巢湖芦苇湿地去除硝酸盐污染的调查与分析

以巢湖野生芦苇湿地为研究对象,调查了芦苇湿地去除浅层地下水中硝酸盐氮的效果。在芦苇生长旺盛阶段(3—5月),在芦苇湿地钻孔,聚水,取样分析了水中三氮含量及水孔不同深度土壤中反硝化细菌的数量。结果表明:芦苇区浅层地下水中硝酸盐氮仅为0.2~0.8 mg/L,远低于湿地周围井水中硝酸盐氮质量浓度(大于20 mg/L),芦苇湿地能够去除浅层地下水中硝酸盐污染;反硝化细菌在土壤中的分布呈现明显的根际效应;野生芦苇湿地较强的生物脱氮作用与反硝化细菌分布有关,地下水中硝酸盐氮含量与反硝化细菌分布呈负相关。

Investigation and analysis of denitrification in natural reed wetland near Chaohu Lake

The natural reed wetland near Chaohu Lake was taken as the research target,and the denitrification efficiency of natural reed wetland in shallow groundwater was investigated. Through boring and gathering water in natural reed wetland, the concentration of three kinds of nitrogen (nitrate-N, nitrite-N and ammonia-N) and the quantities of denitrifying bacteria in the soil of different depths were sampled and analyzed in the bloom period (from March to May) of reeds. The results show that, the nitrate-N concentration in groundwater in the reed area was 0.2～0.8 mg/L and significantly lower than that in surrounding wells (more than 20 mg/L), and the reed wetland can remove nitrate pollution in shallow groundwater. The distribution of denitrifying bacteria showed obvious rhizosphere effect,and the higher biodenitrification in natural reed wetland was related to the distribution of denitrifying bacteria. There was a negative relationship between the nitrate-N concentration and the number of denitrifying bacteria in groundwater.