利用TOC-5000A总有机碳分析仪测定环境水样中包含全部颗粒态有机碳的研究

本文结合TOC总有机碳分析仪和SSM固体样品燃烧装置各自的特点，探索了测定环境水样中包含全部颗粒态有机碳的测定方法．此方法能够全面反映环境水样中总有机碳的含量     

地面水中总有机碳分析

本文研究了国产总有机碳分析仪测定地面水中总有机碳的方法。经过对原仪器中电导检测器电导液的稀释,用加酸搅拌方法除去水样中无机碳,总有机碳检测限可达0.7mg/L。     

呼伦贝尔地区草原表层土壤中总有机碳与有机质初探

通过非分散红外线吸收法测定呼伦贝尔地区具有代表性的16个草原表层土壤(0~20 cm)中总有机碳、溶解性有机碳,使用重铬酸钾容量法测定有机质,并对其总有机碳与有机质水平及两者相关性进行了分析。初步分析了造成各样品之间总有机碳水平差异的原因。结果表明,只以打草场作为利用方式的土壤总有机碳含量较常年放牧场的总有机碳含量高。从草原类型和土壤类型上看,草甸草原总有机碳含量明显高于典型草原,黑钙土总有机碳含量明显高于栗钙土。综上,过度放牧会使草原土壤总有机碳大量释放。总有机碳含量与有机质含量有显著正相关性,相关系数达到0.902。     

大气颗粒物样品中有机碳和元素碳的测定

采用元素分析仪测定大气颗粒物样品中有机碳、元素碳。应用商业化仪器元素分析仪 ,在燃烧炉温度为 4 50°C时 ,一步测出样品中有机碳的含量 ;再运用加酸的方法除去样品中的碳酸盐 ,然后在燃烧炉温度为 950°C时测出样品中有机碳、元素碳含量之和。通过差减计算 ,得出元素碳的值。有机碳、元素碳测量的标准偏差平均值分别为 0 2 5%、0 50 %。     

差减法和直接法对水中总有机碳测定结果比较

为了比较差减法和直接法对水中总有机碳测定结果,分别配制差减法和直接法的工作曲线,并分别通过差减法和直接法对不同水体中的总有机碳含量进行测定。比较测定结果,发现差减法和直接法对较清洁水体样品的TOC测定结果误差不大,而对废水样品的TOC测定结果误差较大。     

京杭大运河(苏北段)底泥中汞的总量与形态的分布研究

对京杭大运河(徐州段)底泥中的18个样品进行研究,分别用冷原子荧光仪和总有机碳测定仪测定,对底泥中的汞的总量和形态进行测定.结果表明,汞在底泥中的含量主要以残渣态存在,可交换态很少,占总合量的0.04%～1.839%,总有机碳的含量与汞的总量分布没有相关性.     

大气颗粒物中元素碳的直接测定

对原来用元素分析仪测定大气颗粒物样品中有机碳、元素碳的方法[1 ] 进行改进 ,将差减法间接测定元素碳改为一步直接测定元素碳。有机碳、元素碳的测量标准偏差的平均值分别为 0 35 %、0 34% ,提高了元素碳的测量精度 ,同时避免了误差传递 ,解决了差减法测定元素碳时出现负值的情况。     

燃烧氧化-非分散红外吸收测定水中总有机碳方法的改进

总有机碳测定的方法分为差减法和直接法。现对测定方法进行改进,将差减法和直接法测定结果结合,先将样品进行酸化初步吹扫,再使用差减法测定总有机碳。试验结果显示,无论在标准曲线、精密度试验、加标回收试验还是标准样品测定方面,改进法均优于直接法测定结果,且能较好地缩短测量时间。     

红枫湖水体中碳的时空分布特征分析

基于2013年8月、10月、11月及2014年3月在红枫湖5个表层水样采集点、3个分层水样采集点测定的总碳、无机碳、总有机碳及二氧化碳数据,结合当时的气象数据对碳的时空分布特征讨论分析。结果表明,虽然调查期间同时间相同水层各个水样采集点的上述4个指标差异并不明显,但同一时间不同分层水体及各水样采集点不同季节在碳分布上存在一定差异。温度越高,光照越长,生物活性越强,湖体碳被生物利用的比例越大,总碳、无机碳、总有机碳含量就越低,较强的生物活性也伴随更多的二氧化碳产生。上、下层水体因光与温度差异所导致的碳分布差异会因季节性翻湖而消失。     

南通市环境监测中心站参加《行政许可法》知识竞赛

目前，国内应用较多的总有机碳自动监测仪是TOC2000型总有机碳自动监测仪(法国Seres公司)，它采用湿法氧化一红外吸收即紫外催化氧化一红外吸收法。今将该监测仪常见故障的处理方法作一介绍，供参考。     

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.      

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.     

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。     

Metal concentrations in deciduous tree leaves from urban areas in Poland

Accumulation of metals in deciduous tree foliage fromurban areas in western-south Poland was monitored duringthe vegetation season of 2000 year. Concentrations of Al,Ba, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sr, Ti and Znwere measured in birch, willow, linden and maple leavesusing the ICP-AES method. Seasonal variations of metalconcentrations and their relations with sampling sitewere investigated. The most dynamic accumulation of Al,Cd, Cr, Ni and Pb was observed for examined species. Thehighest differences in element concentrations forinvestigated sites were found for Ba, Cd, Mn and Ni.Interelement correlations were investigated. In allfoliar samples synergistic relationships between Al–Crand Ca-Sr were found. Statistically significant negativecorrelations were observed only for Cd and Ti in birch leaves.     

Varying Stable Nitrogen Isotope Ratios of Different Coastal Marsh Plants and Their Relationships with Wastewater Nitrogen and Land Use in New England, USA

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.     

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.     

Effect of heavy metal contaminated shooting range soils on mycorrhizal colonization of roots and metal uptake by leek

We grew leek (Allium porrum) in soils of two shooting ranges heavily contaminated with heavy metals in the towns of Zuchwil and Oberuzwil in Switzerland as a bioassay to test theactivity of arbuscular mycorrhizal (AM) fungi in these soils.Soil samples were taken from (1) front of the shooting house(HOUSE), (2) the area between house and target (FIELD) and (3) the berm (BACKSTOP). Samples of Ribwort plantain (Plantagolanceolata) growing naturally within the shooting ranges werealso collected and the colonization of its roots by mycorrhizalfungi was measured. The number of AM spores in the soils wassignificantly reduced concomitant with the increase in thedegree of soil contamination with metals. In Zuchwil,mycorrhizal fungi equally colonized roots of Ribwort plantainsampled from BACKSTOP and HOUSE. In Oberuzwil, however, plantsfrom BACKSTOP had lower colonization when compared with thosesampled from HOUSE. Colonization of leek was strongly reducedin the BACKSTOP soil of Zuchwil and slightly reduced in theBACKSTOP soil of Oberuzwil when compared with plants grown inrespective HOUSE soil. Concentrations of Cd, Cr, Cu, Ni, Pb andZn in the leaves of leek grown in the BACKSTOP soil was withinthe range considered toxic for human consumption. This pointsto the high degree of bio-availability of these metal in thesesoils. Significant decrease in the number of mycorrhizal sporesin the BACKSTOP soils in Zuchwil and the low colonization ofleek roots grown in these soils point to possible changes inthe species diversity of mycorrhizal fungi in these soils.