Discussion on the Green Tax Stimulation Measure of Nitrogen Fertilizer Non-Point Source Pollution Control-Taking the Dongting Lake Area in China as a Case

A study on designing the tax of nitrogen fertilizer can provide a new method for controlling nitrogen fertilizer non-point source pollution. The tax design of nitrogen fertilizer was discussed by utilizing the external theory and the demand elasticity theory. The results indicated that the coefficient of price elasticity of nitrogen fertilizer demand is -0.21, which instructed that the market demand is in lack of elasticity in the short period and the impact of nitrogen fertilizer manufacturers is subtle. The 11 counties （cities and boroughs） in the Dongting Lake area in China, where the farmland nitrogen application surpassed the average ecological fertilization dosage, is listed to the taxation scope of nitrogen fertilizer tax. The environment loss will reduce 0.07 hundred million RMB yuan and the revenue will increase 0.89 hundred million RMB yuan in the country after levying on nitrogen fertilizer. The loss, which was brought by the decreasing food supplies production, will be 0.58 hundred million RMB yuan and the net social benefit will be 0.38 hundred million RMB yuan following revenue collection. The variation scope of the increasing expenditure of farmers will range from 0.95 to 1.49%. The variation scope of the income of farmers will range from -8.41 to 6.44%. The 5 areas, Yunxi Borough, Junshan Borough, Hanshou County, Jinshi City, and Ziyang Borough, had an increase in food supplies production after the revenue collection. The environment loss will reduce 0.01 hundred million RMB yuan and the revenue will increase 0.16 hundred million RMB yuan in the country after levying on nitrogen fertilizer. The economic benefits, which was brought by the increasing cereals production, will be 0.67 hundred million RMB yuan and the net social benefit will be 0.84 hundred million RMB yuan after revenue collection. The variation scope of the increasing expenditure of farmers will range from 0.95 to 1.06%. The variation scope of the increasing income of farmers will range from 0.69 to 6.44%. Considering the entire social welfare, taxation of nitrogen fertilizer will have more advantages than disadvantages in the Dongting Lake area.

Study on the Control Model of Rural Non-point Source Pollution——Taking Ninghe County in Tianjin as an Example

[Objective] The aim was to study the control model of rural non-point source pollution.[Method] Taking Ninghe County(a typical agricultural county in Tianjin) as an example,the current development of local economy and society and characteristics of rural non-point source pollution were studied firstly,then the control model of rural non-point source pollution suitable for Ninghe County was constructed,and its environmental and economic benefits were analyzed finally.[Result] According to the sources of non-point source pollution,the control model of rural non-point source pollution in Ninghe County was divided into three modules from the aspects of planting industry,livestock raising industry and rural living.The main content of non-point source pollution control module of planting industry was composed of rational utilization of chemicals,water-saving irrigation,diversified utilization of straw etc.Non-point source pollution control module of livestock raising industry focused on the site selection of farm or raising zones,choice of raising mode,comprehensive utilization of livestock waste etc.In the non-point source pollution control module of rural living,villages were divided into two types(small town and ecological village) based on various geographical positions.In a word,these three modules were interrelated and targeted for non-point source pollution control in villages under different development situations.[Conclusion] The study could provide references for the rural non-point source pollution control in Hai River basin and other regions of Northern China.

Fractal Analysis on the Spatial Structure of Land Use Patterns in a Non-Point Source Polluted Area in Southern China

Based on the TM remote sensing interpretation of land use data of a non-point source polluted area in southern China in 2015, supported by ArcGIS and the fractal theory, this paper established the perimeter-area fractal equation of the spatial structure of land use types, quantitatively calculated the fractal dimension and stability index of various land use types in this non-point source polluted area in 2015, and analyzed the spatial structure characteristics of land use types. The results showed that the fractal dimension values of the different land use types in the research area ranged 1.141–1.657, and the whole fractal dimension of the research area was 1.206. To be specific, the fractal dimension values of unused land, grass land and rural residential land were high, and the fractal dimension values of dry land, paddy filed and waters were low, and the fractal dimension values of urban land, industrial traffic construction land and forest land were moderate. The area of the land use types whose stability index values were 0.2–0.4 accounted for 89.5% of total area, suggesting that the stability of the spatial structure of land use types of Beibei District in 2015 was not high generally. The rural residential land and urban land of the research area should be planned and managed more properly from now on.

Mechanism of nitrogen loss driven by soil and water erosion in water source areas

Nitrogen(N)present in drinking water as dissolved nitrates can directly affect people’s health,making it important to control N pollution in water source areas.N pollution caused by agricultural fertilizers can be controlled by reducing the amount of fertilizer applied,but pollution caused by soil and water erosion in hilly areas can only be controlled by conservation forests.The catchment area around Fushi Reservoir was selected as a test site and mechanisms of N loss from a vertical spatial perspective through field observations were determined.The main N losses occurred from June to September,accounting for 85.9-95.9%of the annual loss,with the losses in June and July accounting for 46.0%of the total,and in August and September for 41.9%.The N leakage from the water source area was effectively reduced by 38.2%through the optimization of the stand structure of the conservation forests.Establishing well-structured forests for water conservation is crucial to ensure the security of drinking water.This preliminary research lays the foundation for revealing then loss mechanisms in water source areas and improving the control of non-point source pollution in these areas.

DITCHES AND PONDS CAN BE THE SOURCES OR SINKS OF NON-POINT SOURCE POLLUTION:OBSERVATIONS IN AN UPLAND AREA IN THE JINGLINXI CATCHMENT,CHINA

As the common features of agroecosystems,ditches and ponds benefit the irrigation and drainage,as well as intercepting non-point source pollutants.However,most ditch-pond studies have been conducted in lowland areas.To test this source-sink assumption in upland areas,this study made observations on the ecological function of the ditch and pond system in a typical catchment in China.First,the changes in ponds in the catchment were analyzed using high-resolution remote sensing data.Then,the migration of agricultural pollutants in ditches and ponds were analyzed by field sampling and laboratory detection.The results showed that over the past 15 years the length of ditches in the catchment and the number of small ponds(<500 m2)have increased by 32%and 75%,respectively.The rate of change in nutrient concentrations in the ditches and ponds were mostly from-20%to 20%,indicating ditches and ponds can be both sources and sinks for agricultural pollutants.Lastly,the contributing factors were explored and it was found that ditches and ponds are important sinks in dry season.However,during the rainy season,ditches and ponds become sources of pollutants,with the rapid drainage of ditches and the overflow of ponds in upland areas.The results of this study revealed that the ditches and ponds could be used for ecological engineering in upland catchments to balance drainage and intercept pollutants.

Source analysis of dissolved heavy metals in the Shaying River Basin,China

Over the years,the Shaying River Basin has experienced frequent instances of river pollution.The presence of numerous critical pollutant discharge enterprises and sewage-treatment plants in the vicinity of the Shaying River has transformed it a major tributary with relatively serious pollution challenge within the upper reaches of Huaihe River Basin.To study the sources of manganese(Mn),chromium(Cr),nickel(Ni),arsenic(As),cadmium(Cd)and lead(Pb)in Shaying River water,123 sets of surface water samples were collected from 41 sampling points across the entire basin during three distinct phases from 2019 to 2020,encompassing normal water period,dry season and wet season.The primary origins of heavy metals in river water were determined by analyzing the heavy metal contents in urban sewage wastewater,industrial sewage wastewater,groundwater,mine water,and the heavy metal contributions from agricultural non-point source pollution.The analytical findings reveal that Mn primarily originates from shallow groundwater used for agricultural irrigation,While Cr mainly is primarily sourced from urban sewage treatment plant effluents,coal washing wastewater,tannery wastewater,and industrial discharge related to metal processing and manufacturing.Ni is mainly contributed by urban sewage treatment plant effluents and industrial wastewater streams associated with machinery manufacturing and metal processing.Cd primarily linked to industrial wastewater,particularly from machinery manufacturing and metal processing facilities,while Pb is predominantly associated with urban sewage treatment plant effluents and wastewater generated in Pb processing and recycling wastewater.These research provides a crucial foundation for addressing the prevention and control of dissolved heavy metals at their sources in the Shaying River.

Water Pollution Situation and Impacts in Rural China

With the development of national economics, water pollution is becoming a critical problem in rural China. This research presented a brief view of water pollution situation in rural areas of China in terms of water shortage, water-pollutant sources, eutrophication of water bodies and pollution development in temporal scale. Analysis was conducted on the negative effects of water pollution on human health, agricultural plantation and animal husbandry. Subsequently, some suggestions were proposed for wastewater treatment in rural areas.

Identification of the ＂source＂ and ＂sink＂ patterns influencing non-point source pollution in the Three Gorges Reservoir Area

Non-point source pollution is one of the primarily ecological issues affecting the Three Gorges Reservoir Area. In this paper, landscape resistance and motivation coefficient, which integrated various landscape elements, such as land use, soil, hydrology, topography, and vegetation, was established based on the effects of large-scale resistance and motivation on the formation of non-point source pollution. In addition, cost models of the landscape re- sistance and motivation coefficients were constructed based on the distances from the land- scape units to the sub-basin outlets in order to identify the ＂source＂ and ＂sink＂ patterns af- fecting the formation of non-point source pollution. The results indicated that the changes in the landscape resistance and motivation coefficients of the 16 sub-basins exhibited inverse relationships to their spatial distributions. The landscape resistance and motivation cost curves were more volatile than the landscape resistance and motivation coefficient curves. The landscape resistance and motivation cost trends of the 16 sub-basins became increas- ingly apparent along the flow of the Yangtze River. The landscape resistance and motivation cost models proposed in this paper could be used to identify large-scale non-point source pollution ＂source＂ and ＂sink＂ patterns. Moreover, the proposed model could be used to de- scribe the large-scale spatial characteristics of non-point source pollution formation based on ＂source＂ and ＂sink＂ landscape pattern indices, spatial localization, and landscape resistance and motivation coefficients.

十五里河流域初期雨水水质特征与处理方法研究

城市区域初期雨水具有污染负荷较大、随机性较强、有明显季节性等特点,需要选择适合的方式处理后排放河道。研究以安徽省合肥市十五里河流域为例,首先通过整理资料及建立城市面源污染模型分析了该区域初期雨水水质情况,然后模拟了排口污染物浓度变化情况,最后根据初期雨水水质特点,并结合生物接触氧化法处理原理,讨论了生物接触氧化法处理初期雨水的适用性。研究旨在针对初期雨水的特点提出高效稳定的处理办法,并保证系统稳定运行,为河道面源污染处理提供指导,拓展生物接触氧化法的应用范围。

北京市PM_(2.5)中水溶性有机碳污染特征研究

于2019年的1月1日—12月31日采集了315个细颗粒物(PM_(2.5))样品,用于研究北京大气气溶胶中水溶性有机碳(WSOC)的特点和来源。结果表明:2019年北京城区WSOC平均质量浓度为4.58μg/m^(3),浓度范围为0.50~23.87μg/m^(3)。WSOC的质量浓度呈现了显著的季节差异,按照从大到小的顺序排列依次是冬季>秋季>春季>夏季。相关性分析结果表明在夏、秋季受到一次源和二次源的共同影响,而在春、冬季受到一次源的影响更大,在夏、秋季二次源影响高于春、冬季。在冬季WSOC受到燃煤的影响。

盐城市滨海县城区区域枯水期水环境质量调查分析

笔者采用单因子评价法分析与评价枯水期滨海县城区及开发区工业园区范围水质污染特征和现状。调查范围面积约50.8 km^(2),包括主要河道、城市内河、开发区工业园区内部河道及周边支流。调查区域内地表水水质呈重度污染状况,主要原因为时值枯水期,水体长期滞留,在无充足水源补充的情况下,由于环境基础设施建设滞后,区域内生活污染物和工业污染物不断入河导致地表水污染日益加重。该评价结果能为滨海县水环境保护和科学治理提供依据。

2020年冬季石河子市城区和工业区PM_(2.5)中无机元素污染特征及来源

石河子市是位于新疆乌昌石区域中部的工业城市,2020年12月和2021年1月在石河子市城区和工业区共布设2个采样点,全天候采集细颗粒物(PM_(2.5))样品61 d,利用电感耦合等离子质谱仪(ICP-MS)对24种元素含量进行分析,并通过富集因子法(EF)解析PM_(2.5)中无机元素的污染特征及来源.结果表明,冬季采样期间,石河子市重度及以上污染天数占整个采样期的53.2%,以PM_(2.5)为首要污染物的污染天数占整个采样期的98.4%,采样期城区和工业区的PM_(2.5)日均值分别为164.7μg·m^(-3)和113.6μg·m^(-3),表明石河子市冬季PM_(2.5)污染严重;采样期城区和工业区PM_(2.5)中无机元素浓度分别为4.4μg·m^(-3)和3.6μg·m^(-3),主要成分均为K、Ca、Na、Mg、Al、Fe,6种元素之和在城区和工业区元素中的占比分别为97.4%和97.5%,表明这6种元素为城区和工业区元素的主要组分,城区和工业区主要元素组成差异性较小,污染天K和Ca元素的累积速度最快,Na和Ca元素的累积量最大;石河子市2020年冬季PM_(2.5)中主要富集元素为K、Ca、Na、Mg、Fe,富集元素主要来源于工业区、机动车、地壳物质以及餐饮油烟等,城区元素富集程度和污染程度略高于工业区.

Study on phosphorus loss and influencing factors in the water source area

Maintaining drinking water security is a global issue,and phosphorus is a limiting factor affecting drinking water quality.Hence,this study took Fushi Reservoir as a test area,and set up field runoff observation plots around the reservoir catchment,which is covered by moso bamboo stands.Through field observation,the vertical variation of phosphorus loss in different stands of moso bamboo was initially studied.The results showed that:(1)For the vertical dimensions(atmospheric rainfall,stemflow,throughfall,surface runoff)from high to low,the loss of total phosphorus(TP)increased,and the pro-portion of dissolved phosphorus increased from 29.29%(atmospheric rainfall)to 62.76%(surface runoff).(2)Different rainfall factors had various impacts on phosphorus loss at the different vertical levels.The accumulation of rainfall had the greatest impact on surface runoff TP loss,with the correlation coefficient reaching 0.994(P<0.01),while surface runoff particulate phosphorus loss was mostly affected by the average rainfall intensity.(3)Modifying the forest structure in water source areas can reduce the loss of TP via stemflow and throughfall,but the effect on surface runoff TP loss is variable.Thus,it is expected that this novel study can serve as a reference for improving the environmental quality of water source areas,and help in reducing phosphorus loss and controlling non-point source pollution.

城市区域环境噪声污染监测及防治对策

在城市化快速发展的背景下,城市环境污染情况日益严重,导致了城市居民的生活质量下降。城市区域环境噪声问题有点多面广、来源复杂等特点,是城市化进程中亟需解决的环境污染问题。基于此,文章首先阐述了城市区域环境噪声的主要来源以及噪声监测标准,并以深圳市某区噪声环境监测为例,探究了城市区域环境噪声污染监测方法及结果,根据噪声污染监测结果,提出了有效的噪声污染防治对策,以期改善区域声环境质量,为城市发展和居民生活营造良好的环境。

SWMM模型应用于城市住宅区非点源污染负荷模拟计算

以温州市典型住宅区非点源污染为对象,基于SWMM(storm water management model)模型的模拟机理,借鉴国内外相关研究的模型参数,结合降雨径流实测数据率定模型参数,将模型"本地化",构建了基于SWMM模型的研究区非点源污染负荷计算模型,并设计了4种不同降雨情景,分析在不同降雨条件下研究区非点源污染固体悬浮物(TSS)、CODCr、TN和TP的污染负荷量及其累积变化过程.结果表明,构建的SWMM模型的模拟值可以较好地与实测值相吻合,4种污染物模拟的相对误差均小于10%.在设计的4种降雨情景下:①污染物浓度峰值出现在降雨30～40 min内,降雨强度越大,出现浓度峰值的时间越早;②高强度降雨较低强度降雨可对受纳水体造成更大的污染.

Nutrient Loss from Farmland:Research on and Application of Phosphorus Index Method

Phosphorus index method is an effective method to assess the risk of phosphorus loss,identify the critical source areas and reasonably control the agricultural non-point source pollution.The researches on phosphorus index assessment method have been started earlier in foreign countries.Currently,phosphorus index assessment method has been widely used in the United States and European countries through continuous development and improvement.However,the domestic research on non-point source phosphorus pollution assessment has just started,and the phosphorus index method that is suitable for the characteristics of agriculture in China has not yet been established.This paper summarizes and analyzes systematically the related research advances in phosphorus index method at home and abroad,and illustrates the issues presented in phosphorus index method.In addition,the researches on and application of phosphorus index method in China are discussed.

城市植物叶面尘粒径和几种重金属(Cu、Zn、Cr、Cd、Pb、Ni)的分布特征

为研究城市植物叶面尘粒径及重金属元素(Cu、Zn、Cr、Cd、Pb、Ni)的分布规律和污染特征,以西安市不同功能区大叶女贞(Ligus-trum lucidum)和小叶女贞(Ligustrum quihoui)叶面尘为研究对象,用激光粒度分析仪测定叶面尘的粒径分布,用原子吸收分光光度计测定叶面尘重金属质量比,并探讨了叶面尘重金属的可能来源。结果表明,大叶女贞和小叶女贞叶面尘粒径小于50μm。前者叶面尘粒径累积曲线呈双峰分布,平均粒径和粒径峰值从大到小为相对清洁区、工业区、居住文教区、交通枢纽区、商业区;后者呈单峰分布,平均粒径和粒径峰值由大到小为工业区、居住文教区、交通枢纽区、商业区和相对清洁区。不同功能区叶面尘中Cu、Zn、Cr、Cd、Pb、Ni有明显的富集,其质量比分别为(325.5±72.6)mg/kg、(3 965.6±1 112.9)mg/kg、(349.2±149.3)mg/kg、(35.3±6.8)mg/kg、(1 182.0±355.1)mg/kg、(324.1±129.5)mg/kg,为陕西省土壤背景值的7.9～20.8、29.7～77.9、2.6～11.1、262.8～489.4、26.4～71.8和6.9～18.9倍。不同功能区2物种叶面尘各重金属质量比差异显著(p<0.001),物种间差异不显著(p>0.05)。叶面尘中Zn、Pb、Ni、Cr的质量比以工业区最高,Cu、Cd以交通枢纽区最高,其次为商业区,居住文教区和相对清洁区负荷最低。研究认为,叶面降尘中的重金属可能来自外源输入。

城市雨水径流面污染负荷的计算模型

对城市雨水径流的污染负荷进行定量分析评价是制定控制策略和实施有效总量控制的基础,为此建立了一种计算城市径流面污染负荷的数学模型,它具有参数少、因果关系清楚、简便直接等特点。利用该模型可对城市径流非点源污染进行量化分析并合理确定初期雨水径流控制量,这为城市径流污染控制决策的制定提供了一种有效的分析方法。

城市非点源污染及其防治研究

在分析城市非点源污染的机理和特点的基础上,对目前采用多种模型进行概述,提出模型研究中存在的问题和建议,并提出多种控制城市非点源污染的措施。