Wang Yuechang, Zhuang Lin-Lan, Liu Shuang, Su Yuanjun, Hu Zhen, Zhang Jian, Wang Xiaoping, Cui Shaoming, Peng Gang, Xie Shuting
Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science & Engineering, Shandong University, Qingdao, China.
Beijing Further Tide Eco-Construction Co., Ltd, Beijing, China.
PeerJ. 2025 Jan 16;13:e18819. doi: 10.7717/peerj.18819. eCollection 2025.
Constructed wetland (CW) technology has attracted much attention due to its economical and environmentally friendly features. The low dissolved oxygen (DO) and low carbon/nitrogen (C/N) ratio in the wetland influent water affect the treatment performance of CW, resulting in a decrease in the removal efficiency of ammonia nitrogen (NH -N) and nitrate nitrogen (NO -N). In order to address this problem, this study optimized the pollutants removal performance of unsaturated vertical flow constructed wetland (UVFCW) by adding sustained-release carbon sources (corn cobs + polybutylene adipate terephthalate (PBAT)). The results showed that the sustained-release of carbon source increased the carbon source in UVFCW, thus increasing the abundance and activity of denitrifying microorganisms and enhancing the denitrification reaction, ultimately improving the removal of NO -N, with its removal efficiency reaching up to 95.50%. The placement method of sustained-release carbon source mainly affected the distribution of carbon source and DO in water body, thus influencing the relative abundance of microorganisms, finally affecting the removal of pollutants. Among them, the removal efficiency of total nitrogen (TN), NO -N, and total phosphorus (TP), and the relative abundance of denitrifying microorganisms in the CW (uniform placement of sustained-release carbon source) were significantly higher than those in the CW (centralized placement above) and CW (centralized placement below) ( < 0.05). The surface C:O (carbon:oxygen) ratio of sustained-release carbon source after water treatment showed a decreasing trend, and CW exhibited the greatest decrease in C:O ratio. In summary, CW achieved the highest utilization of the carbon source and produced the largest number of heterotrophic microorganisms. This study reveals that CW is a structural process for the efficient removal of nitrogen and phosphorus pollutants, and our findings provide theoretical basis and technical support for actual projects.
人工湿地（CW）技术因其经济和环境友好的特点而备受关注。湿地进水的低溶解氧（DO）和低碳氮比（C/N）影响了人工湿地的处理性能，导致氨氮（NH -N）和硝态氮（NO -N）的去除效率下降。为了解决这一问题，本研究通过添加缓释碳源（玉米芯+聚己二酸丁二醇酯（PBAT））优化了不饱和垂直流人工湿地（UVFCW）的污染物去除性能。结果表明，碳源的缓释增加了UVFCW中的碳源，从而增加了反硝化微生物的丰度和活性，增强了反硝化反应，最终提高了NO -N的去除率，其去除效率高达95.50%。缓释碳源的投放方式主要影响水体中碳源和DO的分布，进而影响微生物的相对丰度，最终影响污染物的去除。其中，人工湿地（缓释碳源均匀投放）中总氮（TN）、NO -N和总磷（TP）的去除效率以及反硝化微生物的相对丰度显著高于人工湿地（上方集中投放）和人工湿地（下方集中投放）（<0.05）。水处理后缓释碳源的表面C:O（碳:氧）比呈下降趋势，人工湿地的C:O比下降幅度最大。综上所述，人工湿地实现了碳源的最高利用率，并产生了最多的异养微生物。本研究表明，人工湿地是高效去除氮磷污染物的结构化过程，我们的研究结果为实际工程提供了理论依据和技术支持。
