Hydrogen phosphate intercalated Mg/Al-layered double hydroxides (LDH-HPO(4)) were synthesized by a homogeneous precipitation method with urea and anion exchange. The intercalated hydrogen phosphate was removed by anion exchange with Na(2)CO(3), NaOH-NaCl, and 1-octanesulfonate solutions. The phosphate removal behavior was characterized by X-ray diffraction (XRD), Fourier Transform-InfraRed (FT-IR) spectroscopy, and elemental analysis. Complete removal of interlayer hydrogen phosphate from LDH-HPO(4) was realized using 1-octanesulfonate solution. Two reasons are proposed to explain complete hydrogen phosphate removal from the interlayer space of LDH-HPO(4). Complete desorption and cyclability suggest this is a viable technique to use as an efficient adsorption/desorption system in industrial applications.