Abstract: A chelate-forming fiber which has, in a fiber molecule, a group having an amino group and at least two hydroxyl groups bonded to carbon (preferably a group represented by the formula (1) described below), and has a capability of forming a chelate with metalloid elements including boron and germanium and compounds thereof, and which can be easily incinerated and can be prepared in a simple and safe manner at low cost; and a process for preparing the same; and a method for capturing metalloids or compounds thereof using the chelate-forming fiber are disclosed. (wherein G represents a sugar alcohol residue or a polyhydric alcohol residue, and R represents a hydrogen atom, a (lower) alkyl group, or G (G is as defined above and may be a group identical with or different from the above G).

Abstract: The present invention provides a metal chelate forming fiber in which a reactive functional group in a molecule in the surface of the fiber is substituted with an acyl group represented by the following formula [1]: ##STR1## (where R.sup.1, R.sup.2, and R.sup.3 respectively are a lower alkylene group, and n is an integer of 1 to 4.) The present also provides a method for preparing the fiber, and a process for treating waste water using the fiber where metal ions contained in the waste water are allowed to be captured by the acyl group.