Removal of Trace Metals from Aqueous Solution by Fe(OH)3 Coprecipitation and Flotation Using Poly-Glutamic Acid

Iron hydroxide (Fe(OH)3) coprecipitation and an eco-friendly flotation technique by use of gamma poly-glutamic acid (γ-PGA) was developed for removal of heavy metals from water. Effects of PGA concentration and the flotating time on the flotation of Fe(OH)3 precipitate and removal efficiencies of metal ions was examined. The removal efficiency of heavy metals was estimated from measurements by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The optimal conditions provided >80 % for Au, Bi, Cd, In, Ga, Mn, Os, Pb, Pt, Te, Sb, Sn, Rh, Ru, W and >60 % for Co, Ni, Se, Zn as the removal efficiency.