Method for removing of multivalent heavy metals from metal plating waste effluents

摘要

An exfoliated vermiculite cation-exchange column is used to remove multivalent heavy metals (copper, zinc, nickel, chromium, etc.) from metal plating wastes. The exfoliated vermiculite may be either chemically or relatively low-temperature thermally expanded vermiculite ore. It preferably has a cation exchange capacity of over 80 meq/100g. Exfoliated vermiculite particle sizes of less than approximately 10 mesh are preferred as the column packing. The ion-depleted vermiculite from the exchange column after use can be further expanded thermally and used as a lightweight filling material.