4种生物滞留填料对径流污染净化效果对比

为提高生物滞留系统净化效果,探讨了绿沸石、蛭石、活性炭、珍珠岩等材料用作特殊填料时对道路径流雨水中NH_4~+-N、TN、TP、COD等污染物的吸附性能。静态摇床实验研究了填料对各污染物的吸附能力,并建立了各填料等温吸附模型。结果表明沸石的综合吸附性能较好,活性炭次之,4种填料的等温吸附过程拟合结果基本符合朗格缪尔(Langmuir)吸附模型。以沸石作为特殊填料的小试结果表明,生物滞留系统对NH_4~+-N、TN、TP、COD的负荷削减率可分别达到70.59%、85.83%、79.98%、66.02%。从净化性能及经济性方面考虑,沸石作为生物滞留系统特殊填料是一种较好的选择。

Comparison of purification effects of 4 kinds of bioretention fillers on runoff pollutants

In order to improve the purification effect of bioretention systems, the adsorption properties of special fillers such as zeolite, vermiculite, activated carbon and perlite to the pollutants such as ammonia nitrogen, total nitrogen, total phosphorus, chemical oxygen demand in the road runoff of rainwater were studied. The adsorption capacity of fillers to various pollutants was studied by static shaking experiments, and the isothermal adsorption models of the fillers were established. The results showed that the comprehensive adsorption performance of the zeolite was better, followed by the activated carbon. The fitting results of isothermal adsorption process of the four fillers basically conform to Langmuir adsorption model. The bench-scale test results of zeolite as the special filler indicated that the load reduction rate of bioretention systems to ammonia nitrogen, total nitrogen, total phosphorus and chemical oxygen demand could reach 70. 59%, 85. 83%, 79. 98% and 66. 02%, respectively. Considering the purification performance and economy, zeolite can be selected as the special filler for bioretention system.