中文摘要：

采用磷酸氢钙吸附去除铀,考察了反应时间、温度、pH值、铀初始质量浓度、磷酸氢钙投加量等因素对铀去除效果的影响,并从热力学和动力学原理进行了分析。结合扫描电镜、X衍射等分析结果探讨了磷酸氢钙去除铀的机理。结果表明,一定量的磷酸氢钙对铀的吸附容量随着铀初始浓度的增大而增大,随着温度的升高而升高。当pH值为4,磷酸氢钙投加量为200 mg/L时去除效果最好,铀的吸附率高达99%,吸附容量最高可达341.157 2 mg/L,吸附反应在120 min时基本达到平衡;吸附反应在动力学上符合准二级动力学方程,在热力学上符合Langmuir方程。X衍射分析表明磷酸氢钙在吸附铀后晶体结构发生了改变;扫描电镜分析表明,磷酸氢钙在吸附铀后由分散而规则的晶体外观转变为粘结且附有无定型絮状物的外观。

英文摘要：

Using calcium hydrogen phosphate to remove uranium, the influences of reaction time, temperature, pH value, initial mass concentration of uranium, and calcium hydrogen phosphate dosage on uranium removal were studied; besides, the adsorption process was analyzed through thermodynamics and kinetics principle at the same time. The mechanism of calcium hydrogen phosphate removing uranium was discussed according to the analysis of scanning electron microscope and X-ray diffraction. The results showed that, the adsorption capacity of calcium hydrogen phosphate on uranium increased with the increase of initial concentration of uranium and temperature. The best uranium removal effect was obtained under the condition that the pH value was 4 and the calcium hydrogen phosphate dosage was 200 mg/L, the adsorption rate and capacity of uranium reached 99%and 341.157 2 mg/L respectively, the adsorption equilibrium was obtained in 120 min; besides, the adsorption process followed pseudo-second order kinetics equation and Langmuir adsorption isotherm. The X-ray diffraction analysis indicated that, the crystal structure of the calcium hydrogen phosphate had been changed after adsorbing the uranium; in addition, the scanning electron microscope analysis demonstrated that, after the adsorption of uranium, the dispersion and regular crystal appearance of calcium hydrogen phosphate had been changed into the bond appearance covered with amorphous flocs.