模拟垂直潜流人工湿地中植物种类和植物多样性对脱氮效果的影响

The effects of plant species and plant diversity on nitrogen removal in simulated vertical sub-surface flow constructed wetlands

在模拟垂直潜流人工湿地中选种了水烛和菩提子两种常见湿地植物,以氨氮为湿地唯一氮源,通过植物单种和混种研究了植物种类和植物多样性对湿地脱氮效果的影响。结果表明,菩提子单种时,出水氮浓度均明显低于水烛单种。菩提子单种时,出水硝态氮、氨氮、总无机氮(TIN)质量浓度分别为72.34、13.80、86.14mg/L;水烛单种时,出水硝态氮、氨氮、TIN质量浓度分别为235.41、32.12、267.53mg/L。水烛与菩提子混种时,出水比菩提子或水烛单种具有更低的硝态氮和TIN,硝态氮和TIN质量浓度分别为55.60、80.50mg/L。因此,相比水烛,菩提子更有利于湿地脱氮;加强植物多样性可提高湿地的脱氮效果。湿地的脱氮效果与植物生物量具有显著相关性。

The effects of plant species and plant diversity on nitrogen removal in simulated vertical sub-surface flow constructed wetlands were studied by monoculture of Typha angustifolia or Coix lacryma-jobi and mixed planting of Typha angustifolia and Coix lacryrna-jobi. Meanwhile,ammonia nitrogen was used as the sole nitrogen source. Results showed that monoculture of Coix lacryma-jobi had lower nitrogen concentrations in effluent than monoculture of Typha angustifolia. Concentrations of nitrate nitrogen, ammonia nitrogen and total inorganic nitrogen （TIN） were 72.34,13.80 and 86.14 mg/L, respectively, under monoculture of Coix lacryma-jobi, while those were 235.41,32.12 and 267.53 mg/L,respectively,under monoculture of Typha angustifolia. Lower concentrations of ni- trate nitrogen and TIN,55.60 and 80.50 mg/L, respectively, were found in effluent under mixed planting of Typha angustifolia and Coix lacryrna-jobi than monoculture of Typha angustifolia or Coix lacryma-jobi. Coix lacryrna- jobi was more beneficial to nitrogen removal than Typha angustifolia and strengthening plant diversity might improve nitrogen removal. In addition,nitrogen removal and plant biomass were significantly correlated.