Keywords: 
• natural zeolite /
• modified zeolite /
• ammonia nitrogen /
• seawater

Abstract: Zeolite has a wide application in wastewater treatment because it has good performance of selective adsorption and ion exchange for its peculiar cage structure. However， modified zeolite is needed because natural zeolite has less adsorption capacity. Aiming at limitation of natural zeolite， the method of modification on absorbing ammonia nitrogen was presented. The optimal modified method for zeolite was confirmed. Meanwhile the process of adsorption equilibrium and kinetics for ammonia-nitrogen adsorption on zeolite were studied. The results show that the modified method which is calcined in 300 ℃ and then immersed 24 hours in the seawater can remove ammonia-nitrogen well. When amount of modified zeolite is 10 g/L， contact time is 150 minutes， influent concentration is 37.91 mg N/L， modified zeolite adsorption capacity for ammonia nitrogen is 4.08 mg/g， ammonia nitrogen removal rate is 90.45%. Its adsorption behavior comforms to Langmuir adsorption isotherm and pseudo first-order kinetics equation. It is confirmed that the modified method for natural zeolite with seawater has high adsorption capacity and adsorption rate for ammonia-nitrogen， and has the advantage of no additive medicaments， simple operation and low cost. This study will provide a theoretical reference for effectively removing ammonianitrogen from wastewater.