活性微藻对镉去除及其解吸剂的优选研究

The Study of Cadmium(Cd)Removal by Living Algae with Optimal Selection of Cd Desorption Reagents in Wastewater Treatment

为优选出吸附在活性微藻表面镉的解吸剂和探究活性微藻去除镉的机制,利用CaCl_(2)、NaCl、EDTA-2Na和纯水等四种解吸剂,研究了其对吸附在铜绿微囊藻(Microcystis aeruginosa)、蛋白核小球藻(Chlorella pyrenoidosa)和斜生栅藻(Scenedesmus obliquus)等3种微藻表面的镉解吸效果,分析了活性微藻对镉去除机理。结果表明,EDTA-2Na对铜绿微囊藻、蛋白核小球藻、斜生栅藻的Cd解吸效果均最好;蛋白核小球藻和斜生栅藻对Cd的去除率分别为94.7%、96.6%,并且胞内吸收率高于胞外吸附率;EDTA-2Na对蛋白核小球藻细胞并无明显的损伤情况,可以作为一种有效的活性微藻表面Cd的解吸剂。

In this study,Microcystis aeruginosa,Chlorella pyrenoidosa and Scenedesmus obliquus were used as experimental microalgae to treat Cd contained wastewater,and four different desorbing reagents(CaCl_(2),NaCl,EDTA-2 Na,and deionized water)were investigated for the Cd recycle experiment.During the experiment,the mechanism Cd removal by living microalgae and the selection of Cd desorption reagent were carefully investigated.Results showed that EDTA-2 Na demonstrated better desorption effect on the surface of three applied microalgaes over other desorption reagents.Both Chlorella pyrenoidosa and Scenedesmus obliquus showed great Cd removal rate with 94.7%and 96.6%individually with higher Cd accumulation concentration inside microalgae cells comparing to adsorption process.No obvious external damage was found on Chlorella pyrenoidosa algae cells when EDTA-2 Na was used as desorption reagent.These results provided an alternative method for Cd removal in wastewater treatment and Cd recycle utilizing EDTA-2 Na as a promising desorbing reagent.