预处理对小球藻吸附Cd(Ⅱ)、Pb(Ⅱ)和Cu(Ⅱ)的影响

Effect of Pretreatment of Chlorella vulgaris Beijerinck Biomass on Adsorption of Cd(Ⅱ),Pb(Ⅱ)and Cu(Ⅱ)

为了研究不同预处理方式对小球藻藻体吸附Cd2+、Pb2+和Cu2+的影响,文章将经过高温灭菌、Ca(NO3)2溶液浸泡和HNO3溶液浸泡预处理的小球藻藻体冷冻干燥,然后在单、两和三组份重金属离子溶液中进行吸附实验。结果表明,在单一系统中,经过Ca(NO3)2溶液浸泡过的藻体吸附效果较好;在混合系统中,冷冻干燥的藻体吸附效果较好。小球藻藻体对重金属吸附动力学曲线表明,在单一或混合系统中,高温灭菌的藻体对Cd2+、Pb2+的吸附于360 min内基本达到平衡,Ca(NO3)2或HNO3溶液浸泡过的藻体对Cd2+、Cu2+的吸附于360 min内基本达到平衡。运用红外光谱仪和扫描电镜对吸附重金属离子前的藻体进行表征。结果表明,不同预处理藻体细胞的功能性基团和形态结构存在着差异,进而影响其对Cd2+、Pb2+、Cu2+的吸附能力。

In order to study the effect of pretreatment of Chlorella vulgaris Beijerinck biomass on adsorption of Cd2＋, Pb2＋ and Cu2＋, the adsorption experiment of heavy metals by the freeze-dried biomasses, which were subject to different kinds of pretreatment such as autoclaving, Ca（NO3）2 solution soaking and HNO＋ solution soaking in advance, was investigated in monometallic, bimetallic and trimetallic solutions. The study showed that the removal efficiency of the Ca（NO3）2 solution soaked biomass was higher in single-metal system and the freeze-dried biomass without pretreatment was more effective in multi-metal system. The adsorption kinetics curves illustrated that the adsorption of Cd2＋ and Pb2＋ by autoclaved biomass and Cd2＋ and Cu2＋ by Ca（NO3）2 or HNO3 solution soaked biomass reached equilibriums within 360 min in single-metal and multi- metal systems. Before the adsorption of heavy metals, the algae biomasses were characterized by using infrared spectroscopy and scanning electron microscopy. Summarily, results of the study demonstrated that the functional groups and morphological structure of the algae cells subjected to different pretreatments had their own characteristics which would exert influence on the adsorption capacity of biomasses for Cd2＋, Pb2＋, Cu2＋afterwards.