College of Earth Science and Engineering, College of Chemical and Biological Engineering, Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals, Shandong University of Science and Technology, 266590, Qingdao, China.
College of Earth Science and Engineering, College of Chemical and Biological Engineering, Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals, Shandong University of Science and Technology, 266590, Qingdao, China.
Chemosphere. 2022 Jul;298:134328. doi: 10.1016/j.chemosphere.2022.134328. Epub 2022 Mar 15.
Calcium ions in industrial wastewater needs to be removed to prevent the production of limescale, which can have negative consequences. Biomineralization has become the focus due to its lower costs than traditional methods of remediation. In this study, calcium ions were bio-precipitated under the action of free and immobilized Bacillus amyloliquefaciens DMS6 bacteria, and the calcium ion removal efficiency was also compared. The results show that it only needed 3 days to decrease the calcium ion concentration to an ideal level of 76-116 mg/L under the action of DMS6 bacteria immobilized by activated carbon fiber, with calcium ion removal ratios reaching 99%-95% by the 7 day. DMS6 bacteria immobilized by activated carbon fiber were superior to free bacteria and bacteria immobilized by sodium alginate in calcium ion removal. Calcium ions are biomineralized into calcite, Mg-rich calcite, aragonite and monohydrocalcite with abundant organic functional groups, 4 types of secondary protein structures, amino acids, phospholipids, negative stable carbon isotope δC values (-16.68‰ to-17.25‰) and negatively charged biomineral surface. Calcium ions were diffused into cells and took part in the intracellular biomineralization of monohydrocalcite, also facilitating calcium ion removal. The formation of intracellular monohydrocalcite has rarely been reported. This study demonstrates an economic and environmentally friendly method to remove calcium ions from industrial wastewater.
工业废水中的钙离子需要去除，以防止产生水垢，因为水垢可能会带来负面影响。由于生物矿化的成本低于传统的修复方法，因此它已成为研究的焦点。在本研究中，游离和固定化解淀粉芽孢杆菌 DMS6 细菌作用下对钙离子进行生物沉淀，并比较了钙离子的去除效率。结果表明，在碳纤维固定化 DMS6 细菌的作用下，仅需 3 天即可将钙离子浓度降低至 76-116mg/L 的理想水平，第 7 天钙离子去除率达到 99%-95%。与游离细菌和用海藻酸钠固定的细菌相比，碳纤维固定化的 DMS6 细菌在去除钙离子方面更具优势。钙离子被生物矿化成方解石、富含 Mg 的方解石、文石和一水碳酸钙，同时具有丰富的有机官能团、4 种二级蛋白质结构、氨基酸、磷脂、负稳定碳同位素 δC 值（-16.68‰至-17.25‰）和带负电荷的生物矿化表面。钙离子扩散到细胞内，并参与了一水碳酸钙的细胞内生物矿化，这也促进了钙离子的去除。细胞内一水碳酸钙的形成很少有报道。本研究为去除工业废水中的钙离子提供了一种经济且环保的方法。
