纤维素固体碳源对雨-灰水双模式生物滞留系统除污性能的影响研究

生物滞留系统以工程级配介质土作为填料时,为满足脱氮要求需在介质土中额外添加固体碳源。以生物滞留系统处理阳台洗衣废水和降雨径流为研究对象,探讨了不同纤维素固体碳源(木屑、椰壳、玉米渣、稻壳、小麦秸秆)、不同添加量(0%、3%、5%、7%,质量比)对系统除污性能的影响。结果表明,所有纤维素碳源材料均可释放大量有机碳满足反硝化需求,其中木屑反硝化能力最强,NO_(3)~--N去除率高达95%。雨-灰水双模式下,外加碳源能有效提高生物滞留系统除氮能力,尤其是对于NO_(3)~--N的去除,但过多的碳源会造成出水NH_(4)~+-N的升高;外加碳源可显著提高系统除磷能力,且随添加量而增强;碳源的添加会导致出水COD浓度升高,出现有机物淋洗现象。综合考虑污染物控制目标,在淹没区介质土中添加3%木屑可满足雨-灰水双模式生物滞留系统处理老旧小区阳台洗衣废水和降雨径流对碳源的需求。

Sustainable water system of a green residential zone:demonstrated with a case of a campus construction project

The sustainable water system (SWS) was interpreted based on green residential zone associated codes issued by P.R.China and some other countries,and ecological principles.Its constitution,designing and engineering,and economic and environmental benefits were illustrated with a case of a campus construction project.The SWS incorporates divided nature drainage systems,grey water treatment and reuse technologies,rainwater decentralized collection and purification technologies,and water quality safeguard techniques for reclaimed water reused for landscaping.Application of the SWS is expected to gain remarkable economic and environmental benefits by reducing both the demand for municipal water supply and sewage discharge.