Fe type clay minerals, Fe–montmorillonite, are expected to form in the nuclear waste repositories over a span of few years owing to the interaction of corrosion products from overpack and/or canister with bentonite consisting of montmorillonite (Mt) as the major clay mineral. Therefore, it is important to understand the properties of altered clay minerals, Fe–Mt. In the present study, the sorption behaviour of ¹³³Ba(II), one of the high-yield fission products of uranium-based fuels and analogue of ⁹⁰Sr (t_1/2 = 28.5 y), on Fe(II)–Mt and Fe(III)–Mt has been investigated. Retention behavior of Ba(II) on Fe–Mt has been studied at varying pH (3–9), ionic strength (0.001 M–1 M) and Ba(II) concentration (10⁻⁹–10⁻³ M) by batch sorption method. The distribution coefficient (K_d) of Ba(II) on Fe–Mt was found to be nearly independent of pH while it decreased with increasing ionic strength indicating ion exchange as the dominant Ba(II) sorption mode on Fe–Mt. Adsorption isotherm of Ba(II) exhibited linearity in the entire Ba(II) concentration range. A comparison of Ba(II) sorption behavior on Fe–Mt and Na–Mt has been made. The Fe released from both Fe(III)–Mt and Fe(II)–Mt was measured in all the sorption experiments and was found to be much less in the case of Fe(III)–Mt (≤ 1.7 ppm) when compared to Fe(II)–Mt (~ 25 ppm). The modeling of Ba(II) sorption profiles on Fe–Mt and Na–Mt has been carried out using FITEQL 4.0.

由于外包装和/或罐中的腐蚀产物与以蒙脱石 (Mt) 作为主要粘土矿物组成的膨润土的相互作用，铁型粘土矿物（Fe-蒙脱石）预计会在几年内在核废料储存库中形成。因此，了解蚀变粘土矿物 Fe-Mt 的性质非常重要。在本研究中， ¹³³ Ba(II)（铀基燃料的高产裂变产物之一和⁹⁰ Sr 的类似物（t _1/2  = 28.5 y））在 Fe(II)–Mt 上的吸附行为并对 Fe(III)-Mt 进行了研究。在不同的 pH (3–9)、离子强度 (0.001 M–1 M) 和 Ba(II) 浓度 (10 ⁻⁹ –10 ⁻³ M) 下，按批次研究了 Ba(II) 在 Fe-Mt 上的保留行为吸附法。 Fe-Mt 上 Ba(II) 的分配系数 ( K _d ) 几乎与 pH 无关，但随着离子强度的增加而降低，表明离子交换是 Fe-Mt 上 Ba(II) 的主要吸附模式。 Ba(II) 的吸附等温线在整个 Ba(II) 浓度范围内呈线性。比较了 Ba(II) 在 Fe-Mt 和 Na-Mt 上的吸附行为。在所有吸附实验中测量了从 Fe(III)-Mt 和 Fe(II)-Mt 释放的 Fe，发现与相比，Fe(III)-Mt (≤ 1.7 ppm) 的情况要少得多。 Fe(II)–Mt (~ 25 ppm)。使用 FITEQL 4.0 对 Fe-Mt 和 Na-Mt 上的 Ba(II) 吸附曲线进行了建模。