Synthesis, Properties and Application of Novel Ethylenediamine Triacetate Chelating Surfactants

Abstract

AbstractNovel ethylenediamine triacetate (ED3A) chelating surfactants containing a flexible spacer whose general formula are of CH3(CH2)xCH2OCH2CH(OH)CH2N(CH2COONa)CH2CH2N(CH2 · COONa)2 (D1: × = 10, D2: × = 12) have been synthesized. The structures of their carboxylic acid derivatives (C1 and C2) were characterized with electrospray ionization–mass spectrometry (ESI-MS), 1H-NMR and 13C-NMR. The values of the critical micelle concentration (CMC) of the two surfactants (D1 and D2) are at level 10−4 mol L−1 and the surface tension of the surfactant D1 solution at CMC is only 28.6 mN m−1, which indicates a high surface activity of the D1 surfactant. The surfactants have good foaming, foam stabilizing and emulsifying properties for toluene. When eluting heavy metal contaminated soils with surfactant solution at a concentration of 0.1 mol L−1, where the metals (Pb, Cu and Zn) are mainly in the presence of residual fraction, D1 and D2 can obtain the metal removal efficiencies of 27.82% and 28.19% for Pb, 24.73% and 24.00% for Cu, 9.12% and 8.61% for Zn, respectively. It is suggested that the two chelating surfactants can be used as elution agents to remediate heavy metal contaminated soils.