| Summary: | 碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程所 === 95 === The purpose of this study was aimed to investigate the reaction behavior of heavy metals (Cu、Zn、Pb、Ni、Cr) with zero-valent iron (ZVI) nanoparticles in the wastewater. The influence factors, such as initial pH, dosage of nanoscale ZVI and initial concentration of heavy metal, on the removal efficiency of heavy metals by ZVI in the wastewater were examined by the batch experiments in this study.Furthermore, the analysis of X-ray diffraction (XRD) was carried out to observe the products on the ZVI surface after the treatment of heavy metals from the wastewater.
The results showed that the removal of heavy metals was affected by initial pH. The rate and efficiency of metal removal increased with decreasing initial pH. Higher than 90 % of the heavy metals (Cu、Zn、Pb、Cr) was removed when the initial pH was controlled at 2. The removal efficiency of heavy metal were in the decreasing order: Cu = Cr > Zn = Pb > Ni. In addition, the rate and efficiency of metal removal increased as the dosage of nanoscale ZVI increased. The removal efficiency of heavy metal was higher than 80% when 2.0 g/L of ZVI was added in the wastewater. On the other hand, the slow rate and low efficiency of metal removal from the wastewater treated by nanoscale ZVI was found in the wastewater with high concentration of heavy metal. Generally, the removal kinetic of heavy metals from the wastewater by nanoscale ZVI was well described by the pseudo-first order reaction.
The XRD analysis revealed that iron corrosion products including r-FeOOH、 Fe6(OH)12SO4．nH2O and/or Fe(II)Fe(III)3(OH)12Cl3．H2O were formed at the surface of nanoscale ZVI particles after the treatment of heavy metals from the wastewater.
|
|---|
