Department of Chemical Engineering, College of Engineering, Qatar University, P.O. Box 2713, Doha, Qatar.
Sci Total Environ. 2020 Jun 10;720:137621. doi: 10.1016/j.scitotenv.2020.137621. Epub 2020 Feb 29.
Innovative iron-based nanoparticles were synthesized, characterized and tested for the first time for harvesting single and mixed algal culture from real wastewater. The tailor-made magnetic nanoparticles (MNPs; Fe-MNP-I and Fe-MNP-II) achieved a percentage algae harvesting efficiency (%AHE) higher than 95% using a concentration of MNPs (C) of 25 ± 0.3 (std. dev = 0.08) mg.L, mixing speed (M) of 120 ± 2 (std. dev = 0.10) rpm, short contact time (C) of 7 ± 0.1 (std. dev = 0.05) min and separation time (SP) of 3 ± 0.1 (std. dev = 0.09) min. The optimum operational conditions for harvesting of Chlorella vulgaris (C.v) were determined at (C = 40 ± 0.4 (std. dev = 0.5) g.L, SP = 2.5 ± 0.4 (std. dev = 0.1) min, M = 145 ± 3 (std. dev = 1.50) rpm and C = 5 ± 0.3 (std. dev = 0.10) min using surface response methodology. Langmuir model describes better the adsorption behavior of algae-Fe-MNP-I system, while both Langmuir and Freundlich fit well the adsorption behavior of algae-Fe-MNP-II. The maximum adsorption capacity of Spirulina platensis (SP.PL) (18.27 ± 0.07 (std. dev = 0.19) mg.mg) was higher than that for Chlorella vulgaris (C.v) (11.52 ± 0.01 (std. dev = 0.34) mg.mg) and mixed algal culture (M.X) (17.20 ± 0.07 (std. dev = 0.54) mg.mg) over Fe-MNP-I. Zeta potential measurements revealed that the adsorption mechanism between MNPs and algal strains is controlled by electrostatic interaction. The synthesized MNPs were recycled 10 times using alkaline-ultrasonic regeneration procedure.
创新性的铁基纳米粒子被首次合成、表征，并用于从实际废水中收获单一和混合藻类培养物。定制的磁性纳米粒子（MNPs；Fe-MNP-I 和 Fe-MNP-II）在 MNPs 浓度（C）为 25 ± 0.3（标准偏差= 0.08）mg/L、混合速度（M）为 120 ± 2（标准偏差= 0.10）rpm、短接触时间（C）为 7 ± 0.1（标准偏差= 0.05）min 和分离时间（SP）为 3 ± 0.1（标准偏差= 0.09）min 的情况下，实现了超过 95%的藻类收获效率（%AHE）。确定了从普通小球藻（C.v）中收获的最佳操作条件为（C=40 ± 0.4（标准偏差= 0.5）g/L、SP=2.5 ± 0.4（标准偏差= 0.1）min、M=145 ± 3（标准偏差= 1.50）rpm 和 C=5 ± 0.3（标准偏差= 0.10）min，使用表面响应方法。Langmuir 模型更好地描述了藻类-Fe-MNP-I 系统的吸附行为，而 Langmuir 和 Freundlich 模型均很好地拟合了藻类-Fe-MNP-II 的吸附行为。螺旋藻（SP.PL）（18.27 ± 0.07（标准偏差= 0.19）mg.mg）的最大吸附容量高于普通小球藻（C.v）（11.52 ± 0.01（标准偏差= 0.34）mg.mg）和混合藻类培养物（M.X）（17.20 ± 0.07（标准偏差= 0.54）mg.mg）在 Fe-MNP-I 上的吸附容量。Zeta 电位测量表明，MNPs 和藻类菌株之间的吸附机制受静电相互作用控制。通过碱性超声再生程序，合成的 MNPs 被回收了 10 次。
