The authors developed the HT/Ze phosphorus recovery system which uses Hydrotalcite (HT) like compound and Zeolite (Ze) in previous research. It was found out that Nano-size Layered Double Hydroxide (NLDH) can be used instead of ordinal HT. Fundamental functions of NLDH related phosphate adsorption, desorption, regeneration of adsorption ability and phosphate adsorption from actual wastewater, were experimentally investigated.
 Saturation quantities of phosphate adsorption by powdered- and granular- NLDH were measured, and it was found that the difference in adsorption quantity is small. In desorption tests, it was confirmed that 90% of adsorbed phosphate in NLDH can be desorbed into desorbing solution. MgCl₂ solution which is high cost is usually used for regeneration of adsorption ability of typical HT. A new regeneration method by using HCl-NaCl solution for reducing regeneration cost was tried and more effective regeneration than MgCl₂ is attained under the conditions of pH=3 and NaCl=5.0mol/L. Practical examination by using treated sewerage at wastewater treatment plants was demonstrated to examine the performance of phosphate adsorption ability of NLDH. Anion, such as sulfate and carbonate, inhibit the adsorption of phosphate. Although the effect of carbonate was thought to be high, it was confirmed that NLDH can adsorb phosphate from actual wastewater.