火焰原子吸收法间接测定环境水中的硫化物

利用空气-乙炔火焰原子吸收法间接测定水中硫化物,方法适用于环境水中硫化物的测定.用改进后的装置进行预处理,样品中加入10ml磷酸,用氮气作载气将生成的硫化氢吹出,载气流量50ml/min,吹气40min.用pH4.5的乙酸-乙酸钠缓冲介质中的Cu(Ⅱ)作吸收液,并加入95％的乙醇作气泡分散剂.测定吸收液水相中剩余的Cu(Ⅱ),以达到间接测定硫化物的目的.方法相对标准偏差为1.6％～3.4％,检测下限0.02mg/L.     

尿液中氟化物的离子选择电极法测定

本文叙述了用离子选择电极直接测定尿液中氟化物的分析方法，并通过实验对标准系列的制备、尿液的预处理、加入“假尿溶液”的必要性和样品存放时间等问题进行了探讨。结果表明，用本方法测定尿液中氟含量简捷、快速，方法最低检出限为０．１ｍｇ／Ｌ，无机氟加标回收率为９５～１０３％。     

填充柱气相色谱法测定废水中的乙酸根

废水经蒸馏预处理,采用５％ＰＥＧ２０Ｍ＋０５％Ｈ３ＰＯ４ＣｈｒｏｍｏｓｏｒｂＨＰ８０～１００目,２ｍ×２ｍｍ玻璃填充柱,直接进预处理水样气相色谱法测定废水中的乙酸根,方法操作快速、简便,变异系数为４％和１０％,加标回收率８３％～１０５％,最小检出浓度为２ｍｇ／Ｌ     

工业废水中氨氮测定预处理的新法探讨

针对带色浊度高的工业废水氨氮测定的预处理,提出了使用硫酸铝和聚丙烯酰胺(PAM)复合絮凝沉淀法。试验结果表明,方法不仅具有操作简单,试剂用量少,絮凝效果好,去色、去浊率高(达99.6％),且对pH5～10的各种带色浊度高的废水都能起到良好的效果,并能提高测定的精密度,其变异系数为1.2％～3.6％,回收率为90％～105％,确保了数据的准确和可靠。     

水蒸气蒸馏-离子选择电极法测定矿冶废水中氟化物

建立了采用水蒸气蒸馏进行预处理,用离子选择电极法测定矿冶废水中的氟化物的方法.实验表明,以硫酸为蒸馏试剂,最佳蒸馏条件为,硫酸用量50 mL,蒸馏温度140 ～150℃,蒸馏时间30 min,方法检出限0.05 mg/L.将该方法用于实际样品分析,测定结果的相对标准偏差为2.0％,加标回收率为93.1％.该方法能够有效...     

印染废水中阴离子表面活性剂(AD)的电极法测定

本文以氧化分解一电位滴定法测定印染废水中阴离子表面活性剂的含量。预处理方法简便、快速、对多数染料干扰的消除是有效的。测定的最低含量为4—5 mg/l,测定实际度水样,变异系数<2％,加标回收率>91％,与亚甲兰方法对照,相对误差～2％。     

气相色谱法测定空气中环氧氯丙烷

本文介绍1,2,3,4四(2—氰乙氧基)丁烷—双甘油和β、β~1—氧二丙腈—双甘油的两根色谱柱,用氢火焰离子化检测器对环氧氯丙烷的色谱峰而言,具有时间短,峰形尖锐,拖尾少的优点,并可以同时测定二甲苯和苯乙烯。测定环氧氯丙烷时,方法精度为C.V=0.44-1.06％,回收率为90—112％,检出限可达10ng以下。若按取样60L计,方法检测限可达0.04mg/m~3。能进行大气和污染空气中环氧氯丙烷的测定。本法能在0～1000ng范围内使用,色谱峰值与环氧氯丙烷浓度间的相关系数大于0.999,空白值为零。环氧氯丙烷150.4ng时,测定的相对标准偏差为0.44％;902ng时,测定的相对标准偏差为1.06％。     

银离子电极法现场快速测定水中氰化物

利用银离子电极及银氰络合物的平衡指示作用,探讨了在事故现场快速测定水中氰化物的方法.试验表明方法灵敏,操作简单、快速.银离子电极对氰化物浓度从0.04～20mg/L呈线性响应.     

不同蒸馏装置预处理对氨氮测定的影响

通过实验研究对比,认为改用“磨砂瓶塞全玻璃蒸馏器装置”的预处理方法测定氨氮水样,操作简单方便,省时省力,有利于批量分析.     

紫外感应光分解后分光光度法测定地面水中的总氰化物

在大雪天用NaCl作道路的防冻剂。为了保证均匀分散,用抗粘结剂如:六氰铁(Ⅱ)酸钠处理铺路的盐,以防止生成大的盐块。尽管六氰铁(Ⅱ)酸盐的毒性较小,但暴露于阳光下仍会分解而生成游离氰化物,它对于动植物有剧毒作用。业已报道了在络合氰化物化合物紫外     

Topsoil and Housedust Metal Concentrations in the Vicinity of a Lead Battery Manufacturing Plant

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.     

微波消解-原子吸收光度法测定土壤中铜锌铅镉镍铬

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。     

An Overview of Contaminant-Related Issues Identified by Monitoring in San Francisco Bay

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.     

Biomagnification factors (fish to Osprey eggs from Willamette River,Oregon, U.S.A.) for PCDDs,PCDFs, PCBs and OC pesticides

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.     

The Draft of the New German Guideline VDI 3782/8 to Model Automobile Exhaust Dispersion

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.     

Hydrocarbon Utilization in Yeast Isolates Found to Grow in Association with Petroleum in a Polluted Ultisol of Midwestern Nigeria

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.     

Hydrologic–Economic Model for Managing Irrigation Intensity in Irrigation Areas under Watertable and Soil Salinity Targets

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.     

火焰原子吸收光谱法测定苏州开发区26种蔬菜中铜锌铁锰镍

用火焰原子吸收光谱法测定了苏州开发区26种蔬菜中的铜、锌、铁、锰和镍的含量。蔬菜样品用硝酸高氯酸混合酸进行消解。4次测定值的相对标准差<5%,加标回收率在92%～107%之间。26种蔬菜中铜、锌、铁、锰、镍的含量基本均在世贸组织规定的范围内。     

Using Multiple Taxonomic Groups to Index the Ecological Condition of Lakes

Biological indicators of communitiestypically reflect a common environmental signalreflecting the general condition of the ecosystem, as well asindividual signals by indicators differentiallysensitive to particular environmental conditions. Wedescribe here a method of integrating and interpretingsuch indicators from 19 New England lakes for fivetaxonomic groups (diatoms, benthos, zooplankton, fish,and birds). Our approach provides a systematicstandardized way to integrate multiple metrics fromdifferent taxonomic groups by addressing four elementscrucial to analyzing data from multiple indicators: covariate control, re-scaling of data, standardizing the sign of responses, and dimensional reduction. We evaluated the biologicalmetrics against individual environmental stressors andagainst multivariate physicochemical metricscharacterizing general anthropogenic stress among thelakes. The method detected a response to variationin the gross environmental condition of the lakes thatwas correlated across taxa and metrics. In addition,a differential response to near shore conditions wasdemonstrated for fish. The success of the approach inthis study lends support to its general application toecological monitoring involving complex data sets.     

Cyanobacterial Flora from Polluted Marine Shores

Citation of cyanobacterial cultures from the shores of south west coast of Gujarat, India and their relationship with sea water quality, influenced by extensive pollutant runoff is reported in this study. Intensity of pollution was evaluated by physico-chemical analysis of water. Higher load of suspended solids (60–1000 mg l⁻¹) and nutrients (PO₄ ⁻P: 1.3–4 μmole l⁻¹ and NO₃ ⁻N: 12.5–17.8 μmole l⁻¹) were persistent throughout the analysis. Community structure is seen to be influenced by such persistent pollution. Twenty nine cyanobacterial species were isolated belonging to 9 genera of 4 families, with an elevated occurrence of Oscillatoria and Lyngbya species. No heterocystous cyanobacteria were isolated throughout the study.