南方红壤区雨水花园设计优化及应用研究

发布时间：2018-10-11 09:57

【摘要】：雨水花园是海绵城市中解决径流带来的面源污染及水文问题的可靠设施,但引入我国的时间较短,因地制宜的设计和应用还未充分展开。针对南方红壤区降雨量多、土壤渗透性低的地域特点,从填料配比、植物优选及IWS(Internal Water Storage)设置方面对雨水花园进行设计优化,并探讨其水质净化效果。结合工程实际应用案例,探讨雨水花园的设计及运行情况,并分析其水质净化及水文调控效果,为低影响开发设施的推广及海绵城市的建设提供参考。主要结论如下:(1)沸石、煤渣、砂子、膨胀蛭石、陶粒和红壤等雨水花园填料的NH_(3-)N和P等温吸附实验表明,红壤的NH_(3-)N理论饱和吸附量仅次于膨胀蛭石,为2500mg/kg,沸石的P理论饱和吸附量最高,为2272.73mg/kg,沸石适宜添加在红壤中以提高其N/P吸附效果及渗透系数。综合考量植物生长、径流渗透及堵塞问题,宜在红壤中掺入65%以上的砂子或55%以上的沸石,同时搭配10%的堆肥以配置雨水花园填料层。(2)柳叶马鞭草、菖蒲、鸢尾和美人蕉的水质净化及生长适宜性实验表明,有植物的装置对NO_(3-)N和TN的去除率比无植物的装置分别高2.20%~46.52%和0.77%~29.34%,各装置的COD平均去除率为68.84%~77.28%,植物对TSS、NH_(3-)N和TP的去除影响不显著,其平均去除率分别为97.59%、84.06%和93.36%。综合植物的生理状况及污染物去除效果,柳叶马鞭草和美人蕉较适宜在南方红壤区的雨水花园中种植。(3)IWS的设置使COD、NO_(3-)N和TN的去除率分别增加了6.64%、9.43%和7.68%,但对NH_(3-)N、TSS和TP的去除率影响较小,且植物与IWS对COD、NO_(3-)N和TN的去除有极显著的交互作用,而对TSS、NH_(3-)N和TP去除的交互作用较小。(4)工程案例中,年径流总量控制率为85%,设计降雨量为38.9mm时,以30%砂、10%堆肥和60%红壤配置填料层,面积为203m2的雨水花园可调控1533.24m2汇水区的径流。监测结果表明,雨水花园对TSS和NH_(3-)N的去除效果较好,平均EMC(Event Mean Concentration)去除率分别为71.89%和31.73%,因填料不含沸石等材料,且秋冬季节植物与微生物代谢缓慢,对其它污染物的去除效果较差,NO_(3-)N、COD、TN和TP的平均EMC去除率分别为-38.57%、-9.76%、11.85%和26.16%。SWMM模拟结果表明,雨水花园的水量调控效果与重现期成反比,当重现期为0.5年~5年时,汇水区径流量可降低32.46%~60.81%,径流峰值可降低51.41%~86.34%,洪峰来临时刻可延迟3min~12min;雨水花园的水量调控效果与填料渗透系数成正比,重现期为1年时,以纯红壤为填料,径流量和径流峰值将分别提高20.33%和31.99%,以35%红壤、55%沸石和10%砂子为填料,径流量和径流峰值可分别降低30.90%和40.90%。
[Abstract]:Rain Water Garden is a reliable facility to solve the problem of non-point source pollution and hydrology brought by runoff in sponge city, but the time of introducing it into China is relatively short, and the design and application of measures to local conditions have not been fully carried out. In view of the regional characteristics of high rainfall and low soil permeability in the red soil region of southern China, Rain Water garden was designed and optimized from the aspects of filling ratio, plant selection and IWS (Internal Water Storage) setting, and the effect of water quality purification was discussed. In this paper, the design and operation of Rain Water Garden are discussed, and the effects of water quality purification and hydrological control are analyzed in order to provide a reference for the promotion of low-impact development facilities and the construction of sponge city. The main conclusions are as follows: (1) the isothermal adsorption experiments of NH_ (3-) N and P of Rain Water garden fillers, such as zeolite, cinder, sand, expanded vermiculite, ceramsite and red soil, show that the theoretical saturated adsorption capacity of NH_ (3-) N in red soil is second only to that of expanded vermiculite. The saturation adsorption capacity of zeolites is 2272.73 mg / kg, which is 2500mg / kg. Zeolite is suitable to be added to red soil in order to improve the adsorption effect and permeability coefficient of N _ (-) P in red soil. Considering the problems of plant growth, runoff infiltration and clogging, it is advisable to mix more than 65% sand or 55% zeolite in red soil, and 10% compost to configure Rain Water garden packing. (2) Verbena willow, Acorus calamus, The experiment of water purification and growth suitability of Iris and Canna showed that the removal rate of NO_ (3-) N and TN by the plant was 2.200.52% and 0.777.34% higher than that of the plant without plant, respectively. The average COD removal rate of each plant was 68.84% 77.28, and the effect of plant on TSS,NH_ (3-) N and TP removal was not significant. The average removal rates were 97.59% and 93.36%, respectively. Comprehensive plant physiological status and pollutant removal effect, Verbena willow and Canna were suitable for planting in the garden of Rain Water in southern red soil region. (3) the removal rates of COD,NO_ (3-) N and TN increased by 6.64% and 7.68%, respectively, but the removal rates of NH_ (3-) N-TSS and TP were less affected. The removal of COD,NO_ (3-) N and TN by plant and IWS is very significant, but the interaction between TSS,NH_ (3-) N and TP removal is small. (4) in engineering cases, the total runoff control rate is 85%, and the design rainfall is 38.9mm. With 30% sand, 10% compost and 60% red soil, Rain Water Garden with 203m2 area can control the runoff of 1533.24m2 catchment area. The results showed that Rain Water garden had better removal efficiency of TSS and NH_ (3-) N, the average EMC (Event Mean Concentration) removal rates were 71.89% and 31.73%, respectively, because the fillers did not contain zeolites, and the metabolism of plants and microorganisms was slow in autumn and winter. The average EMC removal rates of NO_ _ (3-) N _ (CODN) TN and TP were -38.57% and 11.85%, respectively, and the results of 26.16%.SWMM simulation showed that the effect of water regulation in Rain Water Garden was inversely proportional to the recurrence period, and when the recurrence period was 0.5 years to 5 years, the average EMC removal efficiency was -38.57% and 11.85%, respectively, and the results of 26.16%.SWMM simulation showed that the effect of water control in Rain Water's garden was inversely proportional to the recurrence period. The runoff of catchment area can be reduced by 32.46 and 60.81, the peak runoff value can be reduced by 51.41 and 86.34.The coming time of Hong Feng can be delayed by 3 mins or 12 mins, and the effect of water regulation and regulation of Rain Water garden is in direct proportion to the permeation coefficient of fillers, and when the recurrence period is one year, the pure red soil is used as the filler. The runoff and runoff peak value will increase 20.33% and 31.99% respectively. With 35% red soil, 55% zeolite and 10% sand as fillers, the runoff and runoff peak can be reduced by 30.90% and 40.90% respectively.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X52;TU986

【参考文献】