【摘要】 以高锰酸钾改性小麦秸秆为吸附剂吸附溶液中重金属离子Cd²⁺,并对其进行表征,研究pH、吸附时间、固液比、温度和解吸对其吸附Cd²⁺的影响。结果表明,对4种不同浓度高锰酸钾改性小麦秸秆观察发现,0. 05 mol·L^-1高锰酸钾改性制备的小麦秸秆表面更加光滑,且带有较多负电荷,有利于提高对Cd²⁺的吸附性能。改性小麦秸秆对Cd²⁺的吸附在300 min后达到平衡,并符合拟二级动力学方程。当吸附溶液pH值为6,m（吸附剂）∶V（溶液）为1∶300时,吸附效果最佳。由Langmuir等温吸附方程拟合发现,0. 05 mol·L^-1高锰酸钾改性制备的吸附剂对Cd²⁺的吸附量最大,为30. 21 mg·g^-1,大于未改性小麦秸秆最佳吸附量(5. 7 mg·g^-1),结合解吸可知该吸附剂对Cd²⁺的吸附具有较好稳定性。更多还原

【Abstract】 Heavy metal ions Cd²⁺ were adsorbed by potassium-permanganate-modified wheat straw. The modified wheat straw was characterized by scanning electron microscopy,zeta potential,and Fourier transform infrared spectroscopy.The effects of pH,adsorption time,solid-liquid ratio,and temperature of the solution and desorption on Cd²⁺ adsorption were also studied. Four different concentrations of potassium-permanganate-modified wheat straw were observed. Results show that,compared with the surfaces of other concentrations,the surface of 0. 05 mol·L^-1 potassium-permanganate-modified wheat straw appeared smoother and had more negative charges. These outcomes were beneficial to improving the adsorption performance of Cd²⁺ . Moreover,the adsorption reached equilibrium at 300 min and fitted the pseudo two-order kinetic equation. The best adsorption effect was obtained when the pH of the modified wheat straw was 6,and the solid-liquid ratio was 1∶300. According to the Langmuir isothermal adsorption equation,the adsorbents prepared using the modified adsorbents of 0. 05 mol·L^-1 had the largest adsorption capacity for Cd²⁺ (30. 21 mg·g^-1) far larger than the optimum adsorption capacity of the unmodified wheat straw(5. 7 mg·g^-1). The adsorbent has been found to have good stability for Cd²⁺ adsorption.更多还原