Chlorinated hydrocarbon contaminants in blood of black and turkey vultures from Savannah River Site,South Carolina,USA

Blood of adult and juvenile black and turkey vultures in the Savannah River Site of South Carolina, USA was analyzed for the presence of 2,3,7,8-chlorine substituted polychlorinated dibenzo-p-dioxins (2,3,7,8-PCDDs), dibenzofurans (2,3,7,8-PCDFs), -dioxin-like and -di-ortho polychlorinated biphenyls. Concentration ranges of 2,3,7,8-PCDD/DFs in blood of black and turkey vultures were 14.2-34.6 and 8.7-56.2 pg/ml wet wt., respectively. Dioxin-like PCBs were in the ranges of 815-4627 and 753-3611 pg/ml wet wt. respectively, in black and turkey vultures. Considerable concentrations of two congeners of di-ortho PCBs were noticed in the ranges of 1415-10325 and 663-7500 pg/ml respectively, in black and turkey vultures. Comparatively, greater toxic equivalency (TEQ) were observed in blood of turkey vultures with the ranges of 3.2-20, whereas black vulture contained 1.8-8.4 pgTEQ/ml wet wt. basis. The species-specific accumulation profiles of PCDD/DFs and dioxin-like PCBs may reflect the different feeding habits, ecology, metabolic capacity and migratory movements of these two scavenging species.     

生物质催化气化制取富氢燃气的研究

以流化床为反应器 ,探讨了一些主要参数如 :反应器温度 ,水蒸气 ,当量比ER以及催化剂对气体成分、氢产率和潜在氢产率的影响。实验所用催化剂为白云石和镍基催化剂。在实验条件范围内 ,氢产率为 2 2— 83g/kg生物质 (湿基 ) ,潜在氢产率为 115— 2 2 3g/kg生物质 (湿基 )。结果表明 ,较高的反应器温度 ,适当的水蒸气添加量可以有效提高氢的产出 ;白云石和镍基催化剂可使产品气中的氢含量提高 10 %以上。     

The effect of particle size reduction by grinding on subsampling variance for explosives residues in soil

Efforts to characterize the surface soil contamination on military training ranges have been compromised by the inability to obtain representative subsamples of soils submitted to analytical laboratories for determination of explosives residues. Two factors affecting subsampling error for explosives residues were examined using soils collected from hand grenade and anti-tank ranges. These factors were increased subsample size and particle size reduction prior to subsampling of soils. Increasing the subsample size from 2 to 50 g did not reduce the soil subsampling error because of the extreme heterogeneous distribution of the solid contaminants. Alternatively, particle size reduction by machine grinding on a ring mill reduced subsampling error to less than 10% relative standard deviation for replicate analyses using 10-g subsamples.     

An alternative approach to photochemical ozone creation potentials applied under European conditions

Photochemical ozone creation potential (POCP) values for 83 different volatile organic compounds (VOCs), including CO and CH4, were calculated under different environmental conditions representative for Europe. These calculations show that variations in POCP values are large between different types of chemical environments and that POCP values for VOCs should be presented as ranges instead of single values. POCP ranges are based on the extremes of the POCP values and are defined with the intention to include all POCP values an individual VOC will obtain in any European environment where O3 formation is of environmental concern. The POCP ranges indicate large differences in O3 production between individual VOCs, which justifies the use of this ranking scale instead of treating all VOCs as a homogeneous group of species in abatement strategies. Both the average O3 production over 96 hr and the maximum contribution to the O3 concentration were studied. The most efficient O3 producers were found to be isoprene, 2-methyl-2-butene, and acrolein. As a group, the alkenes are the most potent O3 producers, followed by higher alkanes and then the aromatics. The calculated values show a good agreement with previously calculated POCP values under northern European conditions.     

Performance of wastewater subsurface drip emitters at low and normal pressure.

Subsurface drip distribution is an important on-site wastewater treatment technique widely used with various soil types and restricted site conditions. This study evaluated the performance of five subsurface wastewater drip products under eight pressures, ranging from 0 to 310 kPa. Results showed that Netafim Bioline pressure-compensating emitters (Netafim Irrigation Inc., Fresno, California) had an application uniformity coefficient of 95% and a coefficient of variance (C(v)) of 4.9%. The average uniformity coefficient of Geoflow Wasteflow products (Geoflow USA, Charlotte, North Carolina) was 94.4%, with a C(v) value of 6.8%. Flowrate and pressure relationships were developed by analyzing low and normal operational pressure ranges, and R-square values ranged from 1.000 to 0.301. Geoflow pressure-compensating products were non-pressure-compensating emitters under low pressure. Netafim pressure-compensating emitters were partially pressure-compensating under low pressures. In normal operational pressure ranges, both Geoflow and Netafim products were fully pressure-compensating. Netafim pressure-compensating products were characterized as pressure-compensating over the full range of operational pressures.     

Dioxin-like potencies and extractable organohalogens (EOX) in medical, municipal and domestic waste incinerator ashes in Japan

Ash samples collected from medical, municipal and small-scale domestic incinerators in Japan were tested for dioxin-like activity using bioassay technique (ethoxyresorufin-O-deethylase: EROD assay) and for extractable organohalogens (EOX) using instrumental neutron activation analysis in order to estimate potential toxicity and responsible chemicals in those samples. Crude extracts and fractions cleaned-up for dioxin analysis from the samples were used for the analysis. The ranges of dioxins in the ashes were between 2.23 and 12.29 ng TEQ/g (dry weight). Relative potency ranges estimated by EROD assay in the medical incinerator ashes were 3.8-17.6 times higher than the results of conventional chemical analysis. EOX analysis suggested that ash samples contained plenty of organochlorine compounds apart from chlorinated dioxins. In addition, medical waste incinerator ashes were considered to have relatively higher amount of organoiodine compounds. In the cleaned-up fractions, bioassay potency ranges were lower than those in the crude extracts. However, some samples still exhibited higher potency than expected from chemical analysis. Though some polycyclic aromatic hydrocarbons were found in the fractions, the amounts were relatively low (0.39-10.56 ng/g). The results imply that some bioactive organohalogens that cannot be detected in the conventional chemical analysis might have potential for dioxin-like toxicity, and contribute to higher bioassay activities. The combination of the chemical analysis with the bioassay and EOX provides rough figure of dioxin-like toxicity and suggests types of organohalogen compounds that should be identified as a part of dioxin analysis for control emission from an incineration plant.     

The effect of export to the deep sea on the long-range transport potential of persistent organic pollutants

BACKGROUND: Export to the deep sea has been found to be a relevant pathway for highly hydrophobic chemicals. The objective of this study is to investigate the influence of this process on the potential for long-range transport (LRT) of such chemicals. METHODS: The spatial range as a measure of potential for LRT is calculated for seven PCB congeners with the multimedia fate and transport model ChemRange. Spatial ranges for cases with and without deep sea export are compared. RESULTS AND DISCUSSION: Export to the deep sea leads to increased transfer from the air to the surface ocean and, thereby, to lower spatial ranges for PCB congeners whose net deposition rate constant is similar to or greater than the atmospheric degradation rate constant. This is fulfilled for the PCB congeners 101, 153, 180, and 194. The spatial ranges of the congeners 8, 28, and 52, in contrast, are not affected by deep sea export. With export to the deep sea included in the model, the spatial ranges of the heavier congener are similar to those of the lighter ones, while the intermediate congeners 101 and 153 have the highest potential for long-range transport. CONCLUSIONS: Transfer to the deep ocean affects the mass balance and the potential for LRT of highly hydrophobic chemicals and should be included in multimedia fate models containing a compartment for ocean water.     

A2O-MBR工艺处理城市污Z作农业灌溉用水中试研究

为开发一种污水再生利用于农田灌溉领域的新型技术,本实验以城市污水为研究对象,采用A2O—MBR工艺进行中试研究,并将系统出水水质与《农田灌溉水质标准（GB5084—2005）》的主要水质指标进行对比分析。结果表明,系统COD和BOD,出水浓度范围分别为3．2～59．6mg／L、1．0～7．6mg／L,系统出水pH为7．16～7．54,悬浮物浓度几乎为0,上述指标均符合标准;TP、TN和氨氮的出水范围分别为0．03～0．79mg／L、1．6～17．7mg／L和0．8～10．3mg／L。《农田灌溉水质标准》没有对上述3个指标提出具体要求,且少量的氮磷是植物生长的营养元素。该系统出水的主要水质指标符合标准兽求．     

A case study of contaminants on military ranges: Camp Edwards, Massachusetts, USA

An extensive investigation at the Camp Edwards, Massachusetts Military Reservation (MMR) demonstrates that assessment of groundwater and soil contamination at military ranges can be limited primarily to explosive-related compounds such as RDX, HMX, perchlorate, TNT and their transformation products. A modified analytical method is recommended to expand the list of explosives and to improve the detection limits. Analyses of metals, VOCs, SVOCs, and TICs are unnecessary. Soil samples may require the analyses of PAHs and PCNs for burn areas. Camp Edwards, as one of the few military ranges that have been exhaustively investigated for contaminants, is an ideal point of departure for evaluating other ranges. The permeable site soils promote leaching of contaminants and inhibit biotic and abiotic transformations. Moreover, the site has experienced an unusual extent of activities in its more than ninety years of active use. The recommendations in this report are based on data obtained for more than 200 analytes from more than 15,000 environmental samples.     

A2O-MBR 工艺处理城市污水作农业灌溉用水中试研究简

为开发一种污水再生利用于农田灌溉领域的新型技术,本实验以城市污水为研究对象,采用A²O-MBR工艺进行中试研究,并将系统出水水质与《农田灌溉水质标准（GB5084-2005）》的主要水质指标进行对比分析。结果表明,系统COD和BOD₅出水浓度范围分别为3.2~59.6 mg/L、1.0~7.6 mg/L,系统出水pH为7.16~7.54,悬浮物浓度几乎为0,上述指标均符合标准;TP、TN和氨氮的出水范围分别为0.03~0.79 mg/L、1.6~17.7 mg/L和0.8~10.3 mg/L。《农田灌溉水质标准》没有对上述3个指标提出具体要求,且少量的氮磷是植物生长的营养元素。该系统出水的主要水质指标符合标准要求。     

Distribution of organochlorine compounds in the sea-surface microlayer, water column and sediment of Singapore's coastal environment

Hexachlorocyclohexanes (HCHs), dichlorodiphenylethanes (DDTs) and 38 PCB congeners were determined in the water column (sea-surface microlayer, subsurface, mid-depth and bottom water) and sediments from Singapore's coastal environment. The concentration ranges for summationHCHs, summationDDTs and summationPCBs in the seawater dissolved phase (DP) were 101-6110 (mean 1833), <5-405 (mean 76) and 60-6979 (mean 1611)pg/l, respectively. The concentration ranges for summationHCHs, summationDDTs and summationPCBs in the suspended particulate matter (SPM) were 26-2395 (mean 243), <5-124 (mean 19) and 38-3793 (mean 715) pg/l, respectively. Concentration levels in sediments ranged between 521 and 1758 (mean 1094), 50 and 290 (mean 88) and 339 and 1356 (mean 858) pg/g for summationHCHs, summationDDTs and summationPCBs, respectively. It was shown that the interfaces of the sea-surface microlayer (SML) and near bottom water are important compartments for the distribution of organochlorine compounds (OCs) in the water column. In comparison with data from China, the concentration levels in the water column and sediments of Singapore can be considered as low, but the reported levels were higher compared to available data from Europe.     

An Alternative Approach to Photochemical Ozone Creation Potentials Applied under European Conditions

ABSTRACT

Photochemical ozone creation potential (POCP) values for 83 different volatile organic compounds (VOCs), including CO and CH₄, were calculated under different environmental conditions representative for Europe. These calculations show that variations in POCP values are large between different types of chemical environments and that POCP values for VOCs should be presented as ranges instead of single values. POCP ranges are based on the extremes of the POCP values and are defined with the intention to include all POCP values an individual VOC will obtain in any European environment where O₃ formation is of environmental concern. The POCP ranges indicate large differences in O₃ production between individual VOCs, which justifies the use of this ranking scale instead of treating all VOCs as a homogeneous group of species in abatement strategies.

Both the average O₃ production over 96 hr and the maximum contribution to the O₃ concentration were studied. The most efficient O₃ producers were found to be iso-prene, 2-methyl-2-butene, and acrolein. As a group, the alkenes are the most potent O₃ producers, followed by higher alkanes and then the aromatics. The calculated values show a good agreement with previously calculated POCP values under northern European conditions.     

Seasonal variation of heavy metals in ambient air and precipitation at a single site in Washington, DC

Atmospheric samples of precipitation and ambient air were collected at a single site in Washington, DC, for 7 months (for ambient air samples) and 1 year (for wet deposition samples) and analyzed for arsenic, cadmium, chromium and lead. The ranges of heavy metal concentrations for 6-day wet deposition samples collected over the 1-year period were 0.20-1.3 microg/l, 0.060-5.1 microg/l, 0.062-4.6 microg/l and 0.11-3.2 microg/l for arsenic, cadmium, chromium and lead, respectively, with a precision better than 5% for more than 95% of the measurements. The ranges of heavy metal concentrations for the 6-day ambient air samples were 0.800-15.7 ng/m(3), 1.50-30.0 ng/m(3), 16.8-112 ng/m(3), and 2.90-137 ng/m(3) for arsenic, cadmium, chromium and lead, respectively, with a precision better than 10%. The spread in the heavy metal concentration over the observation period suggests a high seasonal variability for heavy metal content in both ambient air and wet deposition samples.     

Data ranges in aquatic toxicity of chemicals

A significant problem for effect assessment of aquatic ecosystems arises from the large ranges of toxicity data, which can be found in different databases and literature. Here, ranges are given for the aquatic toxicity of 27 high production volume chemicals. Based on these illustrative examples and on the current literature on uncertainty in aquatic effect assessment, toxicity ranges are discussed for their possible causes (variation in experimental condition, species, endpoint, time) and ways to handle them (safety factors). Implications and recommendations on the procedure of risk analysis of chemical substances are drawn. Two main requirements for a comprehensive risk assessment are identified, which often play a minor role in current practice (as they are often neglected) as well as in scientific discussion (as they are meant to be trivial). First, data quality must be checked critically before applying any result of a toxicity test. Secondly, experimental data should take into account different species and acute as well as chronic data. If these aspects are considered in risk analysis, which is common practice in ecotoxicology but not always in the context of practical applications in risk engineering, a more comprehensive picture of the environmental toxicity of a chemical substance can be obtained.     

Assessment of combined antiandrogenic effects of binary parabens mixtures in a yeast-based reporter assay

To date, toxicological studies of endocrine disrupting chemicals (EDCs) have typically focused on single chemical exposures and associated effects. However, exposure to EDCs mixtures in the environment is common. Antiandrogens represent a group of EDCs, which draw increasing attention due to their resultant demasculinization and sexual disruption of aquatic organisms. Although there are a number of in vivo and in vitro studies investigating the combined effects of antiandrogen mixtures, these studies are mainly on selected model compounds such as flutamide, procymidone, and vinclozolin. The aim of the present study is to investigate the combined antiandrogenic effects of parabens, which are widely used antiandrogens in industrial and domestic commodities. A yeast-based human androgen receptor (hAR) assay (YAS) was applied to assess the antiandrogenic activities of n-propylparaben (nPrP), iso-propylparaben (iPrP), methylparaben (MeP), and 4-n-pentylphenol (PeP), as well as the binary mixtures of nPrP with each of the other three antiandrogens. All of the four compounds could exhibit antiandrogenic activity via the hAR. A linear interaction model was applied to quantitatively analyze the interaction between nPrP and each of the other three antiandrogens. The isoboles method was modified to show the variation of combined effects as the concentrations of mixed antiandrogens were changed. Graphs were constructed to show isoeffective curves of three binary mixtures based on the fitted linear interaction model and to evaluate the interaction of the mixed antiandrogens (synergism or antagonism). The combined effect of equimolar combinations of the three mixtures was also considered with the nonlinear isoboles method. The main effect parameters and interaction effect parameters in the linear interaction models of the three mixtures were different from zero. The results showed that any two antiandrogens in their binary mixtures tended to exert equal antiandrogenic activity in the linear concentration ranges. The antiandrogenicity of the binary mixture and the concentration of nPrP were fitted to a sigmoidal model if the concentrations of the other antiandrogens (iPrP, MeP, and PeP) in the mixture were lower than the AR saturation concentrations. Some concave isoboles above the additivity line appeared in all the three mixtures. There were some synergistic effects of the binary mixture of nPrP and MeP at low concentrations in the linear concentration ranges. Interesting, when the antiandrogens concentrations approached the saturation, the interaction between chemicals were antagonistic for all the three mixtures tested. When the toxicity of the three mixtures was assessed using nonlinear isoboles, only antagonism was observed for equimolar combinations of nPrP and iPrP as the concentrations were increased from the no-observed-effect-concentration (NOEC) to effective concentration of 80 %. In addition, the interactions were changed from synergistic to antagonistic as effective concentrations were increased in the equimolar combinations of nPrP and MeP, as well as nPrP and PeP. The combined effects of three binary antiandrogens mixtures in the linear ranges were successfully evaluated by curve fitting and isoboles. The combined effects of specific binary mixtures varied depending on the concentrations of the chemicals in the mixtures. At low concentrations in the linear concentration ranges, there was synergistic interaction existing in the binary mixture of nPrP and MeP. The interaction tended to be antagonistic as the antiandrogens approached saturation concentrations in mixtures of nPrP with each of the other three antiandrogens. The synergistic interaction was also found in the equimolar combinations of nPrP and MeP, as well as nPrP and PeP, at low concentrations with another method of nonlinear isoboles. The mixture activities of binary antiandrogens had a tendency towards antagonism at high concentrations and synergism at low concentrations.     

Preliminary measurements of summer nitric acid and ammonia concentrations in the Lake Tahoe Basin air-shed: implications for dry deposition of atmospheric nitrogen

Over the past 50 years, Lake Tahoe, an alpine lake located in the Sierra Nevada mountains on the border between California and Nevada, has seen a decline in water clarity. With significant urbanization within its borders and major urban areas 130 km upwind of the prevailing synoptic airflow, it is believed the Lake Tahoe Basin is receiving substantial nitrogen (N) input via atmospheric deposition during summer and fall. We present preliminary inferential flux estimates to both lake surface and forest canopy based on empirical measurements of ambient nitric acid (HNO3), ammonia (NH3), and ammonium nitrate (NH4NO3) concentrations, in an effort to identify the major contributors to and ranges of atmospheric dry N deposition to the Lake Tahoe Basin. Total flux from dry deposition ranges from 1.2 to 8.6 kg N ha-1 for the summer and fall dry season and is significantly higher than wet deposition, which ranges from 1.7 to 2.9 kg N ha-1 year-1. These preliminary results suggest that dry deposition of HNO3 is the major source of atmospheric N deposition for the Lake Tahoe Basin, and that overall N deposition is similar in magnitude to deposition reported for sites exposed to moderate N pollution in the southern California mountains.     

Multivariate analysis of photo-Fenton degradation of the herbicides tebuthiuron, diuron and 2,4-D

The degradation of herbicides in aqueous solution by photo-Fenton process using ferrioxalate complex (FeOx) as source of Fe2+ was evaluated under blacklight irradiation. The commercial products of the herbicides tebuthiuron, diuron and 2,4-D were used. The multivariate analysis, more precisely, the response surface methodology was applied to evaluate the role of FeOx and hydrogen peroxide concentrations as variables in the degradation process, and in particular, to define the concentration ranges that result in the most efficient degradation of the herbicides. The degradation process was evaluated by the determination of the remaining total organic carbon content (TOC), by monitoring the decrease of the concentrations of the original compounds using HPLC and by the chloride ion release in the case of diuron and 2,4-D. Under optimized conditions, 20 min were sufficient to mineralize 93% of TOC from 2,4-D and 90% of diuron, including oxalate. Complete dechlorination of these compounds was achieved after 10 min reaction. It was found that the most recalcitrant herbicide is tebuthiuron, while diuron shows the highest degradability. However, under optimized conditions the initial concentration of tebuthiuron was reduced to less than 15%, while diuron and 2,4-D were reduced to around 2% after only 1 min reaction. Furthermore, it was observed that the ferrioxalate complex plays a more important role than H2O2 in the photodegradation of these herbicides in the ranges of concentrations investigated.     

Source profile and health risk assessment of PM2.5 from coal-fired power plants in Fuxin,China

In order to improve and establish the localized source profile of PM_2.5 in Fuxin, the ashes under dust catcher were collected from four typical coal-fired power plants in Fuxin and twenty-eight components were measured. The source profile of PM_2.5 in the soot of the four coal-fired power plants was established. SO₄^2? was the most abundant component in the PM_2.5 of the soot of the four coal-fired power plants, followed by Ca²⁺ and organic carbon (OC). The content of element components in PM_2.5 smoke ranges from 5.06 to 10.97%, the content of ionic components ranges from 36.53 to 48.59%, and the total carbon content ranges from 9.43 to 11.36%. The divergence coefficient of PM_2.5 source profile in Fuxin coal burning smoke is mostly similar to that of Fushun, whereas the divergence coefficient of Colorado reaches 0.65, indicating that Fuxin coal burning power plant smoke has no similarity to Colorado. The order of the geological accumulation index of Ni, Cu, V, Mn, and Cr was Cr (4.58) > Mn (4.42) > V (4.38) > Cu (4.09) > Ni (4.06), showing a heavy pollution level. The health risk assessment model recommended by the USEPA was used to assess the health risk of heavy metals in soot of coal-fired power plants, and the non-carcinogenic risk values of As for children and adults were 45.7 and 4.90, respectively. The carcinogenic risk values of Cr for adults and children were the highest, with values of 3.66 × 10^?5 and 2.06 × 10^?5, respectively, followed by As.

     

Qualitative and quantitative analysis of municipal solid waste in Iran for implementation of best waste management practice: a systematic review and meta-analysis

Environmental Science and Pollution Research - With the rapid growth of population, development of different industries, and production of several ranges of products, the generation of municipal...     

The risk of forfeiting the ranges of reptiles under nonrandom and stochastic scenarios of moving climate conditions: a case study for 115 species in China

Environmental Science and Pollution Research - Revealing the hazard features of forfeiting areal ranges for nonidentical scenarios of shifting climatic conditions is pivotal for the conformation of...