以沸石、无烟煤、页岩、蛭石、砾石、陶瓷滤料、高炉钢渣、生物陶粒等8种基质为材料,在1 000—2 500 mm/d的高水力负荷条件下,研究了不同基质在垂直流人工湿地模拟柱中运行1年的水力学特性和系统堵塞动态。结果表明:基质系统的水力停留时间和水头损失可间接反映湿地堵塞状况;基质自身结构与其水力学特征密切相关。生物陶粒、高炉钢渣和沸石3种基质分别填充的系统内部水头损失较小、水力停留时间短、堵塞不明显;砾石、蛭石堵塞较为严重。通过对不同基质的含水率和孔隙率的分析发现,基质的高含水率(如蛭石)有利于垂直流人工湿地对污染物的去除,但却不利于湿地的运行管理;基质的高孔隙变化率(如页岩和砾石)是湿地系统发生堵塞的重要驱动因素。因此,如何根据不同结构特性和水力学特征选择基质对垂直流人工湿地的设计和运行管理非常关键。

Rsearch on Hydraulics Performance of Different Filter Media in Vertical Flow Constructed Wetlands Under High Hydraulic LoadingZHANG Xiang-ling1,WU Zhen-bin2,WU Jun-mei2,WANG Rong2,HE Feng2 (1.School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China;2.State Key Lab of Freshwater Ecology and Biotechnology,Institute of Hydrobiology,Chinese Academy of Science,Wuhan 430072,China)Several kinds of filter media were utilized in eight simulative vertical flow constructed wetland systems to research on hydraulics characteristic at hydraulic loading rate of 1 000—2 500 mm/d,including zeolite,anthracite,shale,vermiculite,gravel,ceramic filter media,blast furnace steel slag and bioceramsite.During one year's entire experimental cycle,the results showed that head loss and hydraulic retention time could indirectly reflect the extent of the wetlands clogging.The structural characteristics of each media could influence hydraulics characteristic.Little clogging were found in bio-ceramsite,zeolites and blast furnace steel slag systems,and head loss were least in the their systems.But in the gravel and vermiculite systems the problems were serious relatively.Through the experiments of porosity and water contents,we could found that the vermiculite media had better performance for removal of pollutants because of its good water-holding capacity and the degree of water capacity,but it was disadvantageous to the wetland's movement and management because of vermiculite media's bigger water content rate of change.And the shale and gravel media influenced clogging greatly because of big change for their porosity.So the choice of media base on special structural characteristics and hydraulics characteristic might be treated as the important target for the design and running for the vertical flow constructed wetland.vertical flow constructed wetlands;high hydraulic loading;clogging;filter media;hydraulics characteristic