Abdulmajeed Abdulmajeed Ali Tahreer, Gokoglan Hatice, Ozdogru Emine, Erdogan Mehmet Kaan, Yildirim Feyza Nur, Sahin Selmihan, Ozmen Ismail, Ulugol Huseyin, Sahin Oguzhan
Suleyman Demirel University, Institute of Science, Department of Chemistry, Cunur, Isparta, 32200, Turkiye.
Ankara University, Faculty of Engineering, Department of Civil Engineering, Golbasi, Ankara, 06830, Turkiye.
Environ Res. 2025 Jun 28;284:122255. doi: 10.1016/j.envres.2025.122255.
This study presents a novel approach to enzyme-induced precipitation of calcium carbonate (CaCO) using bovine carbonic anhydrase II (bCAII) purified from bovine erythrocytes, focusing on the effective use of a purified enzymatic system to facilitate controlled biomineralization. The enzyme was successfully purified with a recovery of 18% and a 516-fold purification, as confirmed by Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis. The effects of various parameters, including pH, temperature, and CaCl concentration, on bCAII-induced CaCO precipitation were examined. The results revealed that pH 8.0 was optimal for CaCO formation, and the highest precipitation occurred at a temperature of 22 °C. The crystalline phases of the precipitated CaCO were identified using X-ray diffraction (XRD) analysis. The results confirmed the presence of calcite, vaterite, and minor amounts of aragonite in the precipitate, with calcite being the dominant phase. Thermogravimetric (TG) analysis and Fourier-transform infrared spectroscopy (FTIR) further confirmed the presence of calcite and its stability in the bCAII-mediated precipitate. Furthermore, recycled concrete aggregate (RCA), both untreated and treated with bCAII, was exposed to carbonation in a CO chamber. The results showed a significantly higher formation of CaCO on the surface of the bCAII-treated RCA compared to the untreated RCA. This enhancement suggests that bCAII can effectively promote the carbonation process in RCA, potentially improving its performance and making it more suitable for reuse in concrete production. Overall, the study introduces an environmentally friendly and efficient biocatalytic method for mineralization, with promising implications for carbon sequestration and circular construction technologies.
本研究提出了一种利用从牛红细胞中纯化得到的牛碳酸酐酶II（bCAII）诱导碳酸钙（CaCO₃）沉淀的新方法，重点在于有效利用纯化的酶系统促进可控生物矿化。经十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）分析证实，该酶成功纯化，回收率为18%，纯化倍数为516倍。研究了包括pH值、温度和氯化钙浓度等各种参数对bCAII诱导CaCO₃沉淀的影响。结果表明，pH 8.0最有利于CaCO₃形成，最高沉淀量出现在22℃。使用X射线衍射（XRD）分析确定沉淀的CaCO₃的晶相。结果证实沉淀中存在方解石、球霰石和少量文石，其中方解石为主相。热重（TG）分析和傅里叶变换红外光谱（FTIR）进一步证实了方解石的存在及其在bCAII介导沉淀中的稳定性。此外，将未处理和经bCAII处理的再生混凝土骨料（RCA）置于CO₂室中进行碳酸化。结果表明，与未处理的RCA相比，经bCAII处理的RCA表面CaCO₃的形成量显著更高。这种增强表明bCAII可以有效促进RCA中的碳酸化过程，有可能改善其性能并使其更适合在混凝土生产中再利用。总体而言，该研究引入了一种环境友好且高效的生物催化矿化方法，对碳封存和循环建筑技术具有广阔的应用前景。
