小麦秸秆对含铜废水的吸附性能和动力学特征

Adsorption properities of Cu^(2+)-laden wastewater with wheat straw and characteristic of its kinetics

利用小麦秸秆对含铜废水进行吸附研究.采用平衡吸附法研究秸秆投加量、溶液pH和反应时间对小麦秸秆吸附水溶液中Cu2+的影响.结果表明,pH显著影响小麦秸秆对Cu2+的吸附;其动力学行为很好的符合Lagergren准二级反应动力学模型,吸附等温线符合Langmuir模型,在30℃时秸秆对Cu2+的饱和吸附量qm为24.6mg.g-1;分离因子RL值为0～1,为有利吸附;用0.2mol.L-1的HCl对吸附饱和的秸秆解吸效果良好,解吸率>90%,且再生后秸秆的吸附效果与新鲜秸秆差不多.

The adsorption of Cu^2＋-laden wastewater with wheat straw was investigated. By means of equilibrium adsorption approach, the influence of experiment were carried out by considering additive amount of wheat straw, pH-value of solution, and reaction time on adsorptive capacity of Cu^2＋ in the solution by using wheat straw. The results showed that the adsorption was remarkably affected by the pH-value. The kinetics of the reaction exhibited better agreement with the Lagergren quasi-second-order kinetic model and the adsorption isotherm showed a good agreement with Langmuir model. The saturate adsorp- tion capacity qm was 24. 6 mg· g^-1 at 30 ℃. Its separation factor （RL） was in the range of 0---1, showing a favorable adsorption. Saturated wheat straw could be regenerated by HCl solution of 0. 2 mol · L^-1 with a better result, the regeneration rate being greater than 90%. The regeneration of the adsorbent showed such a favorable adsorption capability as almost the fresh wheat straw.