Mohammed Ahmed A, Najim Aya A, Al-Musawi Tariq J, Alwared Abeer I
Department of Environmental Engineering, College of Engineering, University of Baghdad, Baghdad, Iraq.
J Environ Health Sci Eng. 2019 Apr 2;17(2):529-538. doi: 10.1007/s40201-019-00367-w. eCollection 2019 Dec.
The present study provided a comprehensive description regarding the application of a mixture of three nonliving classes of algae as a promising and inexpensive biosorbent for removing toxic nickel (Ni(II)) ions from the aqueous medium.
The biosorption process was tested by varying several experimental parameters such as pH (2-8), contaminant concentration (20-300 mg/L), biosorbent content (0.2-2 g/100 mL), and temperature (20-40 °C). In addition, the competition effects of the presence of Pb(II), Cu(II), and Zn(II) ions on the Ni(II) removal efficiency was studied by varying their concentrations from 30 to 40 mg/L.
The microscopic analysis of algae demonstrated that the used biosorbent consisted mainly of Chrysophyta (80%), Chlorophyte (14%), and Cyanophyta (6%). Results demonstrated that these environmental parameters influenced the removal efficiency with a different degree and there was no stable effects rank at conditions under examination. FT-IR and SEM analysis revealed that the biosorbent surface consists of many strong and active groups of negative valences such as hydroxyl and carboxyl groups, thus exhibiting several morphological properties of interest. Further, it was found that the Temkin model best fitted the isotherm biosorption data. The kinetic study showed that the Ni(II) biosorption was rapid within first 20 min of reaction time, thereby following a pseudo-second-order model, which in turn demonstrated a chemisorption process of Ni(II) ions reaction with the biosorbent binding sites. Also, the thermodynamic study suggested that the biosorption process of Ni(II) onto algal biomass was a spontaneous and endothermic in nature. The maximum uptake of Ni(II) was 9.848 mg/g under optimized conditions and neutral environment.
Thus, this significant finding suggested a favorable and eco-friendly treatment mechanism for removal of Ni(II) ions from aqueous medium via biosorption onto the used mixture of nonliving algal biomass.
本研究全面描述了将三类非活性藻类的混合物作为一种有前景且廉价的生物吸附剂，用于从水介质中去除有毒镍（Ni(II)）离子的应用情况。
通过改变几个实验参数来测试生物吸附过程，如pH值（2 - 8）、污染物浓度（20 - 300 mg/L）、生物吸附剂含量（0.2 - 2 g/100 mL）和温度（20 - 40 °C）。此外，通过将Pb(II)、Cu(II)和Zn(II)离子的浓度从30变化到40 mg/L，研究了它们的存在对Ni(II)去除效率的竞争影响。
藻类的微观分析表明，所使用的生物吸附剂主要由金藻门（80%）、绿藻门（14%）和蓝藻门（6%）组成。结果表明，这些环境参数对去除效率有不同程度的影响，在所研究的条件下没有稳定的影响顺序。傅里叶变换红外光谱（FT - IR）和扫描电子显微镜（SEM）分析表明，生物吸附剂表面由许多强的和活性的负价基团组成，如羟基和羧基，因此呈现出一些有趣的形态学特性。此外，发现Temkin模型最适合等温生物吸附数据。动力学研究表明，Ni(II)的生物吸附在反应的前20分钟内迅速进行，遵循准二级模型，这反过来证明了Ni(II)离子与生物吸附剂结合位点反应的化学吸附过程。而且，热力学研究表明，Ni(II)在藻类生物质上的生物吸附过程本质上是自发的且吸热的。在优化条件和中性环境下，Ni(II)的最大吸附量为9.848 mg/g。
因此，这一重要发现表明了一种通过生物吸附到所用的非活性藻类生物质混合物上来从水介质中去除Ni(II)离子的良好且环保的处理机制。
