METHOD FOR ADSORBING AND SEPARATING HEAVY METAL ELEMENTS BY USING A TANNIN ADSORBENT AND METHOD OF REGENERATING THE ADSORBENT

摘要

A method of adsorbing and separating a heavy metal element by usingan insoluble tannin or a gelled tannin adsorbent comprising:(a) adjusting the pH of a solution containing a plurality of heavy metalelements to a predetermined pH;(b) contacting the adsorbent with the solution in which the pH thereofis adjusted;(c) adjusting the pH of the solution contacted with the adsorbent to apH different from the predetermined pH of step (a); and(d) contacting the solution in which the pH thereof is adjusted at step(c) with the adsorbent prepared at step (b). According to the inventive method,all of the heavy metal elements can be efficiently separated and adsorbed byusing a tannin adsorbent from a solution containing a number of heavy metalelements. A method of regenerating a tannin adsorbent is also disclosed.