Application of a Sediment Quality Index to the Lower Laurentian Great Lakes

A sediment quality index (SQI) was developed using an equation incorporating three elements; scope--the % of variables that did not meet guidelines; area frequency--the % of failed tests divided by the total number of tests in a group of sites; and amplitude - the magnitude by which failed variables exceeded guidelines. The SQI calculation produces a numerical score with a maximum value of 100 representing the highest sediment quality. A modified SQI was also developed using only the scope and amplitude elements, which computed a score per site with no grouping. The SQI was applied to assessment of sediment quality in Lakes Erie and Ontario using Canadian Federal and Ontario Provincial guidelines for 34 compounds, Spatial trends in sediment quality in both lakes reflected overall trends for most individual contaminant classes, including mercury and polychlorinated biphenyls. In Lake Erie, there was a trend toward lower SQI values from the eastern basin to the western basin, and from the northern area to the southern area of the central basin. Sediment quality in the eastern basin and the northern area of the central basin was classified as excellent (>95); sediments in other areas of Lake Erie ranged from fair to good. In Lake Ontario, the poorest sediment quality was associated with the three major depositional basins; sediment quality among the three basins was quite consistent. The SQI values based on all three elements (scope, frequency and amplitude) for the Niagara basin. Mississauga Basin and Rochester Basin were 67 (fair), 65 (fair) and 70 (fair), respectively. Comparison of SQI values for all lower lake basins showed generally poorer sediment quality in Lake Ontario, compared to Lake Erie.     

Optimization of the Microwave-Assisted Solvent Extraction of Petroleum Hydrocarbons in Marine Sediment and Soil

A microwave-assisted solvent extraction (MASE) technique was developed for the quantitative extraction of gasoline- and diesel-range petroleum hydrocarbons (PHs) from soil and marine sediment samples. The influence of different extracting solvents, extraction temperature and duration of extraction on the recoveries of PHs was evaluated using a two-level orthogonal array design (OAD) with a OA8(27) matrix. Gas chromatographic-mass spectrometry (GC-MS) in multiple selective ion monitoring (MSIM) mode was used for the analysis of the PHs in environmental samples. The spiking range of the PHs in the environmental samples was between 1 to 1000 g/g. Good recoveries (>80%) could be obtained for most of the PHs using the optimum MASE conditions. The limit of detection (LOD) achieved by the GC-MS-MSIM was 0.02 g/g. A preliminary survey for the levels of PHs in marine sediment and soil samples from different parts of Singapore was carried out using the method.     

Possible Routes for Lead Accumulation in Feral Pigeons (Columba Livia)

This study examined possible routes for lead (Pb) accumulation in resident pigeons collected from rural, urban, and four industrial sites in Korea. The accumulation pattern of Pb was comparable to the study sites. The highest Pb concentration was found in the bone, followed by kidney, liver, and lung of pigeons. Highest Pb residues in bones were found in urban (Seoul), and two industrial complex areas (Busan and Ulsan), which were about 15 times higher than rural area (Duckjuk island), and followed by Ansan and Yochon industrial areas. Regional Pb variations in liver, kidney, and lung tissues were also similar pattern with the bone Pb difference. These findings indicate that Pb accumulation in tissues of pigeons may be affected by the Pb exposure in their respective habitats. Crop contents and gizzard materials were investigated as representing the ingested items. No difference of Pb concentration was observed in major foods (maize and/or wheat) of crop contents in the study sites except Busan, whereas variations of Pb levels in gizzard materials were indicative of a similar pattern with tissue Pb differences. The Pb concentration in tissues of pigeons did not correspond well to the atmospheric Pb levels. With regard to possible Pb sources, ingested items especially materials present in the gizzard are important sources for Pb contamination to pigeons because Pb-containing sources may be expected to present in roadside particles, dusts, paint chips and building flakes. However, air Pb value being low may not affect significant as the regional variations in tissues of pigeons.     

Seasonal Variation of Chemical Composition in Fine Particles at Gosan, Korea

PM_2.5 aerosol samples were collected at Gosan in Jeju Island during six intensive measurement periods between November 2001 and August 2003. In order to investigate the chemical composition of fine particles, major ion components, trace elements, and elemental and organic carbon were analyzed. Quite different seasonal characteristic in the chemical composition of fine particles was observed. The concentration of most secondary aerosol components showed a summer minimum and a winter maximum with higher correlation between them at Gosan. This fact clearly reveals the possibility of long-range transport of such pollutants in winter. On the other hand, OC and EC had the highest concentration and good correlation with ion components, such as K⁺, Ca²⁺ in fall. It means that biomass burning could significantly influence the ambient fine carbonaceous particulate in fall, which was primarily long-range transported.     

Estimates of emissions of SO2, NOx, HCl and NH3 from a densely populated region of the UK

Estimates of emissions of SO2, NOx, HCl and NH3 have been made for a densely populated region of the UK, the North-West of England, using data on power generation, incinerator plant capacity, fuel usage and animal and human population statistics. The spatial distributions of SO2 and NOx emissions are quite different, reflecting their different source strengths. The emissions from motor vehicles make up 52% of the NOx emissions from the North-West of England, whilst those from fossil-fuel-fired power stations make up 20%. The emissions of fossil-fuel-fired power stations make up 58% of SO2 emissions from the North-West. A large fossil-fuel-fired power station is the largest known point source for emissions of SO2, NOx and HCl. The largest contribution to NH3 emissions in the North-West is from cattle. Humans may contribute some NH3 to overall emissions but there is considerable uncertainty as to how much is emitted and what fraction of this is deposited within buildings. The uncertainties in the methodologies used are high-lighted and, where possible, recommendations are made as to how future emissions estimates might be improved. Potential reductions in emissions of SO2, NOx and HCl are discussed under basic scenarios of planned power station closures in the area and the compliance of the electricity generation industry with the European Community Directive on Large Combustion Plants.     

Impact of land-use types on nitrate concentration and δN in unconfined groundwater in rural areas of Korea

An understanding of the long-term changes in the nitrate contamination pattern of unconfined groundwater is critical to conservation of drinking water in rural areas supporting mixed land-use activities such as cropping, livestock farming, and residence. To examine the effect of different land-use activities on nitrate contamination, groundwater samples were collected monthly for 3 years (1997–1999) from 12 wells in rural areas with different land-use activities and analyzed for the concentrations and N isotopic ratios (δ¹⁵N) of nitrate. The characteristics of nitrate contamination clearly differed with land-use activities. The percentages of samples that had a nitrate concentration exceeding the national standard for drinking water (10 mg N L⁻¹) were 0, 23, 43, and 67% for the uncontaminated natural area, cropping area, cropping-livestock farming complex area, and residential area, respectively. The range of δ¹⁵N values was between +1.4 and +4.5‰ for groundwater nitrate from the uncontaminated natural area. In the cropping area, the δ¹⁵N values were slightly different with the type of fertilizer applied to fields in the vicinity of the well, and the values ranged between +8.7 and +14.4‰ for the compost-applied area and between +4.5 and +8.5‰ for the area where urea was applied with compost. The δ¹⁵N values of the cropping-livestock farming complex area ranged from +1.0 to +17.7‰, probably resulting from mixed contamination sources (inorganic fertilizer and livestock manure). The well located closest to the livestock feedlot had relatively higher δ¹⁵N values, with a range between +8.7 and +17.6‰. In the residential area, a higher δ¹⁵N (most frequently above +10‰) of nitrate suggested that the major source of contamination was effluent from leaky septic tanks. Our data showed that unconfined groundwater is susceptible to land-use activities above the aquifers, and the impacts of the activities could be more precisely inferred from long-term data on the concentration and δ¹⁵N of nitrate. By determining the impacts, more effective (specific to contamination sources) measures for preventing groundwater quality could be implemented.     

测微技术在废水生化处理中的应用

利用测微技术对扬子石化公司水厂厌氧装置进行菌种分布，颗粒污泥粒径的测定，从微观的角度来反映装置的运行情况，为实际运行操作提供参考。     

环保型煤炭开采与利用技术--煤炭地下气化

介绍了煤炭地下气化技术的开发与应用，相比传统煤炭开采燃用技术，煤炭地下气化实现了煤炭清洁开采与利用，指出煤炭地下气化技术是环保型开采与利用技术，应用积极推广利用。     

The effect of taconite tailings on primary productivity in the Silver Bay area of Western Lake Superior

Considerable concern has arisen over the possibility that the discharge of taconite tailings into Lake Superior could affect algal primary productivity. In 1972, primary productivity studies utilizing the carbon-14 technique were run in the Silver Bay area. Samples were collected and analyzed on a weekly basis for a three month period that included a five week plant shutdown period. Resultant productivity data indicate that there is no apparent relationship between primary productivity and the discharge of taconite tailings. Productivity trends in the Silver Bay area tend to conform to the known seasonal behavior of phytoplankton in western Lake Superior.     

Dynamics of the TIT FOR TAT strategy during predator inspection in the guppy (Poecilia reticulata)

Summary One well-known solution to the iterated Prisoner's Dilemma is the TIT FOR TAT strategy. This strategy has three characteristics associated with it. TIT FOR TAT is nice (cooperates on the first move of a game), retaliatory (plays defect against an individual that defected on the prior move), and forgiving (cooperates with an individual which has defected in the past but cooperates in the present). Predator inspection behavior in guppies (Poecilia reticulata) was examined in order to determine whether guppies displayed these three characteristics. Results indicate that while it can be quite difficult to translate the abstract concepts of niceness, retaliation, and forgiveness into measurable behaviors, the data support the hypothesis that guppies display the three characteristics associated with the TIT FOR TAT strategy.The selfish herd and dilution effect are discussed as possible alternative explanations for the observed behavior. These hypotheses alone were insufficient to explain the results.