Research on the enhancement effect of ultrasonic field combined with monoclinic FeS on arsenic removal behavior

Abstract

Arsenic is a toxic element in industrial wastewater. The removal of arsenic by sulfide method has been a prominent research topic in the academic community. In this paper, arsenic was removed from arsenic-containing wastewater by ultrasound intensification combined with monoclinic FeS. This method avoids the common problems of H₂S gas spillage and inefficiency in the sulfide method, and has the advantages of being clean and efficient. The effects of S/As molar ratio, initial temperature, reaction time and ultrasonic power on arsenic removal were studied. Under the optimum condition, the arsenic concentration was reduced from 1889 mg/L to 0.32 mg/L, and the arsenic removal rate reached 99.98 %. The precipitation after arsenic removal was characterized by X-ray diffraction (XRD), Scanning electron microscope-energy dispersive spectrometry (SEM-EDS), X-ray fluorescence spectrum analysis method (XRF) and X-ray photoelectron spectroscopy (XPS) to analyze the precipitation phase, surface morphology, element content and chemical composition. A high-speed camera was used to observe the effect of ultrasound on the kinematic behavior of monoclinic FeS.