Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China; School of Environmental Science, Nanjing XiaoZhuang University, Nanjing, 211171, China.
Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, China.
Chemosphere. 2021 Mar;267:129324. doi: 10.1016/j.chemosphere.2020.129324. Epub 2020 Dec 15.
A highly efficient bioflocculant, i.e., Na-Bsp was successfully prepared by using a tolerant strain-Bacillus sp. under high-salt condition without sterilization. Salt-containing medium was not infected by other strains throughout the whole incubation period in 168 h. The as-prepared Na-Bsp was found to be cation-dependent, exhibiting high flocculant efficiency (FE) i.e., 97.69 ± 0.61%, towards kaolin particles by aid of Fe. High FE values were well maintained under a wide pH range and/or boiled water treatment, likely because of the main constituent of polysaccharide. The presence of hydroxyl, carboxyl, and amine groups on the bioflocculant surface were possibly responsible for strong interactions with heavy metals. The adsorption capacities of Pb, Cu and Cr were 1000.0, 434.8 and 384.6 mg g, respectively. The changing of structure and configuration of bioflocculant during the metal adsorption were explored by the scanning electron microscope with electron energy loss spectroscopy and three-dimensional excitation-emission fluorescence spectrometry. This study provided a novel production method, whereby the conventional sterilization could be avoided, which is of great environmental significance for steam-saving. Furthermore, the as-prepared Na-Bsp exhibited high adsorption capacities toward heavy metals, which sheds lights on its potential usage as an alternative adsorbent.
一种高效的生物絮凝剂，即 Na-Bsp，在高盐条件下成功地由耐盐菌株-芽孢杆菌制备而成，无需灭菌。在 168 小时的整个孵育过程中，含盐水介质没有被其他菌株感染。所制备的 Na-Bsp 被发现是阳离子依赖性的，通过 Fe 的辅助，对高岭土颗粒表现出高絮凝效率（FE），即 97.69±0.61%。高 FE 值在较宽的 pH 范围和/或沸水处理下得到很好的维持，可能是由于多糖的主要成分。生物絮凝剂表面上的羟基、羧基和胺基可能是其与重金属之间强相互作用的原因。通过扫描电子显微镜与电子能量损失光谱和三维激发-发射荧光光谱研究了重金属吸附过程中生物絮凝剂的结构和构象变化。本研究提供了一种新的生产方法，避免了传统的灭菌方法，这对于节约蒸汽具有重要的环境意义。此外，所制备的 Na-Bsp 对重金属表现出高吸附容量，这为其作为替代吸附剂的潜在用途提供了依据。
