中国东海陆架海域柱状沉积物对磷的吸附行为

Behaviors of Phosphorus Sorption on the Core Sediments in Eastern Continental Shelf Seas of China

通过研究磷在海洋柱状沉积物上的吸附动力学曲线和吸附等温线,并结合沉积物表面电荷性质以及磷形态分析,考察了我国东部陆架海域沉积物对磷的吸附特征。结果表明,所研究海域沉积物对磷的吸附过程明显分为快慢两段,48h后吸附可达到平衡;吸附后的磷主要为可交换态磷,吸附过程以物理作用为主;吸附等温线可用Langmuir交叉型模式描述,在磷初始浓度较低时,沉积物对磷存在解吸现象;沉积物对磷吸附参数的垂直分布较为复杂,受自身性质影响较大;盐度增大,沉积物对磷的吸附能力呈下降趋势。

Kinetic curves and isotherms were investigated to study the phosphorus sorption characteristics onto the core sediments of the eastern continental shelf seas of China, together with phosphorus forms distribution and surface charge properties of the sediment. The sorption kinetic curves obviously showed two stages, a rapid fraction and a slow one. The equilibration time was about 48 hrs. The sorbed phosphorus mainly consisted of Ex-P, indicating that the physical sorption plays an important role. The equilibrium isotherms could be fitted well with a modified Langmuir equation. At low phosphorus concentrations the net effect is the release of the preserved phosphorus from the sediment. The vertical variation of sorption capacity was complex, which was mainly due to the different physicochemical properties of the sediments. The phosphorus sorption showed a decreasing trend with the increase in salinity.