微动力曝气对复合垂直流人工湿地脱氮效果研究

为构建复合垂直流人工湿地,通过单因素、多因素正交实验法得到系统运行所需最佳运行条件,微动力曝气最佳运行条件为曝气位置为下行流湿地60 cm,曝气时间为3.5 h,曝气量为600 mL/min,曝气方式为连续曝气0.5 h,停机1.0 h。在最佳运行条件下,考察微动力曝气对系统内DO、pH值、COD、NH_4~+-N、TN浓度的影响,同时考察复合垂直流人工湿地系统的运行效果。结果表明:在最佳运行条件下,出水的DO质量浓度为7.89 mg/L,pH值为7.26,COD、NH_4~+-N和TN的去除率均达到了90%以上;NH_4~+-N出水浓度达到了地表水I类标准,TN出水浓度达到了地表水II类标准;湿地系统CW1对微污染水NH_4~+-N、TN和COD的去除率均明显高于空白对照组的湿地系统CW1和CW2。可见,通过微动力曝气,能明显增强复合垂直流人工湿地对微污染水源的脱氮效果,并且能极大地提高湿地系统内的COD、NH_4~+-N和TN去除率。

Study on the Denitrification Effect of Micro-Dynamic Aeration on Compound Vertical Flow Constructed Wetland

This paper aims to construct a composite vertical flow constructed wetland, with the optimal operation conditions for the system operation to be obtained by single factor and multi-factor orthogonal experiments. Under the optimal operation conditions (optimal operation condition of micro-dynamic aeration is that the aeration position is 60 cm down flow wetland, with 3.5 h the aeration time, 600 ml / min the aeration amount, the aeration mode being continuous aeration for 0.5 h and shutdown for 1.0 h.), an investigation has been made of the influence of the system on DO, pH, COD, NH4+-N, TN concentration in the system, as well as the operation effect of the composite vertical flow constructed wetland system. The results show that under the optimal operating conditions, the DO concentration of the effluent is 7.89 mg/L, the pH value 7.26, and the removal rates of COD, NH4+-N and TN reaching more than 90%. The effluent concentration of NH4+-N meets class I standard of the surface water, and the effluent concentration of TN meets class II standard of the surface water. The removal rates of NH4+-N, TN and COD in micro-polluted water by the wetland system CW1 are over 90%, significantly higher than that of the wetland system CW1 and CW2 in the blank control group. Through micro-dynamic aeration, the denitrification effect of compound vertical flow constructed wetlands on micro-polluted water sources can be significantly enhanced, with the removal rates of COD, NH4+-N and TN in the wetland system greatly improved.