水华束丝藻对汞的吸附-解吸特征

通过室内模拟实验，探究不同丰度的活、死水华束丝藻对Hg²⁺的吸附动力学特征和等温吸附模型以及解吸特征。结果表明，水华束丝藻对Hg²⁺有较好的吸附效果，能在短时间内吸附大量Hg²⁺，120 min左右达到吸附平衡，且活藻对Hg²⁺的吸附效果比死藻好；活藻和死藻吸附Hg²⁺的动力学过程符合准一级、准二级动力学模型，且准二级动力学模型拟合效果更好；活、死水华束丝藻对Hg²⁺的吸附分别符合Langmuir模型、D-R模型，最大吸附量分别为2.07×10^-2 ng/（10⁶ cells）、3.56×10^-2 ng/（10⁶ cells）；水华束丝藻对Hg²⁺的单位吸附量随着藻丰度的增加而减少，吸附总量随着藻丰度的增加而增加。反应初期（0～5 min），活、死水华束丝藻对Hg²⁺进行生物吸附，吸附速度快且效率高；随后活藻依靠新陈代谢将Hg²⁺转移至细胞内进行生物富集，因而活藻的单位吸附量高于死藻。活藻和死藻对Hg²⁺的解吸量随藻丰度的增加而增加，且死藻变化更明显。

Sorption and Desorption Characteristics of Hg2+ by Aphanizomenon flosaquae

Laboratory simulation experiments were conducted to investigate kinetics and isotherm patterns of sorption and desorption of Hg²⁺ by a biosorption agent, Aphanizomenon flosaquae, under different conditions, e.g. live or dead, and abundance. The results showed that algae, Aphanizomenon flosaquae, is a good sorbent for Hg²⁺ and can uptake a large amount of Hg²⁺ in a short time, sorption equilibria can be reached in about 120 minutes. The sorption ability of Hg²⁺ on live algae is much higher than that of dead algae. The sorption kinetics of Hg²⁺ by algae can be described with either quasi-first-order or quasi-second-order kinetic model. The quasi-secondary kinetic model showed a better fitting result. The sorption isotherms of Hg²⁺ by live algae and dead algae are consistent with the Langmuir model. The maximum sorption capacity of Hg²⁺ by live algae and dead algae was 2.07×10^-2 ng/(10⁶ cells) and 3.56×10^-2 ng/(10⁶ cells), respectively. The concentration of Hg²⁺ on algae decreased while the total uptake amount of Hg²⁺ on algae increased as the abundance of algae increased. Both live and dead algae sorbed Hg²⁺ quickly and effectively within 5 min through biosorption, but the sorption amount of live algae was higher than that of dead algae since live algae can transfer Hg²⁺ into algae cell. The desorption amount of Hg²⁺ from live and dead algae increased with the increase of algae abundance, and this trend was more significant for dead algae.