羟基磷灰石对棕壤和红壤铜吸附的影响

Effect of hydroxyapatite on copper sorption in brown earth and red soil

采用等温平衡法,观测了羟基磷灰石对红壤、棕壤铜吸附量的影响,并应用Freundlich方程Cs=KfCen分析了土壤铜的吸附特征。结果表明,棕壤对铜的吸附能力明显高于红壤。以n(磷)∶n(铜)=1∶1向棕壤与红壤中施用羟基磷灰石,会增加两种土壤对铜的吸附量。其中,羟基磷灰石影响红壤对铜吸附能力明显高于棕壤。增加羟基磷灰石的施用量,会增加红壤与棕壤对铜的吸附量,提高土壤铜的吸附能力。高量羟基磷灰石[n(磷)∶n(铜)=4∶1]的作用效果最为明显;与对照相比,铜的吸附量分别增加62.1%和28.4%。据此推测,在铜污染红壤或棕壤上,可以选用羟基磷灰石作为磷肥的肥源。

The present paper uses the isothermal equilibrium theory to investigate the effect of hydroxyapatite on copper sorption in brown earth and red soil,and Freundlich equation（Cs= KfCen） to characterize the sorption behaviors of copper.The results showed that brown earth had stronger ability to absorb Cu.than red soil.Compared to the non-phosphorus system,applied hydroxyapatite could increase capability to absorb copper in both brown earth and red soils,when applied at n（P）： n（Cu）]= 1：1.The effect of applied hydroxyapatite on sorption by red soil was higher than by brown earth.Increasing the amount of applied hydroxyapatite increased sorption of copper and enhanced capability of copper adsorption by brown earth and red soils.The effect of applied high volume HA [n（P）： n（Cu）]= 4：1 was the most noticiable.Compared to the non-phosphorus system,total sorption capacity（Kf value）for brown earth and red soils increased by 62.1% and 28.4%,respectively.It is speculated that hydroxyapatite could be a candidate phosphate fertilizer in copper contaminated brown earth and red soil.