Selective removal of some heavy metal ions from aqueous solution using treated polyethylene-g-styrene /maleic anhydride membranes

Radiation graft copolymerization of styrene/maleic anhydride (Sty/MAn) como nomer onto low density polyethylene (LDPE) membrane was investigated. The p repared grafted membranes were treated with different reagents containing v arious functional groups and studied as a matrix for the purpose of water p urification from heavy metals. The metal ion uptake by the functional group s of membranes was determined by the use of X-ray fluorescence (XRF) and at omic absorption (AA). The effect of pH of the metal feed solution and immer sion period needed for maximum capacity was investigated. The selectivity o f different prepared membranes towards some selected metal ions such as Fe, Cu, Pb. . . . etc. which commonly exist in waste water was determined. The affinity of the treated grafted films to recover Fe(III), Cu(II) or Pb(II) from their aqueous solutions containing other metal ions such as Cd(II), N i(II) or Hg(II) was studied. Also the selectivity of treated grafted membra nes towards Cu(II), Cr(III) and Fe(III) in a mixture was investigated at ro om temperature and 70 degrees C. It was found that the thiosemicarbazide-, hydroxylamine . HCl- and NaOH-treated grafted films showed high selectivity towards Cu(II), Cr(III) and Fe(III), respectively, at 70 degrees C. Howeve r, the selectivity of such treated grafted membranes was remarkable towards Fe(III) at room temperature. The results obtained suggested that the treat ed grafted membrane possessed good chelating properties towards different m etal ions. This suggests that such membranes could be accepted for practica l uses. (C) 2000 Elsevier Science B.V. All rights reserved.