单双离子体系中酵母菌对Pb^(2+)的吸附动力学

On the biosorption kinetics of Pb^(2+) on yeast in different single and double-ion heavy metal systems

为了探讨单双离子体系中灭活面包酵母菌吸附Ph^(2+)的动力学,对不同温度、初始浓度的Pb^(2+)单离子体系和不同初始浓度的Cu^(2+)- Pb^(2+)、Ni^(2+)-Pb^(2+)双离子体系中灭活面包酵母菌对Pb^(2+)的动力学吸附过程进行了研究。结果表明,不同试验条件下酵母菌吸附Pb^(2+)的动力学过程符合准二级吸附模型。在10℃、20℃和30℃下,随环境温度增高,吸附趋于平衡的时间缩短;而在Pb^(2+)初始浓度为0.5 mmol/L、1.0 mmol/L和2.0 mmol/L的条件下,随初始浓度增大,趋于平衡的时间增长。双离子体系的动力学吸附过程中,相同浓度的Cu^(2+)和Ni^(2+)作用下,Cu^(2+)对Pb^(2+)吸附的影响明显大于Ni^(2+)。研究表明,酵母菌对Pb^(2+)的吸附是一个快速高效的过程,Cu^(2+)、Ni^(2+)等重金属离子的加入明显影响了酵母菌对Ph^(2+)的吸附。

On the basis of covering technical literatures published in the recent 30 years on the biosorption of heavy metal ions, the given. paper is to present our study results on the kinetics working mechanism of the biosorption of Pb^2＋ on the autoclaved baker＇ s yeast in different single-ion and double-ion heavy metal systems. For our research purpose, we have chosen single-ion systems operating at dif- ferent temperatures and initial concentrations of Pb^2＋ and double-ion systems of different initial concentrations of Cu^2＋ - Pb^2＋ and Ni^2＋- Pb^2＋ as our case study samples. To make sure the working principle of the iron systems we are interested in, we have tested their bioserption effect by using the instruments known as AAS （atomic absorption spectra）. The results of our testing and measurement have shown that the baker＇ s yeast is by nature a kind of quick and efficient biosorbent, which is expected to display its biosurptive capacity for Pb^2＋ in different kinetic processes in correspondence with the secondorder kinetic model. Within the range of experimental temperatures we have chosen from 10 ℃, 20 ℃ to 30℃, it is found that with the increase of temperature, less time will be needed to get to equilibrium. On the contrary, under the condition of initial concentration of Pb^2＋ in the solutions of 0.5 mmol/L, 1.0 mmoL/L and 2.0 mmol/L, it would take longer time to get to equilibrium state. Thus, kinetics.biosorption theory for double ions systems tends to prove that the effect of Cu^2＋ and Ni^2＋ to the biosorption of Pb^2＋ is likely to be positively correlated with their initial concentration. The antagonism of Cu^2＋ to Pb^2＋ seems bigger than that＇of Ni^2＋ to Pb^2＋. The adsorption quantity of baker＇s yeast to Pb^2＋ tends to get reduced to 72.5 % while the initial concentration coexistence Cu^2＋ is 4.0 mmol/L in the double ions system. The obvious effect on the bisoroption of Pb^2＋ by the concurrent ions in the double-ion system can thus be affirmed, though the complex mechanism remains to be further studied in the future.