摘要: |
1994年5月–1995年6月,利用黄河口悬浮颗粒物,在实验室内于不同温度、盐度、磷酸盐浓度、pH值及悬浮物粒度条件下进行了悬浮物对磷酸盐的吸附和解吸模拟实验,通过水体中几种磷–钙矿物的离子平衡计算,对黄河口磷酸盐的缓冲机制进行了探讨。结果表明,黄河口现场条件下水体中钙与磷之间存在某些离子平衡,黄河口水体中磷–钙矿物的离子积受温度、悬浮物种类及粒度影响较小,而与水体盐度、磷酸盐及钙含量有关,但不足以形成磷–钙矿物沉淀;磷–钙矿物的沉淀和溶解在黄河口磷酸盐浓度的控制机制上所起的作用较小,而悬浮颗粒物表面对磷酸盐的吸附和解吸起了较大的作用。 |
关键词: 黄河口 磷酸盐 缓冲 沉积物 离子积 吸附 解吸 |
DOI: |
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基金项目:国家自然科学基金资助项目,49476286 |
附件 |
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DISCUSSION OF PHOSPHATE BUFFER MECHANISM IN HUANGHE RIVER ESTUARY II. THE IONIC EQUILIBRIUM OF Ca–P MINERAL PHASES IN HUANGHE RIVER ESTUARY |
SHI Xiao-yong, SHI Zhi-li
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College of Chemistry and Chemical Engineering, Ocean University of Qingdao,Qingdao, 266003
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Abstract: |
In May 1994 to June 1995, the effect of adsorption and desorption of phosphate by various sizes of Huanghe estuarine suspended particles were investigated by means of simulation experiments for the Huanghe River Estuary in the laboratory, under various conditions of temperature, salinity, phosphate concentration and pH value. The phosphate buffer mechanism in the Huanghe River Estuary was discussed by means of the ionic equilibrium of several Ca-P mineral phases in the water.
There exists ionic equilibrium between calcium and phosphate in the Huanghe estuary, and salinity, phosphate and calcium concentrations have a more significant effect on the ionic equilibrium than that of temperature and the type and size of suspended particles. It is likely that Ca and P may combine to become ion parts or compounds in the water, but this is not enough to precipitate the Ca-P mineral phases. In the control of the phosphate buffer mechanism, the precipitation and dissolution of Ca-P mineral phases are less effective and the adsorption and desorption of phosphate by the surface of suspended particles have a great effect in the Huanghe River Estuary. |
Key words: Huanghe River Estuary, Phosphate, Buffer, Suspended, Ion product, Absorb, Desorb |