绿地系统处理屋面雨水中污染物的性能研究
刘 茵1,张 龙2,张 琪3,李 洋2,王旭冕4,张建锋4

(1.西安建筑科技大学设计研究总院,陕西 西安 710055; 2.西安建筑科技大学 总务处,陕西 西安 710055; 3.济南市市政工程设计研究院(集团)有限责任公司 青岛分院,山东 青岛 266000; 4.西安建筑科技大学 环境与市政工程学院,陕西 西安 710055)

绿地系统; 混凝; 初期雨水径流; 污染物

Performance evaluation of urban lawn system in controling the pollutants in roof runoffs
LIU Yin1,ZHANG Long2,ZHANG Qi3, LI Yang2, WANG Xumian4, ZHANG Jianfeng4

(1.Architectural Design and Research Institute, Xi'an Univ. of Arch. & Tech., Xi'an 710055, China; 2.General Affairs Office, Xi'an Univ. of Arch. & Tech., Xi'an 710055, China; 3.Jinan Municipal Engineering Design & Research Institute(Group)Co.,Ltd., Jinan 266000, China; 4.School of Environment and Municipal Engineering, Xi'an Univ. of Arch. & Tech., Xi'an 710055, China)

urban lawn system; coagulation; first-flush runoff; pollutants

DOI: 10.15986/j.1006-7930.2021.01.018

备注

开展屋面初期雨水径流污染消减是构建城镇社区中低影响开发雨水系统的重要内容之一,通过强化绿地系统的污染物截留效率,可以实现对屋面降雨初期高污染负荷的原位控制.本文在搭建的绿地实验装置中,研究了绿地中流程、坡度和植草密度等因素对雨水径流中污染物的去除效果,结果表明:最佳条件下,绿地系统对NH3-N、TP、SS、TN、COD的去除率分别为54%～62%、71%～74%、90%～95%、34%～51%和54%～73%; 植草和绿肥可以降低土壤中的交换态Al3+的含量,从而降低向径流雨水中投加铝系混凝剂对植物及土壤带来的潜在毒害.本文提出的强化绿地系统对屋面初期雨水具有较好的净化效果,可为目前城市中低影响雨水系统的构建提供参考.
Great attention has been paid to the reduction of large quantities of pollutants in first-flush runoff during the practices of a low-impact development(LID)stormwater management in urban communities. Through enhancing of the pollutant removal efficiency by a urban lawn system, the in-situ control of the high load of the pollutants in first-flush runoff during the initial rainfall on the roof was expected to be feasible. In the current research, an experimental device of green lawn was established to investigate the removal performance of some main pollutants in the rainwater runoff.The various key influencing factors including the runoff flow distance, slope and grass density in the lawn were investigated.Results indicated that under the optimal experimental conditions, the removal efficiencies of NH3-N, SS, total nitrogen(TN), total phosphorus(TP)and CODcr were 37.1%～60.0%, 49.6%～67.6%, 37.7%～44.6%, 34.3%～46.4% and 36.2%～47.9%, respectively. The treatments of grass planting and green manure could reduce the exchangeable Al contents in the soil by the intruding of aluminum-based coagulants in runoff rainwater, resulting in the reduction of the potential toxicity of Al to ecosystem. Herein, the strengthened lawn system demonstrated a satisfactory purification effect on the first-flush runoff on the roof, thus the proposed technique could provide a helpful strategy for the practices of LID rainwater systems in the urban residential communities.