干旱区牛粪生物炭对水中磷的吸附特性研究

Adsorption Characteristics of Phosphorus in Water by Dairy Manure-Derived Biochar in Arid Area

以牛粪生物炭为吸附剂,通过静态吸附实验研究生物炭对磷的吸附特性。通过对动力学数据进行分析,发现准二级动力学(R2=0.999)比准一级动力学方程(R2=0.5886)和Elovich方程(R2=0.927)能更好地拟合动力学数据,颗粒内扩散方程拟合结果发现牛粪生物炭对磷的吸附包括表面吸附和颗粒内扩散两个过程。吸附等温线拟合发现Langmuir吸附等温方程能很好拟合等温吸附数据,表明生物炭对磷的吸附以单分子层吸附模式为主。利用牛粪热解产生的生物炭吸附去除水中磷是可行的,不仅成本低廉并且能够达到干旱区农业废弃物资源化利用及废水除磷的目的。

This paper studies the adsorption characteristics of phosphorus by biochar through static adsorption test using dairy manure-derived biochar as an adsorbent. The kinetic data analysis shows that,the pseudo-second-order kinetic equation（ R2= 0.999） fits the kinetic data better than the pseudo-first-order kinetic equation（ R2= 0.5886）and the Elovich equation（ R2= 0.927）,and the intraparticle diffusion equation fitting results indicate that,the adsorption of phosphorus by dairy manure-derived biochar includes two processes： surface adsorption and intraparticle diffusion. Adsorption isotherm fitting turns out that the Langmuir adsorption isotherm equation can fit the isothermal adsorption data well,indicating that the adsorption of phosphorus by biochar is dominated by monolayer adsorption. It is feasible to remove phosphorus from water by using biochar produced by pyrolysis of dairy manure,which is not only cost-effective,but also can achieve the purpose of resource utilization of agricultural residues and removal of phosphorus from wastewater in arid regions.