Adsorption of ammonia nitrogen on modified palygorskites and zeolite in waste water

In order to improve ammonia nitrogen removal by modified palygorskites and zeolite,basification was selected from four kinds of modified methods such as roast,NaCl activation,acidification and basification.The absorption characteristic of ammonia nitrogen in waste water on modified palygorskites and zeolite was discussed in this research.Results showed that the maximum adsorption capacity of modified samples was observed at pH 2.5~8.0 when the initial concentration of ammonia nitrogen was 300 mg/L.The ammonia nitrogen adsorption data on modified samples were well fitted by Freundlich and Langmuir isotherm.The ammonia nitrogen adsorption dynamics can be best described by the pseudo second-order model,chemical adsorption predominated its adsorption process.Modified samples can remove ammonia nitrogen in demostic farming waste water with the efficiency of 87.6%.