| 人工湿地氮转化与氧关系研究 |
| 摘要点击 2332 全文点击 1501 投稿时间：2005-05-06 修订日期：2005-06-21 |
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| 中文关键词 人工湿地 硝化 反硝化 硝化需氧量 |
| 英文关键词 constructed wetlands nitrification denitrification nitrogen oxygen demand |
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| 中文摘要 |
| 应用N转化迁移模型分析廊道式人工湿地氮转化与氧供应的关系,验证目前湿地全程硝化反硝化脱氮机制的有效性.对各个廊道进出水NH4+-N、NO3--N、TN、B5、DO进行了测定和分析.在水力负荷5cm/d条件下,各廊道湿地有机氮矿化率为0.01～0.28g·(m2·d)-1、氨氮硝化率0.50～1.54 g·(m2·d)-1,反硝化率0.41～1.13 g·(m2·d)-1(占总氮损失的3.4%～35.4%)、植物净吸收氮0.07～0.26 g·(m2·d)-1(占总氮损失的7%～33%).硝化反硝化与有机质降解同时进行,在进水端最明显,这与传统认识相悖.按照全程硝化化学计量学得到的硝化需氧量(NOD)高于实际的表面复氧和植物根系放氧.最后对在高浓度有机质存在条件下,能减少对氧需求的2种新型脱氮机制进行了讨论. |
| 英文摘要 |
| A simplified model of sequential N transformations and sink was applied to investigate the relationship between the nitrogen removal and oxygen demand to verify the validity of full nitrification-denitrification mechanism in a newly-built multi-stages constructed wetlands.Average net rates of N mineralization ranged from 0.01 to 0.28 g·(m2·d)-1,nitrification from 0.50 to 1.54 g·(m2·d)-1,denitrification from 0.41 to 1.13 g·(m2·d)-1(3.4%～35.4% of measured N removal in different stage) and plant assimilation from 0.07 to 0.26 g·(m2·d)-1 in the five tanks.Nitrification and denitrification occurred concurrently with BOD removal,even in the first stage receiving the higher-strength wastewater.Surprisingly,net areal nitrification rates,was correlated with BOD removal rates positively.Nitrification rates were also correlated linearly with average NH4+-N concentrations in the cascade tanks.The nitrogenous oxygen demand(NOD) required to support full nitrification of ammonia and mineralized Org-N in the wetland was in the upper range of that expected to be able to be supplied through surface and plant-mediated oxygen transfer.Some potential alternative nitrogen removal pathways with reduced overall oxygen requirements that have relevance to constructed wetlands were discussed. |
