改性黄豆粕对废水中Cu^(2+)的生物吸附特性  

Biosorption of Cu^(2+) onto de-oiled soybean modified by NaOH

作　　者：司春英[1] 高景峰[1] 张志红[1] 

机构地区：[1]北京工业大学环境与能源工程学院,北京100124

出　　处：《安全与环境学报》2013年第5期44-51,共8页Journal of Safety and Environment

基　　金：国家自然科学基金项目(51078007;51378027);北京市自然科学基金项目(8112007);北京工业大学京华人才项目(2013-JH-L06);北京市教委中青年骨干教师计划项目(PHR20110819)

摘　　要：采用NaOH浸泡的方法制备改性黄豆粕吸附剂(DOS-NaOH)考察了初始pH值、吸附剂用量、初始Cu2+质量浓度、温度等对DOSNaOH吸附Cu2+的影响。结果表明,pH值对DOS-NaOH吸附Cu2+重要影响,最佳pH值为5.0。相对于Freundlich等温线,Langmuir等线更适合描述DOS-NaOH吸附Cu2+的行为,20℃时最大单分子层附量为112.36 mg/g。吸附动力学研究表明,内部扩散和边界层扩都可能影响生物吸附速率,DOS-NaOH吸附Cu2+的过程可以用准二动力学模型描述。热力学分析表明,吸附过程是一个自发的吸热程。FTIR分析结果表明,DOS-NaOH上的官能团如胺基、羧基、羟基硅酸根等可能是Cu2+生物吸附的活性结合位点。EDS分析表明DOS-NaOH在吸附前几乎不含铜元素,而吸附后铜质量分数达12.20%。研究表明,DOS-NaOH是一种廉价高效的生物吸附剂,可用于去除废水中的Cu2+。The paper is aimed at presenting an experimental analysis of the characteristic features of the de-oiled soybean modified by NaOH （DOS- NaOH） as an effective biosorbent for removing Cu^2＋ cations from aqueous solution. For the said research goal, we have conducted batch biosorptive experiments to test the effects of the biosorbent dosage, the pH value of the solution, the initial Cu^2＋ con- centration and temperature on the features of the biosorbent. The ex- perimental results indicate that the pH value has a noticeable effect on the features of the biosorbent and the optimal pH value should be set on 5.0. The biosorption feature has been found enhanced with the in- crease of initial Cuz ＋ concentration, but reduced with the increase of its dosage. We have also found that the biosorption of Cu^2＋ onto DOS - NaOH relies to ,a slight extent on the temperature. That is to say, it is possible for Cu2 ＋ with the help of DOS - NaOH to gain its re- moval capacity at a normal temperature, which should be regarded as the result of our detailed analysis from the point of view of biosorptive mechanism, as well as that of isotherm, kinetics and thermodynam- ics. Langmuir isotherm should be said more fit for describing the biosorptive equilibrium state within the total concentration range than simply Freundlich isotherm on the condition when Q0 is equal to 112.36 mg/g at 20 ℃ . Kinetically speaking, the experimental data we have gained can better be explained v/a the pseudo-second-order model for the dominant absorption belongs to chemisorptive nature. In addition, the intra-particle diffusion and boundary layer diffusion can both influence the biosorptive efficiency. To understand the mechani- cal behavior of Cu^2＋ removing process, we have also tried to use BET, FTIR, SEM and EDS to characterize the process of DOS - NaOH pro- and post-biosorption, indicating that FTIR pro- and post Cu^2＋ binding tends to be active when the functional groups, such as amine, carboxyl, hydroxyl, silicate and either, all ac

关 键 词：环境工程学 生物吸附 黄豆粕 CU^2+ 等温线 动力学 

分 类 号：X703.1[环境科学与工程—环境工程]