用于人工湿地的渗管跌水复氧技术研究

Study on Reoxygenation Technology of Seepage Pipe for Constructed Wetland

针对人工湿地的增氧需求,项目开发设计了渗管跌水设备进行布水的周期滴滤式人工湿地,研究了不同初始DO值、渗水速率、跌水高度对其复氧效果的影响。结果表明随着渗水速率降低、复氧量快速增加,渗管表面渗水形态由表面连续型向分散液滴型过渡、其氧传质系数由流态表面更新率主导型转变为暴露时间主导型。渗管布管密度为0. 05～0. 12 m/m^2即可满足湿地供氧要求,布管成本为0. 04～0. 10元/m^2,最佳渗水速率1. 5 L·min^(-1)·m^(-1)时,最大复氧量为6. 28 mg/L,渗管跌水的复氧动力效率最高可达4. 02 kgO_2/k W·h。

Aiming at the demand of reaeration in constructed wetlands,a new process was designed which was periodic-driping-filter-constructed-wetland(PDFCW)using the seepage-waterfall pipe as the reaeration equipment,and the effects of different initial dissolved oxygen values,seepage rate and waterfall height on its reaeration effect were studied.The results showed that with the decrease of seepage rate and the rapid increase of reaeration,the surface seepage pattern of seepage pipe was transitioned from surface continuous to dispersed droplet type,and its oxygen mass transferred coefficient changes from the dominant type of flow surface renewal rate to the dominant type of exposure time.The pipe density of the seepage pipe was 0.05-0.12m/m^2,met the requirements of wetland oxygen supply,the cost of the pipe was 0.04-0.10Y/m^2,the optimum seepage rate was 1.5L ·min^-1·m^-1,the maximum reaeration was 6.28 mg/L, The reaeration dynamic efficiency of seepage pipe waterfall can be up to 4.02kgO2/kW ·h.