The Spectra of Pyrite and Its Cinder on Removing Thallium from Simulated Tl-Containing Wastewater

The efficiencies of using pyrite and its cinder for the removal of thallium (Tl) from the simulated wastewater were tested. Results showed that the removal efficiencies of thallium exceeded 96%. In addition, reflectance spectroscopy was utilized to study the simulated Tl-containing wastewater treatment process. Results showed that the hydroxyl groups in pyrite cinder were caused by the residual pyrite. Analysis by diffuse reflectance infrared Fourier transform spectroscopy confirmed that the superficial hydroxyl groups in pyrite or pyrite cinder both reacted with thallium ions in the process of Tl-removing treatment. And the absorption peaks at 3,350 and 3,402 cm^-1 associated with hydroxyl groups both weakened. However, when using pyrite cinder for the wastewater treatment, the absorption peak at 3,350 cm^-1 had an obvious displacement for 70cm^-1 compared with the spectrum of using pyrite. Reflectance spectroscopy in the visible region was used to characterize the variation in particle size and specific surface of pyrite and its cinder in the process of wastewater treatment, which explained their increasing activity when reutilized.