河口感潮区表层沉积物PO₄^3--P的吸附特征

The Characteristics of Phosphate Adsorption on Surface Sediments in Estuary

摘要: 本文研究了胶州湾李村河河口感潮区3个典型采样点表层沉积物对PO₄^3--P吸附动力学和热力学行为，并探讨了盐度、温度对PO₄^3--P吸附动力学过程的影响。PO₄^3--P吸附动力学过程可分为3个阶段：0~1 h快速吸附阶段，1~12 h缓慢吸附阶段，12 h之后平衡阶段；盐度升高对PO₄^3--P吸附则呈现抑制作用；温度升高有利于PO₄^3--P的吸附作用，温度升高加快了吸附速率，使固液体系更快的达到平衡。PO₄^3--P吸附等温曲线符合Langmuir等温吸附方程，三个取样点的PO₄^3--P的吸附–解吸临界浓度分别为：0.034 mg∙L⁻¹、0.289 mg∙L⁻¹和0.067 mg∙L⁻¹。

Abstract: The adsorption kinetics and thermodynamics of phosphate onto 3 typical surface sediments from the estuary of Li Cun River and the influencing of temperature and salinity on kinetics were inves-tigated. The adsorption kinetics process can be divided into 3 phase: fast adsorption stage (0 - 1 h), slow adsorption stage (1 - 12 h) and balance stage (>12 h). Increased salinity can inhibit phosphate adsorption and increased temperature promotes the adsorption. The reaction rate of the system speeded up and the balance time advanced when the temperature improved. Adsorption isothermal curve ofPO₄^3--Pcorresponds with Langmuir isothermal adsorption equation. The critical concentrations of adsorption-desorption of the three sediments samples were: 0.034 mg∙L⁻¹, 0.289 mg∙L⁻¹ and 0.067 mg∙L⁻¹.