无植物生物滞留池连续运行处理污水的渗流特性实验

为探究连续运行条件下生物滞留系统处理污水时的渗流特性,通过对不同水力负荷条件下系统渗透系数及孔隙率变化的监测考察其性能。结果显示:同一水力负荷下,随着运行时间推进,标准渗透系数K₂₀呈先降低再升高最后达到稳定阶段(15 d左右)的变化趋势,而且水力负荷越大对相对渗透系数的影响越大,二者关系达到显著负相关水平(P<0.01)。在低水力负荷<1.0 m3/(m2·d)]条件下,渗透系数与孔隙率呈正相关,在较高水力负荷>2.0 m3/(m2·d)]条件下,渗透系数与孔隙率无显著相关性。在连续运行过程中,生物滞留系统处理污水时水力负荷应控制在2.0 m3/(m2·d)以内,且水力负荷为1.0 m3/(m2·d)时系统性能最佳。该研究成果可为有效预防生物滞留系统填料堵塞提供理论参考和借鉴。

PERMEABILITY CHARACTERISTICS TEST ON WASTEWATER IN UNPLANTED BIORETENTION CELL UNDER CONTINUOUS OPERATION

To explore the permeability of the bioretention cell during sewage treatment under continuous operation, the system performance was investigated by monitoring the changes of the permeability coefficient and porosity under different hydraulic load conditions. The results showed that under the same hydraulic load, the standard permeability coefficient, K₂₀ showed a trend of first decreasing, then increasing, and finally reaching a stable stage(on about the 15 th day). The greater the hydraulic load, the greater its impact on the relative permeability coefficient. The relationship between two parameters reached a significant negative correlation level(P<0.01). Under the condition of low hydraulic load less than 1.0 m3/(m2·d)], the permeability coefficient was positively correlated with porosity. Under the condition of higher hydraulic load more than 2.0 m3/(m2·d)], the permeability coefficient and porosity had no significant correlation. The hydraulic load of the BRC should be controlled lower than 2.0 m3/(m2·d), when the sewage was processed under continuous operation, and the system performance was best when the hydraulic load was 1.0 m3/(m2·d). This study could provide theoretical guidance for effectively preventing BRC clogging.