3种海洋硅藻藻粉吸附水中镉离子特性研究

发布时间：2018-04-03 08:35

本文选题：镉离子　切入点：海洋硅藻　出处：《环境科学学报》2017年12期

【摘要】：利用3种海洋硅藻(角毛藻、菱形藻、海链藻)干粉对水中重金属镉离子进行吸附.实验结果表明,3种海洋硅藻对Cd~(2+)的吸附容量在一定范围内均与吸附时间、Cd~(2+)初始浓度和温度3个变量分别呈正相关关系.3种硅藻干粉对Cd~(2+)的吸附均很好地符合Pseudo二级动力学模型;吸附等温数据均更符合Langmuir等温吸附;在不考虑温度对吸附焓和吸附熵影响的前提下,计算得到的3种海洋硅藻的ΔG值均小于0.以上结果表明,3种海洋硅藻对Cd~(2+)的吸附过程是一个自发进行、有化学吸附参与的以单分子层吸附为主的吸附过程.角毛藻、菱形藻和海链藻最大实验吸附容量分别为275.25、303.75和224.36 mg·g~(-1),大大高于已报道各类生物吸附剂.以吸附容量最大的菱形藻干粉为吸附剂,考察实际水体中可能存在物质对其吸附性能的影响.结果表明,菱形藻对Cd~(2+)的吸附容量随着溶液中盐(Na Cl、Ca(NO_3)_2、Mg(NO_3)_2)浓度和浊度的增加而下降,而随着腐植酸浓度的增加不断升高.最后,利用HCl对吸附Cd~(2+)后的菱形藻进行解吸附再生实验,结果表明HCl可有效解吸菱形藻上的Cd~(2+),实现Cd~(2+)的脱附回收.
[Abstract]:The heavy metal cadmium ion in water was adsorbed by dry powder of three kinds of marine diatoms (Corydophyta, diamondophyta, Dioscorea albicans).The experimental results show that the adsorption capacity of the three marine diatoms for Cd~(2) is positively correlated with the initial concentration and temperature of the three diatoms in a certain range. 3. 3 kinds of diatom dry powder can adsorb Cd~(2) well.Pseudo secondary kinetic model;The adsorption isotherm data are more consistent with Langmuir isotherm adsorption, and the calculated 螖 G values of the three marine diatoms are less than 0, without considering the influence of temperature on adsorption enthalpy and adsorption entropy.The results show that the adsorption process of Cd~(2 by the three marine diatoms is a spontaneous adsorption process with chemisorption involved in the monolayer adsorption process.The maximum experimental adsorption capacities of Corydophyta, diamondzia and Chlorophyta were 275.25303.75 and 224.36 mg / g, respectively, which were much higher than those of all kinds of biological adsorbents reported.The effect of possible substances in the real water body on the adsorption performance was investigated by using the diamondzia powder with the largest adsorption capacity as the adsorbent.The results showed that the adsorption capacity of Cd~(2 decreased with the increase of the concentration and turbidity of Cd~(2 in the solution, but increased with the increase of humic acid concentration.Finally, HCl was used to desorbate and regenerate the diamondback algae after Cd~(2 adsorption. The results showed that HCl could effectively desorb the Cd~(2 on the diamondback algae and realize the desorption and recovery of Cd~(2.
【作者单位】：北京大学环境与能源学院;中国石化集团国际石油工程有限公司;
【基金】：海洋公益性行业科研专项(No.201305022) 广东省自然科学基金博士启动项目(No.2014A030310326)~~
【分类号】：X703.1

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