[Show abstract][Hide abstract] ABSTRACT: The prepared chitosan-coated diatomite (CCD) was characterized using Fourier transform infrared spectroscopy and SEM techniques. The effects of pH, contact time, sorbent dosage, metal concentration, and temperature on the adsorption (%) of mercury (Hg(II)) from aqueous solution using the CCD sorbent were studied systemically. The monolayer sorption capacities of raw diatomite and CCD sorbents at pH 5 were found to be 68.1 and 116.2 mg/g, respectively. The mean adsorption energy (8.2 kJ/mol) calculated from the Dubinin–Radushkevich (D–R) model indicated that the sorption process occurred via chemisorption. The modified sorbent had good adsorption and desorption performance with respect to reusability after 10 repeated cycles. The thermodynamic calculations revealed that the sorption was viable, spontaneous, and exothermic in nature under the conditions studied. The kinetic calculations indicated that the sorption mechanism was well-explained by a pseudo-second-order model. All results demonstrated that the prepared CCD is an effective sorbent for the removal of Hg(II) from aqueous solution.
[Show abstract][Hide abstract] ABSTRACT: We developed a new method three phase liquid-liquid microextraction (TPLLME) for simultaneous speciation of vanadium. This efforts were launched to know the species and aqueous transport chemistry of the binary V-(1-(2-Pyridylazo)-2-naphthol) complex across the interface of the three phases. Various analytical parameters were optimized. The limit of detection (LOD) was 0.034 mu g L-1 and 0.028 mu g L-1 for V(V) and V(IV) with preconcentration factor of 100. Relative standard deviation (RSD) was found 4.32% for V(V) and 4.22% for V(IV). The proposed method was applied to species of vanadium successfully in sea water and tap water samples. The method was also applied to certified reference material and food samples for total vanadium determination. 0 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
No preview · Article · Jul 2014 · Journal of Industrial and Engineering Chemistry
[Show abstract][Hide abstract] ABSTRACT: A microextraction procedure was established for the speciation of total Cr, Cr(III), and Cr(VI). Sudan blue II was used as a ligand for speciation works. Some factors affecting the recoveries of chromium species, including type of extraction and dispersive solvents, pH, ligand amount, extraction time, and matrix ions, were examined. Optimum values for the dispersive liquid-liquid microextraction method were pH 6, LOD 0.34 mu g L-1, and preconcentration factor 400. Chromium(III) was quantitatively recovered under optimal conditions, while the recovery of chromium(VI) was below 10%. The relative standard deviation for Cr(III) determinations for the 10-replicate measurement of 0.3 mu g mL(-1) Cr(III) was 6.2%. The accuracy was verified using BCR-144R Sewage Sludge, IAEA 336 Lichen, and TMDA 25.3 certified water for trace elements. The procedure was applied to speciation of chromium in water samples. Total chromium was determined in various wheat, bread, and hair samples.
No preview · Article · Jan 2014 · Turkish Journal of Chemistry
[Show abstract][Hide abstract] ABSTRACT: Inorganic arsenic (iAs) in drinking water and food items has been associated with lung and bladder cancers in several countries including Pakistan. In present study water, food items were collected from Arsenic (As) endemic areas (southern part of Pakistan) during 2008-2012, to evaluate its impact on the health of local population. Exposure of As was checked by analyzing biological samples (blood and scalp hairs) of male lung and bladder cancer patients (smokers and non-smokers). For comparative purpose the healthy subjects of same age group and residential area as exposed referents (EXR) and from non-contaminated area (Hyderabad, Pakistan) as non-exposed referents (NER) were also selected. As concentration in drinking water, food and biological samples were analyzed using electrothermal atomic absorption spectrometry. The validation of technique was done by the analysis of certified reference material (CRM) of blood and hair samples. The As contents in drinking water and food were found 3-15-folds elevated than permissible limits, where as in biological samples; EXR have 2-3-folds higher than NER and cancer patients have 5-9-folds higher than NER. The significant difference was observed in smokers (P < 0.01). The outcomes of the study revealed that As levels were elevated in blood and scalp hair samples of both types of cancer subjects as compared to referents (P < 0.001). It was observed that the lung cancer patients (LCP) have 20-35% higher levels of As in both biological samples as compared to bladder cancer patients (BCP) due to smoking habit. This study has proved the correlation among As contaminated water, food and cigarette smoking between different types of cancer risks.
No preview · Article · Dec 2013 · Journal of Environmental Science and Health Part A Toxic/Hazardous Substances & Environmental Engineering
[Show abstract][Hide abstract] ABSTRACT: In this work, the manganese oxide-modified vermiculite (Mn-MV) was prepared from raw vermiculite (RV) and characterized chemically and morphologically. The adsorption surface of RV was increased about 10 times after the modification due to the increase in negative charge onto the sorbent surface. The adsorption performance of RV and Mn-MV sorbents in the removal of silver (Ag(I)) ions from aqueous solution was examined using batch method. The effects of initial pH of solution, contact time, adsorbent concentration, initial silver ion concentration, modifying agent concentration and temperature of solution on the adsorption efficiency were investigated systemically. The maximum adsorption capacity of RV and Mn-MV sorbents was found as 46.2 and 69.2 mg g−1, respectively. The calculated adsorption energy (9.6 kJ mol−1) from the Dubinin–Radushkevich (D–R) model indicated that the adsorption process onto modified sorbent was taken place mainly by chemical ion exchange. A 95% portion of the Ag(I) ions adsorbed was desorbed successfully from the sorbent surface by using 0.5 M 10 mL HCl. The Mn-MV sorbent had good reusability performance after 10 adsorption–desorption cycles. The calculated thermodynamic parameters showed that the adsorption of Ag(I) onto Mn-MV sorbent process was feasible, spontaneous and exothermic. The kinetic evaluation also suggested that the adsorption process followed well the pseudo-second-order kinetic model.
No preview · Article · Apr 2013 · Microporous and Mesoporous Materials
[Show abstract][Hide abstract] ABSTRACT: In this study, the adsorption potential of expanded perlite (EP) and manganese oxides-modified EP (Mn-MEP) for the removal of Sb(III) from aqueous solution were investigated. The influence of solution pH, adsorbent concentration, contact time and temperature on the Sb(III) adsorption were studied using the batch method. Modification of the surface of EP with 0.18 g of manganese oxide per gram EP showed an increase of 1.6-fold in its surface area. The raw EP and Mn-MEP samples with Sb(III) ions were characterized before and after the adsorption process using FT-IR and SEM analysis techniques. The monolayer adsorption capacity of EP and Mn-MEP for Sb(III) was found to be 54.4 and 76.5 mg g–1 at pH 4, respectively. The mean adsorption energy (6.3 kJ mol–1) calculated from the Dubinin–Radushkevich model indicated that the adsorption of Sb(III) onto Mn-MEP was physically carried out. After 10 times of adsorption/desorption cycles, the reusability of Mn-MEP decreased as slightly as 5% for adsorption and 7% for desorption. The calculated thermodynamic parameters (ΔGo, ΔHo, and ΔSo) showed that the adsorption was feasible, spontaneous, and exothermic. The kinetic parameters revealed that the adsorption of Sb(III) onto Mn-MEP followed well the pseudo-second-order kinetic model. In addition, from a practical viewpoint, Mn-MEP is a promising adsorbent for the removal of Sb(III) from aqueous solutions since it has large surface area, high adsorption capacity, easy availability, low-cost, and good reusability performance.
No preview · Article · May 2012 · Industrial & Engineering Chemistry Research
[Show abstract][Hide abstract] ABSTRACT: The present research is to investigate the possibility of macrofungus Lycoperdon perlatum biomass, which is easily available, renewable plant, low-cost, as a new biomass for the removal of mercury (Hg(II)) ions from aqueous solutions. The effects of various parameters like pH of solution, biomass concentration, contact time, and temperature were studied by using batch method. The Langmuir model adequately described the equilibrium data. The biosorption capacity of the biomass was found to be 107.4 mg · g at pH 6. The mean free energy value (10.9 kJ · mol) obtained from the D–R model indicated that the biosorption of Hg(II) onto fungal biomass was taken place via chemical ion-exchange. Thermodynamic parameters showed that the biosorption of Hg(II) onto L. perlatum biomass was feasible, spontaneous and exothermic in nature. The kinetic results showed that the biosorption of Hg(II) onto fungal biomass followed second-order kinetics. This work also shows that L. perlatum biomass can be an alternative to the expensive materials like ion exchange resins and activated carbon for the treatment of water and wastewater containing mercury ions due to its ability of selectivity and higher biosorption capacity and also being low cost material.
No preview · Article · May 2012 · Separation Science and Technology
[Show abstract][Hide abstract] ABSTRACT: This study is focused on the investigation of the equilibrium, thermodynamics and kinetics of arsenic(III) biosorption from aqueous solution by dead green algae (Maugeotia genuflexa) biomass. Optimum biosorptin conditions were determined under the optimum pH, biomass concentration, contact time, and temperature. The equilibrium data were applied to the Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherm models. From the Langmuir model, the maximum monolayer biosorption capacity of the biosorbent was found to be 57.48mg/g at pH 6, biomass concentration 4g/L, contact time 60min, and temperature 20°C. The calculated mean biosorption energy (10.2kJ/mol) using D–R model indicated that the biosorption process was carried out via chemical ion-exchange. Biosorbent could be regenerated using 0.5M HCI solution, with up to 96% recovery and permitted a slightly decrease about 20% in recovery of As(III) ions after repeated ten times sorption–desorption processes. Thermodynamic parameters showed that the biosorption of As(III) onto algal biomass was feasible, spontaneous and exothermic under studied conditions. Kinetic results indicated that the pseudo-second-order kinetic model was well fitted to the experimental data. The performance of the algal biosorbent was also compared with that of many other reported sorbents for arsenic removal and it was observed that the proposed biosorbent is effective in terms of its high sorption capacity.
No preview · Article · Feb 2011 · The Chemical Engineering Journal
[Show abstract][Hide abstract] ABSTRACT: In the presented study, five different fish species and sediment samples were collected from polluted areas, control samples from unpolluted areas in Yeşilirmak River during 2008-2009. The samples were analyzed using flame and/or graphite furnace atomic absorption spectrometry after various digestion methods. The relative standard deviations (RSD) were found below 10%. The accuracy of the methods was confirmed by certified reference materials. The maximum iron, zinc, copper, lead, manganese, nickel and cadmium concentrations were found to be as 116 (Fe), 63.5 (Zn), 2.5 (Cu), 0.56 (Pb), 9.4 (Mn), 10.2 (Ni) and 0.75 (Cd) microg/g in fish samples. The maximum metal concentration in sediment was 3566 microg/g for Fe, 463 microg/g for Mn, 45.5 microg/g for Zn, 38.7 microg/g for Cu, 17.3 microg/g for Pb, 79.2 microg/g for Ni and 0.55 microg/g for Cd, respectively. Some species is accumulated trace metals at high ratio.
No preview · Article · Mar 2010 · Food and chemical toxicology: an international journal published for the British Industrial Biological Research Association
[Show abstract][Hide abstract] ABSTRACT: The element contents (Fe, Mn, Zn, Cu, Pb, Co, Cd, Na, K, Ca and Mg) in edible oils (olive oil, hazelnut oil, sunflower oil, margarine, butter and corn oil) from Turkey were determined using atomic absorption spectrometry after microwave digestion. The concentrations of trace element in the samples were found to be 291.0-52.0, 1.64-0.04, 3.08-1.03, 0.71-0.05, 0.03-0.01, 1.30-0.50, 84.0-0.90, 50.1-1.30, 174.2-20.8 and 20.8-0.60 microg/g for iron, manganese, zinc, copper, lead, cobalt, sodium, potassium, calcium, and magnesium, respectively. Cadmium was found to be 4.57-0.09 microg/kg. The high heavy metal and minerals accumulation levels in the samples were found in olive oil for Cu, Pb, Co, margarine for Fe, K, corn oil for Zn, Mn, butter for Na, Mg, sunflower oil for Ca and hazelnut oil for Cd, respectively.
No preview · Article · Nov 2008 · Journal of hazardous materials
[Show abstract][Hide abstract] ABSTRACT: Trace metal levels in seven different wild-growing mushroom species from Kayseri, Turkey were determined by flame and graphite furnace atomic absorption spectrometry after microwave digestion. The contents of trace metals in the mushroom samples were found in the ranges, 13.4–50.6, 0.14–0.95, 0.75–1.99, 33.5–89.5, 14.2–69.7, 102–1580, 0.34–1.10, 1.72–24.1 and 0.47–1.51 μg/g for Cu, Cd, Pb, Zn, Mn, Fe, Cr, Ni and Co, respectively. Results obtained are in agreement with data reported in the literature.
[Show abstract][Hide abstract] ABSTRACT: The concentrations of Fe, Mn, Zn, Cu, Pb, Cd, Cr, Ni in mushroom species of Turkish origin were determined by atomic absorption spectrometry after microwave digestion. The mushrooms were collected from Ordu, Turkey. The highest Fe level was 628 mg/kg in Mycena inclinata. The highest Mn levels was 103 mg/kg in Coprinus comatus. Zn level was 162 mg/kg in Panellus stipticus. Cu level was 86.2 mg/kg in M. inclinata. Pb level was 11.4 mg/kg in P. stipticus. Cd level was 1.6 mg/kg in Panaeolus campanulatus. Cr level was 4.4 mg/kg in C. comatus and Ni level was 21.6 mg/kg in M. inclinata.
[Show abstract][Hide abstract] ABSTRACT: The concentrations of trace metals in seven fish species collected from some lakes in Tokat, Turkey were determined using flame and graphite furnace atomic absorption spectrometry after microwave digestion methods. The average metal concentrations in the seven fish species varied in the following ranges: Fe, 64.3–197; Mn, 11.7–72.9; Zn, 11.9–38.6; Cu, 1.0–4.1; Pb, 0.7–2.4; Cr, 0.6–1.6; Ni, 1.2–3.4; Cd, 0.1–1.2 μg/g.
[Show abstract][Hide abstract] ABSTRACT: Five modern and ten traditional potato varieties grown in Black Sea coastal region of Turkey were studied for copper, cadmium, manganese, zinc and iron contents. Some traditional cultivars had quite low levels of cadmium. For other minerals, in general, there were not clear differences between traditional and modern varieties. However, there were relatively high levels of variation within both groups for these minerals. The potato samples were analyzed using flame (FAAS) and graphite furnace (GFAAS) atomic absorption spectrometry after microwave digestion.
[Show abstract][Hide abstract] ABSTRACT: In this study, cultivars, planting time and seed size were examined as potential factors to improve mineral composition of barley grain. Ten barley genotypes of different origins were studied. Fall and spring plantings were compared using five cultivars. Four seed size groups of two cultivars were also studied. There were considerable variations for most minerals among barley cultivars and hence, choice of appropriate cultivars may result in better mineral compositions. H. spontaneum, a wild relative of cultivated barley, contained high amounts of Ca, Fe and Mn minerals. In general, fall planted barley had higher mineral content than spring planted barley. Seed size did not affect mineral contents of the seed except copper where smaller seeds had higher copper.
[Show abstract][Hide abstract] ABSTRACT: Contents of Fe, Cu, Mn, Zn, Pb, and Cd in 10 mushrooms species from Tokat, Turkey were determined by atomic absorption spectrometry. The results indicate that Fe, Cu, Mn, and Pb levels in the species Fomes fementarius were the highest with means of 3904±307 mg/kg, 54±4 mg/kg, 64±5 mg/kg, 2.7±2.0 mg/kg, respectively. The highest level of Zn was 122±11 mg/kg in the species Polyporus frondosus. Content of Cd in Boletus appendiculatus and Fomes fomentarius were the highest with a mean of 1.8±0.2 mg/kg.
[Show abstract][Hide abstract] ABSTRACT: Sequential extraction procedure (acid extractable, reducible, oxidizable, and residual) proposed by Standards, Measurements and Testing Programme, formerly: Community Bureau of Reference (BCR) was applied for the determination of trace metals in the house dust samples collected from Kayseri Turkey. The determination of trace metals in the samples was performed by flame atomic absorption spectrometry. The proposed method showed satisfactory recoveries, detection limits and standard deviations for trace metals determination in dust samples. Generally, most of the elements were found in the oxidizable and residual fractions. The total concentrations of trace metals analyzed were found in the range, for Cu: 62.4-119.8, Ni: 37.8-97.8, Cd: 2.54-4.27 and Cr: 38.7-53.5 mg/kg. The results are in agreement with the reported values in the literature.
No preview · Article · Jan 2004 · Fresenius Environmental Bulletin
[Show abstract][Hide abstract] ABSTRACT: The concentrations of trace metals in the fish species were determined using flame and graphite furnace atomic absorption spectrometry after microwave digestion. The proposed method showed satisfactory recovery rates, detection limits and standard deviations. The average metal concentrations of the five species varied in the following ranges: Fe 90.16-102.51; Cu 1.34-1.72; Mn 1.29-9.21; Zn 25.76-112.71; Pb 0.53-1.73; Cd 0.98-2.25; Cr 1.43-1.92 and Ni 2.90-9.36 μg g-1, respectively.
No preview · Article · Jan 2004 · Fresenius Environmental Bulletin
[Show abstract][Hide abstract] ABSTRACT: The concentrations of heavy metals in the soil, mushroom and plant samples collected from Tokat, Turkey have been determined by flame and graphite furnace atomic absorption spectrometry after dry ashing, wet ashing and microwave digestion. The study of sample preparation procedures showed that the microwave digestion method was the best. Good accuracy was assured by the analysis of standard reference materials. The relative standard deviations for all measured metal concentrations were lower than 10%. In all cases, quantitative analytical recoveries ranging from 95 to 103% were obtained. Metal accumulation factors were calculated for mushroom and plant samples. High ratio of plants to soil cadmium, zinc and copper concentrations indicate that these elements are accumulated by mushrooms. Results obtained are in agreement with data reported in the literature.
Preview · Article · Jun 2003 · Microchemical Journal
[Show abstract][Hide abstract] ABSTRACT: Sequential extraction procedure (acid extractable, reducible, oxidizable, and residual) proposed by BCR was applied for the determination of trace metals in the River Yesilirmak sediments, Tokat, Turkey. The determination of trace metals in sediment samples was performed by flame atomic absorption spectrometry. The proposed method showed satisfactory recovery, detection limits and standard deviation for trace metals determination in sediment samples. Generally, most of the elements were found in the oxidizable and residual fractions. The total concentrations of trace metals analyzed were found to be (mg/kg) Cu: 37.9, Mn: 392.2, Zn: 126.2, Fe: 3726, and Pb: 29.6, respectively. Results obtained are in agreement with data reported in the literature.
No preview · Article · Feb 2003 · Microchemical Journal