杭锦2~#土复合吸附剂对磷的吸附动力学

通过静态试验考察杭锦2#土/聚合硫酸铝复合吸附剂对生活污水中磷酸根的吸附特性,研究吸附过程的动力学模型,并从动力学角度探讨其吸附机理。结果表明,在杭锦2#土/聚合硫酸铝复合吸附剂用量5 g.L-1、吸附时间60 min、废水pH值6.0、温度25℃、磷初始质量浓度小于16.72 mg.L-1条件下,磷酸根的去除率在96%以上;复合吸附剂对磷酸根的吸附动力学特征符合假二级方程,吸附速率在前10 min为内扩散控制,后期由膜扩散和内扩散共同控制,且膜扩散占主导地位;磷酸根的初始浓度越高,吸附质粒子的表观内扩散系数和表观传质系数越小;使用不同再生次数的再生吸附剂（添加量为5 g.L-1）处理16.72 mg.L-1含磷生活污水,随着再生次数的增加,吸附能力有所下降,但磷酸根的去除率均大于89%。

Phosphate Adsorption Kinetics of Hangjin 2~# Clay Complex Adsorbent

Adsorption equilibrium and kinetic behavior of phosphate onto the Hangjin 2# Clay-improved polyaluminium sulphate complex adsorbent was investigated through a series of batch adsorption experiments.The adsorption kinetic models were explored and adsorption mechanism was discussed from kinetic point of view.Results show that the removal rate of phosphate may reach as high as 96%,when the adsorbent is used at a rate of 5 g·L-1 and the adsorption lasted for 60 min in wastewater with pH at 6.0,temperature at 25 ℃ and the initial mass concentration of phosphorus less than 16.72 mg·L-1.The pseudo-second-order equation is found to be fit to the adsorption kinetics and the adsorption rate controlled by internal diffusion within the first 10 minutes and then jointly by film diffusion and internal diffusion later on,with the former in dominancy.The higher the initial concentration of phosphate,the lower the apparent internal diffusion coefficient and the apparent mass transfer coefficient.The adsorbent can be recycled.When recycled absorbent is used（5 g·L-1） to treat wastewater containing 16.72 mg·L-1 phosphorus,its adsorption capacity decreased somewhat with the number of recycling increased,but its phosphate removal rate still stayed above 89%.