The interaction of EDTA with barium sulfate

Abstract

Ethylenediaminetetraacetic acid (EDTA) is a known complexing agent that interacts with a host of cations. In this paper, various techniques are used to elucidate the mechanism of interaction between EDTA and barium sulfate surfaces. It is shown that complexation with metal ions is not sufficient to explain the inhibition of barite crystallization but that other processes such as chemisorption must also occur. EDTA is shown to always adsorb as the mono-protonated species - suggesting that the molecule is able to lose a proton when it adsorbs at lower pH. Molecular modelling shows that the interaction of the surface barium ions with the carboxylate group is an important one. Finally, in situ turbidity measurements provide information about the mechanism of nucleation/growth modification. It is found that the EDTA molecule inhibits barium sulfate nucleation and that this could be its primary means of inhibiting precipitation of barium sulfate.

Fabrication of submicron barium sulfate aggregates in the presence of ethylenediaminetetraacetic acid anions

“…In the present study, following addition of Na2SO4 solution, the liquid mixture remained mostly clear for the first 5 min at pH 7. This finding agrees with the previous results (Jones et al, 2007;Wang et al, 2013), whereby EDTA was primarily present as EDTA-Ba complex with fewer free Ba 2+ ions in the reaction solution at pH 7.…”

“…The EDTA consumption was very small and EDTA could be recycled during the synthesis process (Liu, Tang, Lv, Li, & Ding, 2014;Pieper, Aman, & Tomas, 2012). The as-obtained aggregates were of comparable sizes with those reported in the literature (Jones et al, 2007;Zhang et al, 2009a;Zhang et al, 2011). In a particular system, the growth units do not aggregate randomly, but in an ordered manner, subsequently forming regular geometric structures.…”

“…It is well known that EDTA can interact with Ba 2+ cations in solution, thereby reducing the number of free ions available to participate in the crystallization process and further enhancing the crystal growth of BaSO4 (Jones et al, 2007;Zhang et al, 2009a;Zhang, Zhang, Li, Yin, & Guo, 2011). However, it is shown in this paper that EDTA does not operate in this manner only, and that direct EDTA-surface interactions are also important to consider.…”

Adsorption of EDTA on activated carbon from aqueous solutions

“…EDTA is a chelating agent widely used in industry and agriculture. For example, Jones et al [15] studied the interaction of EDTA with barium sulfate. Repo et al [16] reported their study on the Removal of Co(II) and Ni(II) ions from contaminated water using silica gel functionalized with EDTA and/or DTPA as chelating agents.…”

Formation and Application of High Reflectivity Controllable Barium Sulfate Microspheres

“…Uchida et al [16,17] prepared needle-like barium sulfate nanoparticles by complexation. It has been widely used as an important complexing agent [18][19][20][21][22].…”