Browsing by Author "Duran C."

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Assessment of the Enrichment of Heavy Metals in Coal and Its Combustion Residues
(2022-06-21) Altlkulaç A.; Turhan Ş.; Kurnaz A.; Gören E.; Duran C.; Hançerlioǧullarl A.; Uǧur F.A.
Coal-fired thermal power plants remain one of the main sources of electricity generation in Turkey. Combustion of coal creates coal ash and slag, which are often stored in landfills located near residential and agricultural fields, increasing the potential for high environmental contamination and health risks. This study investigates the content and enrichment factor (EF) of heavy metals in pulverized lignite coal and its combustion residues from the Kangal lignite coal-fired thermal power plant situated in the Central Anatolian Region of Turkey. The concentration of heavy metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Zr, Cd, Hg, and Pb) in lignite coal, slag, and fly ash samples were analyzed using an energy dispersive X-ray fluorescence technique. The concentration of Fe is highest while Hg concentration is lowest in the samples. The concentrations of heavy metals are higher in slag and fly ash samples than in lignite coal. Average values of EF (related to Earth's crust average) revealed that extreme enrichment has been shown by arsenic and mercury in lignite coal and fly ash samples while very high enrichment has been shown in slag samples.
Determination of elemental concentrations of radionuclides in Turkish bentonite and calculation of radiogenic heat generation
(2022-01-01) Turhan; Metin O.; Hançerlioğulları A.; Kurnaz A.; Duran C.
Bentonite containing smectite group clay minerals is an industrial raw material with a wide range of uses. In this study, the concentration of uranium, thorium, and radioactive potassium in ninety bentonite samples collected from quarries in Turkey was determined using an energy-dispersive X-ray fluorescence spectrometer. The concentrations of uranium, thorium and potassium varied from 0.4 to 18.2 with an average of 4.3 mg/kg, 5.4 to 53.4 with an average of 22.7 mg/kg and 0.3 to 3.4 with an average of 1.4 mg/kg, respectively. The radiogenic heat generation caused by the ionising radiation emitted from these radioactive elements in bentonite samples was calculated in the range of 0.9 to 6.6 µW/m3 with an average of 2.8 µW/m3.
Ecological assessment of heavy metals in soil around a coal-fired thermal power plant in Turkey
(2020-03-01) Turhan; Garad A.M.K.; Hançerlioğulları A.; Kurnaz A.; Gören E.; Duran C.; Karataşlı M.; Altıkulaç A.; Savacı G.; Aydın A.
In this study, heavy metal concentrations in agricultural surface soil (0–5 cm) samples collected from the area around the Kangal lignite-fired thermal power plant were determined using energy-dispersive X-ray fluorescence spectrometry. Also, the pH values of agricultural soil samples were measured to assess the level of acidification. Geo-accumulation index (Igeo), enrichment factor (EF), contamination factor (CF), contamination degree (CD), modified contamination degree (mCD), and pollution load index (IPL) were estimated to assess the heavy metals pollution in soil samples. The average concentration of Fe, Ti, Mn, Cr, Ni, Zn, Zr, Co, Cu, Pb, As, Sn and Hg was found as 39,065 ± 5096, 2262 ± 738, 721 ± 119, 713 ± 236, 610 ± 199, 82 ± 37, 65 ± 26, 64 ± 19, 29 ± 3, 17 ± 7, 9 ± 7, 3 ± 1 and 2 ± 1 mg kg−1, respectively. The values of pH varied from 7.5 to 8.2 with an average value of 8.0 (moderately alkaline). The Igeo, EF and CF results reveal that the study area is heavily or very highly contaminated with Cr, Ni, and Hg. On the basis of the IPL value, the soil samples are polluted with heavy metals. However, the mCD indicates moderate heavy-metal contamination of the soil samples.
Environmental evaluation of natural radioactivity in soil near a lignite-burning power plant in Turkey
(2017-11-01) Gören E.; Turhan; Kurnaz A.; Garad A.; Duran C.; Uğur F.; Yeğingil Z.
Natural radionuclides are released into the environment together with fly ash from the coal-burning power plant and cause an increase in the natural radioactivity in environmental samples. The study concerns to the evaluation the influence of Kangal lignite-burning power plant (LBPP) with a power of 457 MWe, which has been in operation since 1989, on natural radionuclide a concentration in surface soil samples around it. Activity concentrations of natural radionuclides (226Ra, 232Th, 40K and 222Rn) in the soil samples, and emanation coefficient (EC) and mass (ERM) and surface (ERS) exhalation rate of radon were determined by using a gamma-ray spectrometer with an HPGe detector. The average values of 226Ra, 232Th, 40K and 222Rn, EC, ERM and ERS were found as 37±5, 17±3, 222±30 Bq kg−1 and 9±1 kBq m−3, 12%, 12.1 µBq kg−1 s−1 and 7.1 mBq m−2 s−1, respectively. Absorbed gamma dose rate in outdoor air and the corresponding effective dose rate from external exposure and excess lifetime cancer risk were estimated to evaluate radiological hazards for human population. The results revealed that the Kangal LBPP has caused a small increment in 226Ra concentration in the studied area. No influence was observed for 232Th and 40K.
Evaluation of terrestrial radionuclide levels and concomitant radiological risks of bentonites used in many industries
(2022-01-01) Kurnaz A.; Turhan Ş.; Metin O.; Altıkulaç A.; Duran C.
Bentonite is a soft, porous, easily shaped, and absorbent material rich in aluminum, sodium, and potassium. Bentonite is a mineral widely utilized as drilling mud, ore pelletizing, absorbent/adsorbent, bleaching agent, water impedance, coating, and raw material in various industries. In this study, radiometric measurements of 90 bentonite samples collected from 21 quarries in Turkey were performed using gamma-ray spectrometry. The radiological hazards caused by indoor exposure to adults due to the utilization of bentonites as raw materials in the construction industry and outdoor external exposures to quarry workers were evaluated by estimating the activity concentration index, annual effective doses, and lifetime cancer risk. The average activity concentrations of 226Ra, 232Th and 40K measured in bentonite samples were found as (50 ± 5) Bq/kg, (76 ± 4) Bq/kg and (373 ± 19) Bq/kg, respectively. The evaluation results reveal that the bentonites examined could be safely utilized as raw materials.
Impact of toxic metal pollution on surface water pollution: a case study of Tohma stream in Sivas, Turkey
(2021-01-01) Turhan; Duran C.; Kurnaz A.; Hançerlioğulları A.; Metin O.; Altıkulaç A.
This study was executed to investigate the acidification and heavy metal (Cr, Mn, Fe, Ni, Cu, Zn, and Pb) pollution of Tohma stream flowing near Kangal lignite-fired thermal power plant located in Kangal district of Sivas province in the Central Anatolia region of Turkey. All water samples were screened for pH to evaluate the acidification of the Tohma stream. Water samples were found in moderately alkaline according to pH values (8.1–8.7). The average concentrations of Cr, Mn, Fe, Ni, Cu, Zn and Pb in water samples from the Tohma stream were determined as 0.94, 2.27, 13.78, 1.24, 1.98, 0.32 and 0.54 mg L−1 using energy dispersive X-ray fluorescence spectroscopy, respectively. Metal pollution index (MPI) and metal evaluation index (MEI) were estimated to evaluate the pollution of Tohma water samples with heavy metals. The values of MPI and MEI varied from 312 (medium pollution) to 9715 (high pollution) with an average of 4713 (high pollution) and 181(medium pollution) to 317 (high pollution) with an average of 226 (medium pollution), respectively. The results of MPI and MEI revealed that investigated water samples are seriously polluted with toxic heavy metals and inadequate for drinking and irrigation water utilisation.
Radiometric measurement of lignite coal and its by-products and assessment of the usability of fly ash as raw materials in Turkey
(2018-07-26) Turhan Ş.; Gören E.; Garad A.M.K.; Altlkulaç A.; Kurnaz A.; Duran C.; Hançerlioǧullarl A.; Altunal V.; Güçkan V.; Özdemir A.
Lignite coal (LC) is a key energy source for electricity generation in Turkey. During lignite burning, huge amounts of fly ash (FA), bottom ash and slag are produced as by-products which contain radionuclides in the natural radioactive series of uranium and thorium, and radioactive potassium. These radionuclides may lead to radiological exposure of workers and the public and cause environmental problems. Therefore, finding diverse uses for the by-products in the construction sector and earthwork applications has considerable economic and environmental importance. In this study, the activity concentrations of 226Ra, 232Th and 40K in and radon emanating power (EP) and radon mass exhalation rate (EXRM) from LC, slag and FA obtained from the Kangal lignite-burning power plant with a power of 457 MWe were measured using gamma-ray spectroscopy. The major chemical components (SiO2, Al2O3, Fe2O3, CaO and MgO) of fly ash samples were analysed using an energy dispersive X-ray fluorescence spectrometer. The annual effective doses received by workers and members of the public were estimated using different scenarios specified in Radiation protection 122. The average activity concentrations of 226Ra, 232Th and 40K in LC, slag and FA samples were 187±21, 16±1 and 99±9 Bq kg-1, 620±18, 41±2 and 330±13 Bq kg-1, and 937±30, 38±2 and 272±17 Bq kg-1, respectively. The average values of EP and EXRM of the lignite, slag and FA samples were 8 %, 7 % and 10 %, and 0.1, 0.3 and 0.7 Bq kg-1 h-1, respectively. The highest average of the total annual effective dose is estimated at 153 μSv for members of the public and 74 μSv for workers, lower than the recommended annual limit of 1000 μSv.