水和废水中亚硝酸盐氮的现场快速分析方法研究

在现行水中亚硝酸盐氮分析方法的基础上,通过试验研究,采用便携式分光光度计建立了水体中亚硝酸盐氮的分析方法。该法与GB7493-87[N-(1-萘基)-乙二胺光度法]具有良好的可比性,分析结果的精密度和准确度均为良好,该方法可在现场简便快速测定水和废水中的亚硝酸盐氮。     

气相分子吸收光谱法测定海水中亚硝酸盐氮

采用气相分子吸收光谱仪测定海水中亚硝酸盐氮,方法在低浓度(0.00~0.50 mg/L)和高浓度(0.00~2.00 mg/L)范围内均具有良好的线性,线性相关系数R2均≥0.999 7,检出限为0.003 mg/L,准确度和精密度良好。用本法与国标法(萘乙二胺分光光度法)同时测定若干实际海水样品中亚硝酸盐氮,两种方法的测定结果相对偏差为0.00%~4.90%。对两组测定结果进行线性拟合,结果显示相关系数R2为0.998 7,说明两组测定结果具有良好的一致性。相比国标法,气相分子吸收光谱法具有操作简单、分析快速准确、干扰少等优点,能够替代国标法。     

锌—镉多相还原法测定硝酸盐氮

水中硝酸盐氮的测定,常用比色法和物理化学法.比色法中,酚二磺酸法精密准确,但试剂制备和实验操作麻烦,且受氯离子(>10mg/L)和亚硝酸盐氮(>0.2mg/L)的严重干扰,对这两种离子含量较高的水样去除干扰步骤繁;物理化学法中的紫外分光光度法,简单快速,但灵敏度低;离子选择电极法受氯离子和碳酸氢根(HCO_3~-/NO_3~->5)干扰;锌—镉还原柱法,灵敏度高,但还原速度慢,且因流速不同使得试样和还原剂接触     

重氮偶联法测定水中亚硝酸盐氮的改进

重氮偶联法作为测定亚硝酸盐氮的标准方法,因具有方法灵敏、选择性强、仪器较易获得等优点,被实验室广泛采用,但也存在测定上限较低,适用样品范围较窄等缺点。通过将显色剂中磷酸改为盐酸,把重氮试剂含量提高到国标法的3倍,明显提高亚硝酸盐氮的测定上限,即由原国标法上限的0.2 mg/L提高到0.6 mg/L,灵敏度与国标法接近,且准确度和精密度良好,6组标准溶液平行测定的相对误差为1.60%,相对标准偏差为1.34%,加标回收率为96.5%~104.9%,适用于生活污水、工业废水、地表水、养殖废水等水体的测定。     

饮用水源水中水合肼测定的注意事项及解决方法

对国标法( GB/T 5750.8-2006)中的二甲氨基苯甲醛分光光度法测定饮用水源水中水合肼进行了深入研究,同时指出了水合肼测定全过程中应注意的问题及解决方法.指出在标准分析方法基础上,选用合格的最新生产的分析纯以上的试剂,现场调节水样酸度至1 mol/L,正确进行浑浊带色干扰因素校正消除,利用氨基磺酸去除亚硝酸盐...     

新方法在挥发酚测定中的探讨

新型显色剂2-对氨基苯基-2'-羟基二乙胺与水中挥发酚在碱性条件下,经铁氰化钾作用发生反应,反应产物用乙酸丁酯萃取后在可见紫外分光光度计600 nm波长下比色定量。该方法测定挥发酚在0.001 mg/L~0.100 mg/L范围内线性良好,方法检出限为0.000 8 mg/L,加标回收率为100%。用该方法与4-氨基安替吡啉三氯甲烷萃取分光光度法同时测定实际水样,结果无显著差异。     

湟水桥断面亚硝酸盐氮的监测分析

本实验采用GB7493—87标准方法对湟水河湟水桥点位上,水体中亚硝酸盐氮进行24h连续监测,检测下限为0.003mg/L,上限为0.2mg/L。湟水河是青海境内的重要河流,也是西宁地区和海东地区的主要污水受纳水体,对其水质的监测就显得尤为重要。通过实验分析,找出亚硝酸盐氮的浓度变化规律。     

用紫外分光光度法测定地表水中油的改进

漂浮于水体表面的油可影响与水体界面中氧的交换;分散在水中的油易被微生物分解,从而消耗水中溶解氧,使水质恶化,因此水中油含量是环境评价的重要指标。测定地面水中油的方法通常采用紫外分光光度法,但该法的测定回收率约为72.7％,不够满意,本文在油标、石油醚及无水硫酸钠的选择与用量等方面存在的问题作了条件试验,并以工作曲线代替标准曲线,使回收率达到96.2％左右,提高了测定准确性,改进后的方法最低检出限D、L为0.1mg/L,定量下限Q、L为0.4mg/L,实验室内相对标准偏差为3.3％与原方法的实测情况相仿。     

自动进样系统结合分光光度法快速测定水质中总磷

基于自动进样系统结合分光光度法,通过对波长、消解条件及显色条件的优化,建立了水中总磷的快速检测分析方法。在优化条件下,总磷的检出限为0.005 mg/L,测定下限为0.020 mg/L。对地表水、生活污水和工业废水3种不同基质的样品进行了加标测定,其回收率为95.0%～102%,相对标准偏差为0.5%～2.7%;与国标方法钼酸铵分光光度法测定水体中总磷进行比对研究,对国家有证标准样品、地表水、生活污水和工业废水测试的结果显示,方法相对偏差为0.4%～3.5%。该方法操作简单、快速、准确,可为应对突发环境事件中总磷的测定提供技术参考。     

环境水质氨氮的快速检测

采用全固体混合试剂,将改进的水杨酸分光光度法应用于水质氨氮的测定.络合物的最大吸收波长为697 nm,表观摩尔吸光系数为2.00×104 L/(mol·cm),氨氮质量浓度在0.01 mg/L～1.00 mg/L之间符合比尔定律,反应产物颜色在3 h内保持稳定,常见的共存离子均不干扰测定,混合试剂保存期长,可用于环境水质氨氮的快速检测.     

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.