摘要：

碳源不足已成为人工湿地脱氮受限的重要因素。植物材料因富含丰富的纤维素，且成本低廉、可再生，在自然环境中可广泛获取，具有作为外加碳源应用于人工湿地脱氮过程中的潜力。为研究添加植物碳源对人工湿地脱氮过程的影响，选取3种常见植物材料作为潜在碳源，探究其释放特性，并作为外加碳源，研究在不同条件下对人工湿地脱氮效果和N₂O的释放量的影响。研究结果表明：植物材料可以很好地释放有机碳，其累积释碳量为119.78~172.84 mg/g，添加植物碳源进行人工湿地试验，HRT为3 d、碳氮比为6、温度为30 ℃时，脱氮效率最高。其水解产物多为类腐殖酸化合物，TN去除率从24.5%~37%提升至64.1%~75.7%，但投加植物碳源可使N₂O释放量升高。植物材料作为外加碳源可以有效提高人工湿地的脱氮效率。

关键词: 外加碳源, 植物碳源, 反硝化, 人工湿地

Abstract:

Nitrogen removal in constructed wetland was mainly restricted by insufficient carbon source. Plant materials were utilized as external carbon sources in nitrogen removal of constructed wetland, considering its cellulose-rich, low-cost, renewable, widely available in natural environment. In order to research the effects of plant carbon sources on nitrogen removal process in constructed wetlands, three common plants were selected as potential carbon sources, explored the releasing characteristics. The effects on the nitrogen removal effect and N₂O release of constructed wetland under different conditions were investigated. The results showed that the plant materials could release organic carbon well with the cumulative carbon release of 119.78-172.84 mg/g. The highest nitrogen removal efficiency was achieved, when plant carbon source was added in construct wetlands with HRT of 3 d, carbon/nitrogen ratio of 6 and temperature of 30 ℃. In addition, the hydrolysate was mostly humic acid-like compounds, and TN removal rate increased from 24.5%-37% to 64.1%-75.7%. The release amount of N₂O increased by the addition of plant carbon source. Plant materials as external carbon source in constructed wetlands can effectively improve the nitrogen removal efficiency.

Key words: external carbon source, plant carbon source, denitrification, constructed wetlands

中图分类号: 

• X703