黄河上中游水体沉积物对磷酸盐的吸附/释放行为  

Adsorption and Release Behaviors of Phosphate on Sediments in the Upper and Middle Reaches of Yellow River

作　　者：李北罡[1] 高娜[1] 马钦[1] 

机构地区：[1]内蒙古师范大学化学与环境科学学院,内蒙古呼和浩特010022

出　　处：《生态与农村环境学报》2010年第4期356-360,共5页Journal of Ecology and Rural Environment

基　　金：国家自然科学基金(20467002);内蒙古自治区自然科学基金(200711020214);内蒙古师范大学科研基金(ZRYB08019)

摘　　要：研究了黄河上中游8个沉积物磷酸盐的吸附/释放动力学,比较了不同沉积物吸附磷的差别,分析了沉积物磷形态对磷吸附特征的影响。结果表明,沉积物对磷酸盐的吸附与释放均主要在前8h内完成,在前0.5h内对磷的吸附和释放速率均最快,在24h内吸附基本达到平衡;沉积物对磷的等温吸附曲线既符合线性方程和Freundli-ch模型,同时也较好地符合Langmuir模型。据Langmuir模型计算得出沉积物对磷的最大吸附容量为0.095～0.272mg·g-1,且最大吸附容量与沉积物总磷、可交换态磷和有机质含量呈显著正相关;沉积物在相应的上覆水中对磷酸盐的吸附过程存在一个吸附/解吸平衡点,对应的吸附/解吸平衡质量浓度为0.009～0.031mg·L-1,均大于相应上覆水体中磷浓度,说明沉积物有向上覆水释磷的趋势。A total of 8 sediment samples collected from the upper and middle reaches of the Yellow River were studied for adsorption and release kinetics,adsorption isotherms,adsorption-desorption equilibrium phosphate concentration,differences among the sediments in adsorption and influences of P forms on P adsorption characteristics in sediments.Results show that both the processes of adsorption and release of phosphate in the sediments completed mainly within the initial 8 h,and the highest adsorption and desorption rates were observed within the first 0.5 h and the reactions basically reached equilibrium in 24 h;P adsorption isotherms accorded with both the linear equation and the Freundlich equation as well as the Langmuir equation（4）.Calculation using the Langmuir equation（4）,indicate that the maximum P adsorption capacity of the sediments varied from 0.095 to 0.272 mg·g-1,showing significant positive correlations of the capacity with total P（TP）,exchangeable loosely-bound phosphorus（Ex-P）,and organic matter in the sediments;the sediments have a P adsorption-desorption equilibrium point during adsorbing P in the overlying water,and its corresponding adsorption-desorption equilibrium mass concentration was in the range of 0.009-0.031 mg·L-1,higher than the P concentration in the overlying water,indicating a trend of sediments releasing P to the overlying water.

关 键 词：黄河 沉积物 磷酸盐 吸附 释放 

分 类 号：X131.2[环境科学与工程—环境科学]