Experiment of the Phosphate Adsorption Characteristics by Peat

Effect of reaction time,initial concentration of PO3-4,pH,temperature,amount of adsorbent and solution salinity on the phosphorus adsorption on peat is experimentally studied.The results indicate that the phosphorus adsorption capacity of peat increases rapidly at the beginning of the adsorption process(0~2 h),and then decreases slowly.The adsorption kinetics can be described by the pseudo-second order model.The adsorption capacity increases while the adsorption rate declines with the increasing initial PO3-4 concentration.The isothermal adsorption process of phosphate on peat can be fitted by Langmuir and Freundlich equations with a high correlation coefficient.Both the distribution coefficient and the adsorption capacity decrease as pH increases.The maximal adsorption capacity decreases as the temperature increases in following order:2 380.95 mg/kg(25 ℃)2 008.03 mg/kg(35 ℃)1 848.42 mg/kg(45 ℃).As the adsorbent amount increasing,the unit adsorption capacity decreases and the adsorption rate increases.The adsorption can be influenced by salinity in a certain extent.