PROBLEM TO BE SOLVED: To provide a waste treatment agent capable of safely and certainly detoxifying waste containing heavy metals forming oxoanions and/or harmful elements because there is a problem corroding treatment equipment and incapable of performing certain detoxification in a method for together using a metal trapping agent and a divalent iron salt or a reducing agent in order to detoxify waste containing heavy metals forming oxoanions such as selenium, arsenic, hexavalent chromium, antimony, molybdenum, vanadium, tin, tungsten, manganese, mercury and the like and harmful elements forming oxoanions such as phosphorus, boron and the like, and also to provide a waste treatment method using the same. SOLUTION: The waste treatment agent has a functional group having a metal coordinating capacity and at least a part of the functional group is formed into a salt of a reductive metal. In the waste treatment method, the waste treatment agent is added to waste such as liquid, solid or gaseous waste containing heavy metals and harmful elements forming oxoanions and heavy metals and harmful elements forming oxoanions in waste are detoxified in the presence of water. COPYRIGHT: (C)2004,JPO
