垂直流人工湿地不同填料长期运行效果研究

在高水力负荷(2400~3400mm/d)条件下,以沸石、无烟煤、页岩、蛭石、陶瓷滤料、砾石、钢渣和生物陶粒为填料,进行垂直流人工湿地模拟柱净化污水实验(历时25个月).结果表明,随着系统的运行,各填料对COD的去除能力均有不同程度提高.沸石对污水中氮素的处理能力保持在较高的水平,对TN和NH4+-N的平均去除率分别高达82.03%和91.32%.钢渣对TP和可溶性反应磷(SRP)的平均去除率分别高达89.61%和96.77%,且净化效果稳定;无烟煤第2阶段对磷素的净化能力低于钢渣,之后与钢渣无显著性差异.在垂直流人工湿地中,针对水质特性选择长期高效的填料,如沸石、无烟煤和生物陶粒,在高水力负荷条件下可获得更好的处理效果.

Long term performance of pilot-scale vertical flow constructed wetland using different substrates

In order to investigate the long-term performance of pilot-scale vertical-flow constructed wetland(CW),different substrates,including zeolite,anthracite,shale,vermiculite,ceramic filter media,gravel,blast furnace steel slag and bio-ceramic were used.Colmnn experiments were carried out in a greenhouse,and their purification performance at a high hydraulic loading rate of 2400～3400 mm/d was assessed.The whole experiment lasted for 25 months.With the operation of the systems,COD removal rates by all the substrates increased gradually in varying degrees;nitrogen removal by zeolite maintained at a high and stable efficiency,among which the removal rates of total nitrogen(TN)and ammonia nitrogen (NH4+-N) were up to 82.03% and 91.32%,respectively.The removal rates of total phosphorus (TP) and soluble reactive phosphate (SRP) by steel slag reached 89.61% and 96.77%,respectively.Removal efficiency of phosphorus by anthracite was lower than that by steel slag during the second stage,whereas no significant differences between them during the following stages.Proper selection of long-term high-efficiency substrates(e.g.,zeolite,anthracite and bio-ceramic)based on the characteristic of wastewater was a-guarantee of better performance at a high hydraulic loading rate.