便携式分光光度计快速测定水中镍

对3种便携式分光光度计快速测定水中镍的方法进行了优化和比对研究。通过研究各仪器性能指标以及测定实际水质样品,对不同便携式分光光度计的优势进行了比较,为突发性环境污染事故应急监测选择合适的监测仪器提供了技术参考。结果表明:JH916检测仪快速测定水中镍的方法检出限(0.01 mg/L)低于ZZW-II测试仪和PORS-15 V光谱仪方法检出限(均为0.2 mg/L),在突发性环境污染事故应急监测中具有相对较高的灵敏度。ZZW-II测试仪和JH916检测仪快速测定水中镍的方法精密度大体相当,测定结果相对标准偏差均未超过6.5%(n=6),PORS-15V光谱仪快速测定水中镍的方法精密度稍差,最大相对标准偏差达到13.5%。3种便携式分光光度计测定实际样品时,加标回收率分别为79%~96%(ZZW-II测试仪)、83%~113%(PORS-15V光谱仪)、90%~114%(JH916检测仪),表明3种便携式分光光度计均有较好的准确度。     

便携式分光光度计快速测定水中镉

对3种便携式分光光度计快速测定水中镉的方法进行比对试验,考察不同便携式分光光度计方法效能。结果表明,ZZW-Ⅱ型测试仪、PORS-15V型光谱仪、JH 916型检测仪快速测定水中镉的方法检出限分别为0.04 mg/L、0.05 mg/L、0.006 mg/L,对中、高浓度样品测定结果的RSD均低于5.9%,实际样品的加标回收率分别为89.0%~114%、81.0%~108%、80.0%~90.0%。与国标法相比,3种便携式分光光度计测定结果相对偏差较大。     

便携式分光光度计在地表水环境应急监测中的适用性分析

考察了便携式分光光度计对地表水中化学需氧量(COD)、氨氮(NH_3-N)、氟化物(F~-)、总磷(TP)和六价铬(Cr~(6+))的应急监测的适用性。对方法精密度和准确度进行测定,并将便携式方法与实验室方法的测定结果进行比对。结果表明,方法精密度为2.3%~7.4%,标准样品除Cr6+外,其他均在保证值范围内;加标回收率为86.0%~110%,2种方法比对的相对偏差为2.9%~6.4%。该方法精密度与准确度良好,可以较好地应用于地表水环境应急监测中。     

氢化物发生-原子荧光法同时测定水中的砷和铅的研究

目的是建立一种同时测定水中微量砷和铅的方法。方法采用酸消解法消解水样,氢化物发生-原子荧光法同时测定水中微量砷和铅。结果显示,砷和铅方法的检出限分别为0.20μg/L和0.24μg/L,回收率分别为92.9%~104.4%和93.5%~103.8%,相对标准偏差分别为2.3%和3.5%。水中微量砷和铅用氢化物发生-原子荧光法测定能满足要求,可以同时测定。     

水中砷快速检测方法研究

采用实验室与现场相结合的方法对砷快速测定方法的可靠性和应用价值进行研究。研究显示,该法检出限为2μg/L,具有较好的准确度,对于砷质量浓度5μg/L的水样,相对误差为1.00%~10.00%,对于砷质量浓度为5μg/L的水样,虽然相对误差较大,为22.40%,但其测定结果在砷污染快速监测可接受的结果范围内;精密度较高,相对标准差为5.27%~16.54%;同时具有较好的再现性。该方法能减少砷污染筛查的工作量,可满足应对砷污染突发事件应急监测的需求。     

土壤中7种重金属和砷测定的精密度控制指标研究

通过对浙江省近700组实际土壤样品进行分析,研究了土壤中铜、铅、锌、铬、镍、镉、砷、汞7种重金属和砷测定的精密度控制指标(实验室内相对偏差和实验室间相对偏差),并与行业标准分析方法和文献进行了比较,旨在为环境监测质量控制与质量保证工作提供参考。经统计分析,建议实验室内相对偏差控制指标如下:铜,≤15%;铅,≤15%;锌,≤15%;铬,≤15%;镍,≤15%;镉,≤20%;砷,≤15%;汞,≤50%。建议实验室间相对偏差控制指标如下:铜,≤25%;铅,≤25%;锌,≤20%;铬,≤20%;镍,≤25%;镉,≤35%;砷,≤25%;汞,≤55%。     

原子荧光法同时测定地表水中的砷和硒条件的选择

本文应用AFS-230E型原子荧光光度计同时测定水中砷和硒，选择最佳仪器条件，As检出限为0．0793μg／L，se检出限为0．0068μg／L，As加标回收率为97．7％～102％，Se加标回收率为97．6%-103％，精密度和准确度满足分析要求，通过研究确定仪器和方法条件测定地表水中砷和硒，大大提高分析效率。     

便携式气相色谱质谱测定水中挥发性有机物再现性和准确度研究

建立了便携式顶空-气相色谱-质谱（HS-GC-MS）测定水中挥发性有机物的方法。以水中苯系物、卤代烃和氯代苯等VOCs为研究对象，在同一实验室内，使用3台便携式HS-GC-MS模拟现场应急监测环境开展检测活动，研究测定结果的再现性和准确度。实验结果表明，检测结果的相对标准偏差为0.7%~13%；绝大多数目标化合物测定结果的回收率为80%~120%。综合来看，方法的精密度和准确度基本满意，能够满足应急监测工作的需要。     

便携式气相色谱法快速测定恶臭气体样品中的硫化物

建立一种利用便携式气相色谱仪快速、简便地测定恶臭气体样品中硫化物的方法,对硫化氢、甲硫醇、甲硫醚及二硫化碳能实现良好分离,光离子化检测器PID可实现甲硫醇、甲硫醚、二硫化碳的快速定性、定量分析,还能避免高浓度二氧化硫对测定的干扰,检出限分别为0.05、0.03、0.02ppm,精密度好,相对标准偏差RSD分别小于11.6%、7.89%和2.14%,经实际应用,效果良好。     

便携式XRF土壤重金属检测仪在环境应急监测中的应用探讨

系统评估了便携式XRF重金属检测仪的精密度、准确度及测定影响因素,开展了该方法测定土壤中Cu、Zn、As、Pb、Cr与国标分析方法的系统比对。结果表明:上述5种元素的方法检出限为5.7 mg/kg~16.0 mg/kg,土壤标准样品测定6次结果的RSD为1.0%~4.7%,Zn、Pb和As测定结果的相对误差10%;与国标法相比,便携式XRF重金属检测仪测定Cu、Zn、As、Pb的准确度较好,测定Cr的准确度波动较大。将该方法用于应急污染事故监测,可迅速锁定污染物及污染区域,实现野外分析的预判。     

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.      

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).     

土壤和底泥中砷、铬、锰测定的前处理技术

试验了土壤和底泥中砷的前处理技术，其目的是能对土壤、底泥中砷、铬、锰在一次前处理中制备成试液，比色法分析。试验表明，用Ｈ２ＳＯ４－Ｈ３ＰＯ４－Ｈ２Ｏ２进行前处理是可行的。方法简单、挥发酸雾少，用标准参考物质检验证明，分解完全，数据准确，有粒较好一致性。     

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.     

Geochemical assessment of metal transport in glacial till during electrokinetic remediation

This paper presents the chemical speciation and retention behavior of chromium (Cr), nickel (Ni), and cadmium (Cd) prior to and after the electrokinetic remediation in glacial till soil. The speciation of the metals was predicted using the chemical speciation program MINEQL⁺. The simulations were performed for single-contaminant with only Cr(VI) or Ni, and multi-contaminants consisting of: (1) Cr(VI), Ni, and Cd; (2) Cr(III), Ni and Cd; (3) Cr(VI), Cr(III), Ni and Cd; (4) Cr(VI), Ni, and Cd with reducing agents; and (5) Cr(III), Ni, and Cd with oxidizing agent (Mn). The results showed that the speciation and distribution of cationic metals [Ni, Cd, and Cr(III)] in glacial till soil remain unaffected or slightly affected during electrokinetics. This is attributed to the high pH buffering capacity of the glacial till, leading the metals to precipitate in the soil prior to and after electrokinetics. This study showed that during electrokinetics, Cr(VI) existed as anionic complex and migrated towards the anode and the migration is maximum in case of a single-contaminant system. The study also showed that near the anode in the absence of any reducing and oxidizing agent, Cr(VI) mostly adsorbed, and some of Cr(VI) reduced to Cr(III) and migrated towards the cathode and finally precipitated due to high pH conditions. Ni and Cd remain adsorbed or precipitated due to the high pH conditions throughout the soil. Among the reducing agents, the sulfide had significant effect on the migration of metals compared to ferrous ions. While in the presence of oxidizing agent (Mn), no noticeable Cr(VI) was found in the soil sample indicating the reduction of Cr(VI) to Cr(III) and the predominance of reducing conditions due to the presence of naturally occurring iron in the glacial till soil. Overall, this study provides a reasonable explanation of the speciation and distribution of chromium, nickel and cadmium during the electrokinetic remediation of glacial till soil.     

Biomonitoring of Lead, Zinc, and Cadmium in Streams Draining Lead-Mining and Non-Mining Areas, Southeast Missouri, USA

We evaluated exposure of aquatic biota to lead (Pb), zinc (Zn), and cadmium (Cd) in streams draining a Pb-mining district in southeast Missouri. Samples of plant biomass (detritus, periphyton, and filamentous algae), invertebrates (snails, crayfish, and riffle benthos), and two taxa of fish were collected from seven sites closest to mining areas (mining sites), four sites further downstream from mining (downstream sites), and eight reference sites in fall 2001. Samples of plant biomass from mining sites had highest metal concentrations, with means 10- to 60-times greater than those for reference sites. Mean metal concentrations in over 90% of samples of plant biomass from mining sites were significantly greater than those from reference sites. Mean concentrations of Pb, Zn, and Cd in most invertebrate samples from mining sites, and mean Pb concentrations in most fish samples from mining sites, were also significantly greater than those from reference sites. Concentrations of all three metals were lower in samples from downstream sites, but several samples of plant biomass from downstream sites had metal concentrations significantly greater than those from reference sites. Analysis of supplemental samples collected in the fall of 2002, a year of above-average stream discharge, had lower Pb concentrations and higher Cd concentrations than samples collected in 2001, near the end of a multi-year drought. Concentrations of Pb measured in fish and invertebrates collected from mining sites during 2001 and 2002 were similar to those measured at nearby sites in the 1970s, during the early years of mining in the Viburnum Trend. Results of this study demonstrate that long-term Pb mining activity in southeast Missouri has resulted in significantly elevated concentrations of Pb, Cd, and Zn in biota of receiving streams, compared to biota of similar streams without direct influence of mining. Our results also demonstrate that metal exposure in the study area differed significantly among sample types, habitats, and years, and that these factors should be carefully considered in the design of biomonitoring studies.     

Comparative studies on accumulation of Cr from metal solution and tannery effluent under repeated metal exposure by aquatic plants: its toxic effects

The present study demonstrates comparison of Cr accumulatingpotential by the plants of Najas indica Cham. (submerged),Vallisneria spiralis L. (rooted submerged) and Alternanthera sessilis R. Br. (rooted emergent) under repeatedmetal exposure and its effect on chlorophyll and protein concentrations. These plants were treated with different concentrations of Cr under repeated exposure in controlled laboratory conditions to assess the maximum metal accumulationpotential. The plants of V. spiralis accumulated significantly high amount of Cr under laboratory conditions incomparison to N. indica and A. sessilis. The maximumaccumulation of 1378, 458 and 201 g g^-1 dw Cr was found in the leaves of V. spiralis, N. indica and A. sessilis, respectively at 8 mg L^-1 after 9 day of Cr exposure. These plants have shown a decrease in chlorophyll andprotein concentrations with increase in Cr concentrations. In view of high accumulation of Cr in V. spiralis, the plantswere treated with different concentrations of tannery effluent collected from Common Effluent Treatment Plant, Unnao (UP). Theplants of V. spiralis treated with 100% tannery wastewatershowed the maximum accumulation (57.5 g g^-1 dw) of Cr in the roots after 10 days of exposure. The plants were foundeffective in removing Cr from solution and tannery effluent.     

Assessment of Air Quality After the Implementation of Compressed Natural Gas (CNG) as Fuel in Public Transport in Delhi, India

Public transport in Delhi was amended by the Supreme Court of India to use Compressed Natural Gas (CNG) instead of diesel or petrol. After the implementation of CNG since April 2001, Delhi has the highest fraction of CNG-run public vehicles in the world and most of them were introduced within 20 months. In the present study, the concentrations of various criteria air pollutants (SPM, PM₁₀, CO, SO₂ and NO_x) and organic pollutants such as benzene, toluene, xylene (BTX) and polycyclic aromatic hydrocarbons (PAHs) were assessed before and after the implementation of CNG. A decreasing trend was found for PAHs, SO₂ and CO concentrations, while the NO_x level was increased in comparison to those before the implementation of CNG. Further, SPM, PM₁₀, and BTX concentrations showed no significant change after the implementation of CNG. However, the BTX concentration demonstrated a clear relation with the benzene content of gasoline. In addition to the impact of the introduction of CNG the daily variation in PAHs levels was also studied and the PAHs concentrations were observed to be relatively high between 10 pm to 6 am, which gives a proof of a relation with the limited day entry and movement of heavy vehicles in Delhi.