Removal of toxic arsenic (As(Ⅲ)) from industrial wastewater by ultrasonic enhanced zero-valent lead combined with CuSO_4

摘要

Arsenic was one of toxic element in industrial wastewater. Removal of arsenic has always been a hot research topic in academia. Herein, arsenic (As(III)) in industrial wastewater was removed by ultrasonic enhanced zero valent lead combined with copper sulfate (CuSO4). Secondary pollution would not be caused by the addition of zero-valent lead and copper sulfate. Parameters, such as Pb/As molar ratio, the amount of CuSO4 added, reaction temperature, ultrasonic power and reaction time were investigated in this study. It was concluded that the removal of arsenic could be described by an unreacted shrinking nuclear model with activation energy 1.857 kJ/ mol. The process of ultrasonic enhanced zero-valent lead combined with CuSO4 to remove arsenic was a diffusion controlled process. The precipitation after arsenic removal was characterized by XRD, SEM-EDS, XRF, and XPS to analyze the precipitated phases, topography, element content and different valence state of element. Based on the above analysis, the thermodynamic data and changes in ion concentration, the mechanism of efficient removal of arsenic (As(III)) from industrial wastewater by ultrasonic enhanced zero-valent lead combined with CuSO4 was revealed.