摘要
在室内模拟条件下,研究了蛋白核小球藻、月牙藻、鱼腥藻对重金属Cd^2＋的吸附动力学和热力学特征,并采用傅里叶红外光谱和扫描电镜等手段对微藻吸附前后进行结构表征,进一步探讨吸附机理。结果表明：（1）自然光照条件下微藻吸附Cd^2＋的准二级动力学模型拟合结果较好,且吸附速率为蛋白核小球藻〉月牙藻〉鱼腥藻;（2）不同微藻受光照的影响不同,黑暗条件下蛋白核小球藻、月牙藻、鱼腥藻的吸附速率分别下降了60.5%、28.8%、10.9%;（3）用Langmuir模型对吸附热力学的实验结果进行拟合,达到显著水平,蛋白核小球藻、月牙藻、鱼腥藻对Cd^2＋的最大吸附量分别为23.8、23.2、18.1 mg/g;（4）微藻多孔的细胞壁结构和大量胞外产物中的氨基和羧基等基团是引起Cd^2＋吸附的主要原因,微藻的不同结构导致其对Cd^2＋吸附能力有所差异。
Three microalgae, namely Chlorella pyrenoidosa, crescent algae and Anabaena algae, were chosen to study their kinetic and thermodynamic features in the adsorption of a heavy metal ion Cd（Ⅱ） by the simulation in laboratory. Structures of the microalgae before and after the adsorption were characterised by means of Fourier transform infrared spectroscopy（FTIR） and scanning electron microscopy（SEM）, and its adsorptive mechanisms were further explored. The results showed that under natural light conditions, the microalgae adsorption process could fairly well fi t quasi second order kinetic equation with Chlorella pyrenoidosa having the highest adsorbing rate whilst Anabaena algae having the lowest one. As different light conditions would make various effects, the adsorbing rates of Chlorella pyrenoidosa, crescent algae and Anabaena algae could decline 60.5 %, 28.8 % and 10.9 %, respectively, under a dark condition. It would be at significant levels when fitted by Langmuir equation, and the maximum Cd（Ⅱ） adsorbance of Chlorella pyrenoidosa, crescent algae and Anabaena algae could reach 23.8, 23.2 and 18.1 mg/g, respectively. The porous cell-wall structure of microalgae and amino-, carboxyland etc. groups in a great deal of its extracellular products were found to be the main causes to bring about the adsorption of Cd（Ⅱ）. The capacity of adsorbing Cd（Ⅱ） could be varied according to different structures of microalgae.
出处
《上海环境科学》
CAS
2017年第4期179-184,共6页
Shanghai Environmental Sciences
基金
嘉兴学院大学生研究训练(SRT)计划项目,编号:851716047
关键词
微藻
重金属
生物吸附
吸附量
Microalgae
Heavy metal
Bio-adsorption
Adsorbance
