A Cu(II)-interference-resistant SPE/UiO-66 integrated with a portable electrochemical device for detection of Cd(II) in electroplating wastewater
摘要
Cd(II) in electroplating wastewater can cause serious harm to the environment and human health. Although portable electrochemical equipment enables rapid on-site detection, the interference of Cu(II) affects the detection accuracy of Cd(II). To address this issue, we developed a novel sensor (SPE/UiO-66) with anti-Cu(II) interference properties and integrated it with portable electrochemical equipment. Experiments indicate that when both Cd(II) and Cu(II) concentrations are at 100 µg/L, the signal of Cd(II) on screen-printed electrode (SPE) is completely suppressed, whereas SPE/UiO-66 maintains 91% of the Cd(II) signal intensity. The SPE/UiO-66 exhibits excellent performance: a detection range of 50–200 µg/L and a limit of detection of 17 µg/L. Even if the electroplating wastewater contains a high concentration of Cu(II) (500 and 1000 µg/L), the recovery of Cd(II) after pretreatment with potassium ferricyanide can still reach 96% and 108%, respectively. The experiments and theory calculations revealed that UiO-66 enhances the adsorption capacity for Cu(II), causing Cu(II) to preferentially adsorb on UiO-66 rather than replace nearby Cd, thereby effectively alleviating the interference from Cu(II). This study provides a reliable portable electrochemical device for detecting Cd(II) in electroplating wastewater, which is of significant importance for environmental pollution prevention and control.
Graphical Abstract