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Potential of Tin Slag-containing Aggregates as Road Pavement Material
Syazwani Mohd Fadzil,Ahmad Daniel Ahmad,Rohyiza Ba’an,Norsyahidah Mohd Hidzir,Shahrul Sazuan Ariffin 한국방사성폐기물학회 2022 한국방사성폐기물학회 학술논문요약집 Vol.20 No.1
Tin slag is a byproduct obtained from the tin smelting industry and contained naturally occurring radioactive material (NORM); therefore, it has to be managed accordingly. This study focuses on recycling the waste in exchange for natural aggregates for road pavement due to the potential features as construction materials. The main objective of this study is to analyze the use of tin slag by diluting its radioactivity level and as the replacement of natural aggregates while focusing on identifying the mechanical properties of the mixture. Tin slag was used as coarse aggregate in the range of 0–85% while the percentage of recycle glass was maintained at 15% and granite rocks in range of 0–100%. In this research, the concentration activity of NORM in tin slag have been measured using a gamma ray spectrometer. Few laboratory tests for the final product are carried out such as Los Angeles abrasion value (LAAV), aggregate crushing value (ACV), and aggregate impact value (AIV). This study was also conducted to analyze the leachability of As, Cd, Ba, Cr, Pb, Se and Ag from the different composition. From the measurement result, the average concentration of 226Ra, 232Th and 40K are 318.21 Bq·kg?1, 602.07 Bq·kg?1 and 89.84 Bq·kg?1, respectively. The outdoor dose rates were found to be lower than 1.5 mSv·yr?1 in sample A1, A2 and A3 which is the recommended limit for construction materials. The sample toxicity was assessed using the toxicity characteristic leaching procedure (TCLP) and the concentration of the elements studied was analysed using ICP-MS. The result from the analysis indicated that the concentrations of the heavy metal elements were between 0.001–26.94 mg·kg?1, which is lower than the limit for each element. As a conclusion, addition of tin slag between 5 to 25% in exchange of granite rocks as road pavement have showed potential evidence in the test for construction material. Besides, it has low leachability to the environment while diluting the radioactivity level.
Acute oral toxicity and bioavailability of uranium and thorium in contaminated soil
Rashid Nur Shahidah Abdul,엄우용,Ijang Ibrahim,Khoo Kok Siong,SINGH BHUPENDRA KUMAR,Mahzan Nurul Syiffa,Fadzil Syazwani Mohd,Rodzi Nur Syamimi Diyana,Nasir Aina Shafinas Mohamad 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.4
A robust approach was conducted to determining the absolute oral bioavailable (fab) fractions of 238U and 232Th in rats exposed to contaminated soil along with their hematotoxicity and nephrotoxicity. The soil sample is the International Atomic Energy Agency-312 (IAEA-312) certified reference material, whereas blood, bones, and kidneys of in vivo female Sprague-Dawley (SD) rats estimate 238U- and 232Th-fab fractions post-exposure. We predict the bioavailable concentration (Cab) and fab values of 238U and 232Th after acute soil ingestion. The blood 238U (0.750%) and 232Th (0.028%) reach their maximum fab values after 48 h. The 238U (fab: 0.169–0.652%) accumulates mostly in the kidney, whereas the 232Th (fab: 0.004–0.021%) accumulates primarily in the bone. Additionally, 238U is more bioavailable than 232Th. Post 48 h acute ingestion demonstrates noticeable histopathological and hematological alterations, implying that intake of 238U in co-contaminated soil can lead to erythrocytes and proximal tubules damage, whereas, 232Th intake can harm erythrocytes. Our study provides new directions for future research into the health implications of acute oral exposures to 238U and 232Th in co-contaminated soils. The findings offer significant insight into the utilization of in vivo SD rat testing to estimate 238U and 232Th bioavailability and toxicity in exposure assessment.