椭圆小球藻和鱼腥藻对甲基汞吸附特征研究

Study on adsorption characteristics of methylmercury byChlorella ellipticus and Anabaena sp.

以活、死椭圆小球藻和鱼腥藻为研究对象,探究其对甲基汞(MeHg)的吸附特征。结果表明:活、死椭圆小球藻和鱼腥藻对MeHg均有较强的吸附能力,随着MeHg浓度的增加,吸附量逐渐增加。0~5 min时,活、死椭圆小球藻和鱼腥藻吸附MeHg速率较快,随后变缓,最终在120 min时达到吸附平衡。5 min时,活、死椭圆小球藻对MeHg的最大吸附率分别为98.38%、79.80%,活、死鱼腥藻最大吸附率分别为98.07%、84.62%;120 min时,活、死椭圆小球藻的最大吸附率分别为99.30%、93.36%,活、死鱼腥藻的最大吸附率分别为99.21%、91.76%;活椭圆小球藻对MeHg的吸附动力学符合准一级和准二级动力学模型,死椭圆小球藻和活鱼腥藻对MeHg的吸附动力学均符合准二级动力学模型,死鱼腥藻对MeHg的吸附动力学符合准一级动力学模型;活椭圆小球藻和鱼腥藻对MeHg的吸附均符合Freundlich等温吸附模型;死椭圆小球藻对MeHg的吸附符合Langmuir等温吸附模型;死鱼腥藻对MeHg的吸附均不符合Freundlich和Langmuir等温吸附模型;细胞结构分析表明,椭圆小球藻吸附MeHg的基团主要为-OH和C-O,鱼腥藻吸附MeHg的主要基团为C-O。活椭圆小球藻和鱼腥藻对MeHg的吸附主要包括细胞壁吸附和细胞内吸附过程,而死椭圆小球藻和鱼腥藻对MeHg的吸附主要包括细胞壁吸附过程。因此,活藻对MeHg的吸附率高于死藻。

The adsorption characteristics of methylmercury(MeHg)by living and dead Chlorella ellipticus and Anabaena sp.were studied.The results showed that the adsorption capacity of the living,dead Chlorella ellipticus and Anabaena sp.had strong adsorption capacity,and the adsorption capacity increased with the increase of the concentration of MeHg.At 0~5 min,the adsorption rate of MeHg by living and dead Chlorella ellipticus and Anabaena sp.was faster,then slowed down,and finally reached the adsorption equilibrium at 120 min.At 5 min,the maximum adsorption rates of MeHg by living and dead Chlorella ellipticus and Anabaena sp.were 98.38%,79.80%,98.07%,84.62%,respectively.At 120 min,the maximum adsorption rates of living and dead Chlorella ellipticus and Anabaena sp.were 99.30%,93.36%,99.21%and 91.76%,respectively.The kinetic adsorption process of MeHg by living Chlorella ellipticus was in accordance with quasi-first-order and quasi-second-order kinetic models,the kinetic adsorption process of MeHg by dead Chlorella ellipticus and living Anabaena sp.was in accordance with quasi-second-order kinetic model,and the kinetic adsorption process of MeHg by dead Anabaena sp.was in accordance with quasi-first-order kinetic model.The adsorption of MeHg by living Chlorella ellipticus and Anabaena sp.was in accordance with Freundlich isotherm adsorption model,and the adsorption of MeHg by dead Chlorella ellipticus was in accordance with Langmuir isotherm adsorption model.The adsorption of MeHg by dead Anabaena sp.does not conform to the isothermal adsorption model of freundlich and langmuir.The cell structure analysis showed that the main groups involved in the adsorption of MeHg by Chlorella ellipticus were-OH,C-O,and the main group involved in the adsorption of methyl mercury by Anabaena sp.was C-O.