TRAPPING AGENT FOR HEAVY METAL AND TRAPPING METHOD OF HEAVY METAL

摘要

PROBLEM TO BE SOLVED: To obtain such a trapping agent that gives excellent trapping and fixing effects for heavy metals even when the amt. of the agent added is small and that flocs fast grow into large flocs and can be easily separated when the agent is used for a liquid waste by preparing the agent from a mixture of polysaccharides and sulfides. ;SOLUTION: This trapping agent for heavy metals consists of polysaccharides as nuclei combined with sulfides. The polysaccharides used as the nuclei are polysaccharides having D-glucose as the constitutional sugar, polysaccharides having fructose as the constitutional sugar, or polysaccharides having glucose, mannose, glucuronic acid, etc., as constitutional sugar components. As for the sulfides, various inorg. sulfides can be used. When this trapping agent for heavy metals is added to a liquid waste to trap heavy metals, the pH range for trapping is from 1 to 12, and usually the pH is preferably controlled to 5 to about 9. The acid or alkali to be used to control the pH is not limited as far as it does not inhibit production of flocs.;COPYRIGHT: (C)1998,JPO