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利用芦苇湿地去除农业污水中的氮是博斯腾湖流域控制富营养化的重要手段.但是,污水中的盐分往往会抑制芦苇(Phragmites australis)湿地的除氮效果.为了探索不同盐度对芦苇湿地脱氮效果的影响和机制,研究4个不同的盐度梯度(淡水、2‰、5‰和10‰)对芦苇表流湿地中氮去除的影响,测定不同盐度下湿地表层(0~10.0 cm)和下层土壤(10.0~20.0 cm)中硝化、反硝化作用强度的变化.结果表明,盐度上升显著降低了湿地氮的去除率,但是不同离子形态的氮变化趋势并不一致.5‰和10‰盐度下的芦苇湿地中总氮、铵态氮去除率分别下降了9.03%、31.80%和23.10%、39.20%,亚硝态氮累积率分别上升了190%、690%,而硝态氮并未发生明显变化.相对于参与反硝化作用的菌群,盐度对参与硝化作用菌群的抑制作用更强是产生此现象的主要原因.除此之外,盐度升高导致植物根系泌氧减少也是土壤中的硝化作用强度降低的重要原因之一.
The use of reed wetland to remove nitrogen from agricultural wastewater is an important means of controlling eutrophication in the Bosten Lake basin.But the salinity in wastewater often inhibits the nitrogen removal efficiency of Phragmites australis wetlands.In order to explore the effects of different salinities on the denitrification of reed wetlands Effects of different salinity gradients (fresh water, 2 ‰, 5 ‰ and 10 ‰) on the removal of nitrogen from surface flow of reed wetland were studied, and the effects of different salinity gradients (0 ~ 10.0 cm) And the changes of nitrification and denitrification in the lower soil (10.0-20.0 cm). The results showed that the salinity increased the nitrogen removal efficiency significantly, but the trends of nitrogen change in different ion forms were not consistent.5 and 10 ‰ The removal rate of total nitrogen and ammonium nitrogen in reed wetlands decreased by 9.03%, 31.80% and 23.10%, 39.20% and 190% and 690% respectively in reed wetlands under salinity, while nitrate nitrogen No significant change occurred.Compared with the bacteria involved in denitrification, salinity had a stronger inhibitory effect on the nitrobacteria, which was the main reason for this phenomenon.In addition, The reduction is also nitrate in the soil One of the important reasons for the reduction of the intensity of action.