不同处理褐煤腐殖酸对磷吸附特性的研究

Characteristics of Adsorption of P on Humic Acid Extracted from Different Treated Brown Coal

采用吸附等温线的试验方法,研究了平衡溶液中磷浓度、反应时间及介质pH对不同处理的2种褐煤腐殖酸吸附磷的影响及其规律性。结果表明:在试验pH范围内,pH的升高减缓了吸附反应进行的速度,对于未经硝酸处理的样品S1,在pH为4.7时,吸附量和分配系数有一最大值,而样品S2,随着pH的升高,吸附量和分配系数一直减小;经硝酸处理后,样品对磷的吸附能力降低,一定条件下其单位吸附量仅为处理前的5.33%。适宜的固液比例可提高2个不同处理供试样品对磷的单位吸附量,其等温吸附规律可用Langmuir方程来加以描述;其吸附动力学用Elovich方程描述最佳。

Recently, more and more people pay close attention to humic acid. Purpose of this research was offering basic data for the production of humic acid slow-release fertilizers. The effects of P concentration, equilibrium time, ratio of solid to liquid and pH value on characteristics of the P adsorption on humic acid extracted from brown coal and its absorptive regularity was studied by isothermal adsorption methods and the characteristics of isothermal adsorption and kinetics adsorption on humic acid was discussed too. Results showed that pH increase of medium was of great disadvantage of P adsorption and could decrease the velocity of adsorption reaction. As to sample one, the distribution coefficient and adsorption capacity was the maximum at pH was 4.7. Even the pH was higher, as to sample two, the distribution coefficient and adsorption capacity was decreased. Besides, the distribution coefficient and adsorption capacity of the experimental humic acid treated by nitric was significant lower than that of the brown coal without treated. With the increase of P concentration in the medium, adsorption capacity of P increased too. Adsorption capacity rose markedly in the beginning of the adsorption process, however, it slowed down later. Suitable ratio of solid to liquid could increase the unit adsorption. The adsorption of P on humic acid could be well described by Langmuir equation and its kinetics adsorption fit Elovich equations best.