Uptake of bisphenol A from aqueous solution by Mg-Al-layered double hydroxides intercalated with 2-naphthalene sulfonate and 2,6-naphthalene disulfonate

Mg-Al-layered double hydroxides (Mg-Al LDHs) modified with aromatic anions were suspended in solutions of bisphenol A to investigate their properties as scavengers. The Mg-Al LDHs were intercalated with 2-naphthalene sulfonate (2-NS^-) and 2,6-naphthalene disulfonate (2,6-NDS^2-) ions, which contain a naphthalene ring with one and two sulfonate (-SO ₃^-) groups in their respective structures. The changes in the concentrations of the hazardous aromatic compounds in the suspensions with time were followed. The organic-modified Mg-Al LDHs decreased the bisphenol A concentrations very rapidly, which was attributable to the association between the aromatic ring of bisphenol A and the aromatic anions intercalated in the interlayer. Mg-Al LDH with lower content of aromatic anion in the interlayer was superior to that with the higher content for the uptake of bisphenol A. This was attributed to the larger spaces to accommodate more bisphenol A in the interlayer.