Three-year monitoring results of nitrate and ammonium wet deposition in Thailand

Wet deposition is one of the important sources of nitrogen input into the ecosystem. It also contributes to rain acidity in some environments. In this study we reported the annual as well as seasonal trends of nitrogen wet deposition at three locations in Thailand: Bangkok, Chiang Mai and Nan. Comparison of nitrogen wet deposition between in rural and in the urban areas was also made. Daily rainfall was measured and monthly rainwater was collected for nitrogen analysis during 1999–2002. The average NO₃ ^– concentration in rainwater collected from the rural sites (60 km from urban area) was around 0.2–0.3 mg L^–1, while that from the urban areas of Chiang Mai and Nan cities it was 0.4–0.5 mg L^–1. NH₄ ⁺ concentration in rainwater showed the similar ranges to that of NO₃ ^– , except at Nan where concentration was not significantly different between the urban and rural sites. On the other hand, the average concentrations of NO₃ ^– were higher at Bangkok site than other sites, while concentration of NH₄ ⁺ was almost the same between Chiang Mai and Bangkok. Wet deposition of NO₃ ^– at the rural sites of Chiang Mai and Nan ranged from 2.1 to 3.2 kg N ha^–1 yr^–1, while at the urban sites this ranged from about 6 kg N ha^–1 yr^–1 in Chiang Mai and Nan Cities to 8.6 kg N ha^–1 yr^–1 in Bangkok. Wet deposition of NH₄ ⁺ at the rural sites of Chiang Mai and Nan was about 2.4 to 3.6 kg N ha^–1 yr^–1 and at the urban sites of Chiang Mai, Nan and Bangkok this was 7.7, 4.9 and 8.1 kg N ha^–1 yr^–1, respectively. Thus, it was concluded that wet deposition of both nitrogen species was significantly higher at the urban sites than at the rural sites.     

A Global Overview of Atmospheric Acid Deposition Fluxes

This paper presents a summary of globalacid deposition flux data taken from a globalassessment report on acid deposition prepared forUNEP/WMO (Whelpdale and Kaiser, 1996). There is a largevariation in the spacial coverage and reliability ofmonitoring around the world. Many more stationsmeasure wet deposition than collect appropriate datafor estimating dry deposition. The widespread regionswith highest precipitation concentrations anddeposition fluxes of sulphate and nitrate coincideclosely with the regions of highest density ofSO₂ and NO_x precursor emissions occurringprimarily in the mid-latitude, northern hemispherebelt where a large fraction of the worlds fossilfuels is consumed. Organic acids in precipitation makea minor contribution to acidity (<20%) inindustrial regions, but in the rest of the world theyare of same order, or even exceed, inorganic acids.Less is known about dry deposition, but it appears topredominate near strong emission sources with wetdeposition predominating farther downwind. The molarratio of the N/S contribution to acidic deposition isclose to 1.0 over large areas of Europe and NorthAmerica, but is highly variable elsewhere, beinghighest in equatorial regions due to biomass burningand lowest near smelters and other large sources of SO₂.     

新疆大气氮沉降监测研究进展浅析

通过对新疆12个监测点氮沉降研究结果发现,无机活性氮浓度(pNH4+、pNO3-、NH3、NO2)在不同生态系统存在较大的时空差异,氮沉降通量变化随人为干扰程度呈递增趋势.总结了当前新疆大气氮沉降监测研究进展,包括主要监测方法、不同生态系统大气氮素干沉降的时空差异性分析、大气氮素干湿沉降通量估算.对大气氮素干湿沉降通量...     

Deposition Monitoring in Europe

A monitoring station for atmospheric deposition was designed and constructed. Three such stations were applied in a pilot project for a year on three sites (Speulder forest in The Netherlands, Auchencorth in Scotland and Melpitz in Germany) in different regions in Europe to estimate local inputs and to validate deposition models which are currently used or developed to estimate ecosystem specific deposition in Europe. Fluxes at Auchencorth Moss are lowest for all components, except for those much influenced by the sea as a source. As Melpitz is located far away from seas, these components are lowest at this site. Wet deposition is the dominant source of input at Auchencorth, whereas at Speulder forest, through its roughness and pollution climate, dry deposition is dominant. At this site dry deposition velocities are highest. Melpitz is a polluted site. Particularly sulphur deposition is high. It is recommended to equip several locations in Europe with intensive deposition monitoring methods. Such a network will be an extension of existing monitoring programmes on air pollution, such as that run by Eurepean Monitoring and Evaluation Programme for the long-range transmission of air pollutants in Europe (EMEP). The intensive monitoring locations should be selected based on pollution climates and type of vegetation, common in Europe.     

太湖氮磷大气干湿沉降时空特征

为了探索太湖氮磷营养盐干湿沉降特征及对太湖营养盐输入的贡献,于2011年不同季节采集太湖不同位点的大气干湿沉降样品,分析干湿沉降中氮（N）和磷（P）的形态和沉降量。研究结果表明,输入太湖的磷以干沉降为主,而氮以湿沉降为主。在太湖干沉降中总无机氮（TIN）占总氮（TN）的77.1%,溶解性磷（DIP）占总磷（TP）的77.9%。干沉降中TIN主要以NH+4-N为主。西太湖是TN与TP通过大气干湿沉降输入太湖的最高湖区。太湖全年大气TN沉降总量为20 978 t,TP沉降总量为1 268 t,因此,氮磷大气干湿沉降是太湖营养盐输入的重要来源之一。     

大气磷干沉降采样方法对比分析

以四川农业大学成都校区为监测点,采用大气主动采样法(AA)、大气干表面法(ADS)及大气湿表面法(AWS)3种常用干沉降采集方法做大气磷干沉降通量对比试验。结果表明,3种采样方法获得的大气磷干沉降通量间具有显著的差异性及相关性(P0.05),三者间可以进行换算统一;AA法适用于较短采样周期的连续性监测研究,ADS法适用于较长采样周期(5 d)的监测研究,而AWS法更适用于在长采样周期(月)内选取一段时间作为干沉降监测的研究。     

东亚酸沉降中国网湿沉降分析研究

东亚酸沉降监测网是由日本于 1 993年发起并组织 ,我国于 1 999年 4月开始参加该网络的试运行监测工作。文章针对我国 1 999年度重庆、西安、厦门和珠海四城市湿沉降监测结果进行了分析研究     

重庆市主城区农业源氨排放研究

对重庆主城区畜禽养殖业氨(NH3)排放因子进行了本地化修正,估算了农业源NH3排放量。主城区农业源年排放NH38 482 t,其中化肥施用NH3排放量最大,占总排放量的66.7%;畜牧养殖业占26.3%;农作物释放占6.9%。巴南区农业源NH3排放量最大,占主城区排放总量的41%,渝中区为零排放。主城区农业源NH3排放强度为1 552.1kg/km2,大渡口区排放强度最高。主城区畜禽养殖业NH3排放比例低于全国平均水平,化肥施用NH3排放比例高于全国平均水平,但与全国农业源NH3排放结构类似。     

Analysis of Wet Precipitation of Air Pollutants in Mumbai (India)

Bulk precipitation samples at Mumbai (India) were collectedduring the monsoon seasons of 1991 to 1996 and analysed forionic concentrations using an Ion Chromatograph DIONEX model100. The variability of sulphate to nitrate ratio in rainwaterfluctuates in a wide range from 1.5 to 20 and governed by thesulphate concentrations in the sample. The regression analysisof the data reveals that in the bulk precipitation at Mumbai, SO₄^2- is becoming increasingly important relative toNO₃^-. The role of meteorological influences onscavenging of air pollutants by rain water has been tried toexplain the phenomena. The computed wet deposition rates for Sand N during 1991–1996 show that the S deposition is higherthan N in all the years. There is a wide fluctuation indeposition rates of S ranging from 2 to 55 kg km² per annum.     

青岛市降水中的铅及其变化规律

对青岛市四个站位 1 997年 1 1月～ 1 998年 1 0月 33次降水中铅浓度进行了监测 ,降水中铅浓度在 <0 .5～2 7.7μg/ L之间 ,均值为 4 .2μg/ L,降雪高于降雨。讨论了 p H、交通和季节对铅浓度变化的影响 ,并与其它城市地区降水中铅进行了比较     

“十一五”期间重点流域化学需氧量排放及减排潜力分析

根据\"十一五\"期间七大流域化学需氧量(COD)排放总量、工业COD排放量及生活COD排放量的变化情况对各流域的减排幅度进行了综合评价,根据单位水资源COD负荷、单位工业产值COD排放强度及人均生活COD排放强度对各流域的污染压力进行了综合评价,以七大流域的减排幅度和污染压力为基础分析了各流域COD的减排潜力,并对各流域的重点防控领域和配套减排措施等方面提出了政策建议。     

洛阳市2017年大气氨排放清单的建立及其空间分布特征

基于洛阳市不同类型氨排放源的活动水平数据,主要采取排放因子法构建了2017年洛阳市大气氨排放清单,并以GIS技术为基础进行2 km分辨率的空间网格分配。通过研究得出,2017年洛阳市的大气氨排放量为63.2 kt,排放强度达到4 t/km²以上,全市主要的氨排放源为畜禽养殖和农田生态系统,排放量分别为43.7 kt和10.4 kt,分别占氨排放总量的69.2%和16.5%。在畜禽养殖源中,肉牛是最大的贡献源,贡献率为30.4%;在农田生态系统中,氮肥施用是最大的贡献源,贡献率为87.7%。各区县中,宜阳县和伊川县排放量最大,共占氨排放总量的32.0%;偃师市、伊川县为排放强度最高;空间分布特征上呈现北部氨排放量大、南部排放量少、在城市区周边氨排放量较突出的现象。     

Characteristic Study of Dry Deposition, Concentration, Compositions for Particulates Mass and Ionic Species During Summer and Autumn Season at a Traffic Sampling Site

Aerosol samples for dry deposition and total suspend particulates (TSP) were collected from August to November of 2003 in central Taiwan. Ion chromatography was used to analyze the related water-soluble ionic species (Cl⁻, NO₃ ⁻, SO₄ ²⁻, Na⁺, NH₄ ⁺, K⁺, Mg²⁺ and Ca²⁺). The results obtained in this study indicated that the ambient air particulate mass concentrations in the daytime period (averaged 975.4 μg m⁻³) were higher than the nighttime period (averaged 542.1 μg m⁻³). And the daytime dry deposition fluxes (averaged 58.12 μg m⁻² sec⁻¹) were about 2.2 times as that of nighttime dry deposition fluxes (averaged 26.54 μg m⁻² sec⁻¹) of the downward dry deposition. The average values downward and upward of dry deposition fluxes for the weekend period were almost higher than the weekday period for either daytime or nighttime period. Furthermore, the average daytime dry deposition fluxes (averaged 26.37 μg m⁻² sec⁻¹) were also about 2.3 times as that of nighttime dry deposition fluxes (averaged 11.52 μg m⁻² sec⁻¹). Moreover, the results also indicate that SO₄ ²⁻ and Ca²⁺ have higher average composition for total suspended particulates in the daytime period while Ca²⁺, SO₄ ²⁻, and Na⁺ have the higher average composition for total suspends particulates in the nighttime period.     

利用四段滤膜法进行干沉积监测

在酸雨研究领域,人们普遍是对降雨或降雪等湿沉积过程进行研究.近年来,干沉积也引起了大家的关注,但尚未建立成熟的方法.文章介绍了利用四段滤膜法进行干沉积监测的方法,作为日本全国公害研究协会的合作项目在日本神户和丰冈市进行了实际测量和评估.     

A Comparison of Precipitation Sensors Used on the Wet-Only Collectors

The variability in performance of three precipitation sensor types, mounted on three identical wet-only collectors, has been compared for eight months at a single site. The catch efficiencies, determined from the sample volumes, are relatively high for these three apparatuses, since they exceed 89% on average. The recorded data of openings and closings of collector lids reveal that the highest losses of collection efficiency, observed for rainfalls of low intensity and low amount, are largely imputable to design and running characteristics of each sensor. Ionic compositions between the samples of these three collectors are relatively close, although significant differences are especially found for H⁺, Ca²⁺, Mg²⁺ and K⁺, suggesting that these apparatuses are differently exposed to the dry deposition of soil particles. The RS 85 sensor seems to be the most suitable one of the three, since it ensures a high catch efficiency for all rain types and tends to limit the exposures of funnel to the dry deposition.     

Field Survey of Trans-boundary Air Pollution with High Time Resolution at Coastal Sites on the Sea of Japan during Winter in Japan}

An intensive field survey, with 6-h measurement intervals, of concentrations of chemical species in particulate matter and gaseous compounds was carried out at coastal sites on the Sea of Japan during winter. The concentration variation of SO₂(g) and HNO₃(g) were well correlated, whereas the NH₃(g) concentration variation had no correlation with those of SO₂(g) and HNO₃(g). The NH₄ ⁺ (p)/non-sea-salt- (nss-)SO₄ ^{2 −}(p) ratio in particulate matter was mainly affected by the location of the sampling site. One or more concentration peaks of nss-Ca^{2 +} for survey period were observed. Backward trajectories analyses for the highest nss-Ca^{2 +} concentration peaks showed some inconsistency in pathways. We consider that insufficient mixing of the atmosphere and/or insufficient time for the transported air pollutants to react with those discharged locally are the most likely explanations for the discrepancies between the measured products [HNO₃][NH₃] and the calculated values.     

太湖大气氮、磷干湿沉降特征

于2018年1—12月,采集太湖湖滨及湖面共计9个点位600多个干湿沉降样品,估算了N、P干、湿沉降率以及全太湖2018年N、P干、湿沉降通量。结果表明,2018年太湖TN和TP月湿沉降率均值分别为161. 2和7. 1 kg/(km~2·月),TN和TP月干沉降率均值分别为103. 6和4. 5 kg/(km~2·月)。TN和TP年干沉降率空间分布规律为:湖面之上开阔水域处的TN和TP年干沉降率大于其他湖滨点位,TN和TP总沉降通量为7 702和333 t/a。2018年相比于2002—2003年,TN和TP总沉降通量分别降低了22. 6%和53. 8%。     

污水处理厂氮排放特征

为了更好地掌握污水处理厂运行和排放情况,在全国南方、北方分别选取3个省共11个城市122家污水处理厂,于2013年8—10月进行了专项监测。结果表明：75?4％的污水处理厂氨氮出水质量浓度小于2 mg／L,氨氮平均去除率达90?2％,但总氮的平均去除率仅为55?5％,污水处理厂排水中仍存在较多非氨氮形态的氮污染进入环境。氨氮排放达标的污水处理厂中,有约20％的总氮排放未达标。65?5％的污水处理厂出水氨氮占总氮的比例低于10％,而84?4％的污水处理厂进水中氨氮占总氮的比例高于50％。总氮是影响污水处理厂达标排放的主要污染因子。     

降雨对长三角区域PM2.5浓度的影响

利用WRF-CAMx模式分析首届中国国际进口博览会(简称进博会)期间一次降雨过程对长三角地区PM2.5浓度影响,结果表明,降雨量分布区域与因降雨造成的PM2.5浓度减少量分布区域并不完全一致,湿沉降量受降雨量、PM2.5浓度和风速等多个因素共同影响。数值模拟结果表明,降雨导致浓度下降幅度排前5位的组分分别是有机气溶胶、硫酸盐、硝酸盐、铵盐和细颗粒原生气溶胶,下降幅度分别为44. 28%、16. 55%、11. 55%、9. 53%和5. 23%。结合观测资料和数值模式模拟结果可知,首届进博会期间上海本地减排和周边区域协同控制作用使PM2.5日均质量浓度降低33. 23μg/m3,因降雨引起的湿沉降作用使上海市PM2.5质量浓度降低15. 88μg/m^3。     

The development of loads of cations, anions, Cd and Pb in precipitation and of atmospheric concentrations of N-components, in Switzerland from 1988 to 2003

This study presents the results of the analyses of Cd, Pb, cations and anions present in precipitation and dust at a pre-alpine and a suburban site in Switzerland in the period from 1988 to 2003. The aim of these measurements was to monitor the success of measures taken to diminish pollutant emissions. No change was found for Ca²⁺, K⁺, Na⁺ and Mg²⁺ loads – in line with expectations, as no reducing measures had been taken. Statistically significant and largely decreasing values (50–90%) were found for Cl⁻ and Cd (linked to the fitting of filters in incineration plants), Pb (unleaded petrol), (diminishing the use of mineral oil with high S content), and the proton (lower HCl and SO₂ emissions). A smaller decrease (up to 30%) or none was registered for oxidised nitrogen components (fitting cars with catalytic converters, but an increase in numbers of cars and trucks). No significant change was found for NH₃ as farming techniques had undergone no major changes. The long-term measurements show that the measures taken to reduce emissions were successful. A shorter monitoring period would have been misleading owing to data variability and temporary incidents e.g. amount of precipitation.