METHOD FOR TREATING HEAVY METAL-CONTAINING WASTEWATER

摘要

PROBLEM TO BE SOLVED: To provide a high-degree treatment method for heavy metal-containing wastewater capable of removing heavy metals in heavy metal-containing wastewater up to a low concentration of 0.05 mg/l or less by one-stage treatment, low in running cost and capable of also reducing the generation amount of sludge. SOLUTION: In treating heavy metal-containing wastewater, ferrous ions or ferric ions are added to heavy metal-containing wastewater in a reaction tank and the pH of this wastewater is subsequently adjusted to 5 or more by an acid or an alkali agent to form ferrite or pseudo-ferrite and the formed suspended substance is subjected to solid-liquid separation treatment and a part of the obtained ferrite sludge is returned to the reaction tank to be circulated to remove heavy metals from the heavy metal-containing wastewater.