Sait Erdogan

Polymer Supported Humic Acid for Separation and Preconcentration of Thorium(IV)

Abstract The resin impregnating humic acid (HA) onto XAD‐4 has been prepared to investigate adsorption behaviour of Th(IV). The characterization of the resulting resin has been carried out by infrared spectral data and sorption capacity. Maximum adsorption capacity of Th(IV) on the resin is found to be 1.51 × 10−4 mol g−1 at pH 4. The sorbent was found to possess a high selectivity for Th(IV) with an optimum extraction pH around 3–7. Recoveries for Th(IV) determined prior to breakthrough were found to be quantitative (96–99%). The resin exhibits good chemical stability, reuseability, and a faster rate of equilibration for Th(IV) determination. The influence of several ions as interferents is discussed. The method has been successfully applied for the separation of Th(IV) in synthetic mixtures.

Removal of sulfur and ash from coal using molten caustic leaching, a case study from Hazro fields, Turkey

Molten caustic leaching process is effective in reducing significant amount of ash derived from minerals, pyritic sulfur, and organic sulfur from coal. The effect of leaching coal samples from Hazro fields, situated in Southeast Anatolia region of Turkey with molten sodium hydroxide as well as followed by mild acid on demineralization and desulfurization was investigated. The effects of alkali/coal ratio, time, and temperature on the leaching efficiency were detailed and the experimental results are presented here. Chemical demineralization and desulfurization of coal samples using molten sodium hydroxide was investigated in the temperature range of 200−400°C. The percentage of demineralization and desulfurization increased with the increase in alkali/coal ratio. The removal of total sulfur and ash increases with increasing leaching temperature and time. As a result of MCL, ash content of Hazro coal was reduced from 18.31 to 6.77 %, and 70% of combustible was recovered. Total sulfur and volatile matter content was reduced from 7.54 to 1.01% and from 47.80 to 12.41%, respectively. Most of the inorganic sulfur and a significant portion of the organic sulfur were removed.

Formation And Characterization Of Humic Acids From Low Rank Anatolian Coals By Air Oxidation

Abstract The results of this study are aimed at evaluating the effects of air oxidation time, temperature and demineralization on humic acid production from two low-rank Anatolian coals. Two Anatolian low rank coals were studied at 120 and 200°C up to 10 days with and without demineralization. The best results for humic acid formation were obtained at a high temperature for longer times. Demineralization effect is negligible for studied coals. The rate of humic acid formation increased at first with increase in oxidation time, reached a maximum, and then decreased at high oxidation time. Also, a detailed study of the elemental composition, the characterization by FTIR, and the acidity of humic acids are reported.

Effect of Molten Caustic Leaching on Demineralization and Desulfurization of Asphaltite

Abstract Molten caustic leaching process is effective in reducing significant amounts of ash-forming minerals, pyritic sulfur, and organic sulfur from solid fossil fuels. The effect of leaching asphaltite samples from Seguruk and Harbul collieries of Sirnak and Silopi asphaltite fields (situated in the Southeast Anatolia region of Turkey) with molten sodium hydroxide and followed by mild acid on demineralization and desulfurization was investigated. The effects of alkali/asphaltite ratio, time, and temperature on the leaching efficiency were detailed, and the experimental results are presented here. Chemical demineralization and desulfurization of asphaltite samples using molten sodium hydroxide were investigated in the temperature range of 200°C–400°C. The percentage of demineralization and desulfurization increased with the increase in alkali/asphaltite ratio. The removal of total sulfur and ash increased with increasing leaching temperature and time. Most of the inorganic sulfur and a significant portion of the organic sulfur were removed.

Chemical Leaching on Sulfur and Mineral Matter Removal from Asphaltite (Harbul, SE Anatolia, Turkey)

Abstract Desulfurization and demineralization by an aqueous caustic leaching method was investigated of an asphaltite sample from Harbul (Silopi, SE Anatolia, Turkey). The effects of different parameters, such as alkali concentration, time, and temperature, on the leaching efficiency were detailed and the experimental results are presented here. The caustic concentration varied from 0.1–1.0 M, temperature was 100–180°C, and leaching time varied from 4–16 h. The removal of total sulfur and ash increases with increasing alkali concentration, leaching temperature, and time. As a result of aqueous caustic leaching, the ash content of asphaltite was reduced from 32.49 to 18.00%, and 76% of combustible was recovered. Total sulfur and volatile matter content was reduced from 7.02 to 2.68% and from 46.74 to 25.10%, respectively.

The basic properties of transesterified corn oil and biodiesel-diesel blends.

Abstract Biodiesel, one of green fuels and clean energies, is compatible with traditional petroleum-based diesel and both can be completely blended without any stratification. Biodiesel was prepared from corn by transesterification of the crude oil with methanol in the presence of NaOH as catalyst. Transesterified corn oil has better properties globally because it has the greater monounsaturated content. Determination of blend levels is one important issue to the quality control of biodiesel due to the increase of biodiesel-diesel blends commercialization. The objective of this study was to characterize how the key fuel properties changed when the commercial petroleum diesel fuel was blended with methyl ester produced from corn oil. In the present study, commercially available diesel fuel was blended with the biodiesel prepared from corn oil. The blends of biodiesel petroleum diesel were prepared on a volume basis. The important properties of corn oil methyl ester (biodiesel)-diesel fuel blends, such as density and kinematic viscosity, are found out and compared to those of No. 2 petroleum diesel, ASTM, and EN biodiesel standards.

Extremely low-frequency magnetic field induces manganese accumulation in brain, kidney and liver of rats.

The aim of the present study was to determine the effects of extremely low-frequency magnetic field (ELF-MF) on accumulation of manganese (Mn) in the kidney, liver and brain of rats. A total of 40 rats were randomly divided into eight groups. Four control groups received 0, 3.75, 15 and 60 mg Mn per kg body weight orally every 2 days for 45 days, respectively. The remaining four groups received same concentrations of Mn and were also exposed to ELF-MF (1.5 mT; 50 Hz) for 4 h for 5 days a week during 45 days. Following the last exposure, kidney, liver and brain were taken from all rats and they were analyzed for Mn accumulation levels using an inductively coupled plasma-optical emission spectrometer. In result of the current study, we observed that Mn levels in brain, kidney and liver were higher in Mn groups than in control groups. Mn levels in brain, kidney and liver were also higher in Mn plus ELF-MF groups than in Mn groups. In conclusion, result of the current study showed that the ELF-MF induced manganese accumulation in kidney, liver and brain of rats.

Effect of electromagnetic fields and antioxidants on the trace element content of rat teeth

The purpose of this study was to examine the possible effect of extremely low-frequency electromagnetic fields (ELF-EMFs), from a high-voltage source, on rat teeth in terms of changes in trace elements (TEs) and the effect of antioxidants (melatonin [MLT] and Ganoderma lucidum [GL]) in counteracting these effects. We used adult male Wistar albino rats with a mean weight of 250–300 g and divided the rats into eight groups. The groups were subjected to an ELF-EMF that was applied with a high-voltage line for 8 hours/day for 26 days (Groups I, II, and III) or 52 days (Groups V, VI, and VII). Groups IV and VIII were the 26- and 52-day control/sham groups, respectively. Groups II and VI were treated with GL, and Groups III and VII were treated with MLT. MLT and GL were administered daily based on the weight of the animals and appropriate standards. At the end of the study, the rats were euthanized, and their anterior teeth were extracted. The teeth were preserved in pure water before evaluating the major TEs. At the end of the study, TE concentrations (in mg/kg) were assessed in the control and test groups. Compared with Group V, statistically significant differences in the concentrations of zinc (Zn) and strontium (Sr) were found for Group VII (ELF-EMF + MLT) (P<0.05). Therefore, ELF-EMF exposure can change the content of certain TEs in teeth and, after administering MLT and GL, the values of some of the TEs return to normal.

The Characterization of Liquid Product via Flash Pyrolysis of Coal (Hazro, SE Anatolia, Turkey)

Abstract Coal can be converted into a variety of secondary products, such as light hydrocarbon gases, tar, and high quality fuel char, by means of pyrolysis. Liquefaction of Hazro (Diyarbakir, SE Anatolia, Turkey) coal, −0.60 + 0.25 mm particle size, and using flash pyrolysis was performed in a fixed-bed reactor with a heating rate 40°C min−1 at a temperature ranging from 400 to 800°C under nitrogen atmosphere. The effect of temperature on conversion and liquid yield was examined. The flash pyrolysis temperature resulted in a large increase in the oil yield, tar, and gases; a large increase in the yield of hydrocarbon gases occurred as a result of temperature at 550°C, which was attributed to an increased thermal cracking of pyrolysis vapors. Pyrolysis oil was treated with silica gel column chromatography. Using n-hexane, toluene, and methanol, the oil was separated into aliphatic, aromatic, and polar components, respectively. The fractions from silica gel chromatography of liquid product obtained both by nitrogen pyrolysis were characterized by Fourier transform infrared spectroscopy.

Molybdenum Speciation in Coal Bottom Ash Using a Sequential Extraction Procedure and Determination by FAAS

Coal bottom ash contains many elements that exist in different forms, which may change throughout the coal combustion process. This study presents the concentration and speciation of molybdenum in bottom ash of coal. Determination of total molybdenum was performed by two-stage microwave-acid digestion followed by flame atomic absorption spectrometry. A sequential extraction process to speciation of molybdenum from coal bottom ash was investigated. The most abundant form of molybdenum in samples is sulfide fraction of molybdenum. Relative abundances of the remaining fractions follow the order: Residual > Reduciple > Oxidizable > Exchangeable > Carbonate > Water soluble.