不同类型人工湿地对洞庭湖水质净化效果研究

同等条件下开展了3种不同类型人工湿地（垂直流、潜流和表面流人工之地）对洞庭湖水质净化效果的研究。结果表明:（1）洞庭湖水体中NH₄⁺-N，TN，TP，高锰酸钾指数，BOD₅和COD_Cr的进水浓度与3种不同类型人工湿地出水浓度季节变化规律保持一致，冬季明显高于夏季，洞庭湖进水中NH₄⁺-N，TN，TP，高锰酸钾指数，BOD₅和COD_Cr浓度均高于3种不同类型人工湿地出水浓度，相同时期，3种不同类型人工湿地出水水质NH₄⁺-N，TN，TP，高锰酸钾指数、BOD₅和COD_Cr浓度基本表现为表面流 > 潜流 > 垂直流；（2）3种类型人工湿地对TN，TP，高锰酸钾指数、BOD₅和COD_Cr的去除率依次表现为垂直流 > 潜流 > 表面流，而对NH₄⁺-N的去除率依次表现为垂直流 > 表面流 > 潜流，其中以BOD₅的去除效果最好（去除率最高），但3种类型人工湿地对BOD₅的去除率差异均不显著（p > 0.05）；（3）3种类型人工湿地植物地上和地下生物量均表现为垂直流 > 潜流 > 表面流，差异均显著（p < 0.05），垂直流人工湿地植被N含量、P含量、N积累量和P积累量均显著高于潜流和表面流（p < 0.05）；（4）3种不同类型人工湿地植物的N，P积累量分别与生物量、N含量、P含量均呈显著的线性关系（p < 0.01），人工湿地植物生物量对N，P积累量的影响大于植物体内N，P含量的影响，可以通过生物量来评价人工湿地植物对N，P去除效果。

Research on Water Purification in Different Types of Constructed Wetlands in Dongting Lake

Three different constructed wetland types [the vertical flow wetland (VFW), subsurface flow wetland (SFW) and free surface wetland (FSW)] to treat Dongting Lake water and the removal efficiencies were compared. The results are as follows. (1) The inlet water concentrations of NH₄⁺-N, TN, TP, potassium permanganate index, BOD₅ and COD_Cr of Dongting Lake had the same seasonal change trend and were higher than three different constructed wetland types, which showed that these indicators in winter were higher than those in summer, and in the same time, the outlet water concentrations of NH₄⁺-N, TN, TP, potassium permanganate index, BOD₅ and COD_Cr of three different constructed wetland types showed the sequence: FSW > SFW > VFW. (2) The removal of TN, TP, potassium permanganate index, BOD₅ and COD_Cr of three different constructed wetland types showed the order: VFW > SFW > FSW, and the removal of NH₄⁺-N showed the order: VFW > FSW > SFW, among which the removal of BOD₅ was the best, but it had no significantly difference among the three different constructed wetland types (p > 0.05). (3) The above and underground biomass of three different constructed wetland plants showed the order: VFW > SFW > FSW, which had a significant difference among the three different constructed wetland types (p < 0.05), and the contents of N, P and N, P accumulation of VFW were higher than SFW and FSW. (4) The N, P accumulation had a significant linear correlation with the contents of N, P of three different constructed wetland plants with the higher correlation index, which indicated that the influence of constructed wetland plant biomass was greater than the contents of N, P in plants, so it could evaluate the removal efficiency of constructed wetland plant N, P based on the biomass.