School of Resources, Environment and Materials, Guangxi University, Nanning, Guangxi, 53004, People's Republic of China.
School of Resources, Environment and Materials, Guangxi University, Nanning, Guangxi, 53004, People's Republic of China.
Chemosphere. 2021 Jul;275:130125. doi: 10.1016/j.chemosphere.2021.130125. Epub 2021 Feb 26.
Microalgal biofilm has been recognized as a cost-effective biorsorbent for heavy metal and a promising method for microalgae-water separation. In this study, living suspended Scenedesmus obliquus FACHB-12 (isolated from southern China) and its biofilm with different carriers were investigated to remove cadmium from aqueous solution. S. obliquus FACHB-12 biofilm with luffa sponge carrier showed highest cadmium removal efficiency at 92.7% compared to biofilm with K3 carrier (75.3%) and significantly higher than suspended S. obliquus FACHB-12 (61.8%) in 2 h experiment with initial Cd concentration at 3.0 mg/L at pH = 6.0 with 0.8 g/L of biomass under room temperature. S. obliquus FACHB-12 biofilm with K3 and luffa sponge carrier also demonstrated higher tolerance towards increased Cd concentration with highest biosorption efficiency at 85.1% and 90.35% respectively under 20 mg/L of Cd, while suspended S. obliquus FACHB-12 biosorption efficiency achieved 81.4% under 10 mg/L of Cd and started to decline over increased cadmium concentration. The adsorption kinetics for all experimental groups followed the pseudo-second-order adsorption model, with biosorption equilibrium favored in Langmuir isotherm. The maximum biosorption capacity estimated by Langmuir isotherm reached 133.14 mg/g biomass in S. obliquus FACHB-12 biofilm with luffa sponge carrier, followed by 78.76 mg/g with K3 carrier, and 60.03 mg/g with suspended S. obliquus FACHB-12. Results suggest an efficient, inexpensive microalgal biofilm with biological carrier system could enhance high cadmium removal for advanced wastewater treatment and provide a cost-effective method for microalgae harvesting process.
微藻生物膜已被公认为一种从水溶液中去除重金属的高效生物吸附剂，也是一种从水中分离微藻的很有前途的方法。在这项研究中，研究了来自中国南方的活悬浮斜生栅藻 FACHB-12 及其不同载体的生物膜，以去除水溶液中的镉。与 K3 载体（75.3%）相比，丝瓜络载体上的斜生栅藻 FACHB-12 生物膜在初始 Cd 浓度为 3.0mg/L、pH=6.0、生物量为 0.8g/L、室温下 2h 实验中对镉的去除效率最高，达到 92.7%，明显高于悬浮斜生栅藻 FACHB-12（61.8%）。K3 和丝瓜络载体上的斜生栅藻 FACHB-12 生物膜也表现出更高的耐受增加的 Cd 浓度的能力，在 20mg/L 的 Cd 下，最高生物吸附效率分别为 85.1%和 90.35%，而悬浮斜生栅藻 FACHB-12 的生物吸附效率在 10mg/L 的 Cd 下达到 81.4%，并随着 Cd 浓度的增加而开始下降。所有实验组的吸附动力学均遵循拟二级吸附模型，生物吸附平衡有利于朗缪尔等温线。在丝瓜络载体上的斜生栅藻 FACHB-12 生物膜中，通过 Langmuir 等温线估计的最大生物吸附容量达到 133.14mg/g 生物质，其次是 K3 载体上的 78.76mg/g 生物质和悬浮斜生栅藻 FACHB-12 上的 60.03mg/g 生物质。结果表明，具有生物载体系统的高效、廉价的微藻生物膜可以增强对高浓度镉的去除，为高级废水处理提供了一种经济有效的微藻收获方法。
