直接加热消解法测定土壤底质中的有机质

选用ＸＪⅠ型ＣＯＤ消解装置作加热器,测定土壤、底质的有机质。通过不同消解时间的实验设计,选取８ｍｉｎ作为该法的消解时间;通过４种不同类型土壤、底质有机质的测定,并将其测定值与甘油浴法〔１〕作比较,得出该法精密度好,准确度高,相对标准偏差在１４％～２７％之间,相对误差在－３４％～１５％之间     

总磷测定中样品消解加热时间的改进

在《水和废水监测分析方法（第３版）》（以下简称《方法》）中,地面水总磷测定一般可采用过硫酸钾消解法消解。《方法》规定,在高压蒸汽消毒器内加热,在锅内压力达到１１ｋｇ／ｃｍ２（相应温度为１２０℃）时,要保持此压力３０ｍｉｎ。此法消解时间较长,对大批样...     

气候条件对内蒙古地区地带性土壤有机质环境背景值的影响

用“油浴加热——重铬酸钾容量法”测定了内蒙地区从东向西的339个剖面的土壤剖面的样品有机质含量,并将其结果做了相关分析和t检验,分析表明:内蒙古地区地带性土壤有机质含量水平基本随热量增加而降低,随湿润度增加而升高;与全区土壤有机质含量水平相比,有机质含量显著高     

原子吸收光谱法测定空气污染源中镉和镍

试验了用王水消解、火焰原子吸收光度法测定空气污染固定源中镉、镍;石墨炉原子吸收光度法测定散源中镉、镍。检测限分别为９０×１０－４ｍｇ／Ｎｍ３,００１８ｍｇ／Ｎｍ３（采样体积１０００Ｌ）;９５×１０－７ｍｇ／Ｎｍ３,１５×１０－４ｍｇ／Ｎｍ３（采样体积１０ｍ３）。     

用不同酸溶方法对三类土壤中Pb、Cr、Ni、Cd、Mn、Cu、Zn的溶出比较

Pb、Cr、Ni、Cd、Mn、Cu、Zn是土壤中的微量成分,用直接测定固体试样的x-射线荧光法难以给出准确可靠的结果。一般在测定之前须对土样进行消解处理。近几年世界各国在土壤背景值调查中采用了不同的消解方法,日本用HNO_3—H_2SO_4—HClO_4法;美国主要用HCl—HNO_3法,意大利、南斯拉夫等用热王水提取;英国认为未污染土壤中大多数金属存在于土壤晶格中,唯有用HF和Na_2CO_3熔融才能完全分解,其它各种酸溶法     

测定废水重金属样品的高压蒸汽消解方法

本文采用正交实验方法，用自己研制的“自控式高压蒸汽消解器”，详细研究了测定废水重金属，样品的最佳消解条件，并用于实际废水样的消解和重金属的测定，准确度和精密度均优于传统的敞口消解法，并具有试剂用量少、时间短、不受污染、操作简单，批处理样品量大等优点，可作为测定废水中重金属，样品的常规消解方法。     

土壤中钴、镍火焰原子吸收测定

土壤中钴、镍的分析其前处理方法,一般可采用三酸(HNO_3—HClO_4—HF)敞口消解法和高压消解法等。其消解液用直接火焰原子吸收法,或萃取—火焰原子吸收法测定。但直接用火焰原子吸收法测定灵敏度不够,而且有基体盐的背景吸收。有人采用2-亚硝基-1萘酚(NNP)/MIBK萃取体系,以酒石酸铵作掩蔽剂,研究了萃取——火焰法测定钴、镍的最佳条件。但萃取法操作繁杂。     

消解仪－麝香草酚分光光度法测定水中总氮

采用消解仪替代高压蒸汽灭菌器消解水样,用麝香草酚分光光度法替代紫外分光光度法测定总氮.试验表明,方法在0mg/L～10.0mg/L范围内线性良好,相关系数R为0.9999;方法检出限为0.04mg/L;测定低、中、高质量浓度的标准溶液,RSD为1.1% ～5.5%;对3份实际水样进行加标回收试验,回收率为94.6% ～98.2%,测定总氮标准品,结果在保证值范围内;用该方法与国标方法同时测定水样,测定结果的相对偏差〈5%.     

异丙醇增感电感耦合等离子体质谱法直接测定土壤和沉积物中硒

提出了沸水浴混合酸法消解,以异丙醇为增感剂,电感耦合等离子体质谱直接测定土壤和沉积物中硒的方法。实验表明2mol/L硝酸-4mol/L盐酸混酸能有效溶出土壤和沉积物中各种形态的硒。相对于1%硝酸基体,4%(V/V)异丙醇基体中硒的ICP-MS响应值提高了12.1倍;而且4%(V/V)异丙醇基体可有效抑制硒的质谱干扰。ICP发射功率和雾化气流速是影响异丙醇在ICP-MS测定过程增敏效应的主要因素。以78硒为测定同位素,方法检出限为0.005mg/kg,实际样品测定精密度均小于5%。用于测定土壤和沉积物国家标准样品并对其消解液进行加标回收实验,结果令人满意。     

全自动石墨消解-原子荧光法测定土壤中砷和汞

采用全自动石墨消解仪代替水浴锅加热王水消解法处理土壤样品,用原子荧光法测定消解液中的砷和汞。该方法在0μg/L~20.0μg/L范围内线性良好,测定有证标准土壤样品的结果均在标准值允许范围内,砷、汞测定结果的RSD分别为2.5%~4.8%、2.9%~5.4%,比王水消解法的测定结果更靠近标准值,实际土壤样品的加标回收率分别为94.6%~104%、92.6%~105%。     

A New Mathematical Approach in Environmental and Life Sciences: Gene–Environment Networks and Their Dynamics

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.      

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。     

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.     

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.     

Assessing health consequences in an environmental impact assessment: The case of Amsterdam Airport Schiphol

In this article a comprehensive approach for the evaluation of possible health effects in an environmental impact assessment (EIA) is described, illustrated with the example of Amsterdam Airport Schiphol. Unlike many EIAs, we estimated quantitatively the impact of aircraft-related pollution in terms of the number of affected people for aircraft noise annoyance, odour annoyance and hypertension. In addition, an analysis of health registry data on cardiovascular and respiratory diseases and a short survey on annoyance and risk perception were carried out. The scope of a health impact assessment depends on the situation, available knowledge and data, concern in the population about the impact and the number of people concerned. It is important to pay attention to the perception of risks and concerns from all parties involved. Moreover, the results demonstrate that far more people outside the area for which standards apply were affected than inside.     

Contaminant Profiles of Two Species of Shorebirds Foraging Together at Two Neighboring Sites in South San Francisco Bay, California

The San Francisco Bay estuary isused by over one million shorebirds during springmigration and is home to several hundred thousandduring the winter. Most shorebird use occurs in thesouthern reach of the estuary (South Bay). Thereduced water circulation and discharge fromindustrial sources in the South Bay are responsiblefor the highest levels of some trace elements in theestuary. Wintering shorebirds have been found to havestrong site fidelity to areas as small as a fewkilometers in the South Bay, which may increase theirexposure to contaminants near local point sources. Inaddition, different shorebird species foraging at thesame site have been shown to have differentcontaminant burdens. Thus, our objectives were totest whether contaminant burdens differed by species,or whether contaminant burdens differed in shorebirdscollected at adjacent sites. We examined thecontaminant profiles of two species of shorebirds,long-billed dowitchers (Limnodromus scolopaceus)and western sandpipers (Calidris mauri) thatforage together at two sites, Hayward and Newark,separated by 8 km in the South Bay. We usedmultivariate analysis of variance tests to compare thecomposition of 14 elemental analytes in their livertissues and estimated their molar ratios of Hg and Se. Composite samples were used for contaminant analysesbecause of the small body size of the shorebirds. Seven elemental analytes (Ag, Ba, Be, Cr, Ni, Pb, V)were below detection limits in a majority of thesamples so statistical analyses were precluded. Inthe measurable analytes (As, Cd, Cu, Hg, Mn, Se, Zn),we found no significant intra-site differences ofcontaminant profiles for the two species. We pooledthe samples to examine inter-site differences andfound significant differences in contaminant profilesbetween shorebirds at the neighboring sites (P = 0.03). Shorebirds at Newark had higher (P < 0.05) concentrations of As, Cd, and Se than those at Hayward. Dowitchers at Newark had concentrations of Hg and Se which were highly correlated (P < 0.003) in a mean molar ratio of 1:19, similar tothat reported in other birds. In the larger dowitcherspecies, we also examined exposure to 20organochlorine compounds. Organic analyses showedthat the dowitchers had been exposed to DDE, PCBs,dieldrin and trans-nonachlor, but with no significantdifferences in concentrations between Hayward andNewark (P > 0.05).     

An investigation on biological stability of product water generated by lab-scale and pilot-scale distillation systems

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, 240}Pu,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.     

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.