垂直潜流人工湿地堵塞及其运行效果影响研究

在净化猪场沼液中开展了垂直潜流人工湿地堵塞过程及其运行效能变化的研究.结果表明,人工湿地堵塞的主要成因是由于填料层中不可滤过性物质的积累所致.不可滤过性物质是由有机物和无机物组成,且大部分不可滤过性物质的粒径均超过5.00 μm.填料层的孔隙率和水力传导系数均随系统运行时间的延长而减小,而填料层中被截留物质的含量则随系统运行时间的延长而增大,其空间变化特征均受到了系统中水力流态的影响;当系统HLR为0.02m3/(m2·d)时,VSSF在运行1380d后对猪场沼液的净化开始恶化,系统对COD、TSS、TN、NH4+-N和TP的去除率分别降至37.31%、57.82%、20.80%、32.13%和51.18%.

Clogging of vertical subsurface flow constructed wetland and its effects on purifying efficiency

The clogging of vertical subsurface flow constructed wetland (VSSF) and its effects on purifying efficiency were investigated during treating digested swine wastewater. The results suggest that accumulation of non-filterable material in substratum layer was the main cause resulting clogging in the VSSF, and the non-filterable material consists of both organic substances and inorganic substances, which sizes of the most part of granular non-filterable material were larger than 5.00 micrometers. Porosity and hydraulic conductivity of the substratum layer decreased, and the content of the non-filterable material in the substratum layer increased correspondingly with the operation of the VSSF. The spatial variation profiles of them alone the vertical direction depended on vertical flow state of the wastewater fed onto the substratum layer. As the hydraulic loading rate was kept at 0.02m3/(m2·d), the purification effect of the VSSF deteriorated after operations of 1380 days, which the removal efficiencies of COD, TSS, TN, ammonium nitrogen and TP declined to 37.31%, 57.82%, 20.80%, 32.13% and 51.18%, respectively.