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通过研究桑沟湾表层沉积物对磷的吸附动力学曲线和吸附等温线,并结合沉积物的表面电荷性质及磷的形态分析,考察了沉积物对磷的吸附性能和吸附机制.结果表明,桑沟湾表层沉积物对磷的吸附过程包括快吸附过程和慢吸附过程,可用快慢二段一级动力学方程描述,等温线符合Langmuir交叉式模型.夏季沉积物样品的最大吸附量高于春季样品,粒级较小的沉积物吸附能力较强.沉积物样品对磷的最大吸附量Qm在0.047 1~0.123 0 mg·g-1之间,吸附/解吸平衡磷浓度(EPC0)范围在0.059 6~0.192 7 mg·L-1,沉积物充当“磷源”的作用.不同站位表层沉积物中无机磷(IP)是磷在沉积物中的主要赋存形态,吸附后的沉积物样品中弱吸附态磷(Ex-P)、铁结合态磷(Fe-P)明显增加.吸附过程包括物理吸附和化学吸附,以物理吸附为主.
In this paper, the adsorption kinetics and adsorption isotherm of phosphorus on surface sediments of Sanggou Bay were studied, and the adsorption properties and adsorption mechanism of phosphorus on sediments were investigated by the surface charge properties and phosphorus morphology of the sediments. The adsorption process of phosphorus on surface sediments in Sanggou Bay includes fast and slow adsorption processes, which can be described by two-stage first-order kinetic equation, and the isotherms conform to the Langmuir cross model. The maximum adsorption of summer sediment samples is higher than that of spring The adsorption capacity of samples with smaller particle size is stronger.The maximum adsorption capacity of phosphorus for sediment samples is between 0.047 1 and 0.123 0 mg · g-1, and the adsorption / desorption equilibrium phosphorus concentration (EPC0) is between 0.059 6 ~ 0.192 7 mg · L-1, the sediments play the role of “source of phosphorus ” Inorganic phosphorus (P) in surface sediments of different stations is the main speciation of phosphorus in sediments, and the sediment after adsorption The weakly-adsorbed phosphorus (Ex-P) and iron-bound phosphorus (Fe-P) increased obviously in the samples, which included physical adsorption and chemisorption, which were dominated by physical adsorption.