To provide a method for removing heavy metal ions in wastewater by which the heavy metal ions in the wastewater can be removed to sufficiently low concentration satisfying an environmental standard and which is simple and has high treatment efficiency.
The method for removing the heavy metal ions in the wastewater comprises: a process of adding a base to the wastewater where the heavy metal ions are dissolved to make the wastewater basic and to make at least a part of the heavy metal ions insoluble as hydroxide or the like to form suspended solid; a process of adding an inorganic flocculant to the wastewater to carry out flocculation sedimentation of the suspended solid; a process of adding a mulukhiya-containing treating agent to the wastewater to adsorb a part of the heavy metal ions remaining in the wastewater to the mulukhiya; and a process of separating the suspended solid and the mulukhiya from the wastewater and removing them by solid-liquid separation. Preferably a polymer flocculant of mass less than mass of the mulukhiya as well as the mulukhiya-containing treating agent is added to the wastewater.
NOGUCHI TSUTOMU
OE TAKAHIRO
| JP2005028246A | 2005-02-03 | |||
| JPH11114313A | 1999-04-27 |
Masaaki Yoshii
Takahisa Yamamoto