FA causes significant reductions in compressive strength at all curing times.
By the substitution of 20 mass% GBFS with LS compared to the optimum percentage of 80 mass% GBFS
and 20 mass% FA, the studied mechanical properties of the produced mixture (60 mass% GBFS, 20 mass%
FA, and 20 mass% LS) were enhanced. The Pb-concentration (mg/l) in the leachate of this mixture was
below the safe limit of toxicity characteristic leaching procedure (TCLP). The partial or total substitution
of Portland cement by these materials provides an ideal way to get rid of waste in a good and environmentally
safe manner.
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- key words
Stabilization ,
Fly ash (FA) ,
Ground blast-furnace slag (GBFS),
Geopolymer , matrix
Compressive-strength,
Lead-bearing sludge (LS)
Assessments of toxic heavy metals contamination in cosmetic product
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Research Summary
We quantified the contents of four toxic metals in cosmetic products that are commercially available
in Jordan; 112 cosmetics, representing 10 product types, were tested in triplicate after acid digestion
using inductively coupled plasma optical emission spectrometry and a mercury analyzer. Ni was
most abundant, detected in 104/112 (92.8%) products (average, 2.32 ppm; and median, 1.47 ppm);
66/112 (59%) contained >1 ppm and 13/112 (11.6%), >5 ppm Ni. Cd was second-most abundant,
detected in 86/112 (76.7%) products (mean, 1.71 ppm; range from3 ppm in 15/112 (13.4%) products. The highest content of Hg was observed in
skin lightening creams (mean concentration, 1,008 ppm). Hg was detected in 20 (62.5%) of the 32
skin lightening creams tested, of which 11/32 (34.4%) contained > 3 ppm Hg. Of the 112 cosmetics
tested, 17 (15.1%) products contained Ni, Pb, Cd, and Hg; 19/112 (16.9%) contained Cd, Pb, and Hg –
no product exceeded the maximum acceptable limits for all three elements, and 9/112 (8%)
products exceed the maximum recommended levels for at least two elements (Hg, Cd, and Pb).
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- key words
Cadmium; mercury; lead;
nickel; cosmetics; toxic
elements
Positive impact performance of hybrid effect of nano-clay and silica nano-particles on composite cements
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Research Summary
This study evaluates the synergistic impact of nano-silica (NS) and nano-clay (NC) on the hydration characteristics
and microstructure of ordinary Portland cement (OPC) paste. Two main parameters, which
strongly affect the physico-chemical and mechanical performance of OPC-pastes, including the hybrid
NS and NC mass% (0, 1, 2, 4 and 6 wt% at NS:NC mass ratio of 1:1) and superplasticizer (SP) content,
SP% (0 and 1 mass% with respect to OPC) have been studied. The results proved the addition of hybrid
NS/NC has a good impact on the performance of OPC-pastes. All NS/NC-cement composites containing
1% SP showed the highest engineering properties comparing with composites with no SP. The composite
containing the hybrid effect of 3 wt% NS:3 wt% NC:1 wt% SP presented the highest performance at all ages
of curing as confirmed by X-ray diffraction, thermal analysis and scanning electron microscopy.
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- key words
Cement paste,
Nano-silica,
Nano-clay,
Superplasticizer,
Compressive-strength
Levels of mercury, cadmium, lead and other selected elements in canned tuna fish commercialized in Jordan
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Research Summary
During 2010, the concentrations of mercury and eight other trace elements in
90 canned tuna samples commercialised in Jordan were determined using mercury
analyser (Hydra C) and the inductively coupled plasma-optical emission
spectrometer (ICP-OES). The mean concentrations and ranges for elements
analysed in mg kg1 (wet base) were as follows: total Hg (0.21; 0.06–0.57),
Cd (0.06;50.01–0.63), Pb (0.09; 50.04–0.24), total As (0.74; 0.11–1.56), Ni
(0.51; 0.03–2.85), V (0.04; 50.03–0.1), Al (0.26; 0.08–1.63), Ba (0.13; 0.05–0.42)
and Ag was not detected in any of the analysed samples (50.02 mg kg1). The
data obtained in the present study compared well with data obtained from similar
studies carried out in different parts of the world. Few samples had the mercury
and cadmium levels slightly exceeding the Codex Committee on Food Additives
and Contaminants draft guidelines. However, the estimated weekly intakes
of these metals showed that there was no health risk associated with the
consumption of the analyzed canned tuna samples.
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- key words
canned tuna; trace elements; ICP OES; mercury analyzer; seafood;
Jordan
Microwave-assisted total digestion of sulphide ores for multi-element analysis
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Research Summary
A new two-stage microwave-assisted digestion procedure using concentrated HNO3, HCl, HF and H3BO3
has been developed for the chemical analysis of major and trace elements in sulphide ore samples prior
to inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis. In the first stage 0.2 g
of the certified reference material (CRM) sample was digested with a combination of acids (HNO3, HCl,
and HF) in a closed Teflon vessel and heated in the microwave to 200 ◦C for 30 min. After cooling, H3BO3
was added and the vessel was reheated to 170 ◦C for 15 min. The precision of the method was checked
by comparing the results against six certified reference materials. The analytical results obtained were in
good agreement with the certified values, in most cases the recoveries were in the range 95–105%. Based
on at least 17 replicates of sample preparation and analysis, the precision of the method was found to be
≤5%.
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- key words
Microwave digestion
Sulphide ores
Total digestion
Inductively coupled plasma atomic
emission spectroscopy