酒糟对模拟矿山酸性废水中Pb2+和Zn2+的吸附特征

为了探索生物质材料酒糟对重金属离子的吸附效果，采用静态吸附实验研究废水pH值、Pb2+和Zn2+初始质量浓度以及吸附时间对酒糟吸附模拟矿山酸性废水中Pb2+和Zn2+的影响. pH值为4时酒糟对Pb2+和Zn2+的吸附量分别达到最高值，酒糟对Pb2+的吸附等温线特征符合Langmuir方程，对Zn2+的吸附等温线特征符合Freundlich方程，对Pb2+和Zn2+的最大吸附量分别为8.29 mg·g-1和15.31 mg·g-1.酒糟对Pb2+和Zn2+的吸附反应在4 h后达到平衡，吸附动力学特征均符合拟二级动力学模型.酒糟中纤维素、半纤维素和木质素的质量分数分别为23.3%、65.5%和0.5%，吸附Pb2+和Zn2+后3种物质的含量发生变化，分别为19.6%、42.3%和2.6%.酒糟电负性随pH值升高呈正比增加，吸附Pb2+和Zn2+后电负性减弱.红外光谱分析结果显示酒糟中参与吸附反应的基团主要有酰胺基和酯基.

Adsorption characteristics of Pb2+ and Zn2+ from simulated acid mine drainage using lees

In order to study the ability of lees to adsorb heavy metals, this article was focused on the effects of wastewater pH values, Pb2+ and Zn2+ mass concentrations, and adsorption time on the adsorption quantity of Pb2+ and Zn2+ from simulated acid mine drainage using lees. Test results show that the maximum removal rate appears when the pH value is 4. The adsorption of Pb2+ by lees accords with the Langmuir equation, but the adsorption of Zn2+ is followed by the Freundlich equation. Under the optimal condi-tions, the maximum adsorption capacity of Pb2+ and Zn2+ by lees is 8. 29 mg·g-1 and 15. 31 mg·g-1 , respectively. The adsorption process reaches equilibrium after 4 h, in agreement with the second-order kinetics model. The contents of cellulose, hemicelluloses and lignine in the lees is 23. 3%, 65. 5% and 0. 5%, while become 19. 6%, 42. 3% and 2. 6% after adsorption of Pb2+ and Zn2+, respectively. The electro-negativity of lees increases while the pH value raises, and it reduces after adsorption of Pb2+ and Zn2+. Fou-rier transform infrared spectra indicate that the main functional groups are amide and ester reacting in the adsorption process.