生物炭对水体中铵氮的吸附特征及其动力学研究

Adsorption and Kinetics of Ammonium from Aqueous Medium onto Biochar

以生物炭作为吸附剂,通过静态实验研究了生物炭对水体中铵氮的吸附特性,并从动力学角度探讨了其吸附机理。结果表明,生物炭对铵氮的吸附在60min内基本达到吸附平衡,其吸附量随着水溶液中铵氮的增加而增加,Langmuir方程能够更好的描述铵氮在生物炭上的等温吸附行为,最大吸附量为1.24mg/g,铵氮在生物炭上的吸附动力学数据符合假二级方程,吸附过程受外部液膜扩散、表面吸附和颗粒内扩散过程的影响。

The experiment was conducted on the adsorption characteristics of biochar for removing ammonium in aqueous medium.The adsorption equilibrium and kinetic behavior of ammonium onto biochar were investigated by a series of batch adsorption experiments,and adsorption mechanism was discussed from the kinetic point of view.Results indicated that ammonium adsorption equilibrium was reached in about 60 minutes,and the capacity of biochar adsorbing ammonium tended to increase with increasing concentrations of ammonium in water.The Langmuir isotherm equation could well describe the isothermal adsorption behavior of ammonium on biochar,and the Langmuir maximum adsorption capacity was 1.24 mg/g.The pseudo-second-order model was established to explain the adsorption kinetics most effectively,and pore diffusion,surface adsorption and intra-particle diffusion would affect the adsorption.