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为了研究U(Ⅵ)在石棉尾矿酸浸渣上的吸附行为,利用红外光谱仪、X射线衍射仪和扫描电镜等手段分别对石棉尾矿和石棉尾矿酸浸渣进行详尽表征。采用静态实验法考察吸附剂浓度、时间、pH、离子强度和温度等因素对吸附的影响,并进一步分析了吸附动力学和热力学。在研究范围内,U(Ⅵ)在石棉尾矿酸浸渣上的吸附受pH值、离子强度和温度的影响明显。当pH<6时,吸附率随pH的增大而增大,此时吸附作用主要是离子交换作用或表面络合;当pH>6,随pH的增大吸附率会降低,且离子强度越大,吸附率越低,则表明静电吸附或表面络合是其主要的吸附机制。动力学符合准二级动力学方程,热力学符合Langmuir吸附等温线方程。
In order to study the adsorption behavior of U (Ⅵ) on acid leachate from asbestos tailing, the acid leaching residue of asbestos tailings and asbestos tailings were characterized by means of infrared spectroscopy, X-ray diffraction and scanning electron microscope. The effects of adsorbent concentration, time, pH, ionic strength and temperature on the adsorption were investigated by static experiments. The adsorption kinetics and thermodynamics were further analyzed. Within the scope of the study, the adsorption of U (Ⅵ) on acid leachate of asbestos tailings is significantly affected by pH, ionic strength and temperature. When the pH value is less than 6, the adsorption rate increases with the increase of pH. At this time, the adsorption is mainly ion exchange or surface complexation. When pH> 6, the adsorption rate decreases with increasing pH, and the ionic strength Large, the lower the adsorption rate, indicating that electrostatic adsorption or surface complexation is its main adsorption mechanism. Kinetics consistent with quasi-second-order kinetic equation, thermodynamic fit Langmuir adsorption isotherm equation.