Removal of Heavy Metals from Laboratory Wasteliquid by the Ferrite Process at Different Reaction Temperature

摘要

After treatment of laboratory wasteliquid by the ferrite process, the concentration of total chromium and lead in the laboratory wasteliquid was treated from 343,000 ppb and 20.9 ppb, respectively to lower than the effluent standards of the Environmental Protection Administration (EPA) in Taiwan. The Toxicity Characteristic Leaching Procedure (TCLP) test results for total chromium and lead at different reaction temperature was dropped to the TCLP standard of the EPA. X-ray Diffraction (XRD) showed that the total numbers of the spinel-structured ofrnCr-ferrites was formed at 70 ℃. The X-ray Absorption Near Edge Structure (XANES) spectra shows that 29.26% of FeOOH and 66.64% of Fe_3O_4 in the precipitates when reaction temperature was raised up to 70℃, it means that reactionrntemperature higher than 70℃ was better for formation of Fe_3O_4. The hysteresis loops of precipitates generated from Fe_3O_4 by the ferrite process at 70℃, resulted in a saturation magnetization of 5.63 emu/g.