人工湿地中可溶性有机物对多环芳烃生物耦合去除的影响机制及调控研究

Polycyclic aromatic hydrocarbons (PAHs) is a kind of persistent organic pollutants that can affect the reuse of tail water. PAHs can be removed by constructed wetlands, and in wetlands systems dissolved organic matter (DOM) is the key substance affecting the migration and removal of PAHs. DOM is active in nature and rich in functional groups, which can couple the wetland substrate, plants and microorganisms to participate in or influence the removal process of PAHs. However, the specific influencing mechanism is still unclear. By studying the combination process and interaction between DOM and PAHs, the influence mechanism of DOM on PAHs adsorption and desorption in wetlands substrate will be concluded. By analyzing the distribution of PAHs in tissues of wetland plant, the influence mechanism of DOM on PAHs input, transportation and migration behavior within plants will be revealed. And the influence on key metabolic pathways of PAHs will be studied by software simulation. By determining the changes in quantity, activity and community structure of functional microorganisms for PAHs degradation, the biological coupling mechanism of PAHs removal under the influence of DOM in constructed wetland will be summarize. Finally, regulation will be proposed based on key steps of the coupling process, so as to improve PAHs removal in constructed wetlands. The proposed project will provide theoretical foundation for revealing the influence of DOM on geochemical behavior of PAHs, controlling pollution risk of PAHs and promoting further application of constructed wetlands.

多环芳烃（PAHs）是一类能够影响尾水再生及回用的持久性有机污染物。PAHs可通过人工湿地系统去除，湿地中可溶性有机物（DOM）是影响PAHs迁移代谢的关键物质。DOM性质活跃官能团丰富，能够耦合湿地基质、植物和微生物参与和影响PAHs的去除过程，但影响机制目前尚不清晰。本项目通过研究DOM与PAHs的结合过程及相互作用，掌握DOM对基质中PAHs吸附-解吸的影响机制；追踪湿地植物组织器官中PAHs的累积分布情况，掌握DOM对PAHs在植物体内的输入传输模式和迁移行为的影响机制；模拟PAHs关键代谢途径，分析PAHs降解功能菌数量活性及群落结构的变化规律，揭示DOM影响下PAHs去除的生物耦合作用机制；针对耦合过程关键步骤进行调控，实现人工湿地系统对尾水PAHs处理效果的强化。项目为揭示DOM对PAHs地球化学行为的影响、控制PAHs水体污染风险、促进人工湿地技术的进一步推广应用奠定基础。

本项目基于可溶性有机物（DOM）在有机污染物迁移代谢和水体环境功能发挥中的关键作用，开展了DOM对人工湿地系统污水深度处理过程PAHs去除的影响机制及调控的研究工作。通过项目的开展，分析了不同种类湿地植物DOM特征，掌握了湿地植物种类、状态等在DOM浸出过程中的影响规律，通过光谱学技术明确了植物源DOM和PAHs的结合模式，且类腐殖酸组分在DOM与PAHs的相互作用中起着更关键的作用。通过荧光区域积分，发现了不同环数PAHs的优先结合DOM组分存在差异，环境条件改变时，两者之间的相互作用强度也随之改变，其中偏酸性条件和高溶解氧态易于DOM与PAHs相互作用。明确了人工湿地系统中外加植物源DOM对PAHs去除的强化作用，研究明确了不同种类DOM对基质中PAHs吸附-解吸的影响规律，DOM投加可促进PAHs从基质向水相中的解吸和迁移，显著提高PAHs在基质表面的生物有效性，利于植物的吸收和微生物的代谢，通过物料平衡核算，DOM投加使通过植物吸收作用和微生物代谢等去除的PAHs分别提高1%-5%和6%-23%。DOM还能促进PAHs在植物根-茎-叶间的转运过程，有利于通过收割地上部分植物去除湿地系统PAHs。通过蛋白质组学分析掌握了DOM对PAHs生物代谢通路的影响，为人工湿地技术在尾水PAHs优化去除的应用提供理论依据，也为湿地植物资源化利用提供了技术支持。