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1.
基于Meta分析,研究畜禽粪肥类型、耕作方式和施肥量对土壤中Cu、Zn、Cd和As含量的影响。结果表明:畜禽粪肥(鸡粪、猪粪和牛粪)施用会显著提高耕地土壤中Cu、Zn、Cd和As含量,其平均含量的增幅分别可达18.14%、16.44%、16.61%和14.81%;与施用鸡粪和牛粪相比,施用猪粪土壤Cu含量增加显著,且其Zn和As含量的增幅也最高;高粪肥施用量(≥60 t/hm2)下土壤Cu、Zn和Cd含量的增幅均达35%以上,而低粪肥施用量(≤30 t/hm2)下其含量的增幅均低于20%;旱地和水旱轮作2种耕作方式下施用粪肥土壤中金属元素含量显著增加,而水田耕作方式下其含量无显著变化。  相似文献   

2.
基于河南省常规空气污染物、颗粒物组分等数据,开展烟花爆竹燃放对空气质量影响的定量评估。结果表明:2023年元宵节期间,河南省PM2.5质量浓度小时峰值为226μg/m3,仅次于2019年的239μg/m3,明显高于2022年的86μg/m3,正月十六重度及以上污染天数为历史最高值;烟花爆竹燃放造成K+、SO42-、Cl-浓度快速上升,对K+浓度影响最为显著,河南省K+小时峰值浓度较基准时刻平均上升了26.6倍;烟花爆竹燃放对河南省正月十五、十六PM2.5日均值贡献分别为31.5%、31.8%,使PM2.5质量浓度分别上升39μg/m3和57μg/m3,2 d的烟花爆竹燃放可使河南省2023年PM2.5年均质量浓度上升0.26μg/m3,造成...  相似文献   

3.
采用多元线性回归-分光光度法进行电镀排放废水中Cr3+、Ni2+、Zn2+的同时测定研究。以4-(2-吡啶偶氮)间苯二酚(PAR)为显色剂,探索了同时测定模拟电镀废水中Cr3+、Ni2+、Zn2+的实验方法,建立多元线性回归模型。根据实际电镀排放废水中Cr3+、Ni2+、Zn2+的质量浓度分布调查结果,设计了测定较低和较高浓度范围2种模型,分别对应不同水质波动程度的电镀企业废水,前者浓度范围设置基本覆盖大多数实际电镀排放废水中Cr3+、Ni2+、Zn2+的浓度,且具有较高精度。测定浓度范围较小模型对应水质波动较小的电镀排放废水,模型中Cr3+、Ni2+、Zn2+的质量浓度分别为0.32~0.44、0.32~0.50、0.72~0.84 mg/L,平均相对误差MR...  相似文献   

4.
利用2014—2020年河南省18个地级城市空气质量监测资料和气象数据,运用空间自相关分析、ArcGIS制图及相关性分析等方法,从时空分布特征上揭示河南省PM2.5污染特征,并分析其气象成因。结果表明:河南省2014—2020年PM2.5年均浓度为40~100μg/m3,总体呈递减趋势。PM2.5浓度季节分布特征为冬季>秋季=春季>夏季。河南省2019年和2020年PM2.5污染空间分布存在显著自相关,污染程度严重的地区主要是中部和东北部地区。冷热点分析发现,热点城市为濮阳、安阳、济源、郑州、新乡、焦作、鹤壁,冷点城市为信阳、驻马店、周口。PM2.5在年尺度上与气压、气温、相对湿度、风向、风速、能见度显著相关,其中,与气温相关性最高,相关系数为-0.424。当相对湿度处于90%以下时,PM2.5浓度与相对湿度呈正相关;而在相对湿度超过90%之后,PM2.5浓度下降至70μg/m3...  相似文献   

5.
基于2016—2020年台州市区大气污染物监测数据及气象观测资料,分析了台州市区PM2.5和O3的污染特征及受气象因素影响情况,并探究了不同季节下的PM2.5浓度和O3浓度的相关性及相互作用关系。2016—2020年,台州市区PM2.5年均浓度和超标天数呈显著下降趋势,O3-8 h年均浓度和超标天数总体呈上升趋势。PM2.5浓度在冬季最高,且易发生超标;O3浓度在春、夏、秋季均较高,且均会发生超标。通过相关性分析可知:PM2.5浓度与气温、相对湿度、风速、降水量呈负相关,与大气压呈正相关;O3浓度与气温、风速呈正相关,与相对湿度、降水量呈负相关。不同季节下的PM2.5浓度与O3浓度均呈正相关,两者存在协同增长。在春、夏、秋季,二次PM2.5在总PM2.5中的占比随着O3  相似文献   

6.
以新疆渭干河-库车河三角洲绿洲耕层土壤为研究对象,通过对原始光谱反射率(R)、包络线去除(CR)和一阶微分(R′)变换光谱数据结合连续小波变换生成小波系数,筛选出与砷含量具有极显著相关性的特征波段(P<0.001),运用偏最小二乘回归、BP神经网络、随机森林回归及支持向量机回归分析方法建立耕层土壤砷含量的高光谱估测模型。结果表明,经一阶微分结合连续小波变换处理后,光谱数据与砷含量之间的相关性提升尤为明显。综合考虑各模型估测精度及稳定性,认为R′-CWT-26-SVMR模型可作为研究区耕层土壤砷含量的最佳估算模型,其训练集和验证集的决定系数(R2)分别为0.753和0.740,均方根误差(RMSE)分别为1.350 mg/kg和1.819 mg/kg,相对分析误差(RPD)分别为2.03和2.00。  相似文献   

7.
基于漯河市大气灰霾站在线观测数据,分析2022年10月12—19日PM2.5-O3复合污染过程中VOCs的污染特征及来源,以期判别复合污染过程中需要优先管控的VOCs物种及来源,为PM2.5和O3协同管控提供依据。结果表明:污染期间VOCs平均质量浓度(96.7μg/m3)显著高于污染前(49.4μg/m3)和污染后(54.8μg/m3),以烷烃和卤代烃占比较高;整个污染过程中质量浓度较高的物种包括乙醛、乙烷、丙烷、异戊烷、氟利昂-12、二氯甲烷、甲苯、苯、一氯甲烷、氟利昂-11、正丁烷和1,2-二氯乙烷;污染期间正丁烷、异戊烷、丙烷、二氯甲烷、一氯甲烷和苯的质量浓度增幅均超过100%。漯河市VOCs的O3生成潜势(OFP)以OVOC和烯烃占比较高,二次有机气溶胶生成潜势(SOAp)以芳香烃占比最高。OFP贡献较高物种为乙醛、乙烯、甲苯和丙烯,SOAp贡献较高物种为甲苯、苯、间、对二甲苯、乙苯和邻二甲苯;污染期间...  相似文献   

8.
于2018年冬季在广州城区磨碟沙站点开展细颗粒物(PM2.5)样品采集,并获得PM2.5中水溶性离子、含碳组分、稳定碳氮同位素的组成及时间变化特征,重点讨论了PM2.5浓度升高时段的化学组成特征变化,进而利用稳定碳氮同位素变化特征探究了主要污染来源。结果表明:采样期间,研究站点PM2.5平均质量浓度为22.1μg/m3,共出现两个PM2.5浓度水平升高时段,所对应的平均质量浓度分别达46.0μg/m3和63.0μg/m3。风速降低、温度升高等不利气象条件是导致上述时段PM2.5浓度上升的重要原因。在上述时段,伴随着PM2.5浓度的升高,NO-3和NH+4浓度均出现显著升高,NO-3与SO2-4的摩...  相似文献   

9.
徐州市地处四省交界,大气污染物来源复杂,颗粒物污染在气象条件不利时较为显著。通过地面观测数据、颗粒物组分连续观测、源解析及轨迹溯源等方法,对徐州市2019—2021年颗粒物变化特征进行了全面分析,以定量解析各类污染源的贡献,识别对颗粒物贡献显著的化学成分。结果表明:PM2.5各组分质量占比中二次无机盐和有机碳相对较高,其中二次无机盐SNA(SO■、NO-3、NH+4)占比达到59.1%~62.7%;水溶性离子总浓度逐年降低,但Mg2+和Ca2+浓度2021年分别同比增加2%和12.5%,说明扬尘污染存在反弹。秋冬季水溶性离子明显较高,Cl-浓度明显高于其他季节,表明徐州市秋冬季受移动源、燃煤源和二次有机气溶胶共同影响。PM2.5中OC与EC质量浓度比为4.88~8.40,说明徐州市颗粒物受多源影响,柴油、汽油机动车尾气排放以及燃煤排放对颗粒物贡献较大。后向轨迹分析表明,污染严重的1月污染物主...  相似文献   

10.
根据2011—2020年云南辐射环境质量土壤国省控点238U、232Th、226Ra、40K、137Cs、90Sr的监测结果,给出云南环境土壤放射性水平,得出云南环境土壤放射性水平总体平稳;云南环境土壤国省控点238U、232Th、226Ra、40K的监测结果与云南省环境天然放射性水平调查结果相近,与云南土壤238U、232Th、226Ra、40K分布趋势基本吻合;云南土壤238U、232Th、226Ra活度浓度略低于全国平均水平;由于大气迁移、沉降作用,早期核试验、核事故释放的核素137Cs、90Sr在云南环境土壤均有不同程度的检出。云南属伴生放射性矿产资源大省,滇西南某地...  相似文献   

11.
河流沉积物中有机污染物的分析研究进展   总被引:8,自引:2,他引:6  
总结了近年来河流沉积物中有机污染物的研究进展 ,集中评述了国内有关沉积物中多环芳烃、有机氯农药和多氯联苯的分析研究现状 ,包括样品采集、样品前处理和样品分析 ,并对今后河流、湖泊及水库沉积物中污染物的分析工作作了展望  相似文献   

12.
Concern about nitrogen loads in marine environments has drawn attention to the existence and possible causes of long-term trends in nitrogen transport in rivers. The present study was based on data from the Swedish environmental monitoring programme for surface water quality; the continuity of these data is internationally unique. A recently developed semiparametric method was employed to study the development of relationships between runoff and river transport of nitrogen since 1971; the observed relationships were then used to produce time series of flow-normalised transports for 66 sites in 39 river basins. Subsequent statistical analyses of flow-normalised data revealed only few significant downward trends (p 0.05) during the time period 1971–1994, and the most pronounced of these downward trends were caused by reduced point emissions of nitrogen. The number of significant upward trends was substantially larger (15 for total-N and 18 for NO3-N). Closer examination of obtained results revealed the following: (i) the most pronounced upward trends were present downstream of lakes, and (ii) observed increases in nitrogen transport coincided in time and space with reduced point emissions of phosphorus or organic matter. This indicated that changes in the retention of nitrogen in lakes were responsible for the upward nitrogen trends. The hypothesis that nitrogen saturation of forest soils has caused a general increase in the riverine export of nitrogen from forested catchments in Sweden was not confirmed. Neither did the results indicate that improved agricultural practices have reduced the export of nitrogen from agricultural catchments.  相似文献   

13.
HPLC法测定饲料中维生素A、维生素D 3 和维生素E   总被引:2,自引:0,他引:2       下载免费PDF全文
建立了以w(C2H5OH)=95 %乙醇直接提取,高效液相色谱仪在波长280 nm和254 nm处连续测定饲料中维生素A、维生素D3和维生素E的方法.色谱柱为大连依利特Hypersil ODS C18(25 cm×4.6 mm×5 μm),流动相为甲醇-水,流速为1.2 mL/min.维生素A、维生素D3、维生素E的质量浓度分别在1.0 mg/L~20.0 mg/L、0.5 mg/L~15.0 mg/L 、2.5 mg/L~50.0 mg/L范围内与峰面积呈良好的线性关系,检测限分别为0.3×10-6 μg、0.04×10-6 μg、5.0×10-6 μg,相对标准偏差分别为1.6 %、2.7 %、2.4 %,平均回收率分别为99 %、102 %、98 %.  相似文献   

14.
A study was undertaken to estimate fluoride content in thegroundwater in certain parts of rural Eritrea, North-East Africa,along the River Anseba. Standard procedure was adopted for fluoride detection. Results indicate elevated concentration offluoride in groundwater. The highest concentration was found tobe 3.73 mg L-1, well above the safety level for consumption.Geological basis for the high concentration of high fluoride hasbeen established; it is presumed to be the pegmatite intrusion hosted by a granitic batholith. Extensive dental fluorosis has been observed in the population exposed to drinking water of highfluoride content.  相似文献   

15.
为调查丽水市空气中Pb污染现状,在机动车相对集中的市区布设5个测点,测点高度1.2m;监测周期为1a,每星期采样1d或2d,每天采集1个样,每次采样6h;监测项目为TSP、Pb;评价标准采用GB3095—1996《环境空气质量标准》。结果表明,丽水市各测点空气中Pb最大的季均值、年均值均未超标;常规测点和交通路口测点之间TSP、Pb质量浓度值均存在显著的差异性。  相似文献   

16.
Samples of breast muscle from 32 species of waterfowl collected from 123 sites across Canada were analyzed for chlorobenzenes (CBz), chlordane-related compounds (CHL), hexachlorocyclohexanes (HCH), DDT, mirex, dieldrin, PCBs and mercury. ΣDDT, ΣCBz and ΣPCB were the compounds most frequently found above trace levels. ΣHCH and ΣMirex were detected the least often. Mercury was detected in all of the mergansers, over 50% of dabbling, bay and sea ducks, and in less than 2% of the geese analysed. The highest levels of contaminants were generally found in birds feeding at higher trophic levels such as sea ducks and mergansers. With the exception of a few samples of mergansers and long-tailed ducks from eastern Canada, which contained ΣPCB concentrations of 1.0–2.4 mg kg−1, ΣPCB levels were less than 1 mg kg−1 wet weight. Only one merganser from eastern Canada had a ΣDDT concentration (2.6 mg kg−1 ww) which was greater than 1 mg kg−1 ww. The highest ΣCHL (0.10 mg kg−1 ww) was also found in mergansers from eastern Canada. Levels of total mercury in breast muscle were either low (< 1 mg kg−1 ww) or below detection limits with the exception of a few samples of mergansers from eastern Canada which contained mercury concentrations of 1.0–1.5 mg kg−1 ww. Health Canada determined that the organochlorine and mercury levels found in samples of breast muscle of ducks and geese analysed in this study did not pose a health hazard to human consumers and therefore these waterfowl were safe to eat.  相似文献   

17.
为了解兰州市大气PM2.5中金属元素的污染水平和分布,于2013年冬季和春季在兰州市区4个在线监测点进行PM2.5样品采集,利用ICP-MS分析金属元素浓度。结果表明,Pb、B元素含量高于200 ng/m3,V、Fe元素含量在100~200 ng/m3,其余元素含量低于100 ng/m3,其中Pb含量最高,平均含量达到373.8 ng/m3.各监测点元素含量在冬季和春季各有不同,整体上是冬季高于春季。金属元素在兰州市区的空间分布与兰州市工业排放和气象因素有关,工业排放为主导因素。  相似文献   

18.
The air temperature distributions in August (summer) and December (winter) were measured in an approximately 15 × 15-km urban area in Hyogo Prefecture, Japan, in order to study the spatial distribution of the air temperature and to propose effective measures against the heat island phenomenon. The air temperature was measured mainly by using thermometer shelters installed in an elementary school and a junior high school. The characteristic air temperature distribution depended on the season. The air temperature was higher inland than in the coastal region in August but was higher in the coastal region in December. The air temperature index indicated that the area where higher air temperatures would most likely appear was 5 to 10 km inland from the coast in August and around the coast in December. The seasonal air temperature distribution was presumably due to the strength of solar radiation and anthropogenic exhaust heat.  相似文献   

19.
中国1998年度环境质量状况   总被引:8,自引:0,他引:8  
对我国1998年度的环境空气质量,酸雨,主要流域水质,近岸域海水水质,地下水水位与水质,城市声环境、射环境质量,典型区域生态环境的状况进行了综述了与分析,指出了我国的环境污染问题主要是城市空气污染,地面水体污染和城市噪声污染。  相似文献   

20.
天津市空气颗粒物中酞酸酯的分布特征   总被引:2,自引:1,他引:1  
采用气相色谱-质谱仪(GC-MS)对天津市空气颗粒物中15种酞酸酯(PAEs)夏季和冬季的浓度进行了分析测定,研究了酞酸酯污染水平的季节变化,不同季节酞酸酯的功能区差异,15种酞酸酯在颗粒物中的分布特征,以及DBP和DEHP在夏冬两季中的污染特点,分析了产生上述结果的原因,基本说明了天津市空气颗粒物中酞酸酯的污染状况和特点。  相似文献   

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