open access

https://hdl.handle.net/2115/68411

Strontium adsorption and penetration in kaolinite at low Sr2+concentration

英語

strontium

2017-02-02

Taylor & Francis Asia Pacific (Singapore)

Soil Science and Plant Nutrition

63(1)

14-17

This is an Accepted Manuscript of an article published by Taylor & Francis in Soil Science and Plant Nutrition on 02 Feb 2017, available online: http://www.tandfonline.com/10.1080/00380768.2016.1277435.

ABSTRACT: Behavior of radioactive strontium (Sr2+) in contaminated soils is an important issue in relation to nuclear power plant accidents. The Sr2+adsorption on kaolinite and its migration in a kaolinite soil were investigated because toxic effects of radioactive Sr2+have been found to be very severe for living organisms at low Sr2+concentrations. Adsorption isotherms of Sr2+on kaolinite at different salt (NaCl) concentration and pH were obtained by the batch method. The calculated distribution coefficients (KD) ranged between 600 and 40,000 L kg−1, which showed a strong preference for the adsorbed phase. The results were used to evaluate the ratio (r) of penetration length of Sr2+relative to that of water in a model kaolinite soil. When the Sr2+solution was percolated constantly into the kaolinite soil, the penetration ofSr2+was delayed strongly at low Sr2+concentration due to adsorption. The Sr2+penetration length was only 0.001–0.056 of the water penetration length at pH 6.5 (0.1–10 mmol L−1NaCl). At pH 4.1 (1 mmol L−1NaCl) the effect was about 17 times less than at pH 6.5 (1 mmol L−1NaCl). Under all conditions, the Sr2+penetration increased when the Sr2+concentration increased due to the KD decrease. The Sr2+isothermscould be fitted well to the Langmuir adsorption equation, which indicates that only one site type is involved in the Sr2+adsorption.

学術雑誌論文

Accepted Manuscript

0038-0768

1747-0765