公开(公告)号：JPH10130623A

公开(公告)日：1998-05-19

申请号：JP30246596

申请日：1996-10-28

Applicant: AGENCY IND SCIENCE TECHN

Inventor： ISHIGAMI YUTAKA ,  TOKUNAGA SHUZO ,  KOU KIYOUCHIN ,  KAJIUCHI TOSHIO ,  SAI EIKOKU ,  TOMIKAWA AKIO

IPC: B09B3/00 ,  B09C1/02 ,  B09C1/08 ,  C09K3/00 ,  C09K17/32

Abstract: PROBLEM TO BE SOLVED: To clean soil polluted by a heavy metal by bringing the soil into contact with an aq. soln. of a metal ion scavenger comprising saponin obtd. from fruits of high deciduous trees of the family Aesculus turbinata to cause heavy metal ions to migrate into the aq. soln. SOLUTION: A saponin having three saccharide groups and one carboxyl group is obtd. from fruits of trees of the family Aesculus turbinata. The saccharide groups include residues of glucuronic acid, glucose, and xylose. The saponin is called escin and is solid at normal temp. Escin has not only a metal-ion- scavenging capablity but also a function as a dispersant capable of converting a heavy metal salt of huminic acid or a metal oxide into fine particles and dispersing them. Therefore, escin can clean soil polluted by a harmful heavy metal, such as Cd, Cu, Zn, or Pb. The polluted soil is cleaned by putting it into and stirring it in a 0.8-7wt.% aq. soln. of escin. A heavy metal caught in the soln. is adjusted to a pH of 2.5 or lower and is recoverd.