雨前干旱期对生物滞留系统氮素去除的影响  

Effect of Antecedent Dry Periods on the Nitrogen Removal in Bioretention Systems

作　　者：黎雪然 王凡 秦华鹏 曾祥飞 LI Xueran;WANG Fan;QIN Huapeng;ZENG Xiangfei(Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Shenzhen Graduate School of Peking University, Shenzhen 518055, China)

机构地区：[1]北京大学深圳研究生院环境与能源学院城市人居环境科学与技术重点实验室,广东深圳518055

出　　处：《环境科学与技术》2018年第3期118-123,140,共7页Environmental Science & Technology

基　　金：国家自然科学基金青年基金(41603073);深圳市科技计划项目(JCYJ20150518092928547)

摘　　要：生物滞留系统是海绵城市建设中控制径流污染的主要设施之一,但生物滞留系统对氮素的去除效果不稳定并受雨前干旱期(antecedent dry period,ADP)影响较大。该研究通过设计带有淹没层的生物滞留体系,设置一定强度的人工模拟地表径流和不同雨前干旱期(1、3、5和10 d),研究短期ADP对各种形态氮素去除率的影响,并根据出流过程中水质的变化规律,分析影响的机理。结果表明:生物滞留系统对氨氮的去除较为稳定,受ADP的影响不显著;硝氮的去除率波动较大,范围为37%~78%,ADP越长其去除率越高;有机氮的去除率随ADP的增大而减小;不同ADP条件下总氮的去除率没有显著差异。不同ADP条件下各种氮素去除率变化的主要原因是ADP的长度会影响生物滞留体系的种植土层和淹没层中硝化、吸收、矿化和反硝化等氮转化作用的进行程度,进而影响不同形态氮的综合去除能力。Bioretention is one of the main facilities to control urban runoff pollution during the construction of the sponge city, but its nitrogen removal performance is not stable and can be affected by the length of the antecedent drying period（ADP）. This study was designed to investigate the effects of different lengths of ADPs（1, 3, 5 and 10 days） on nitrogen removal efficiencies using a series of mesocosm bioretention systems with a submerged zone under artificial simulation stormwater runoff experiments, and the influence mechanism was further investigated by examining the outflow nitrogen concentration variations over the whole flow course. Results showed that the ammonium removal efficiency was relatively stable, not significantly affected by ADP; nitrate removal efficiency varied from 37%~78%, and the efficiency increased as the length of ADP increased; the organic nitrogen removal efficiency decreased with the increasing length of ADP; there was no significant difference in the total nitrogen removal efficiency between systems with different ADPs. Different nitrogen removal efficiencies under different settings of ADPs could mainly be due to that different ADPs can influence the nitrogen transformation processes such as nitrification, absorption, mineralization and denitrification in both the planting soil layer and submerged zone to different extents, and thus the removal of multiple nitrogen species.

关 键 词：生物滞留系统 氮去除 雨前干旱期 海绵城市 

分 类 号：X703[环境科学与工程—环境工程]