粉煤灰对渗沥液氨氮的吸附试验及其动力学研究

为有效提高生活垃圾填埋场渗沥液的C/N,增加渗沥液的可生化性,应用粉煤灰吸附处理实际渗沥液中的氨氮,分别研究投加量,温度,pH值对吸附效果的影响,并在最佳吸附条件下对吸附过程进行动力学分析.结果表明,反应180min时,吸附达到平衡,氨氮去除率达到63.44%,单位吸附量为8.7428mg/g,可有效地调节渗沥液的营养比例,有利于生物处理作用;动力学数据拟合吸附过程符合伪二级动力学方程;动边界模型推算表明,液膜扩散为吸附过程的速度控制步骤;采用Dünwald-Wagner公式,估算有效扩散系数(Dc)为3.058×10-9cm2/s.

Adsorption and kinetics of ammonia-nitrogen from leachate onto fly ash

To effectively improve the C/N and increase the biodegradability ofthe landfill leachate,fly ash was chosen as sorbent to treating ammonia-nitrogen in leachate.The effect of dosage,temperature and pH on adsorption of NH3-N onto fly ash were separately studied,kinetics analysis was used for the adsorption process in the optimum adsorption conditions.Experiment results showed that fly ash had the better adsorption ability of treating ammonia-nitrogen in leachate,the adsorption equilibrium time was 180min,then the removal rate of ammonia-nitrogen was 63.44%,the equilibrium adsorption capacity was 8.7428mg/g.Linearizations of the different kinetic equations showed that adsorption process in line with the pseudo-secondary kinetic equation;Moving boundary model analysis showed that the adsorption formula,estimated the effective diffusion coefficient (Dc) was 3.058× 10-9cm2/s.