Treatment for removing radium in soil and groundwater

• Published in: Applied radiation and isotopes Vol. 182; p. 110127
• Main Authors: Huynh, Nguyen Phong Thu, Nguyen, Van Thang, Vu, Ngoc Ba, Le, Cong Hao, Truong, Thi Hong Loan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-04-2022
• Subjects: Gamma spectrometry; Groundwater; Groundwater - chemistry; Hydrogen-Ion Concentration; Magnesium Oxide; Mobility; PCA; RAD7; Radium; Radium - analysis; Soil; Soil - chemistry; Soil Pollutants, Radioactive - analysis; Vietnam; Water Pollutants, Radioactive - analysis; Water Purification - methods; Water Supply; Vietnam; Groundwater; RAD7; Soil; Mobility; Radium; PCA; Gamma spectrometry
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2022.110127

The results of 226Ra activity concentration measurements in 50 soil and groundwater samples in Ninh Son region, Vietnam were evaluated in the present study. Average activity concentration in the soils was significantly higher than the worldwide average concentration in soils published by UNSCEAR, 2008. 90% of groundwater samples had concentrations of 226Ra that were higher than the USEPA drinking water standard. The results showed that there was a linear correlation between the 226Ra radioactivity in the soils and the concentration of 226Ra in the groundwater samples. The procedure for removal of 226Ra from soil and groundwater samples was built upon the chemistry behavior of radium. 226Ra in contaminated groundwater samples was removed by using MnO2 fiber. The removal efficiency of 226Ra reached ∼ 91% for the groundwater samples and ∼ 70% for the soil samples. Chemical removal of 226Ra from soils was investigated using a three-step extraction procedure (Easily leachable and exchangeable, Acid-reducible, and Oxidisable-organic). A moderate mobility of 226Ra (22–52%) was noted and mainly found in acid-reducible fractions, which suggests that 226Ra is mainly bound to Fe/Mn oxides and hydroxides. A multiple regression indicates that the 226Ra removal efficiency appears to be significantly dependent on Fe/Mn and organic matter content.
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•Activity concentrations of 226Ra in soil and groundwater were determined.•A sequential extraction procedure for removing 226Ra from soil and groundwater samples was built.•A high mobility of 226Ra in soil was noted and mainly found in acid-reducible fraction.•The multiple regression indicates that the 226Ra removal efficiency is significantly dependent on Fe/Mn and organic matter content.