利用人工湿地去除饮用水硝酸盐氮研究

文章采用砂砾与土壤层构建垂直流人工湿地栽培芦苇和水花生,通过在同种基质上栽种相同数目的芦苇和水花生,以高质量浓度硝酸盐氮的配水进行浇灌,研究了这2种净水植物对饮用水中硝酸盐氮的脱除效果,并考察了净水效果较好的水花生的种植密度对其人工湿地脱氮的影响。研究表明,在人工湿地系统中,脱氮主要靠植物吸收,同时也存在硝化-反硝化途径;水花生和芦苇均能将饮用水中的硝酸盐氮有效脱除,在15d内,当进水硝酸盐氮质量浓度为50mg/L时,硝酸盐氮的去除率分别为94.0%和83.9%,当进水硝酸盐氮质量浓度为100mg/L时,硝酸盐氮的去除率分别达到96.8%和88%;相同条件下水花生去除硝酸盐氮的效果比芦苇更好;增加湿地植物的种植密度可获得更好的脱氮效果。

Removal of nitrate-nitrogen for drinking water in constructed wetlands

Phragmites communis and Alternanthera philoxeroides were.planted in vertical-flow constructed wetland built with gravel and soil,respectively.Effect of nitrate-nitrogen removal of these two water-purified plants for drinking water was studied under the following circumstance:the two plants were planted in the same substrates with the same quantity,and the two kinds of constructed wetlands were irrigated by artificial water with high nitrate-nitrogen concentration,influence of planting density of better-purified Alternanthera philoxeroides on nitrate removal was studied as well.The results showed that:nitrate was mainly removed by the absorption of plants,and nitrification-denitrification also existed in the constructed wetland system;nitrate-nitrogen in drinking water can be removed availably in short time by the two plants within 15 d;nitrate-nitrogen removal rates reached 94.0% and 83.9% respectively when initial concentration was 50 mg/L,and 96.8% and 88% respectively when initial concentration was 100 mg/L within 15 d;Alternanthera philoxeroides was superior to Phragmites communis in nitrate-nitrogen removal under the same condition;better effect of denitrification by plants was obtained with the increased planting density.