南湖新闻网讯(通讯员 王攀攀)近日,我校工学院袁巧霞课题组研究人员在沼液中实现了抗生素的高效降解,解释了沼液理化特性与抗生素降解的相关性,为沼液中污染物的去除提供了理论依据和参考数据。
抗生素被广泛使用以预防和治疗动物疾病。然而,大量的抗生素在动物体内难以吸收消化而随粪尿排除体外,并在厌氧发酵后仍部分残留在沼液中。随着沼液在农田的广泛施用,残留的抗生素在土壤和水体中积累,对生态系统和人类健康构成潜在威胁。因此,从生态环境和人类健康的角度来看,去除沼液中的抗生素对沼液的安全利用至关重要。
基于此,研究人员利用光催化技术以TiO2为催化剂,探究了光催化降解沼液中抗生素的最佳工艺参数,并对不同预处理后的沼液中抗生素的降解进行了研究。结果表明,高压汞灯对沼液中抗生素的降解具有显著效果,降低沼液处理深度能有效提高抗生素的降解率。最佳工艺条件下,四环素类抗生素的平均降解率达到93.14%。絮凝预处理能有效降低沼液的色度、浊度和总固体含量,进而提高抗生素的降解率。
沼液中抗生素的迁移和转化途径主要包括三个阶段:沼液中有机物等对抗生素的吸附、催化剂对抗生素的吸附以及抗生素的光催化降解。通过对不同阶段下沼液理化性质与抗生素降解率进行相关性分析发现,沼液的pH与浊度对抗生素的吸附阶段影响较大,抗生素去除率与沼液浊度、色度等呈正相关。沼液的色度和pH对抗生素的光催化阶段影响较大,抗生素去除率与沼液色度、浊度等呈负相关。本研究为实际工程中沼液中抗生素的光催化降解提供了理论依据和参考数据。
审核人:袁巧霞
【英文摘要】
The high concentration of antibiotics in liquid digestate makes it unviable for use as fertilizer on farmland. This study designed a system for antibiotic degradation and applied the photocatalytic process to degrade tetracyclines in liquid digestate. The effects of different operational variables (e.g., radiation source, TiO2 concentration, photocatalytic time, temperature, and depth of Liquid digestate) on the removal of tetracyclines were analyzed and optimal operation conditions were obtained. The correlation between the physicochemical properties of liquid digestate and tetracyclines removal was also analyzed. The results indicate that a high pressure mercury lamp is effective for the photocatalysis of tetracyclines in liquid digestate. Tetracyclines removal increased with increasing TiO2 concentration, photocatalytic time, and decreasing liquid digestate depth. However, the temperature of liquid digestate had little effect on the removal of tetracyclines. Under the high pressure mercury lamp, the removal of tetracycline, oxytetracycline, and chlortetracycline reached 94.99%, 88.92%, and 95.52%, respectively, under the optimum conditions (TiO2 concentration of 1.0 g/L, liquid digestate depth of 20 mm, and photocatalytic time of 120 min). In addition, the tetracyclines concentration, pH, total solid, and chroma of liquid digestate all had significant effects on the photocatalytic process. Flocculation pretreatment can improve photocatalytic efficiency by reducing the chroma, pH, and TS of liquid digestate. Our findings show that photocatalysis is an effective method for removing antibiotics in liquid digestate and has the potential for application to pollutant removal. Furthermore, our results provide conditions for the popularization and application of apparatus for the degradation of antibiotics in liquid digestate.
论文链接:https://www.sciencedirect.com/science/article/pii/S1385894720344399?via%3Dihub