磺胺类抗生素对人工湿地处理高氨氮养殖废水氨氧化作用的影响机制

Constructed wetland as an ecological treatment technology for treating livestock wastewater has attracted widespread attention in recent years. Due to serious pollution by antibiotics and ammonia nitrogen in livestock wastewater, it is significant to study the effects of sulfonamides antibiotics, a type of veterinary antibiotics, on the microbial ammonia oxidation in constructed wetlands. In this project, the constructed wetlands dealing with high-strength ammonia nitrogen of livestock wastewater are taken as the research object. The removal performance and main removal pathways of ammonia nitrogen and sulfonamides antibiotics from swine wastewater will be studied in a long-term field trial by monitoring the concentrations of different forms of nitrogen and sulfonamides antibiotics in the water and sediment samples of the constructed wetlands. The abundance, and microbial community structure of ammonia-oxidizing microorganisms will be investigated using the qPCR and high-throughput genetic sequencing techniques. Dynamic effects of functional gene abundance and microbial community structure evolution are affected by sulfonamides antibiotics comprising the treatment difference between with and without antibiotics. Combined with the seasonal variation of nitrogen and sulfonamides antibiotics removal and major environmental factors in the constructed wetlands, the mechanisms of influence of veterinary antibiotics on ammonia oxidizing microorganisms will be explored. This project will provide a scientific basis for the development of constructed wetland technology to efficiently remove nitrogen and antibiotics from livestock and poultry wastewater.

近年来，利用人工湿地技术处理养殖废水引起了广泛关注。由于养殖废水中经常存在抗生素与高氨氮复合污染问题，开展常见的兽用抗生素—磺胺类抗生素对人工湿地中氨氮的微生物转化去除影响具有重要的意义。本项目以处理高氨氮养殖废水的人工湿地为研究对象，通过野外定位试验方法，定期监测人工湿地系统的水、底泥样中不同形态氮及磺胺类抗生素的含量，分析人工湿地对养殖废水中氨氮与磺胺类抗生素的去除效应；采用qPCR和高通量测序技术研究人工湿地中氨氧化功能微生物种群结构与功能多样性特征；对比连续添加和不添加抗生素的处理，解析磺胺类抗生素对氨氧化功能基因丰度及微生物群落结构演变的动态影响；结合人工湿地系统中氮和磺胺类抗生素污染及主要环境因素的季节性变化规律，探讨兽用抗生素对氨氧化微生物的影响机制，为研发养殖废水高效人工湿地处理工艺提供科学依据。

近年来，利用人工湿地技术处理养殖废水引起了广泛关注。由于养殖废水中经常存在抗生素与高氨氮复合污染问题，开展常见的兽用抗生素—磺胺类抗生素对人工湿地中氨氮的微生物转化去除影响具有重要的意义。本项目以处理高氨氮养殖废水的人工湿地为研究对象，通过模拟人工湿地试验结合qPCR和高通量测序技术，研究了抗生素对工湿地养殖废水中氨氮与磺胺类抗生素去除效应的影响，探讨了磺胺类抗生素对湿地微生物氨氧化的作用机制。主要研究结果如下：（1）人工湿地对磺胺类抗生素去处理率为79.81%~91.52%，且抗生素浓度越高，效果越显著，100 μg/L处理中，湿地对SM2和SD两种抗生素的去除效果无显著差异；而在2000 μg/L处理中，人工湿地对SM2去除率（91.52%）显著高于SD（80.15%）。（2）抗生素添加降低了湿地出水中氨氮去除效率，人工湿地对氨氮平均去除率依次为CK(80.69%)＞SM2-L(76.03%)＞SD-L (68.91%)＞SD-H(51.51%)、SM2-H (51.25%)，湿地出水中硝态氮浓度均随抗生素添加量增加而减少，高浓度抗生素处理组硝态氮浓度显著低于对照组（p <0.01），SM2-H和SD-H浓度平均值分别为1.14和0.99 mg/L，抗生素对湿地水体氮的转化影响与抗生素浓度呈正比。（3）室内模拟试验表明10 μg/L磺胺嘧啶和磺胺二甲嘧啶对水体中氮素浓度无显著影响，当浓度大于或等于100 μg/L 时，显著降低了水体各形态氮素的转化速率。（4）人工湿地底泥AOA的基因丰度显著高于AOB和 hzsB，说明湿地环境更适合于氨氧化古菌的生存，且磺胺类抗生素显著降低了底泥硝化功能基因丰度；高通量结果表明磺胺类抗生素添加改变底泥中微生物的群落组成，且随浓度增加，差异越明显。本研究结果为研发养殖废水高效人工湿地处理工艺提供科学依据和数据支撑。