铁锰生物污泥吸附磷

Phosphorus adsorption oniron and manganese biological sludge

采用扫描电镜(SEM)、X射线能谱仪(EDS)、比表面和孔隙度分析仪等设备,研究了由生物除铁除锰滤柱反冲洗铁锰生物污泥制得的铁锰氧化物的表征性状,并结合等温吸附-解吸和动力学实验研究对铁锰氧化物吸附磷的吸附特性和相关机制进行探究.结果表明:供试铁锰氧化物是球形颗粒聚合体,孔隙发达且多以微孔形式存在,比表面积为285.6m2/g.铁锰氧化物的磷吸附特性可用Langmuir方程和Freundlich方程来描述,相关系数均大于0.9,达到极显著水平,吸附容量为39.06mg/g.中性盐介质(KNO3)中在最大吸附量时P的解吸率为13.04%.铁锰氧化物对磷的吸附焓变△H0为正值,是吸热过程,吉布斯自由能变△G0为负值,该吸附过程是自发进行的.准二级动力学模型可较好地反映供试铁锰氧化物的等温吸附动力学.

The biogenic iron and manganese oxide applied were gained by backwashing from the biological iron and manganese removal filter columns. The research reported in this paper focused on its characteristics and adsorption-desorption properties on phosphorous. The results indicated that the oxide was spherical particle polymer with a developed pore structure mostly in the form of micropore, with a specific surface area of 285.6m2/g. The adsorption isotherm could be well described by Langmuir equation and Freundlich equation with a correlation coefficient larger than 0.9 and a high adsorption capacity of 39.06mg/g. The desorption percentage of adsorbed phosphorus was 13.04%in a neutral electrolyte of KNO3 under maximum phosphorous adsorption conditions. The adsorption enthalpy change △H0 was positive, which indicated the adsorption process was endothermic, meanwhile the minus Gibbs free energy change△G0 suggested it was spontaneous. It was found that the phosphorous adsorption kinetics fitted pseudo-second-order kinetic models.