Analysis on the Pollution Load of Non-point Source Pollution and Surface Runoff of A Typical Village in Baiyangdian Lake Basin

[Objective] The characteristic of non-point source pollution of a typical village in Baiyangdian Lake basin was studied.[Method] The discharge of domestic sewage and solid wastes of the typical village was investigated,and both pollutant and nutrient element content were monitored,as well as the water quality and quantity of rainfall runoff.[Result] The non-point source pollution of livestock manure was far more serious than the sum of domestic sewage and domestic waste in this village,and the annual emission of total organic carbon(TOC),total nitrogen(TN) and total phosphorus(TP) was 37 794.0,4 102.9 and 1 923.7 kg,respectively.The event mean concentration(EMC)of chemical oxygen demand COD,TN and TP in rainfall runoff was 44.5,78.8,1.3 mg/L,respectively,and annual pollution load was 7.6,13.4 and 0.2 kg/hm2,respectively,while the annual pollution load of COD accounted for 5.1% of standard farmland,and that of TN and TP occupied 4.5% and 0.49% of slope farmland.[Conclusion] Livestock manure was the main source of non-point source pollution in the village and the annual pollution load of non-point source pollution was obtained.

Analysis on the Status of Agricultural Non-point Source Pollution in Xinan River Basin

Taking Xinan River basin as research object,the status of agricultural non-point source pollution was analyzed based on field survey,as well as the effect of fertilizer and pesticide leaching and runoff,livestock and poultry breeding and rural domestic pollution on non-point source TN and TP.At last,some technical countermeasures of controlling non-point source pollution were put forward according to the characteristics of agricultural non-point source pollution in Xinan River basin.

Simulation on the Time Progress of the Non-Point Source Pollution Load in Initial Stage Runoff for Small Watershed

Taking a reservoir in South China as an example, we use rainfall-runoff unit hydrograph method to analyze the time changing process of surface runoff inflow, which generated by typical design rainfall. On the basis of time series data of flow and water quality in control section of the main rivers in Xili Reservoir, we establish mathematical response relation between non-point source pollutants flux, such as flux of COD, flux of NH3-H, in catchment area of control section and runoff. Then we simulate the time dynamic change progress of non-point source pollution load which generate with the initial stage runoff that generated by design rainfall and flow into reservoir. It can provide technical parameters for the design of non-point source which generate from early runoff treatment project.

Assessing effects of “source-sink” landscape on non-point source pollution based on cell units of a small agricultural catchment

Ascertaining the relationship between "source-sink" landscape and non-point source(NPS) pollution is crucial for reducing NPS pollution, however, it is not easy to realize this target on cell unit scale. To reveal the relationships between "sourcesink" landscape and NPS pollution based on cell units of a small catchment in the Three Gorges Reservoir Region(TGRR), the runoff and nutrient yields were simulated first by rainfall events on a cell unit scale based on the Annualized AGricultural Non-Point Source Pollution Model(AnnAGNPS). Landscape structure and pattern were quantified with "sourcesink" landscape indicators based on cell units including landscape area indices and locationweighted landscape indices. The results showed that:the study case of small Wangjiagou catchment highlighted a good prediction capability of runoff and nutrient export by the AnnAGNPS model. Throughout the catchment, the spatial distribution trends of four location-weighted landscape indices were similar to the trends of simulated total nitrogen(TN) and total phosphorus(TP), which highlighted the importance of spatial arrangement of "source" and "sink" landscape types in a catchment when estimating pollutant loads. Results by Pearson correlation analysis indicated that the location-weighted landscape index provided a more comprehensive account of multiple factors, and can better reflect NPS-related nutrient loss than other landscape indices applied in single-factor analysis. This study provides new findings for applying the "source-sink" landscape indices based on cell units in small catchments to explain the effect of "source-sink" landscape on nutrient export based on cell unit, and helps improve the understanding of the correlation between "source-sink" landscape and NPS pollution.

Method for calculating non-point source pollution distribution in plain rivers

The land area in a river network is divided into certain-scale square cells for the sake of precision, and, based on the physical mechanisms of rainfall-runoff processes and runoff pollution, the non-point source pollution from cells is estimated using the export coefficients of different land use types. The non-point source pollution from a land cell should all go into the closest fiver reach, so it is distributed according to the terrain of the plain river network area and the positions of land cells and river network reaches. A relationship between a single land cell and its pollution-receiving reach can be determined using this system. In view of the above, a spatial distribution model of the rainfall runoff and non-point source pollution in reaches of a plain river network area was established. This model can provide technological support for further research on the dynamic effects of non-point source pollution on water quality.

Agricultural Non-point Source Pollution in Drinking Water Conservation Area of the Hongfeng Lake in Guiyang City

On the basis of investigating rural population, land types, livestock and poultry breeding scale in drinking water conservation area of the Hongfeng Lake in Guiyang City, as well as the urban domestic pol utant discharge coefficient, livestock and poultry excretion coefficient, nitrogen fertilizer and phosphate fertilizer loss rate in the first national pollution source survey, this paper tried to explore current situation of agricultural non-point source pollution, and provide scientific support for the pollution control. The results showed that in the drinking water conservation area of the Hongfeng lake in 2013, contribution rate of pollution sources to the water pollution in the Hongfeng Lake followed the sequence "livestock and poultry breeding > rural life > farmland fertilizer". Among all agricultural non-point source pollutants, livestock and poultry breeding pollutants were major pollution sources, with a contribution rate to CODCr, TP and NH3-N in water above 50%; rural domestic pollutants were also important pollution sources, its contribution rate to CODCr and NH3-N was 43.49% and 46.69%, respectively; contribution rate of farmland fertilizer pollutants to TN and TP was 33.76% and 27.71%, respectively, higher than that of rural domestic pollutants(25.87% and 6.75%). Therefore, the control of non-point source pollution within the drinking water conservation area should be enhanced, so as to control the pollution from the source.

Approach to estimating non-point pollutant load removal rates based on water environmental capacity: a case study in Shenzhen

An innovative approach based on water environmental capacity for non-point source NPS pollution removal rate estimation was discussed by using both univariate and multivariate data analysis.Taking Shenzhen city as the study case a 67% to 74% NPS pollutant load removal rate can lead to meeting the chemical oxygen demand COD pollution control target for most watersheds.In contrast it is hardly to achieve the ammonia nitrogen NH4-N total phosphorus TP and biological oxygen demand BOD5 pollution control target by simply removing NPS pollutants. This highlights that the pollution control strategies should be taken according to different pollutant species and sources in different watersheds rather than one-size-fits-all .

Modified Weighting for Calculating the Average Concentration of Non-Point Source Pollutant

The concentration of runoff depends upon that of soil loss and the latter is assumed to be linear to the value of EI that equals the product of total storm energy E times the maximum 30-min intensity I 30 for a given rainstorm. Usually, the maximum accumulative amount of rain for a rainstorm might bring on the maximum amount of runoff, but it does not equal the maximum erosion and not always lead the maximum concentration. Thus, the average concentration weighted by amount of runoff is somewhat unreasonable. An improvement for the calculation method of non-point source pollution load put forward by professor Li Huaien is proposed. In replacement of the weight of runoff, EI value of a single rainstorm is introduced as a new weight. An example of Fujing River watershed shows that its application is effective.

Estimation of ammonia nitrogen load from nonpoint sources in the Xitiao River catchment, China

Ammonia nitrogen (NH4+-N) is one of the three main forms of total nitrogen (TN). Most studies have estimated the load of TN from nonpoint sources instead of one specific form. The relationship between land use and concentrations of NH4+-N in runoff was analyzed using the hydraulic analysis functions of a Geographic Information Systems (GIS), and the annual loads of NH4+-N in the Xitiao River catchment were estimated according to model results. The results suggested that the calculated annual loads of NH4+-N...

Monitoring of non-point source pollutants load from a mixed forest land use

The aim of this study was to determine the unit load of NPS （non-point source） pollutants including organic variables such as BOD （biochemical oxygen demand）, COD （chemical oxygen demand） and DOC （dissolved organic carbon）, nitrogen and phosphorus constituents, and suspended solids （SS） and their event mean concentration （EMC） of runoff flows from a water-shed of mixed forest land use by intensive field experiments. Field monitoring for continuous measurements of rainfall, flow, and water quality was conducted over 12 storm events during 2008-2009 using automated and manual sampling methods. The EMCs of individual runoff event were estimated for each water quality constituent based on the flow rate and concentration data of runoff discharge. The average EMCs of BOD, COD, DOC, SS, TN （total nitrogen）, NH4^＋-N, NO3^--N, TP （total phosphorus）, PO4^3-P from the mixed forest land were 1.794, 3.498, 1.462, 10.269, 0.862, 0.044, 0.634, 0.034, and 0.005 mg/L, respectively. The annual unit loads of BOD, COD, DOC, SS, TN, NH4^＋-N, NO3^--N, TP and PO4^3--P were estimated as 66.9, 133.2, 55.5, 429.8, 36.5, 1.6, 26.9, 1.3 and 0.1 kg/（ha·yr）, respectively. In addition, affecting parameters on the EMCs were investigated by statistic analysis of the field data. As a result, significant correlations with precipitation, rainfall intensity, and total runoff flows were found in most constituents.

连续降雨条件下调蓄池对城市面源污染削减的模拟

目前我国水环境整治工作取得阶段性成效,点源污染问题很大程度上得到了解决,而城市面源污染的问题日益成为水环境治理的难点。为有效解决这一问题,以徐州经开区三八河流域为研究区,构建了雨水调蓄池面源污染控制的SWMM模型。通过在Control编辑模块中编辑水泵启闭的控制语言以控制调蓄池的自动排水,通过水泵曲线TYPE1类型对水泵流量大小进行设置以控制排空时间,分析了连续多年实测降雨情况下末端调蓄池的调节次数与污染物削减率。结果表明,调蓄池的调节次数和污染物削减率受其排空时间的影响相对较大,而受其运行规则的影响相对较小。在相同运行规则下,调蓄池24 h排空比48 h排空,可使调节次数的平均值分别增加11.8次(降雨24 h开泵)和12.9次(降雨48 h开泵),并可使COD和TN削减率的平均值分别提高2.28%~2.92%(降雨24 h开泵)和2.2%~2.59%(降雨48 h开泵)。

肥料用量和养分配比对蔬菜生长及土壤肥力的影响

选择深圳市郊区常年连作菜地,采用田间小区试验方法,设置对照、常规施肥、减量施肥10%、优化施肥(减量施肥50%,氮磷钾优化配比)等不同处理,研究不同肥料用量和养分配比条件下减施化肥对蔬菜生长及土壤肥力的影响。试验以叶菜为供试蔬菜,连续种植2茬。结果表明,与不施肥处理相比,施肥显著增加蔬菜产量和氮、磷、钾养分吸收量,肥料增产贡献率为32.3%~37.7%,且化肥减施与常规施肥处理之间肥料贡献率无显著差异。常规施肥模式下蔬菜氮、磷、钾养分利用率分别为13.98%、5.39%、31.95%,优化施肥相比常规施肥显著提高蔬菜磷肥和钾肥利用率1.87倍、26.3%。施肥对土壤pH、有机质含量无明显影响,常规施肥、减量施肥10%提高土壤碱解氮含量12.27%~27.83%、有效磷含量26.49%~44.24%、速效钾含量13.17%~35.30%。与常规施肥相比,优化施肥显著降低土壤有效磷含量19.96%~23.65%、速效钾含量22.29%~23.23%。各处理土壤综合肥力指数为1.34~1.43,均属于II级水平,连续2茬短期施肥管理对土壤肥力指数无显著影响。总体上,常年连作菜地系统优化施肥即化肥减施50%并优化氮磷钾养分投入比例,可在蔬菜产量不降低的情况下维持土壤肥力水平,降低土壤有效磷累积导致的面源污染风险。

场地基于容积法的海绵城市设计方法研究

海绵城市设计作为一种新兴的城市规划理念,正在获得越来越多的关注。本研究介绍了一种海绵城市设计计算的方法,并提供了参考指导,以帮助其他项目进行海绵城市设计。通过对一座城市的案例研究,验证该方法的有效性和实用性。结果显示,通过合理的海绵城市设计,可以显著减少城市洪涝灾害的发生,并提高城市的可持续发展能力。

Mortality rates of pathogen indicator microorganisms discharged from point and non-point sources in an urban area

This research measured the mortality rates of pathogen indicator microorganisms discharged from various point and non-point sources in an urban area. Water samples were collected from a domestic sewer, a combined sewer overflow, the effluent of a wastewater treatment plant, and an urban river. Mortality rates of indicator microorganisms in sediment of an urban fiver were also measured. Mortality rates of indicator microorganisms in domestic sewage, estimated by assuming first order kinetics at 20℃ were 0.197 day^-1, 0.234 day^-1, 0.258 day^-1 and 0.276 day^-1 for total coliform, fecal coliform, Escherichia coli, and fecal streptococci, respectively. Effects of temperature, sunlight irradiation and settlement on the mortality rate were measured. Results of this research can be used as input data for water quality modeling or can be used as design factors for treatment facilities.

生物炭对粗放型绿色屋顶出流水质的影响

以粗放型绿色屋顶的基质层为研究对象,构建了2组不同基质的粗放型绿色屋顶装置,每组设置了4个梯度(0%、6%、8%、10%)的生物炭,考察各组在经历9次人工降雨过程中,基质淋失率、出流水样的水质和污染负荷削减率的差异.结果表明:添加生物炭在抑制基质淋失率和提高出流水质方面作用明显.其中以在植被混凝土为主要基材中添加8%生物炭对于基质淋失率和出流水样中的N、P质量浓度的抑制作用、污染负荷的整体削减作用都是最好的;以在园林废弃物为主要基材中添加10%生物炭对于提高出流水质、削减污染负荷的效果是最好的,但是在抑制基质淋失率方面添加6%生物炭的设施效果最好.

浅谈南京某新建住宅小区海绵城市设计要点

每逢梅雨季,长江中下游地区降雨量长期过于集中,排水不及时,产生大量的积水和径流,导致严重的环境污染,经济损失。针对此类现象,海绵城市的发展建设愈发重要。海绵城市利用下凹绿地、雨水花园等措施可以增大城市的雨水渗透能力,减小雨水径流,降低城市内涝现象。结合南京某新建小区的海绵设计,对海绵城市年径流总量控制和面源污染削减率两个重要指标进行计算方式分析,以满足城市规划要点要求。

TMDL计划在茅洲河水环境综合治理中的应用

茅洲河2015年以前属于重度黑臭水体,为达到2017年底消除黑臭水体和2020年地表Ⅴ类水的水质目标,有必要开展最大日负荷总量(TMDL)研究。本文根据TMDL的相关方法和流程,基于水质受限水体识别、确定水质目标、水文分析、污染源调查和污染负荷计算,制定茅洲河TMDL计划,根据茅洲河TMDL目标,提出了污染负荷削减目标,从而确定茅洲河综合治理措施。经治理,茅洲河2018年全年实际日负荷量均小于基于消除黑臭目标的TMDL,2020年实际日负荷量均小于基于地表Ⅴ类水目标的TMDL,说明治理措施效果显著。

基于改进输出系数法的矿区重金属面源污染负荷核算模型

借鉴农业面源污染负荷核算研究成果,结合我国实际情况,以输出系数法为基础,提出矿区面源污染负荷核算模型.考虑重金属污染的来源和特点,将矿山地区的土地类型分为尾矿库区、降尘污染区、运输污染区和自然土地4类,分别计算各类型土地的输出系数.考虑到重金属在水中的溶出率影响,在模型中引入了溶出率因子,以构建适应矿区流域的重金属非点源污染负荷核算模型,并用该模型对浑河流域重金属面源负荷进行了估算.结果表明:矿山地区重金属污染主要来自运输污染区和自然土地,占总污染负荷的77%左右.从模拟过程和模拟结果可知,面源污染负荷核算模型所需原始资料较少,参数计算较方便,是计算矿山地区重金属面源污染负荷的可靠方法.

水动力水质模型在温黄平原河网入河污染负荷削减中的应用

为了探究入河污染负荷削减对河网水环境改善的效果,针对台州市提出的河网水质改善需求,以浙南温黄平原河网为例,设定河网主要污染物氨氮为评价指标,建立能反映出河网水动力水质时空变化规律的模型,通过对入河污染物削减率和配水水源的调节,进行方案模拟计算。结果表明:在长潭水库和灵江联合配水、入河污染负荷削减率达到55%时,水质改善效果最好;温黄平原整体河网平均水质达到较好的Ⅳ类水。提高入河污染物削减率虽然能够大幅度的强化内部河网的治污体系,但控制污染物排放、调水引流、加强区域内截污治污多措并举才能从根本上有利于河网水环境改善。本模型的应用研究可为台州及其他类似城市的河网水污染治理和控制提供参考,为建立有效可行的城市河网水污染防治安全体系提供技术支撑。

基于PCSWMM模型的广州典型社区海绵化改造水文效应研究

随着城市化进程加快和海绵城市建设的不断推进,低影响开发(LID)措施在城市建设中备受重视。为评估LID措施效果,构建研究区域PCSWMM模型,模拟分析重现期分别为0.5、1、2、5、10和20年的设计降雨情形下LID设施的水文效应,结果表明下凹式绿地、绿色屋顶和透水铺装等LID措施的不同组合方案对径流量和污染物均有不同程度的削减能力,且削减效果随着降雨重现期增大而减少,同时设置下凹式绿地、绿色屋顶和透水铺装的组合能达到最佳削减效果,对径流量、BOD5、CODCr、TSS、NH3-N、TN和TP的最大削减率分别为64.77%、56.93%、57.44%、51.20%、51.91%、55.29%和71.37%。