NOVEL DYE-ATTACHED MACROPOROUS FILMS FOR CADMIUM, ZINC AND LEAD SORPTION - ALKALI-BLUE 6B-ATTACHED MACROPOROUS POLY(2-HYDROXYETHYL METHACRYLATE)

Alkali Blue GB-attached poly(2-hydroxyethyl methacrylate) (poly(HEMA)) microporous films were investigated as chelate forming sorbents for h eavy metal removal. Poly(HEMA) microporous films were prepared by UV-i nitiated photo-polymerization of HEMA in the presence of an initiator (azobisisobutyronitrile (AIBN)). Alkali Blue 6E was attached covalentl y. These films with a swelling ratio of 58%, and carrying 14.8 mmol Al kali Blue 6E m(-2) which were then used in the removal of Cd(II), Zn(I I) and Pb(II) from aqueous media. Adsorption rates were very high, equ ilibrium was achieved in about 30 min. The maximum adsorption of heavy metal ions onto the Alkali Blue BE-attached films were 41.4 mmol m(-2 ) for Cd(II), 52.4 mmol m(-2) for Zn(II), and 64.5 mmol m(-2) for Pb(I I). When the heavy metal ions competed during the adsorption from a mi xture the adsorption values for Cd(II), Zn(II) and Pb(II) were quite c lose. Heavy metal ions were desorbed by using 0.1 M HNO3. A significan t amount of the adsorbed heavy metal ions (up to 95%) could be desorbe d in 30 min. Repeated adsorption/desorption cycles showed the feasibil ity of these novel dye-attached microporous films for heavy metal remo val. (C) 1998 Elsevier Science B.V. All rights reserved.