Abstract:Mg/Al hydrotalcite was synthesized by liquid-phase coprecipitation with Mg(NO3)2·6H2O and Al(NO3)3·9H2O and characterized by x-ray diffraction and thermal analysis. Its adsorptive property to trace phthalates in water is also studied. It is showed that the adsorption processes of dimethyl phthalate (DMP), di-(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) on Mg/Al hydrotalcite simultaneously fitted Langmuir isotherms and Freundlich isotherms in the range of concentration studied, and the saturated adsorption capacities for the three phthalates reach 23.148 1, 3.933 9 and 8.920 6 μg/mg, respectively. The removal rates of the phthalates with time increase rapidly at the beginning and then stabilized gradually, the equilibriums of the three PAEs are reached in 600, 200 and 200 min, respectively. The adsorption of DMP is mainly affected by pH value, temperature and ionic strength. While the adsorption of DEHP is mainly affected by temperature and pH value is for that of DnOP.