The presence of Naturally Occurring Radionuclides (NORs) in geothermal fluids is a recurring issue in geothermal projects all over the world. During the first pumping tests of the production well MOL-GT-S1-01 at the Balmatt geothermal plant (Mol, Belgium) in 2015, the geothermal water was transferred towards a nearby basin. The original geothermal fluid was characterized by a²²⁶Ra concentration of ~170 Bq L⁻¹ (February 2019). In the meantime, the water in the basin was exposed to multiple cycles of rainfall and evaporation. In June 2019, the concentration of ²²⁶Ra in the basin water was ~24 Bq L⁻¹. As the concentration of the water is still too high to be discarded as non-radioactive waste water, finding a solution to remove the radium from the basin water is required. In order to achieve this objective, two resins, namely the MnO₂-PAN resin and the TK101 resin, were tested for their sorption capacity to remove the ²²⁶Ra by using ¹³³Ba as proxy in batch-type experiments performed in the laboratory. The TK101 resin did not show a sufficient sorption capacity for ¹³³Ba and is therefore not considered to be useful to remove ²²⁶Ra from the basin water. The MnO₂-PAN resin however, showed promising results. A sorption yield of 86% was reached at pH 9.2 after a contact time of one week. At high pH, some co-precipitation of ¹³³Ba with carbonate minerals comprising significant amounts of Ca²⁺ and Mg²⁺ was observed. Total sorption was higher at pH = 9.2 (maximum sorption) than at the pH of the basin water (pH = 7.5). Even at high Ca²⁺ concentrations in the solution (i.e. 5 g L⁻¹), there was almost no competition of Ca²⁺ for Ba²⁺ sorption sites on the resin. The modelling of the sorption edge experiments with the MnO₂-PAN resin showed that mainly Cu and Mn were competitive for the sorption sites at low pH values (2.0 ≤ pH ≤ 4.5), while at acid to neutral pH values (4.5 ≤ pH ≤ 7), Zn and Ni became more competitive. At high pH values (pH ≥ 7.0), Cd started to compete with Ba for the sorption sites of the resin. The modelling of the kinetic experiments showed that these results could best be described by a pseudo second-order kinetic model of the form $\frac{dq}{dt}=k_2{(q_e-q_t)}^2$.

地热流体中天然存在的放射性核素 (NOR) 的存在是世界各地地热项目中反复出现的问题。2015 年，在 Balmatt 地热发电厂（比利时 Mol）的生产井 MOL-GT-S1-01 的第一次抽水测试中，地热水被转移到附近的盆地。原始地热流体的特征是²²⁶ Ra 浓度约为 170 Bq L ^-1（2019 年 2 月）。与此同时，盆地中的水经历了多次降雨和蒸发循环。2019年6月，流域水中²²⁶ Ra的浓度为~24 Bq L ^-1. 由于水的浓度仍然太高而不能作为非放射性废水丢弃，因此需要找到一种从流域水中去除镭的解决方案。为了实现这一目标，在实验室进行的间歇式实验中，使用¹³³ Ba 作为替代物，测试了两种树脂，即 MnO ₂ -PAN 树脂和 TK101 树脂的吸附能力，以去除²²⁶ Ra 。TK101 树脂对¹³³ Ba没有显示出足够的吸附能力，因此被认为不适用于从盆地水中去除²²⁶ Ra。MnO ₂然而，-PAN树脂显示出有希望的结果。在 1 周的接触时间后，在 pH 9.2 下达到 86% 的吸附产率。在高 pH 值下，观察到¹³³ Ba 与包含大量 Ca ²⁺和 Mg ^{2+ 的}碳酸盐矿物的一些共沉淀。总吸附量在 pH = 9.2（最大吸附量）时高于在盆地水的 pH 值（pH = 7.5）下。即使在溶液中的高 Ca ²⁺浓度（即 5 g L ^-1）下，几乎没有 Ca ²⁺竞争树脂上的Ba ²⁺吸附位点。MnO ₂吸附边缘实验的建模-PAN 树脂表明，在低 pH 值（2.0 ≤ pH ≤ 4.5）下，主要是 Cu 和 Mn 竞争吸附位点，而在酸性至中性 pH 值（4.5 ≤ pH ≤ 7）下，Zn 和 Ni 变得更具竞争力。在高 pH 值（pH ≥ 7.0）下，Cd 开始与 Ba 竞争树脂的吸附位点。动力学实验的建模表明，这些结果可以最好地用以下形式的伪二级动力学模型来描述$\frac{dq}{d吨}={克}_2{(q_{\mathrm{电子}}-q_{吨})}^2$.