Using magnetites to remediate heavy metal wastewaters from acid-mine drainage

摘要

The remediation of heavy metal wastewaters using magnetites, also known as ferrites, has been an area of investigation for many years. Early investigators used a synthetic procedure for the production of magnetites at 70 deg C. Although quite effective, as demonstrated by remediation of small waste streams from universities in Japan, this method is too energy intensive for application to large volumes, such as found in acid mine drainage. Other researchers have investigated room temperature production of magnetites using thin film oxidation of ferrous ions or electrolytic oxidation of iron electrodes. Agnain, these methods have not been found to be easily applied to large scale applications. Recently we hhave discovered a catalytic method of production of magnetites at low temperatures using stoichiometric uantities of iron salts. In addition, we have found that the presence of organic chelators can dramatically enhance or inhibit the removal of heavy metals using this technique. Both of these avenues of investigation will be discussed in this lecture.