School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Rd., Shanghai 200240, China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, No. 800 Dongchuan Rd., Shanghai 200240, China.
Sci Total Environ. 2019 Mar 15;656:503-511. doi: 10.1016/j.scitotenv.2018.11.358. Epub 2018 Nov 27.
Constructed wetlands (CWs) have emerged as a promising technology for the purification of micro-polluted water. However, their nitrogen removal performance can be significantly degraded by design, operational, and environmental factors. The present study investigates the effects of ofloxacin (OFL: 0.1, 10, and 1000 μg L) and plants (Cyperus alternifolius L. and Typha angustifolia L.) on nitrogen removal in a micro-polluted CW system over a duration of 12 weeks. The effects were evaluated by investigating NH-N and NO-N removal efficiency, nitrification genes (amoA-AOA and amoA-AOB), denitrification genes (nirK and nirS), fungal 18S rRNA gene and microorganism community structure. The results showed that in unplanted CWs, OFL increased the NH-N removal efficiency (from 72.6% to 80.7-82.1%), the abundances of amoA-AOA, nirS, nirK and fungal 18S rRNA gene, and the bacterial diversity but decreased the abundance of both amoA-AOB and bacterial richness. In contrast, both the nitrogen removal efficiency (83.4-89.5% for NH-N and 33.8-38.5% for NO-N) and bacterial diversity/richness were not significantly affected by OFL in planted CWs. In planted systems, OFL increased the relative abundance of Arthrobacter, Pseudomonas, and Enterococcus, which are proven antibiotic-resistant bacteria. This study showed that CWs are able to remove nitrogen from antibiotic-contaminated micro-polluted water, which might primarily be attributed to the presence of plants that protect the microorganism community.
人工湿地（CWs）已成为一种有前途的微污染水净化技术。然而，设计、操作和环境因素会显著降低其脱氮性能。本研究考察了在 12 周的时间内，氧氟沙星（OFL：0.1、10 和 1000μg/L）和植物（香蒲和芦苇）对微污染 CW 系统中氮去除的影响。通过考察 NH-N 和 NO-N 去除效率、硝化基因（amoA-AOA 和 amoA-AOB）、反硝化基因（nirK 和 nirS）、真菌 18S rRNA 基因和微生物群落结构来评估影响。结果表明，在未种植的 CWs 中，OFL 提高了 NH-N 去除效率（从 72.6%提高到 80.7-82.1%）、amoA-AOA、nirS、nirK 和真菌 18S rRNA 基因的丰度以及细菌多样性，但降低了 amoA-AOB 和细菌丰富度的丰度。相比之下，在种植的 CWs 中，OFL 对氮去除效率（NH-N 为 83.4-89.5%，NO-N 为 33.8-38.5%）和细菌多样性/丰富度没有显著影响。在种植系统中，OFL 增加了节杆菌、假单胞菌和肠球菌的相对丰度，这些都是已被证明具有抗生素抗性的细菌。本研究表明，CWs 能够从含有抗生素的微污染水中去除氮，这可能主要归因于植物的存在，植物保护了微生物群落。
