基质是人工湿地达成脱氮效果的重要部位，该试验研究了底泥（对照）、底泥砾石复合（砾石）、底泥沸石复合（沸石）3种基质条件下上覆水体中NH ＋4 N、NO -2 N、NO -3 N和TN的去除效果，以及底泥耦合水体混合（混合）对脱氮效果的影响。结果表明底泥耦合混合时TN和NO -3 N去除率最高，12 d达到85％和91％；单纯底泥条件次之，为69％和73％；底泥沸石复合和底泥砾石复合时对TN和NO -3 N的去除效果较差，为56％和61％。就NH ＋4 N而言，虽然沸石对NH ＋4 N有较好的吸附效果，但未能完全将NH ＋4 N从系统中去除，当水体中NH ＋4 N浓度较低时还会不断解吸出来。NO -2 N作为中间产物，均先升高后降低，但混合条件下峰值较早出现，且去除速率也较快。%The matrix is an important part of constructed wetlands for denitrification in this experiment. The removal effect of overlying water on NH +4 N,NO -2 N,NO -3 N and TN under three kinds of substrates such as sediments (contrast),sediment-gravel compound (gravel),sediment-zeolite compound (zeolite),and the effect of water mixing on denitrification. The results show that under the condition of mixed-sediment compound,the removal rates of TN and NO -3 N are higher,after 12 d their values are 85% and 91%, respectively;then under the condition of sediment only,they are 69% and 73%,respectively;under the condition of sediment-zeolite compound or sediment-gravel compound,the removal rate of TN and NO -3 N is low,which are 56% and 61%,respectively. As far as NH +4 N,although the zeolite has good adsorption effect on NH +4 N,it can't be completely removed from system,and it will continue to release when NH +4 N concentration in overlying water is low. As an intermediate product,NO -2 N increases firstly and then decreases,but its peak appears earlier under the condition of mixing,and the removal rate is higher.
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