Liu Qijie, Shao Ling, Liu Zhenzhong, Chen Yingwei, Dai Guangze, Ying Jialei
Taizhou Key Laboratory of Medical Devices and Advanced Materials, Research Institute of Zhejiang University-Taizhou, Taizhou, People's Republic of China.
Zhejiang Provincial Key Laboratory for Cutting Tools, Taizhou University, Taizhou, People's Republic of China.
Environ Technol. 2024 Jul;45(18):3600-3611. doi: 10.1080/09593330.2023.2220890. Epub 2023 Jun 14.
Carbon fibres (CF) are commonly used as carriers in biofilm-based wastewater treatment. The surface properties of the CF are herein modified using a combination of nitric acid oxidation and urea to optimise the carrier to immobilise bacterial cells. The capacity of the CF carriers to immobilise bacterial cells and activated sludge is evaluated using bacterial cell adhesion and sludge immobilisation tests. The total interaction energy profiles between the CF supports and bacterial cells were calculated according to the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to explain the mechanism by which these modifications enhance this immobilisation capacity. CF-U has a high capacity for immobilising bacterial cells and activated sludge (3.7 g-sludge/g-CF supports) owing to its low total interaction energy. Nitric acid oxidation reduced the diiodomethane contact angle of CF from 55.1° to 38.5°, which reduced the Lifshitz-van der Waals interaction energy, while urea modification further increased the zeta potential of CF from 12.8 mV to -0.7 mV, thereby reducing the electrostatic interaction energy. Experiments and DLVO theory both determined that a combination of nitric acid oxidation and urea modification significantly enhanced the ability of CF to immobilise microorganisms.
碳纤维（CF）通常用作基于生物膜的废水处理中的载体。本文采用硝酸氧化和尿素相结合的方法对CF的表面性质进行改性，以优化载体来固定细菌细胞。通过细菌细胞粘附和污泥固定试验评估CF载体固定细菌细胞和活性污泥的能力。根据德亚金-朗道-韦弗-奥弗贝克（DLVO）理论计算CF载体与细菌细胞之间的总相互作用能曲线，以解释这些改性增强这种固定能力的机制。由于其总相互作用能较低，CF-U具有较高的固定细菌细胞和活性污泥的能力（3.7克污泥/克CF载体）。硝酸氧化使CF的二碘甲烷接触角从55.1°降至38.5°，降低了 Lifshitz-范德华相互作用能，而尿素改性使CF的zeta电位从12.8 mV进一步提高到-0.7 mV，从而降低了静电相互作用能。实验和DLVO理论均表明，硝酸氧化和尿素改性相结合显著增强了CF固定微生物的能力。
