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1.
采用大型底栖动物生物完整性指数(B-IBI)法对松花江流域的水生态环境质量进行研究分析。结果表明,2015年松花江流域各点位水生态环境质量17.24%为优、10.34%为良好、24.14%为一般、41.38%为较差、6.90%为很差。与2012年松花江流域水生态环境质量的比较和趋势分析表明,松花江干流下游、第二松花江、松花江支流的水生态质量均出现不同程度的改善,松花江干流下游改善尤为显著,松花江干流上游生态质量基本保持不变,嫩江水生态质量有下降迹象。流域总体水生态环境质量得到进一步改善,总物种数和清洁指示类群EPT丰度均有增加。  相似文献   

2.
三岔湖浮游植物四季群落结构变化   总被引:3,自引:2,他引:1  
2008年5月—2009年4月对三岔湖浮游植物群落结构进行调查的结果显示,浮游植物有8门78属299种,浮游生物群落结构、优势种和密度有明显的季节变化。春末和夏季蓝藻占绝对优势,冬季和初春硅藻和绿藻占优势。浮游植物优势种有梅尼小环藻(Cyclotella meneghiniana)、尖针杆藻(Synedra acus Kutzing)、小舟形藻(Naviculaminima)、细小平裂藻(M erism opdeia minima)、湖泊鞘丝藻(Lyngbya lim netia)等。浮游植物优势种群和密度显示,湖区的水体已进入富营养状态。  相似文献   

3.
底栖动物是水生态系统的重要组成部分,其群落特征通常用来评价水生态环境质量。研究了2012—2019年松花江干流水生态环境质量状况、变化趋势,并应用冗余分析(RDA)探究底栖动物群落结构特征与水环境因子之间的响应关系。结果表明:8年间共鉴定出底栖动物246个分类单元,隶属于4门、9纲、25目、58科、69属,其中水生昆虫的EPT物种为99个分类单元,占总物种数的40.24%;水生昆虫的其他物种为68个分类单元,占总物种数的27.64%;软体动物为36个分类单元,占总物种数的14.63%;环节动物为25个分类单元,占总物种数的10.16%;甲壳动物为18个分类单元,占总物种数的7.32%。底栖动物密度总体呈上升趋势,种类组成总体有所增多,其中环节动物、软体动物和甲壳动物有向水生昆虫转变的趋势,群落结构相对稳定且主要以水生昆虫占比最多,底栖动物密度平均值为5.97×103个/m2,变化范围为2.86×103~8.98×103个/m2,优势科(属)主要为小蜉属Ephemerella、小寡脉蜉属Oligoneuriella、扁蜉属Heptagenia、等蜉属Isonychia、纹石蛾科Hydropsychidae、缺叉多距石蛾属Polycentropus、摇蚊科Chironomidae和圆田螺属Cipangopaludina等。生物指数评价结果多数为"中等"及以上,评价结果趋于稳定,且下游评价结果好于上游。松花江干流的水环境质量变化阶段性明显,溶解氧含量升高,氨氮呈下降趋势,其余指标呈波动变化。冗余分析(RDA)结果表明:影响松花江干流底栖动物群落结构变化的主要环境因子是随时间推移而变化的,其中溶解氧、生化需氧量、化学需氧量、总磷、氨氮和总氮等指标是影响该监测区域底栖动物群落分布的重要环境因子。  相似文献   

4.
募集100辆点燃式发动机在用汽车进行遥感法和高怠速法尾气排放对照检测试验。结果表明,多数车辆CO遥测值比高怠速值大,HC则相反。通过对高怠速值(y)与遥测值(x)进行回归分析,得到CO的回归方程为y=0.81x+453.03,t检验显示方程具有线性(α=0.10)。如果将两种方法配合使用,可以有效提高机动车尾气排放日常管理的效果。  相似文献   

5.
采用遥感分布式面源污染评估模型(DPeRS),对2018年黄河流域(甘肃段)面源污染空间分布特征进行分析,具体包括多类型污染量产排特征解析和流域优先管控单元识别。结果表明,污染量上,2018年黄河流域(甘肃段)总氮(TN)、总磷(TP)、氨氮(NH3-N)、化学需氧量(CODCr)的面源污染排放负荷分别为65.6,11.8,19.1和77.2 kg/km2,入河量分别为836.7,33.3,220.2和1 353.3 t;空间分布上,氮型(TN和NH3-N)排放负荷高值区主要分布在流域中部和东部局部地区,流域大部分地区TP排放负荷均较高,CODCr面源污染排放负荷高值区分布较为零散。与排放负荷相比,黄河流域(甘肃段)面源污染入河负荷并不突出,这与该地区水资源量少有密切关系。筛选出黄河流域(甘肃段)面源污染优先控制单元15个,面积占比为85.2%,I类优控单元主要分布在庆阳市、天水市、兰州市和白银市等地区,II类优控单元主要分布在甘南藏族自治州,且TN、TP、NH3-N和CODCr面源污染优控单元识别结果的平均精度达到80%。  相似文献   

6.
南宁城市内河沉积物中SVOCs的分布与风险评价   总被引:1,自引:1,他引:0  
采用加速溶剂萃取-气相色谱-质谱联用技术对南宁市7条城市内河表层沉积物中的64种半挥发性有机物(SVOCs)进行了分析测定,定量检出12种SVOCs,包括7种多环芳烃类(PAHs)、1种酚类和4种酯类,其中属于我国优先控制污染物的有8种,属于美国优先控制污染物的有11种。南宁市城市内河沉积物中的SVOCs总量范围为6.75~34.45 μg/g(以干质量计),均值为15.85 μg/g(以干质量计),以竹排冲的含量最高,污染程度与工业污染源的关系十分密切。特征污染物为酞酸酯,在各测点的比重均占检出总含量的83%以上。除相思湖外的6条城市内河的沉积物均检出PAHs,区域内的工业生产活动对城市内河沉积物的PAHs有重要贡献。应用效应区间低值(ERL)和效应区间中值(ERM)指标对沉积物进行的生态风险评价表明,南宁市城市内河沉积物的生态风险较小。  相似文献   

7.
在pH 3.5~4.4的醋酸盐缓冲溶液中, Ag+与Cl-离子反应形成AgCl。当Ag+离子适当过量时,AgCl能与Ag+结合形成[AgCl·Ag]+阳离子,它能借静电引力和疏水作用力与荧光素一价阴离子(HL-)反应形成离子缔合物[(AgCl·Ag)HL],该疏水性的离子缔合物能在水相挤压作用和范德华力的作用下彼此靠近而进一步聚集,形成平均粒径约为20 nm的纳米微粒[(AgCl·Ag)HL]n。此时仅能引起吸收光谱和荧光光谱的微小变化,但能导致倍频散射(FDS)和二级散射(SOS)等共振非线性散射(RNLS)的显著增强,其最大FDS和SOS波长分别位于350和560 nm处。两种散射增强(ΔIFDS和ΔISOS)在一定范围内均与氯离子浓度成正比,均可用于氯离子的测定。其中以FDS最灵敏,对于氯离子的检测,其线性范围是0.04~1.22 μg/mL, 检出限为10.9 ng/mL;在环境空气或无组织排放废气HCl的检测中,当采气体积为60L时,其线性范围是0.007~0.21 mg/m3,检出限为1.9×10-3 mg/m3;在有组织排放废气样品中,当采气体积为10 L时,其线性范围是0.04~1.25 mg/m3,检出限为1.1×10-2 mg/m3。该文研究了纳米微粒对吸收、RNLS光谱的影响、反应的适宜条件及影响因素,考察了共存物质的影响,表明方法有良好的选择性,据此利用上述反应发展了一种用SOS和FDS技术高灵敏度、高选择性和简便、快速测定环境空气和废气中HCl及环境水样中氯化物的新方法。文中还对反应机理进行了讨论。  相似文献   

8.
采用硫酸溶液为吸收液,顶空进样气相色谱法测定大气中的吡啶,毛细管柱分离,FID检测器分析。吡啶标准溶液在0~98.3 mg/L范围内线性良好,当采样体积为30 L时,最低检出质量浓度为0.006 mg/m3,标准溶液平行测定的RSD≤3.1%,加标回收率为95.3%~99.6%。  相似文献   

9.
气相色谱法测定工业废气中的异丙醇   总被引:1,自引:1,他引:0  
用活性炭吸附管采集吸附工业废气中的异丙醇,经二硫化碳解析后由自动进样器送入气相色谱仪中分离并由FID检测器检测。2 mL二硫化碳解吸溶剂中异丙醇的绝对量为1.57~6.28 mg时,测定结果的相对标准偏差为2.4%~7.6%(n=5);当样品采集量为10 L时,方法检出限为0.3 mg/m3。所用活性炭采样管对异丙醇的吸附效果良好,100 mg活性炭对异丙醇的穿透容量大于15 mg;二硫化碳溶剂对吸附在活性炭中的异丙醇解吸效果较好,异丙醇加标量为3.92~15.70 mg时,解吸效率为93.9%~100.5%。  相似文献   

10.
西南涌流域底泥重金属污染特征及潜在生态危害评价   总被引:2,自引:2,他引:0  
西南涌流域近年来受到比较严重的污染,为了解受重金属污染状况,对该流域底泥重金属污染水平与特征进行了调查与分析,并在此基础上采用地累积指数法和潜在生态危害指数法对西南涌流域底泥重金属污染程度与生态危害进行了评价。结果表明,西南涌流域底泥已不同程度受到重金属Cu、Zn、Pb、Cd、Cr的污染,与珠三角土壤背景值相比,西南涌流域底泥重金属Cu、Zn、Pb、Cd、Cr分别超标11.38、3.32、1.81、19.45、3.20倍;底泥中的Cu、Zn、Cr、Cd之间呈极显著正相关(r=0.615~0.964)。通过地累积指数法评价表明,西南涌流域底泥中的Cd为偏重污染,Cu、Zn为偏中度污染,Pb为轻度污染,Cr为无污染;潜在生态危害指数法评价结果表明,西南涌流域底泥重金属的潜在生态危害程度总体属中等,主要是由Cd的含量过高引起。  相似文献   

11.
微波消解-原子吸收光度法测定土壤中铜锌铅镉镍铬   总被引:24,自引:5,他引:24       下载免费PDF全文
用微波消解-原子吸收光度法测定土壤中铜,锌,铅,镉,镍和铬。通过硝酸-氢氟酸-过氧化氢体系消解液对土壤样品消解,选择出微波最佳消解条件。对硝酸-盐酸-过氧化氢体系消解液和硝酸-氢氟酸-过氧化氢体系消解液进行消解对比试验,发现前者不能将土壤样品完全消解,后者能将样品消解完全,但需将消解液中剩余的酸赶尽,否则测定结果将明显偏低。微波消解土壤与传统电热消解相比,操作简便快速,可提高工作效率。  相似文献   

12.
Material Disposal Area G is the primary low-levelradioactive waste disposal site at Los Alamos NationalLaboratory, New Mexico, and is adjacent to Pueblo of SanIldefonso lands. Pueblo residents and Los Alamos scientists areconcerned about radiological doses resulting from uptake of AreaG radionuclides by mule deer (Odocoileus hemionus) andRocky Mountain elk (Cervus elaphus), then consumption ofdeer and elk meat by humans. Tissue samples were collected fromdeer and elk accidentally killed near Area G and were analyzedfor 3H, 90Sr, total U, 238Pu, 239, 240Pu,241Am, and 137Cs. These data were used to estimatehuman doses based on meat consumption of 23 kg y-1. Humandoses were also modeled using RESRAD, and dose rates to deer andelk were estimated with a screening model. Dose estimates tohumans from tissue consumption were 2.9 × 10-3 mSv y-1and 1.6 × 10-3 mSv y-1 from deer and elk, respectively,and RESRAD dose estimates were of the same order of magnitude. Estimated dose rates to deer and elk were 2.1 × 10-4 mGyd-1 and 4.7 × 10-4 mGy d-1, respectively. Allestimated doses were significantly less than established exposurelimits or guidelines.  相似文献   

13.
The aim of the study was to determine the extent of heavy metal pollution in the vicinity of a lead battery manufacturing plant in the Czech Republic, both in the general environment and within homes. Topsoils (0–5 cm) were sampled from 100 sites along 4 transects which crossed the battery factory, the town centre and outlying rural areas. Housedust samples were collected from 15 plant-workers' homes and 15 non plant-workers' homes located at various distances from the factory. Samples were analysed for levels of Pb, Zn, Cd, Cu, As and Sb, using ICP-AES. Soil concentrations of Pb, Cd, As and Sb peaked at the perimeter fence of the battery factory with Pb levels of up to 12 650 g g> -1. Concentrations of these metals decreased exponentially within 500 m of the plant. Whilst the battery factory does appear to be a source of all the metals with the exception of Zn, emissions do not appear to be transported to any great extent over distances of more than 0.5 km. Topsoil and housedust concentrations of Pb, Zn, Cd, Cu, As and Sb in the general Mlada Boleslav area do not appear to be significantly different from those recorded in a large scale survey of urban soils in the United Kingdom. A comparison of housedust Pb concentrations in homes of plant workers and non-plant workers suggests that there may be a small input of Pb into the home environment by battery plant employees.  相似文献   

14.
An important research area in life sciences is devoted to modeling, prediction, and dynamics of gene-expression patterns. As clearly understood in these days, this enterprise cannot become satisfactory without acknowledging the role of the environment. To a representation of past, present, and most likely future states, we also encounter measurement errors and uncertainties. This paper surveys and improves recent advances in understanding the foundations and interdisciplinary implications of the newly introduced gene–environment networks, and it integrates the important theme of carbon dioxide emission reduction into the networks and dynamics. We also introduce some operational and managerial issues of practical working and decision making, expressed in terms of sliding windows, quadrants (modules) of parametric effects, and navigating (controlling) between such effects and directing them. Given data from DNA microarray experiments and environmental records, we extract nonlinear ordinary differential equations that contain parameters that have to be determined. For this, we employ modern (Chebychevian) approximation and (generalized semi-infinite) optimization. After this is provided, time- discretized dynamical systems are studied. A combinatorial algorithm with polyhedra sequences allows to detect the region of parametric stability. Finally, we analyze the topological landscape of gene–environment networks with its structural (in)stability. By embedding as a module and investigating CO2 emission control and figuring out game theoretical aspects, we conclude. This pioneering work is theoretically elaborated, practically devoted to health care, medicine, education, living conditions, and environmental protection, and it invites the readers to future research.   相似文献   

15.
The San Francisco Estuary Regional Monitoring Program for Trace Substances (RMP) began in 1993 and is sponsored by 74 local, state, and federal agencies and companies through their discharge or Bay use permits. The RMP monitors water, sediment, toxicity, and bivalve bioaccumulation at 25 sites in the Bay that are considered to represent "background" conditions. Several major environmental issues have been identified by the RMP. Polychlorinated biphenyls and mercury were often above water quality guidelines, and often occurred in fish tissues above U.S. Environmental Protection Agency (U.S. EPA) screening values. Concentrations do not appear to be decreasing, suggesting continuing inputs. Episodes of aquatic toxicity often occurred following runoff events that transport contaminants into the Bay from urbanized and agricultural portions of the watershed. Sediment toxicity occurred throughout the Bay, and has been correlated with concentrations of specific contaminants (chlordanes, polynuclear aromatic hydrocarbons) at some locations; mixtures of contaminants were probably also important. Since the RMP does not monitor all ecosystem components, assessments of the overall condition of the Bay cannot be made. However, in terms of contamination, the RMP samples suggest that the South Bay, and North Bay sites are moderately contaminated.  相似文献   

16.
This paper gives mathematical details and sample applications of SWAGMAN Farm (SWAGMAN, Salt Water and Groundwater Management), a farm-scale hydrologic economic model that integrates agronomic, climatic, irrigation, hydrogeological and economic aspects of irrigated agriculture. The model is capable of determining optimum mix of land use to keep watertable and soil salinity within acceptable limits while maximising the economic returns. Alternatively, the model can simulate water and salt balance and economics of a given cropping preference. Web-based and Geographic Information Systems versions of the model are available for integration with the environmental reporting systems of the irrigation areas.  相似文献   

17.
A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g-1 wet weight (ww), PCBs 0.69 g g-1, 2,3,7,8-TCDD 2.3 ng kg-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.  相似文献   

18.
The draft of the German guideline to calculate automobile exhaust dispersion is explained. It contains a two-stage-system: For first quick estimates the guideline contains the simple models MLuS and STREET. In case these models are not applicable or their results shows concentration levels close to the air quality standards, the more complex models PROKAS_V and MISKAM are recommended. PROKAS_V is a Gaussian plume model, MISKAM is a 3-dimensional microscale non hydrostatic flow model for built-up areas with an Eulerian dispersion model. The guideline comprises cases in rural areas without or with few adjacent buildings as well as urban areas with buildings near the roads. The contribution gives information about the models, typical results and some of the problems showing up presently.  相似文献   

19.
The population counts of hydrocarbon-utilising yeasts weremonitored at six sampling stations in the Benin City municipalarea over a four-week period. Although the population countswere relatively constant in each locality, the highest countsoccurred in areas heavily polluted by domestic and industrialeffluents. A total of thirty-five hydrocarbon-degrading yeastswere isolated from soil at the sampling stations usingn-hexadecane as sole carbon source. The isolates were identifiedas belonging to the genera Candida (27 strains), Endomycopsis (4 strains). All the organisms grew on long-chainn-alkane, kerosene, diesel oil and crude oil but failed to growon short-chain n-alkane, aromatic and alicyclic hydrocarbons.Measurement of growth attributes of the isolates usingn-hexadecane, diesel oil and crude oil as substrates showed thatthe Candida species were better utilizers of hydrocarbonsubstrates relative to Endomycopsis and Schizosaccharomyces species.  相似文献   

20.
The stable nitrogen isotope ratios of some biota have been used as indicators of sources of anthropogenic nitrogen. In this study the relationships of the stable nitrogen isotope ratios of marsh plants, Iva frutescens (L.), Phragmites australis (Cav.) Trin ex Steud, Spartina patens (Ait.) Muhl, Spartina alterniflora Loisel, Ulva lactuca (L.), and Enteromorpha intestinalis (L.) with wastewater nitrogen and land development in New England are described. Five of the six plant species (all but U. lactuca) showed significant relationships of increasing δ 15N values with increasing wastewater nitrogen. There was a significant (P < 0.0001) downward shift in the δ 15N of S. patens (6.0 ± 0.48‰) which is mycorrhizal compared with S. alterniflora (8.5 ± 0.41‰). The downward shift in δ 15N may be caused by the assimilation of fixed nitrogen in the roots of S. patens. P. australis within sites had wide ranges of δ 15N values, evidently influenced by the type of shoreline development or buffer at the upland border. In residential areas, the presence of a vegetated buffer (n = 24 locations) significantly (P < 0.001) reduced the δ 15N (mean = 7.4 ± 0.43‰) of the P. australis compared to stands where there was no buffer (mean = 10.9 ± 1.0‰; n = 15). Among the plant species, I. frutescens located near the upland border showed the most significant (R 2 = 0.64; P = 0.006) inverse relationship with the percent agricultural land in the watershed. The δ 15N of P. australis and I. frustescens is apparently an indicator of local inputs near the upland border, while the δ 15N of Spartina relates with the integrated, watershed-sea nitrogen inputs.  相似文献   

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