5种填料对污水中氮磷的吸附特性研究

Study on the adsorption characteristics of nitrogen and phosphorous on five substrates

针对富营养化水体,为筛选吸附氮磷效果较好的填料,选取5种人工湿地填料沸石、陶粒、轮胎颗粒、火山岩、蛭石,采用等温吸附和动态吸附,研究各填料的吸附特性,并模拟污水对5种填料的吸附效果进行分析。结果表明,Langmuir和Freundlich方程都能较好的描述各填料的吸附特征,通过Langmuir的拟合,理论上5种填料对氨氮的吸附量从大到小依次为沸石>火山岩>蛭石>陶粒>轮胎颗粒;对磷的吸附量从大到小依次为陶粒>火山岩>蛭石>沸石>轮胎颗粒;各填料对氮磷的吸附动力学特征可以用双常数方程和Elovich方程拟合,5种填料对污水进行处理时,沸石除氮能力较强,轮胎颗粒除磷能力较强;从吸附效果和经济适用的角度来看,5种填料中轮胎颗粒更适合作为人工湿地填料。

In order to find out better adsorbents for nitrogen and phosphorus, zeolite, haydi/e, tire crumb, volcanic and vermiculite were selected as substrates of constructed wetland to treat eutrophic water. The isothermal adsorption and dynamic adsorption experiments were conducted to study the adsorption charac- teristics of the five substrates. And the adsorption effects＇of substrates were analyzed by simulating the rural sewage. The results indicate that the adsorption characteristics of substrates could be well described by Langmuir and Freundlich equation. The ammonia nitrogen adsorption capacity of five substrates estimated from Langmuir isotherm follow ＂the order zeolite 〉 volcanic 〉 vermiculite 〉 haydite 〉 tire crumb ; the phosphorus adsorption capacity of five substrates estimated from Langmuir isotherm follow the order haydite 〉 volcanic 〉 vermiculite 〉 zeolite 〉 tire crumb. Dual constant and Elovich equations could be suitable to describe adsorption characteristics of nitrogen and phosphorus, zeolite show high ability of ammonia nitrogen removal and tire crumb show high ability of phosphorus removal from the view of removal rate when were treated by five substrates. Comparison from the adsorption effect and economy, the tire crumb is a better substrate of constructed wetland.