摘要
以人工合成的针铁矿和水铁矿为研究对象,就结晶态和无定形态铁氧化物在不同pH值(5,6,7)条件下对磷素的等温吸附特性及Langmuir方程和Freundlich方程对铁氧化物吸附磷的拟合效果进行了研究。结果表明,两种铁氧化物对磷的吸附特性均可用Langmuir方程和Freundlich方程描述,相关系数均达到0.95以上,呈极显著水平,但Langmuir方程的拟合性优于Freundlich方程。比较磷的最大吸附量(Qmax)、吸附反应常数(KL,KF,n)和最大缓冲容量(MBC)可知,在相同pH值时,水铁矿(无定形态)对磷的吸附容量比针铁矿(结晶态)大的多;随着pH值升高,两种铁氧化物对磷的吸附量均降低,且水铁矿的降低趋势明显于针铁矿。
In this study,the adsorption of phosphorus onto both crystal and amorphous iron oxides under different pH conditions （i.e. pH=5,6 and 7） had been investigated using synthetic goethite and ferrihydrite as the materials,respectively. Both Langmuir and Freundlich models were employed to fit the experimental adsorption data to identify the best model. The experimental results showed that these two iron oxides had good adsorption capacity for phosphorus. The modeling results indicated that both models were able to adequately describe the adsorption for both materials,but the Langmuir model was more accurate. Furthermore,through comparison of the equilibrium adsorption quantity （Qmax）,the adsorption constants （KL,KF,n） and the maximum buffering capacity （MBC） of two materials,it was found that adsorption capacity of phosphorus onto the ferrihydrite was higher than that of the goethite in each pH condition,and the adsorption capacity for both materials had a considerable reduction with increasing pH whereas the decline trend observed on the ferrihydrite was more pronounced.
出处
《浙江农业学报》
CSCD
北大核心
2010年第1期77-80,共4页
Acta Agriculturae Zhejiangensis
基金
国家自然科学基金项目(30571266)
关键词
铁氧化物
磷
等温吸附
iron oxides
phosphorus
isothermal adsorption
