基于植物昼夜释氧变化规律的复合垂直流人工湿地氮形态

为了研究植物根系释氧规律对人工湿地中硝化与反硝化作用的影响,采用传统连续运行方式及根据释氧规律调节的新型运行方式(白天连续进水、夜间停水),在复合垂直流人工湿地小试系统中进行实验,采用代表性的挺水植物香蒲作为湿地植物,水力负荷为0.71 m3/(m2.d).结果表明:系统内白天以好氧的硝化作用为主,夜间以厌氧、缺氧的反硝化作用为主,且在新型运行方式下,系统内白天亚硝酸盐氮累积量为传统运行方式的5倍,硝酸盐氮累积量为其2倍,夜间亚硝酸盐氮和硝酸盐氮减少量又分别比传统运行方式高64%和26%.这说明在新型运行方式下,人工湿地脱氮效果优于传统运行方式.

Nitrogen forms in integrated vertical-flow on man-made wetland based on the diurnal fluctuations of oxygen release in cattail roots

In order to study the effects of plants' roots oxygen release on the nitrification and de-nitrification in man-made wetlands, we selected two operation modes,namely traditional continuous operation mode and new operation mode (a continuous feeding during the day and stop feeding during the night).The experiment was carried out in a small integrated vertical-flow man-made wetland system with a hydraulic loading rate of 0.71 m³/(m²·d),and the representative emergent plant cattail as the wetland plant was chosen.The results showed that the aerobic nitrification took place mainly during the day and the anaerobic-anoxic de-nitrification, during the night,in the system.In addition,the daytime nitrite accumulation was 5 times and nitrate accumulation was 2 times in new operation mode comparing to those in traditional mode,the decrements of nitrite and nitrate were 64% and 26% bigger, respectively,than in traditional mode.The new operation mode showed a better nitrogen removal effect.