污染控制技术及原理
陈灿,王建龙.酿酒酵母吸附Zn2+、Pb(2+)、Ag+、Cu2+的动力学特性研究[J].环境科学学报,2007,27(4):544-553
酿酒酵母吸附Zn2+、Pb(2+)、Ag+、Cu2+的动力学特性研究
- Biosorption of heavy metal ions by a brewery's waste:kinetic and equilibrium
- 基金项目：国家自然科学基金资助项目(No50325824);清华大学基础研究基金项目(NoJC2002054)
- 作者
- 单位
- 陈灿
- 清华大学核能与新能源技术研究院环境技术研究室, 北京100084
- 王建龙
- 清华大学核能与新能源技术研究院环境技术研究室, 北京100084
- 摘要：利用静态摇瓶实验方法,研究了工业废弃酿酒酵母无缓冲溶液体系吸附Zn2+、Pb2+、Ag+、Cu2+的动力学特性.结果表明,酵母吸附Zn2+、Pb2+、Ag+、Cu2+的动力学过程可以用准二级动力学方程进行描述.金属离子初始浓度在0.08～3.0mmol·L-1范围内,Langmuir方程可以较好地描述Zn、Pb、Ag的等温吸附行为,Zn、Pb、Ag的理论饱和吸附量分别为0.522mmol·g-1(34.11mg·g-1)、0.577mmol·g-1(119.50mg·g-1)和0.329mmol·g-1(35.50mg·g-1).以mol为基础的金属离子吸附量顺序是:Pb>Zn>Ag;以mg为基础的金属离子吸附量顺序是:Pb>Ag>Zn.Freundlich方程对整个浓度范围内的平衡数据拟合效果较差,但是它可以较好地描述低浓度Zn2+(初始浓度0.08～0.5mmol·L-1)、低浓度Pb2+(0.08～1.0mmol·L-1)以及高浓度Ag+(1.5～3.0mmol·L-1)的等温吸附行为.酵母吸附Zn2+、Pb2+、Ag+、Cu2+过程中,溶液pH值有不同程度的增加,增加幅度大小顺序是Zn>Pb>Ag>Cu,这间接反映出Zn2+、Pb2+、Ag+、Cu2+与水溶液中H+的竞争力逐步减弱.吸附过程中酵母释放大量的K+,其次是Mg2+,而Ca2+、Na+的释放量较低,数量级一般可分别达到几百μmol·g-1、几十μmol·g-1、几到几十μmol·g-1、十几μmol·g-1.
- Abstract：The waste biomass of Sacchramyces cerevisiae collected from a local brewery was used to investigate its performance for sequestering Zn2+,Pb2+,Ag+ and Cu2+ from aqueous solutions. The experimental results indicated that the metal uptake took place rapidly, whereby almost 60% uptake was completed within the first five minutes of exposure. The biosorption kinetics was analyzed using the pseudo second-order kinetic equations. The rate constants for the models were determined. The biosorption equilibrium conformed to the Langmuir adsorption isotherms when the initial concentration of Zn, Pb and Ag ions was below 3.0 mmol·L-1 and the sorbent concentration was 1 g·L-1. The Freundlich equation fitted the data well only when initial concentration of zinc ion was in the range of 0.08～0.5 mmol·L-1 and lead ion was 0.08～1.0 mmol·L-1, silver ion was 1.5 ～3.0 mmol·L-1. The equilibrium sorption capacity of zinc, lead and silver ions was determined from the Langmuir equation and found to be 0.522 mmol·g-1 (34.11 mg·g-1), 0.577 mmol·g-1 (119.50 mg·g-1), 0.329 mmol·g-1 (35.50 mg·g-1), respectively. The increase of pHvalue and the release of physiological cations such as K+, Mg2+, Ca2+, Na+ were observed during the biosorption process, which reflected the intrinsic performance of the microbial cell. However the presence of metal ions would promote the release of those cations such as Kand Mg, and decrease the absorption of H+. Ion exchange was one of the mechanisms for zinc uptake by the biomass.
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