School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
School of Environmental Science and Engineering, Tianjin University, Tianjin 300350, China.
Sci Total Environ. 2018 Jun 1;626:612-620. doi: 10.1016/j.scitotenv.2018.01.078. Epub 2018 Feb 19.
A newly developed adsorbent nano CuO/Cu-modified activated carbon composite (nano CuO/Cu-C) was used to remove radioactive iodide ions (I) from simulated wastewater. The emphasis of this research is to improve adsorption performance and obtain higher I removal efficiency compared with the single-stage adsorption. To fully develop the amount of adsorption by nano CuO/Cu-C, and to increase the decontamination factor (DF) of I, an improved countercurrent two-stage adsorption (ICTA) process was introduced. In the ICTA process, measures dealing with desorption of loaded adsorbent in the stage-two adsorption were taken and more extensive application of countercurrent two-stage adsorption (CTA) process could be made after the improvement to ICTA process in this study. Furthermore, in order to analyze the process and determine the I concentration in the effluent, a calculation method was devised based on the Langmuir isotherm equations and adsorption accumulation principle. The mean DFs were 177, 166, and 89.7, respectively, when the initial I concentrations were 5.00, 10.0, and 20.0 mg/L; and the adsorbent dosage was 1.25 g/L. These results were approximately 8.76, 8.97, and 6.79 times higher, respectively, than with conventional single-stage adsorption. The experimental values of the I concentration were higher than the calculated ones, which could be ascribed to desorption of the residual loaded adsorbent and formation of CuI in the adsorption at stage 1. Formation of CuI in the adsorption at stage 1 was considered to be the predominant reason.
一种新开发的吸附剂纳米 CuO/Cu 修饰活性炭复合材料（nano CuO/Cu-C）被用于从模拟废水中去除放射性碘离子（I）。本研究的重点是提高吸附性能，获得比单级吸附更高的 I 去除效率。为了充分发挥 nano CuO/Cu-C 的吸附量，提高 I 的去污因子（DF），引入了改进的逆流两段吸附（ICTA）工艺。在 ICTA 工艺中，采取了措施处理第二级吸附中负载吸附剂的解吸问题，并且在本研究对 ICTA 工艺进行改进后，可以更广泛地应用逆流两段吸附（CTA）工艺。此外，为了分析该过程并确定流出液中的 I 浓度，根据朗缪尔等温方程和吸附累积原理设计了一种计算方法。当初始 I 浓度分别为 5.00、10.0 和 20.0mg/L，吸附剂用量为 1.25g/L 时，平均 DF 分别为 177、166 和 89.7。这些结果分别比常规单级吸附高约 8.76、8.97 和 6.79 倍。I 浓度的实验值高于计算值，这可能归因于残留负载吸附剂的解吸和在第 1 阶段吸附中形成的 CuI。在第 1 阶段吸附中形成的 CuI 被认为是主要原因。
