腐植酸对氮、磷、钾的吸附和解吸特性研究

Study on the Adsorption-desorption Characteristics of Humic Acid on NPK

通过研究风化煤腐植酸在不同pH值下对氮、磷、钾的吸附和解吸特性,得出结论:(1)在供试的各种pH值(4～8)条件下,随着氮、磷、钾初始处理浓度的增加,腐植酸对其吸附量和解吸量均呈上升趋势,但解吸率均呈下降趋势。(2)在不同pH值的介质溶液中,腐植酸对氮、磷、钾的吸附和解吸特性不尽相同。其中,在碱性条件下,腐植酸对氮的吸附和解吸作用较强;在酸性条件下,腐植酸对磷的吸附和解吸作用较强,而腐植酸对钾的吸附和解吸作用在中性条件下更易发生。(3)腐植酸对氮、磷、钾的等温吸附可用Linear、Langmuir和Freundlich 3个吸附方程来拟合,相关性达显著或极显著水平,但以Freundlich方程为最优。

The effect of humic acid made from weathered coal on adsorption-desorption characteristics of nitrogen, phosphorus and potassium at different pH values were studied in this paper. The major findings were summarized as follows： （1） The amounts of adsorption and desorption of nitrogen, phosphorus and potassium by humic acids all increased with increasing original concentration of NPK at different pH values （from 4 to 8）, while the desorption ratios of NPK all decreased. （2） The characteristics of adsorption and desorption of nitrogen, phosphorus, and potassium by humic acids were different at each pH values, Under alkaline condition, the response of adsorption and desorption of nitrogen by humic acids was strong particularly, and that of phosphorus by humic acid was more forceful in the acidic solution However, the process of adsorption and desorption of potassium by humic acids occured easily in the neutral solution （3） The adsorption properties of nitrogen, phosphorus, and potassium could be depicted with Linear, Langmuir, and Frendlich equations, and the correlation between them were significant or highly significant. Among the three equations, Frendlich equation was the best.