研究了粒径在25~30 mm的天然沸石、浮石、钢渣、砾石在低浓度下对溶液中氮、磷的吸附特性,优选出具氮、磷高效吸附的多孔混凝土材料;通过静态试验和动态试验研究,对数据进行模型拟合及回归分析,得到了各材料对氮、磷的饱和吸附量。结果表明:4种材料对溶液中氨氮的吸附能力大小排列为沸石〉浮石〉钢渣〉砾石,对总磷的吸附能力大小依次为浮石〉钢渣〉沸石〉砾石。沸石对氨氮和浮石对总磷的吸附结果均能很好的拟合Lagergren准二级反应动力学模型。静态试验中当氨氮浓度为2 mg/L时,沸石对氨氮的吸附容量相应为116.28mg/kg;浮石在总磷浓度为0.2mg/L时,浮石对总磷的饱和吸附量为10.06 mg/kg。动态试验中各材料吸附效果明显优于静态吸附效果,在氨氮浓度为5 mg/L时,沸石对氨氮的吸附量达到了823 mg/kg,在总磷浓度为0.5 mg/L时浮石对总磷的吸附量为49 mg/kg。沸石和浮石可作为具氮、磷吸附特性的多孔混凝土优选材料。
Adsorption properties of the natural zeolite,pumice,slag,gravel(between 25~30 mm in size) on nitrogen,phosphorus in the low concentration have been researched.Through the static and dynamic experiments,data model fitting and regression analysis,the saturation adsorptions of four materials on nitrogen and phosphorus has been studied.The results indicated that the adsorption capacity on ammonia nitrogen of solutions was natural zeolitepumiceslaggravel,the adsorption capacity on total phosphorus of solutions was pumicenatural zeoliteslaggravel.The results of adsorption of ammonia nitrogen by natural zeolite and the adsorption of total phosphorus by pumice could be well fitted Lagergren pseudo-second kinetic model.In the case of 2 mg/L of ammonia nitrogen at static experiments,the adsorption capacity of zeolite for ammonia nitrogen was 116.28 mg/kg;when the concentration of total phosphorus at 0.2 mg/L,the result of adsorption capacity was 10.06 mg/kg.Besides,the results of the dynamic experiments were superior to static.When the concentration of ammonia nitrogen at 5 mg/L,the result of adsorption capacity of zeolite was 823 mg/kg.When total phosphorus at 0.5 mg/L,the result of adsorption capacity of pumice was 49 mg/kg.The zeolite and pumice could be chosen for adsorption of nitrogen and phosphorus as porous concrete materials.