A newer efficient U(VI) ion adsorbent was synthesized by impregnating Br-PADAP [2-(5-Bromo-2-pyridylazo)-5-(diethylamino)phenol] onto multiwall carbon nanotubes (MWCNTs). The effects of various operation conditions on uranium adsorption (i.e., pH contact time, temperature, and initial uranium concentration) were systematically evaluated using batch experiments. The results indicated that the uranium adsorption on modified MWNCTs (5.571 × 10⁻³ g/mg × min) reached faster equilibrium than that on pristine MWNCTs (4.832 × 10⁻³ g/mg × min), reflecting the involvement of appropriate functional groups of Br-PADAP on the chelating ion-exchange mechanism of U(VI) adsorption. Modified MWNCTs (83.4 mg/g) exhibited significantly higher maximum Langmuir adsorption capacity than pristine MWNCTs (15.1 mg/g). Approximately 99% of uranium adsorbed onto modified MWNCTs can be desorbed by 2.5 mL of 1 M HNO₃ solution. Therefore, Br-PADAP-modified MWNCTs can server as a promising adsorbent for efficient uranium adsorption applications in water treatment. Subsequently, the proposed solid-phase extraction (using a mini-column packed with Br-PADAP/MWCNT) was successfully utilized for analysing trace uranium levels by the ICP-AES method in different environmental samples with a pre-concentration factor of 300-fold. The coexistence of other ions demonstrated an insignificant interference on the separative pre-concentration of uranium. the detection limit was recognized as 0.14 μg/L, and the relative standard deviation was approximately 3.3% (n = 7).

通过将Br-PADAP [2-（5-溴-2-吡啶基偶氮）-5-（二乙基氨基）苯酚]浸渍到多壁碳纳米管（MWCNT）上，合成了一种新型的高效U（VI）离子吸附剂。使用分批实验系统地评估了各种操作条件对铀吸附的影响（即pH接触时间，温度和初始铀浓度）。结果表明，在改性MWNCTs铀吸附（5.571×10 ^-3 克/毫克×分钟）比上原始MWNCTs（4.832×10达到更快平衡^-3 g / mg×min），反映了Br-PADAP的适当官能团与U（VI）吸附的螯合离子交换机制有关。改性的MWNCT（83.4 mg / g）与原始MWNCT（15.1 mg / g）相比，具有更高的最大Langmuir吸附能力。2.5 mL的1 M HNO ₃可以解吸吸附在改性MWNCT上的铀的大约99％解决方案。因此，Br-PADAP改性的MWNCT可以用作水处理中有效铀吸附应用的有前途的吸附剂。随后，建议的固相萃取（使用装有Br-PADAP / MWCNT的微型柱）通过ICP-AES方法成功地用于分析不同环境样品中的痕量铀水平，预浓缩系数为300倍。其他离子的共存对铀的分离预浓缩没有明显影响。检出限为0.14μg/ L，相对标准偏差约为3.3％（n = 7）。