人工湿地中酸性药物原位生物降解行为机制及其耦合脱氮机理研究

The world widely used acid pharmaceutical compounds are raising concerned ecological and environmental risks. Previous study of this program indicated that constructed wetlands (CW) proved to be an efficient way for acid pharmaceutical (APs) removal, however, because of the “black-box effect”, the in-situ biodegradation mechanism and Biogeochemical behavior of APs was not clearly known. This study makes ibuprofen as main objective, and the main study in this program includes: (1) simulated constructed wetland system, by use of compound-specific stable isotope analysis, to evaluate the biodegradation routes and behavior; (2) simulated core systems, according to DNA stable isotope probing, high throughput sequencing as well as proteomics to distinguish the main function microorganisms, genes and enzyme involving in APs removal in terms of molecular mechanism (3) on basis of the second step, take microcosm experiments, to study the relationship of nitrifying and denitrifying organisms for APs removal. By studying the mechanisms of APs removal, it could provide theoretical advice for the application of constructed wetlands used for advanced nitrogen removal and APs degradation.

酸性药物(APs)在全球频繁大量使用造成生态环境负面效应日益凸显，利用人工湿地去除水中此类新型难降解有机物具有独特优势。然而，人工湿地“黑箱效应”使得准确描述APs在其内部的原位生物降解机制成为难点。因此，本研究拟以布洛芬为典型对象， (1)通过人工湿地模拟试验，结合单体同位素技术研究布洛芬在人工湿地中的消减规律、原位生物降解途径及行为；(2)通过模拟柱试验，结合稳定同位素核酸探针技术、高通量测序和蛋白组学等分子生物学技术，分析与识别参与布洛芬代谢/共代谢过程的功能微生物、功能基因和关键酶，从分子水平上揭示其降解机制；(3)在上述研究的基础上进一步通过微宇宙试验，研究布洛芬代谢与脱氮过程间的耦合关系；为揭示人工湿地对布洛芬生物降解机制、实现人工湿地同步脱氮除碳(APs)修复多重污染提供理论支撑。

酸性药物(APs)在全球频繁大量使用造成生态环境负面效应日益凸显，利用人工湿地去除水中此类新型难降解有机物具有独特优势。然而，人工湿地“黑箱效应”使得准确描述APs在其内部的原位生物降解机制成为难点。针对这一问题，本研究开展人工湿地中布洛芬消减规律、原位生物降解途径机理研究，揭示不同碳源条件下布洛芬降解分子机制，筛选最佳去除工艺，从而丰富和完善人工湿地降解酸性药物的理论和技术。主要结果如下：1）建立了五种酸性药物布洛芬（IBP）、萘普生（NPX）、吉非罗齐（GFB）、酮洛芬（KTP）、双氯芬酸（DCF）及其代谢物共12种目标物的液质检测方法；2）筛选VF-HF-SF组合人工湿地作为同步高效净化布洛芬、吉非罗齐和萘普生等复合污染水体的最佳组合工艺；3）水平潜流人工湿地中布洛芬主要代谢产物为2-OH-IBP，并产生少量的1-OH-IBP和COOH-IBP; 2-OH-IBP在湿地内的水平沿程分布呈现先增长后逐渐降低的趋势，布洛芬在进入湿地初期大量降解转化为羧基和羟基布洛芬，之后被继续降解为其他物质；4）布洛芬能够作为人工湿地中唯一碳源被微生物利用，外加碳源能够促进布洛芬的降解，其在湿地内部的降解即有共代谢也有生长代谢；布洛芬共代谢的功能微生物为变形菌门、放线菌门和厚壁菌门微生物；5）不同碳源和脱氮过程对酸性药物去除效果具有影响，人工湿地脱氮过程参与酸性药物的降解。