College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, South Puzhu Road, Nanjing, 211816, PR China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, No. 30, South Puzhu Road, Nanjing, 211816, PR China.
College of Food Science and Light Industry, Nanjing Tech University, No. 30, South Puzhu Road, Nanjing, 211816, PR China.
J Environ Manage. 2024 Feb 27;353:120199. doi: 10.1016/j.jenvman.2024.120199. Epub 2024 Feb 4.
Nanofibers were prepared by electrospinning a mixture of polycaprolactone and silica, and modified to improve the hydrophilicity and stability of the material and to degrade nitrogenous wastewater by adsorbing heterotrophic nitrifying aerobic denitrifying (Ochrobactrum anthropic). The immobilized bacteria showed highly efficient simultaneous nitrification-denitrification ability, which could convert nearly 90 % of the initial nitrogen into gaseous nitrogen under aerobic conditions, and the average TN removal rate reached 5.59 mg/L/h. The average ammonia oxidation rate of bacteria immobilized by modified nanofibers was 7.36 mg/L/h, compared with 6.3 mg/L/h for free bacteria and only 4.23 mg/L/h for unmodified nanofiber-immobilized bacteria. Kinetic studies showed that modified nanofiber-immobilized bacteria complied with first-order degradation kinetics, and the effects of extreme pH, temperature, and salinity on immobilized bacteria were significantly reduced, while the degradation rate of free bacteria produced larger fluctuations. In addition, the immobilized bacterial nanofibers were reused five times, and the degradation rate remained stable at more than 80 %. At the same time, the degradation rate can still reach 50 % after 6 months of storage at 4 °C. It also demonstrated good nitrogen removal in practical wastewater treatment.
纳米纤维通过静电纺丝聚己内酯和二氧化硅的混合物制备，并进行改性以提高材料的亲水性和稳定性，并通过吸附异养硝化好氧反硝化菌（Ochrobactrum anthropic）来降解含氮废水。固定化细菌表现出高效的同步硝化-反硝化能力，在好氧条件下几乎可以将初始氮的近 90%转化为气态氮，平均 TN 去除率达到 5.59 mg/L/h。与游离细菌的 6.3 mg/L/h 和未经改性的纳米纤维固定化细菌的 4.23 mg/L/h 相比，改性纳米纤维固定化细菌的平均氨氧化速率为 7.36 mg/L/h。动力学研究表明，改性纳米纤维固定化细菌符合一级降解动力学，极端 pH、温度和盐度对固定化细菌的影响显著降低，而游离细菌产生的降解率波动较大。此外，固定化细菌纳米纤维重复使用了五次，降解率仍稳定在 80%以上。同时，在 4°C 下储存 6 个月后，降解率仍可达到 50%。它还在实际废水处理中展示了良好的脱氮效果。
