改性凹凸棒石和沸石对氨氮废水吸附性能的研究

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

采用焙烧、钠化、酸化和碱化4种改性方法对天然凹凸棒石和沸石进行改性,其中碱化改性对氨氮吸附能力提高最大,研究了碱化样品的结构及对氨氮废水的吸附性能。结果表明,碱改性品在氨氮溶液初始浓度300 mg/L,pH值2.5~8.0时,对氨氮的吸附量较高;对氨氮的吸附等温线符合Freund lich和Langmu ir方程式。同时,对氨氮的吸附动力学符合准二级吸附动力学模型,并以化学吸附为主。用于畜禽废水处理中,对氨氮去除率最高达到87.6%。

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%.