广州市典型社区单元面源污染初期冲刷效应

为了向初期雨水截留控制提供基础数据,研究广州市社区单元面源污染初始冲刷效应,采集并分析研究区域中3场降雨道路、屋顶和绿地径流的污染物情况,利用无量纲累积曲线、初期冲刷系数及质量初期冲刷强度指数MFF对径流污染物BOD_5、COD_(Cr)、TSS、NH_3-N、TP、TN的初期冲刷效应进行定性分析和定量分析。结果表明,绿地和屋顶比道路更易发生初期冲刷效应,且冲刷强度一般比道路强,而绿地在连续降雨后初期冲刷效应更加明显;各种初期冲刷污染物中,TN初期冲刷效应更为显著,TP和NH_3-N次之;采用MFF指数法可以得到较为可靠的定量化结果,建议采用该方法作为初始冲刷效应分析方法。     

Water Quality Monitoring and Modeling in Lake Kastoria, Using GIS. Assessment and Management of Pollution Sources

Lake Kastoria, is a very fragile aquatic ecosystem, protected by several national and international conventions, situated in the Region of Western Macedonia, Greece. A monthly monitoring program has been operated by the Municipality of Kastoria, during the past 5 years (2002–2007). The water quality parameters monitored, are: Water Temperature (Tw), dissolved oxygen (DO), BOD, COD, pH, water conductivity (ECw), redox potential (RP), nitrate nitrogen (NO₃-N), nitrite nitrogen (NO₂-N), ammonium nitrogen (NH₄-N) and orthophosphates-dissolved inorganic phosphorus (PO₄-P-DIP). This study focuses on the water quality parameters of Tw, DO, NH₄-N, NO₃-N and PO₄-P. The sampling points are five, scattered in specific positions in the Lake (Sioutista, Xiropotamos, Mavriotissa, Northern Beach and Stavros—Southern Beach). A comparison took place between two spatial–geographic deterministic simulation algorithms “IDW” and “RBF”, using GIS. This resulted in the conclusion that the first algorithm is the most appropriate to formulate the equipotential curves of the selected water quality parameters. Data from two seasons (winter—frozen Lake and summer—high eutrophication level) and 2 years (2005 and 2006) are presented here so the compared periods are February 2005, July 2005, February 2006 and July 2006. The thematic maps obtained indicate the most probable sources of pollution in Lake Kastoria and present the geographic distribution of the water quality parameters using the “IDW” algorithm. The most significant drawback of monthly monitoring is the missing of the data influenced by extreme events. Therefore, the need for daily telemetric monitoring data is suggested, in order to prevent environmental hazards and confront pressures concerning on water quality status. Finally, management strategies of pollution reduction are proposed, in combination with systematic telemetric real time monitoring, in order to upgrade the natural environment of Lake Kastoria.     

Experiences of nitrogen and phosphorus removal in deep-bed filters at Henriksdal sewage works in Stockholm

Deep-bed down-flow two-media filters were used in pilot plant studies with filtration of secondary settled wastewater. FeSO₄ or FeCl₃ was applied as a precipitation agent, and NaAc·3H₂O was chosen as a carbon source when denitrification was desired. The concentration of PO₄-P in the filtrate from the pilot plant study never exceeded 0.05 mg PO₄-P/l when iron salts were dosed. The curves showing the concentration of P-tot and PO₄-P in the filtrate as a function of the quotient between the dosage of iron and the concentration of PO₄-P in the influent to the filter followed approximately an exponential relationship. The total nitrogen reduction over the filter bed increased from an average of 2.3 mg (NO₃+NO₂-N/l at the beginning of each experiment to an average of 4.3 mg (NO₃+NO₂)-N/l towards the end of the lest. When only secondary settled wastewater, suspended solids, primary settled wastewater, iron salts, or sodium acetate was added, at a hydraulic load of 10 m/h, the time before clogging became 100 h, 10 h, 10 – 15 h, 20 – 40 h, and 20 – 40 h, respectively. Almost the entire pressure drop was located on the surface of the filter bed and 0.25 metre down in the expanded clay layer.     

太湖富营养化主要指标及营养水平变化分析

分析了太湖1980-2011年富营养化水质指标的变化情况,同时利用水质富营养化评价结果,分析了2002-2011年不同湖区营养水平的变化特征。结果表明:太湖富营养化水质指标整体呈上升趋势,虽然TN和TP在1996年后开始降低,但仍处于较高水平;NH+4-N和Chl-a的最高值出现在2006年;TN和NH+4-N具有相似的月间变化特征,但是NH+4-N的极值较TN提前一个月出现;CODMn和Chl-a呈单峰的月间变化特征,而TP的月间变化呈双峰特征。西部沿岸区和五里湖的水质改善明显,梅梁湖、竺山湖和南部沿岸区水质改善不明显,东部沿岸区和东太湖水质呈恶化趋势。太湖不同湖区富营养水质出现频次的月变化特征也非常明显。     

城区雨水管网径流污染特征研究

以新乡市城区屋面作为汇水区域,开展试验对雨水管网中场次降雨径流水文水质过程进行研究,可为有效利用城市雨水、控制非点源污染等提供依据。水质指标包括SS、COD和TN。结果表明:水质指标中SS、COD变化趋势基本一致,随着降雨过程的持续浓度逐渐降低并趋于一个稳定值;TN随着雨量的累积浓度逐渐降低,但在降雨结束前有反弹趋势;指标标准差率呈SS>COD>TN的趋势;径流初期屋面冲刷效应明显,初期径流量可定义为前1³mm的降雨量;径流中SS与COD、TN之间的相关性较好,在控制径流污染时可采取措施同时去除;径流污染物直接通过城区排水管网汇入受纳水体后对其水质影响较大,尤以SS、COD的变化最为明显。     

The Role of Green Roofs as a Source/sink of Pollutants in Storm Water Outflows

Green roofs are increasingly used as sustainable urban drainage systems due to their retention and detention capacity; however, the impact of green roofs in term of water quality is still a debated issue among researchers. A monitoring programme was carried out at the University of Genoa on a full-scale experimental site to assess the quality of storm water outflows. As for rainfall, the bulk deposition (dry and wet fractions) is collected to evaluate the role of the overall atmospheric deposition in altering storm water quality. The pollutant load observed in the green roof outflow is limited; concentration values for solids and metals are lower than those generally observed in storm water runoff from impervious surfaces. Suspended solids and Chemical Oxygen Demand (COD) are below respectively 10 and 20 mg/l, on average; as for heavy metals, copper and zinc are equal to 30 μg/l on average, while iron is equal to 120 μg/l. The Event Mean Concentration (EMC) statistics of the pollutant loads associated with the rainfall and outflow have been compared and discussed. The observed green roof behaviour as a sink/source of pollutants with respect to the atmospheric deposition is also investigated based on both concentration and mass. Results demonstrate that: green roof behaves as a source with respect to solids, COD and potassium while zinc and mainly copper are retained within the green roof stratigraphy. The resulting mass delivery behaviour reveals that no significant first flush occurs for pollutant constituents irrespective of the hydrologic characteristics and pollutant sources.     

常用基质对粗放型绿色屋顶雨水滞蓄和出流水质特征的影响

为研究粗放型绿色屋顶常用基质组成对雨水径流水量的滞蓄效果和设施出流氮、磷淋失的影响,分别以不同配比的田园土、泥炭土、蛭石、珍珠岩、陶粒、麦饭石、碎砖、砂为基质,构建了6种不同基质组成的绿色屋顶小试装置以及模拟传统屋面小试装置,进行了模拟降雨试验研究。从设施出流污染物累积淋失质量角度分析,以泥炭土和珍珠岩、陶粒、麦饭石等轻质材料为基质组成的绿色屋顶对TN有较好的控制效果。不同基质组成的绿色屋顶COD和TP淋失现象明显,尽管可能存在一定程度的淋失风险,但为了保证设施植物生长和水量控制效果,仍有必要考虑在基质中添加富磷有机质等。绿色屋顶设施运行稳定后,不同基质组成的绿色屋顶小试装置总体对浊度呈现较好的控制效果。从全年平均或长期运行效果看,采用绿色屋顶设施后,可将实际总量径流系数从传统屋面的0.95以上削减至0.52~0.63。研究结果可为海绵城市建设中的工程技术选择、绿色屋顶设施设计和运行效果评价提供数据参考和依据。     

生态塘对稻田降雨径流中氮磷的拦截效应研究

农田养分的大量流失已成为农业面源污染的主要来源之一,生态塘兼具排水和生态湿地双重功效,研究其对稻田排水氮磷的拦截效应对于防治农业非点源污染具有重要意义。针对降雨径流条件下生态塘对降雨径流中氮磷的动态拦截效应以及降雨径流结束后氮磷在静水中的去除效应有待明了的需求,本文选取太湖西岸何家浜流域典型农田作为研究对象,并将该区域的塘堰改造为生态塘,研究了生态塘对水稻生长期内的三场降雨径流氮磷的拦截去除效果及降雨径流结束后氮磷在静水中的去除效应。研究结果表明:(1)在三场降雨过程中,生态塘对总氮(TN)的平均去除率为34.7%,总磷(TP)的平均去除率为34.8%;(2)生态塘对降雨径流中不同形态氮磷的去除率大小排序为氨氮(NH_4~+-N)颗粒态氮(PN)硝态氮(NO_3~--N),颗粒态磷(PP)溶解态磷(DP),且径流状态下水体垂向分层氮磷浓度分布随降雨进行而变化,总体分布规律为底层氮磷浓度大于表层氮磷浓度;(3)降雨径流结束后,TN在生态塘中的去除率为50.4%,TP在生态塘中的去除率为52.3%,塘2对TN、TP的去除率大于塘1与塘3,生态塘表现了较强的抗冲击自修复性。     

苏州城区不同功能区地表径流污染特征

以苏州城区为例,在多雨季节对商业区、工业区、居民区三大功能区的降雨径流水质进行了6次采样监测,发现不同功能区地表径流水质差异较大,前10min初雨径流中各功能区COD、TN、NH4+-N、SS及工业区TP的平均浓度均劣于Ⅴ类水质标准。另外商业区初雨径流中COD、SS、TN、NH4+-N浓度均高于其他功能区,工业区初雨径流中TP浓度高于商业区和居民区。随着降雨历时的延长,降雨径流中主要污染物浓度均逐渐下降并趋于稳定。     

天津典型居民区不同下垫面雨水径流污染特征

在对天津典型居民区域的不同下垫面雨水径流水质进行监测的基础上,以典型降雨为例,探讨了雨水径流污染物的特征和事件平均浓度(event mean concentrations,EMC)。结果表明,天津典型居民区主干道和菜市场雨水径流中的污染物质量浓度随着降雨历时的延续呈降低趋势,冲刷效应明显;屋顶雨水径流中污染物的质量浓度随降雨历时的延续变化较小,冲刷效应较弱。3种下垫面雨水径流中污染物质量浓度大小差异明显,菜市场和主干道雨水径流中SS质量浓度相差不大,且都远远超过屋顶雨水径流;雨水径流中COD和TP质量浓度的顺序由大到小依次为菜市场、主干道、屋顶;雨水径流中TN质量浓度的顺序由大到小依次为菜市场、屋顶、主干道。以EMC中值计,菜市场雨水径流中污染物平均浓度要高于主干道和屋顶,菜市场雨水径流中TP的质量浓度是主干道的3倍、屋顶的24倍。天津典型居民区雨水径流污染比较严重,如不经截留或处理直接排入城市河道等接纳水体,会严重影响河道的水质和城市的环境。     

广州市中心城区初期雨水面源污染规律初探

选取广州市中心城区典型纯雨水排水口进行了18场降雨的径流污染监测,分析了在典型小雨、典型中雨及典型大雨场次下排水口各水质指标随降雨历时的变化规律。研究结果表明,雨水口的COD浓度峰值一般不超过55 mg/L,均值通常介于20~30 mg/L雨水口水质随降雨过程的变化规律较为复杂,初始冲刷效应最明显的水质指标是SS,其次是COD,NH3-N和TN基本没有初始冲刷效应。     

Phosphorus Loadings Associated with Housing in a Rural Watershed

Phosphorus and biological indicator organisms were measured in a rural watershed to quantify housing and agricultural inputs to the drainage system. Total-P and orthophosphate-P (PO_4-P) were significantly higher downstream from intensive housing areas than at areas with lower housing density. Housing areas discharged 40% particulate-P and 53% PO₄-P while rural areas discharged 62 and 29%, respectively. On the average, rural housing contributed 2 g P/house/day which comprised 27% of the PO₄-P discharged from the study area. For the rural subwatersheds, phosphorus from agriculture was not differentiated from biogeochemical and precipitation inputs. Assuming all phosphorus arose from fertilizer application, total-P losses represented 3.5% of that applied while PO₄-P losses represented less than 1%. It was concluded that housing in rural areas contributes PO₄-P to nutrient enrichment of drainage systems and that measures to control rural erosion may reduce total-P load but increase the proportion ofPO₄-P.     

多种修复技术对城市内河水质及微生物群落的影响

采集城市内河水样,分别采用曝气增氧、碳源添加、生物投菌和综合修复等技术,在实验室进行水质修复模拟实验,并以水质参数、微生物多样性及丰度为鉴定指标,分析不同修复技术对城市河流水质的修复效果及其对河流微生物群落结构的影响。结果表明,曝气、生物投菌和综合修复技术可以提高河流微生物群落结构多样性,水体微生物群落以变形菌门(Proteobacteria)、拟杆菌门(Bacteroidetes)、放线菌门(Actinobacteria)和疣微菌门(Verrucomicrobia)为主;而使用碳源添加技术的水样,河流微生物的多样性下降明显,变形菌门(Proteobacteria)的相对丰度达到了93%;水质修复方面,曝气增氧技术和生物投菌技术都仅能降低水体COD质量浓度,无法降低水体TN及NH+4-N质量浓度;碳源添加和综合修复技术,对水体TN和NH+4-N的去除效果明显,但投加碳源的河流水体中的COD质量浓度显著上升;相关性分析结果表明,影响水体微生物群落结构的主要环境因子为COD和DO。     

渭河陕西段底泥间隙水与上覆水中污染物分布特征研究

通过渭河8个断面2015年4月和9月的采样分析,探讨了表层底泥间隙水和上覆水中污染物的分布特征,并对间隙水和上覆水中的污染物浓度进行了相关性分析。结果表明:在丰水期时上覆水中TN、NO_3—N、NH_3—N及COD含量均高于平水期,其中采样点D5(泾河汇入前渭河干流处)的污染物含量很高;间隙水中TN、NH_3—N、NO_3—N变化趋势相似,丰水期TN、NH_3—N、NO_3—N含量均高于平水期含量,采样点D5、D7(泾河汇入后干流处)丰水期总磷、COD含量很高;相关性分和上覆水中TN、COD浓度在丰水期高度相关,说明间隙水中TN、TP、COD的浓度是其上覆水中TN、TP、COD浓度的决定因素。     

Storm water infiltration in a monitored green roof for hydrologic restoration

The objectives of this study are to provide detailed information about green roof performance in the Mediterranean climate (retained volume, peak flow reduction, runoff delay) and to identify a suitable modelling approach for describing the associated hydrologic response. Data collected during a 13-month monitoring campaign and a seasonal monitoring campaign (September-December 2008) at the green roof experimental site of the University of Genova (Italy) are presented together with results obtained in quantifying the green roof hydrologic performance. In order to examine the green roof hydrologic response, the SWMS_2D model, that solves the Richards' equation for two-dimensional saturated-unsaturated water flow, has been implemented. Modelling results confirm the suitability of the SWMS_2D model to properly describe the hydrologic response of the green roofs. The model adequately reproduces the hydrographs; furthermore, the predicted soil water content profile generally matches the observed values along a vertical profile where measurements are available.     

人工湿地植物水质净化作用的数值模拟研究

研究区域永年洼湿地面临生态退化、水污染严重等问题,已通过人工种植湿地植物进行生态修复及水质改善。永年洼连续2年的水质监测结果表明,随着湿地植物的种植和生长,洼内水体的氨氮(NH3-N)、总氮(TN)、总磷(TP)等都有不同程度的下降。本文根据湿地植物对水质的作用机理,通过MIKE模型的EcoLab中水质过程自定义及编辑功能,基于湿地植物的泌氧、细菌活性增加和植物吸收作用下水化学反应过程,构建"WQ+Veg"水质模块,耦合MIKE21水动力结果,模拟永年洼人工湿地种植前后湖区流速及NH3-N、 TN、 TP等水质指标的变化。在有加密监测的断面上,模拟有植物的2017年情景相比无植物的2016年情景,NH3-N、TN和TP平均下降了14.9%、7.33%和14.3%,与监测结果较为一致。在永年洼出水口处2017年相比2016年,NH3-N、TN和TP的去除率提高了7.2%、5.3%和9.1%。模型描述的反应过程清晰,可考虑湿地植物类型、分布、面积等条件下水质氮磷的响应,为大尺度湿地修复的布局及设计提供研究工具,同时为湿地水质净化效果评估提供依据。     

绿色屋顶对城市流域径流的影响

为使绿色屋顶技术在城市雨洪管理中有效发挥作用,寻求一种高效可靠的评估绿色屋顶应用对城市流域径流影响的方法。以伊利诺伊州CDS-51流域为例,利用Matlab程序建立IUHM-GR(Illinois urban hydrologic model-green roof)组合模型,考虑不同绿色屋顶覆盖率,以及透水-不透水、不透水-透水、组合情况等不同径流方式的情况,分析了绿色屋顶的应用对流域径流的影响。结果表明:绿色屋顶具有较好的蓄滞效果,可有效削减流域径流总量和峰值,且绿色屋顶覆盖率比绿色屋顶径流方式对流域径流有更大的影响。     

北江飞来峡库区典型流域非点源污染特征分析及模拟

为分析飞来峡库区典型流域非点源污染状况,开展社岗流域场次降雨径流水量水质监测试验,采用平均浓度法估算非点源污染负荷量,分析各场次降雨径流污染物特征并计算非点源污染贡献率,应用SWAT模型进行径流及非点源污染模拟。结果表明,径流量对SS、BOD_5等浓度和负荷量均有较强的主导作用,TN、NH_3-N等初期冲刷效应较为明显,污染物负荷量与径流量的相关性好于污染物浓度与径流量的相关性,各污染物的非点源污染贡献率均达到80%以上。SWAT模型径流模拟的率定期和验证期效率系数分别为0.85和0.73,表明所构建的SWAT模型精度良好。在污染物率定期,雨强较大的典型日污染物模拟效果最佳,污染物相对误差基本在10%以内,而在雨强较小时,TN、TP等均出现较大程度的低估现象;在污染物验证期,由于该时期正处于春耕施肥期,TN、TP模拟结果相对误差较大,且均为低估。总体而言,SWAT模型模拟精度良好,基本能反映该流域非点源污染状况,可为飞来峡库区流域的非点源污染模拟与控制提供参考。     

阳澄西湖入湖河道水质时空变化特征

基于2007—2019年阳澄西湖入湖河道逐月水质监测数据,分析了阳澄西湖入湖河道水质时空变化特征。结果表明:阳澄西湖入湖河道呈现出氮磷营养盐春季含量较高的特点;氨氮、总氮和高锰酸盐指数年均质量浓度整体呈下降趋势,2019年比2007年分别下降78.7%、47.9%和34.8%;总磷年均质量浓度2015年后有较大幅度下降,2015—2019年均值比2007—2014年均值下降45.3%;阳澄西湖主要入湖河道中,水质较差的是蠡塘河和白荡,主要污染因子为氨氮、总磷及总氮。     

漓江流域上游非点源污染负荷估算

采用径流分割法(丰枯径流差值法)、降雨量差值法和径流量差值法,基于2005—2014年各月水文和水质数据,进行漓江流域上游非点源污染负荷量的估算。结果表明,径流分割法的非点源污染负荷计算精度最高,丰枯水期污染物负荷差值和流量差值的拟合方程决定系数在0.88以上;基于径流分割法的污染物总负荷计算值和实测值的决定系数在0.91以上,计算值与实测值的结果接近。与氨氮和高锰酸盐指数相比,不同方法计算的总磷非点源污染比例呈现较强的稳定性。径流分割法的计算结果显示,2005—2014年高锰酸盐指数的非点源比例平均值为0.70,氨氮的非点源比例平均值为0.73,总磷的非点源比例平均值为0.74,说明非点源污染对漓江流域上游水质的贡献率较高。