Abstract

Uranium was adsorbed using bentonite treated with 1-amino-2-naphthol-4-sulfonic acid (ANSA). The prepared Bt-(ANSA) was characterized, and its adsorption affinity for uranium(VI) was evaluated. The influence exerted on the uranium adsorption by pH, contact time, adsorbent dose, initial uranium concentration, interfering ions, and temperature was studied. The optimum conditions are pH 8.5, 0.04 g of Bt-(ANSA) per 10 mL of 400 mg/L uranium solution, and 20-min contact at room temperature. The majority of cations except Th, Fe, Cu, and Ni do not interfere with the uranium adsorption. The adsorption kinetics and equilibrium were studied. The application of the Langmuir model showed that the maximum sorption capacity reached 90.9 mg/g at room temperature. The adsorption process was found to follow a pseudo-second order kinetic model at 400 mg/L uranium concentration. Evaluation of thermodynamic parameters (ΔG°, ΔH°, and ΔS°) shows that the adsorption is spontaneous exothermic accompanied by a decrease in randomness. Uranium(VI) ions were efficiently desorbed using a 1 M HNO₃ solution with the adsorbent regeneration. The optimum conditions were applied to separate uranium from carbonate leach liquor solution of a field sample from Abu Hamatta area, SW Sinai, Egypt.

中文翻译：

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使用1-氨基-2-萘-4-磺酸和膨润土的混合物吸附铀（VI）：动力学和平衡研究

摘要

使用经1-氨基-2-萘-4-磺酸（ANSA）处理过的膨润土吸附铀。对制备的Bt-（ANSA）进行了表征，并评估了其对铀（VI）的吸附亲和力。研究了pH，接触时间，吸附剂剂量，初始铀浓度，干扰离子和温度对铀吸附的影响。最佳条件为pH值为8.5，每10 mL 400 mg / L铀溶液含0.04 g Bt-（ANSA），并在室温下接触20分钟。除Th，Fe，Cu和Ni以外的大多数阳离子都不会干扰铀的吸附。研究了吸附动力学和平衡。Langmuir模型的应用表明，室温下最大吸附量达到90.9 mg / g。发现在铀浓度为400 mg / L时，吸附过程遵循拟二级动力学模型。热力学参数评估（ΔG °，ΔH °和ΔS °）表明吸附是自发放热的，伴随着随机性的降低。使用1 M HNO ₃溶液可有效地解吸铀离子，并具有吸附剂再生作用。最佳条件适用于从埃及西南部阿布哈马塔地区的田间样品的碳酸盐浸出液中分离铀。