College of Environmental Science and Engineering, Hunan University and Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
School of Hydraulic Engineering, Changsha University of Science &Technology, Changsha 410114, PR China; Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province, Changsha 410114, PR China.
Chemosphere. 2019 Feb;217:843-850. doi: 10.1016/j.chemosphere.2018.11.073. Epub 2018 Nov 14.
Malachite green effluent with the Coexistence of Cd (П) was efficiently decolorized by kaolinite-laccase (Kaolin-Lac). Laccase from Trametes versicolor was immobilized onto the kaolinite through physical adsorption contact. The optimal conditions were 180 min of immobilization time and 0.8 mg/mL of enzyme solution. Kaolin-Lac could obtain a loading efficiency of 88.22%, a loading capacity of 12.25 mg/g, and the highest activity of 839.01 U/g. Moreover, the process of immobilization increased its pH stability and operational stability. Kaolin-Lac retained above 50% of the original activity and nearly 80% decolorization for MG after 5 cycles. In the presence of 3, 5-Dimethoxy-4-hydroxybenzaldehyde (SA), Kaolin-Lac could degrade over 98% of malachite green. The coexistence of Cd (П) was beneficial to the decolorization of malachite green by Kaolin-Lac. The structural and morphological features of kaolinite, Kaolin-Lac and Kaolin-Lac after degradation were determined by scanning electron microscopy-energy spectrum analysis (SEM-EDS) and Fourier transform infrared spectroscopy (FTIR). Cadmium appeared on the Kaolin-Lac after degradation. After immobilization and degradation, the surface groups on kaolinite were changed. Kaolin-Lac showed its more potential continuous employment than free laccase in practical malachite green dyes effluent mixed with Cd (П).
孔雀石绿废水与 Cd(П)共存时，高岭土-漆酶（Kaolin-Lac）能有效地进行脱色。从变色栓菌中提取的漆酶通过物理吸附接触固定在高岭土上。最佳条件为固定化时间 180min，酶溶液浓度为 0.8mg/mL。高岭土-漆酶的负载效率为 88.22%，负载量为 12.25mg/g，酶活最高可达 839.01U/g。此外，固定化过程提高了其 pH 稳定性和操作稳定性。经过 5 次循环后，高岭土-漆酶的剩余酶活仍保持在 50%以上，对 MG 的脱色率仍接近 80%。在 3,5-二甲氧基-4-羟基苯甲醛（SA）存在的情况下，高岭土-漆酶能降解超过 98%的孔雀石绿。Cd(П)的共存有利于高岭土-漆酶对孔雀石绿的脱色。通过扫描电子显微镜-能谱分析（SEM-EDS）和傅里叶变换红外光谱（FTIR）确定了高岭石、高岭土-漆酶和降解后高岭土-漆酶的结构和形貌特征。降解后高岭土-漆酶上出现了镉。固定化和降解后，高岭石表面的基团发生了变化。与游离漆酶相比，固定化漆酶在实际孔雀石绿染料废水与 Cd(П)混合的应用中具有更大的连续使用潜力。
