Radiological characterization, combustion-related enrichment, and screening-level dose assessment of coal and coal ash from the Karapınar lignite basin (Türkiye)
Environmental Science: Processes and Impacts, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1039/d6em00005c
- Dergi Adı: Environmental Science: Processes and Impacts
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, Chemical Abstracts Core, Compendex, EMBASE, Environment Index, Greenfile, INSPEC, MEDLINE, Zoological Record, Health Research Premium Collection (ProQuest)
- Akdeniz Üniversitesi Adresli: Evet
Özet
This study investigated the natural radionuclide contents of coal from the Konya-Karapınar Neogene basin and laboratory-simulated coal ash, their distribution and enrichment characteristics within the coal ash, and the associated radiological risks. To this end, the activities of 238U, 232Th, and 40K were determined by gamma spectrometry in 15 coal samples taken from five boreholes and their ash phases, and the enrichment behaviour during combustion was evaluated. The activities of 238U, 232Th, and 40K in the coal samples averaged 99.2 ± 8.1, 35.1 ± 2.5, and 313 ± 18 Bq kg−1 respectively. After combustion, these values increased on average by 3.33, 2.55 and 2.56 times on an ash basis, reaching 328 ± 23, 82.3 ± 6.6 and 710 ± 40 Bq kg−1. The relative enrichment factor values for 238U range from 0.71 to 1.47, with an average of 1.06, indicating that uranium is generally retained in the ash. While 238U is controlled by secondary enrichment in organic matter-rich, sulphidic microenvironments, 232Th and 40K are associated with detrital/inorganic minerals. Radiological indices revealed that the radium equivalent activity of ash (500.0 Bq kg−1) exceeds the international safety threshold and that the absorbed gamma dose rate (232.1 nGy h−1) is approximately four times the global average. In the screening-level modelling conducted with RESRAD-ONSITE (v7.2) for the residential farmer scenario, it was determined that the maximum total dose for uncontrolled surface ash accumulation reached 0.164 mSv y−1 at year 23.2. Although the elevated natural radioactivity in Karapınar coal ash requires careful management, the estimated doses under the modeled exposure scenario remain within acceptable limits and do not pose a significant risk to public health.