Direct Effects of Atmospheric Sulfate Deposition on Vegetation

Acid sulfate aerosol (500 μg/m³) had no effect on soybean or pinto bean after a single 4-h exposure. However, visible Injury and chlorophyll loss occurred when plants were sequentially exposed to acid aerosol and ozone (380 μg/m³) for 4 h. In yellow poplar seedlings exposed to ozone (200 μg/m³), sulfur dioxide (210 μg/m³) and simulated rain solutions (pH 5.6, 4.3 and 3.0) for 6 weeks, root dry weight, leaf area increase, mean relative growth rate and unit leaf rate decreased linearly with pH in ozone-treated plants. However, unit leaf rate and mean relative growth rate increased linearly in response to sulfur dioxide as solution acidity increased. Ambient wet and dry sulfate concentrations appear insufficient to directly impact vegetation.     

Regional Variations in Sulfate and Nitrate on Annual,Seasonal, and Synoptic Time Scales

ABSTRACT

Ambient data from Interagency Monitoring of Protected Visual Environments (IMPROVE) monitors are analyzed to evaluate the spatial structure of SO₄ and NO₃ aerosols in the mid-Atlantic region. Sub-weekly, seasonal, and annual data values are compared between the IMPROVE Washington, DC, site and three rural sites. Synoptic perturbations are compared between sites to quantify similarities in short-term temporal perturbations of SO₄ and NO₃. Based on these comparisons between the rural and urban IMPROVE monitors, the spatial structure of SO₄ shows broad regional homogeneity that is recognizable from both the long-term average values and the short-term variations.

NO₃ data on a seasonal and annual basis show much larger spatial gradients between the urban Washington monitor and the three rural monitors than do SO₄ data. Short-term NO₃ perturbations at the three rural monitors also differ significantly from those at the Washington site. These dissimilarities in NO₃ levels between the rural and urban IMPROVE monitors on both short-term and longer-term time scales indicate little homogeneity of NO₃ aerosols in the mid-Atlantic region considered here. The volatility of NO₃ aerosols and the removal rate of HNO₃ via dry deposition could contribute to the spatial variability differences shown here between SO₄ and NO₃.     

Spotting of Automotive Finishes from the Interactions Between Dry Deposition of Crustal Material and Wet Deposition of Sulfate

During the summer of 1988, General Motors Research Laboratories operated a mobile atmospheric research laboratory in Jacksonville, Florida to determine the cause of environmentally- related damage that occurs on automotive finishes In many parts of the U.S. The damage occurs as circular, elliptical, or irregular spots that appear as deposits or precipitates. The results of the present study show that a wetting event (rain or dew) is a prerequisite for damage to occur. Sulfuric acid contained in the rain or dew reacts on surfaces with drydeposited calcium which Is a common constituent of soli. As the droplets evaporate, a calcium sulfate precipitate forms on horizontal surfaces around the perimeter of the droplet. Subsequent washing of the surface may remove the precipitate, but on clearcoats, where the calcium sulfate was present, scars remain.     

硫酸盐还原菌的污染与防治方法

硫酸盐还原菌 ( Sulphate-Reducing Bacteria,简称SRB)是一群严格厌氧的异养型微生物 ,其分布遍及全球 ,主要存在于水体的深部和浅部、下水道和油田等处 ,它们与石油、煤炭矿藏有关 ;它们在生态环境中的广泛分布及其特殊的代谢活动对人类环境和国民经济产生明显的影响 ,人们对此越来越重视 ,对 SRB的研究也在不断深入。在环境科学的研究中 ,SRB在水处理 (特别是厌氧处理工艺 )中的应用已有报道[1 ] ,而对 SBR引起的污染与防治办法却鲜见报道。本文拟对此进行介绍。1　对水体的污染与防治1 .1　对水体的污染SRB对水体的污染是由有机…     

Composition of Aqueous Extracts of Broiler Litter Treated with Aluminum Sulfate,Ferrous Sulfate,Ferric Chloride and Gypsum

More knowledge on the composition of aqueous extracts of broiler litter amended for Water Soluble P (WSP) reduction would help to understand how amendments work. We measured pH, concentrations of Ca, Mg, Fe, Al, Cu, Mn, Zn, Molybdate Reactive P (MRP), and Dissolved Unreactive P (DUP) in water extracts of broiler litter treated with aluminum sulfate (ALS), ferrous sulfate (FES), ferric chloride (FEC), and gypsum (GYP) at 0, 5, 15, and 25% w/w. In order to study the effects of acidification, the same properties were measured in aqueous extracts of broiler litter suspensions that were titrated to end-points 3, 4, or 6 with 0.5N HCl. Concentrations of MRP, DUP, Ca and Mg, were 61%, 53%, 3.8 times, and 2.6 times greater in extracts from suspensions acidified to pH 6 than at the original pH of 8.9. ALS, FES, and FEC reduced pH, and showed similar effects on WSP concentrations, which were greater than with GYP. The magnitude of the reductions in WSP by ALS, FES, and FEC is uncertain because the actual amount of WSP immobilized cannot be determined. This is because of two opposite effects: 1) Through adsorption, soluble aluminum and iron remove phosphates from solution, and 2) Through acidification, iron and aluminum compounds release phosphates to solution.     

Source and Budget of Sulfate in Precipitation From Central Alberta,Canada

Rain, hail, and snow samples collected in central Alberta have been analyzed for sulfate and chloride content using a conductometric titration method. The mean values of sulfate concentration in rain and hail collected in the region of sulfur extraction gas plants were 2.7 mg/l and 2.9 mg/l respectively. The mean value of the sulfate content of a large number of hail samples collected from one severe storm well removed from a major SO₂ source was only 0.6 mg/l. Several snow samples collected in Alberta and southern British Columbia had a mean sulfate content of less than 0.5 mg/l. These results are discussed in terms of the efficiency with which SO₂ is removed from the atmosphere by the different precipitation processes. The results strongly suggest that most of the sulfate found in central Alberta precipitation is of local industrial origin.

By comparing the sulfate deposition in precipitation around one isolated gas plant with the known SO₂ emission rate, a local atmospheric sulfur budget is derived. This budget indicates that the summertime convective storms are a very efficient mechanism for removing the SO₂ from the atmosphere, with between 32 and 46% of the sulfur emitted as SO₂ arriving at the ground as sulfate sulfur within a radius of 25 miles of the source. In contrast snow is a very inefficient removal mechanism, since in winter less than 2% of the sulfur emission is deposited in the snowfall near the source.     

Seasonal and spatial distribution of nonylphenol in Shihwa Lake, Korea

Alkylphenols (APs) have been known as endocrine disruptors and consequently received much environmental concern. This study focused on seasonal variation and spatial distribution of nonylphenol (NP) in various matrixes including dissolved water, particulates, surface sediment, sediment trap and sediment core taken from Shihwa Lake and its adjacent areas. A total of 11 phenolic compounds including nonylphenol, t-octylphenol (t-OP) and bisphenol A (BPA) were measured in February, June and October 2002. NP is the most abundant chemical among the phenolic compounds and its concentrations in dissolved water, particulates and surface sediments from Shihwa Lake were measured as 17.4-1533.1 ng/l, 4.3-831.2 ng/l and 10.4-5054.1 ng/g dw, respectively. NP concentration in dissolved water varied with seasons and generally showed a decreasing order of June > October > February, while the seasonal trend was hardly found in sediment. High levels of NP were measured in surrounding industrial complexes, the concentrations was decreased gradually with distance from the industrial areas. NP in core samples showed an increasing trend toward the core depth. There exists a reasonable correlation between NP in dissolved water and in particulates, whereas the correlation between NP in dissolved water and in sediments is not significant. APs concentrations in Shihwa Lake were comparable to other highly polluted areas of the world and their possible effects on various organisms in the lake are discussed.     

Seasonal flux of nonylphenol in Han River, Korea

In order to understand the behavior of nonylphenol (NP) in Han River, water, suspended particle and sediment samples were analyzed during summer, autumn and winter. Concentrations of nonylphenol in water ranged from 23.2 to 187.6 ng/l, in suspended particle from 6.8 to 190.8 ng/l and in sediment from 25.4 to 932.0 ng/gdrywt. An increasing trend in the concentration is noticed in all matrices along down the river. In case of water and suspended particle, concentrations were higher in warmer season than in colder season. Percentage of nonylphenol in the suspended particle phase decreased from 67% to 28% with decreasing temperature in water. A reasonable correlation (R2 = 0.63) was obtained for water and suspended particle. The partition coefficient Log Kp is 4.8. No seasonal variation of the concentration in sediment is noticed in this study.     

Relationship between Sulfate Aerosol and Visibility

A PM₁₀ monitoring network was established throughout the South Coast Air Basin (SOCAB) in the greater Los Angeles region during the calendar year 1986. Annual average PM₁₀ mass concentrations within the Los Angeles metropolitan area ranged from 47.0 µg m^-3 along the coast to 87.4 µg m^-3 at Rubldoux, the furthest inland monitoring station. Measurements made at San Nicolas Island suggest that regional background aerosol contributes between 28 to 44 percent of the PM₁₀ aerosol at monitoring sites In the SOCAB over the long term average. Five major aerosol components (carbonaceous material, NO^- ₃, SO⁼ ₄, NH⁺ ₄, and soil-related material) account for greater than 80 percent of the annual average PM₁₀ mass at all on-land monitoring stations. Peak 24-h average mass concentrations of nearly 300 µg m^-3 were observed at inland locations, with lower peak values (?130–150 µg m^-3) measured along the coast. Peak-day aerosol composition was characterized by increased NO^- ₃ Ion and associated ammonium ion levels, as compared to the annual average. There appears to be only a weak dependence of PM₁₀ mass concentration on season of the year. This lack of a pronounced seasonal dependence results from the complex and contradictory seasonal variations in the major chemical components (carbonaceous material, nitrate, sulfate, ammonium ion and crustal material). At most sites within the Los Angeles metropolitan area, PM₁₀ mass concentrations exceeded both the annual and 24-h average federal and state of California PM₁₀ regulatory standards.     

Episodic release of methane bubbles from peatland during spring thaw

Methane (CH(4)) flux into the atmosphere during spring thaw was investigated in a small ombrotrophic peatland (141 degrees 48'E, 43 degrees 19'N, Japan) using the conventional chamber method. More than 50 chamber deployments on top of the snow cover were carried out and continued for more than 165h until the surface snow and underlying ice cover on top of the peat layer had thawed completely. Methane emissions were almost absent in the presence of snow cover. At the very moment the surface ice cover thawed, a large CH(4) flush (>10mgCH(4)m(-2)h(-1)) was recorded, which was on the same order of magnitude as episodic ebullition previously observed in the high-summer. Gas bubbles trapped in the ice layer on top of the waterlogged peat were preliminarily analyzed for the volumetric percentage in the total ice volume and their gas species compositions. Results showed that the bubbles occupied about 3.2% volume and that the mixing ratio of CH(4) in the bubbles was about 20%. The abundance of the bubble-form CH(4) was sufficient to explain the observed episodic CH(4) release during the thaw. Results of this study show that CH(4) emissions during the thaw season have great temporal variability; emission occurs as an episodic release of bubble-form CH(4) stored in the frozen layer. The results also imply the possibility that gas-phase CH(4) plays an important role, not only during the growing season but also in cold-season CH(4) dynamics in northern peatlands.     

Sulfate,chloride and fluoride retention in Andosols exposed to volcanic acid emissions

The continuous emissions of SO(2), HCl and HF by Masaya volcano, Nicaragua, represent a substantial source of atmospheric S-, Cl- and F-containing acid inputs for local ecosystems. We report on the effects of such acid depositions on the sulfate, chloride and fluoride contents in soils (0-40 cm) from two distinct transects located downwind from the volcano. The first transect corresponds to relatively undifferentiated Vitric Andosols, and the second transect to more weathered Eutric Andosols. These soils are exposed to various rates of volcanogenic acid addition, with the Vitric sites being generally more affected. Prolonged acid inputs have led to a general pH decrease and reduced exchangeable base cation concentrations in the Andosols. The concentrations of 0.5 M NH(4)F- and 0.016 M KH(2)PO(4)-extractable sulfate (NH(4)F-S and KH(2)PO(4)-S, respectively) indicate that volcanic S addition has increased the inorganic sulfate content of the Vitric and Eutric soils at all depths. In this process, the rate of sulfate accumulation is also dependent on soil allophane contents. For all soils, NH(4)F extracted systematically more (up to 40 times) sulfate than KH(2)PO(4). This difference suggests sulfate incorporation into an aluminum hydroxy sulfate phase, whose contribution to total inorganic sulfate in the Vitric and Eutric Andosols is estimated from approximately 34 to 95% and approximately 65 to 98%, respectively. The distribution of KH(2)PO(4)-extractable chloride in the Vitric and Eutric Andosols exposed to volcanic Cl inputs reveals that added chloride readily migrates through the soil profiles. In contrast, reaction of fluoride with Al and Fe oxyhydroxides and allophanes is an important sink mechanism in the Masaya Andosols exposed to airborne volcanic F. Fluoride dominates the anion distribution in all soil horizons, although F is the least concentrated element in the volcanic emissions and depositions. The soil anion distribution reflects preferential retention of fluoride over sulfate and chloride, and of sulfate over chloride. The primary acidifying agent of the Andosols subject to the volcanic acid inputs is HCl.     

The Analysis of Airborne Sulfate

This report reviews the current state of analytical methodology for sulfate in airborne particles. Methods for determination of total aerosol sulfate and total soluble sulfate are assessed. A more detailed review of the relatively new techniques for quantitative speciation of airborne sulfate then follows. Size distribution methodology and filter sampling difficulties relating to the collection of airborne sulfate-containing particles are enumerated. Experiments are suggested which use new, improved, and potentially applicable sulfate speciation techniques to obtain a better understanding of the generation, transport, transformation and removal processes that, in turn, determine the identity and concentrations of sulfate species in ambient air.     

The Seasonal,Weekly, and Daily Cycles of Atmospheric Smoke Content in Central Montreal

Time variations of soiling index measurements obtained from three AISI smoke samplers located in Central Montreal during the period January I960-April 1963 are analyzed. A marked seasonal cycle is found, with midwinter smokiness two to three times midsummer values. The mean value at an elevation of 600 ft on the summit of ML Royal is only 21% of that in the city below. A 46% reduction in smoke is also observed at the location adjacent to the large Mt. Royal Park. The. average weekend reduction in smoke is approximately 20% with a significant change in the diurnal pattern on Sunday. There are two basic types of weekday daily cycle. A winter type with small amplitude, and morning and evening maxima of similar magnitude; a secondary late evening peak is also noted. A summer type with large amplitude and a marked morning maximum. The time of morning peak at the upper station lags behind the lower stations by 2-3 hr in the winter, but in the summer the peaks occur almost simultaneously. These two types are related to the interaction of the daily cycles in both smoke production and ventilation of the city’s atmosphere.     

Seasonal dynamics of harmful algae in outer Oslofjorden monitored by microarray, qPCR, and microscopy

Monitoring of marine microalgae is important to predict and manage harmful algal blooms. Microarray Detection of Toxic ALgae (MIDTAL) is an FP7-funded EU project aiming to establish a multi-species microarray as a tool to aid monitoring agencies. We tested the suitability of different prototype versions of the MIDTAL microarray for the monthly monitoring of a sampling station in outer Oslofjorden during a 1-year period. Microarray data from two different versions of the MIDTAL chip were compared to results from cell counts (several species) and quantitative real-time PCR (qPCR; only Pseudochattonella spp.). While results from generation 2.5 microarrays exhibited a high number of false positive signals, generation 3.3 microarray data generally correlated with microscopy and qPCR data, with three important limitations: (1) Pseudo-nitzschia cells were not reliably detected, possibly because cells were not sufficiently retained during filtration or lysed during the extraction, and because of low sensitivity of the probes; (2) in the case of samples with high concentrations of non-target species, the sensitivity of the arrays was decreased; (3) one occurrence of Alexandrium pseudogonyaulax was not detected due to a 1-bp mismatch with the genus probe represented on the microarray. In spite of these shortcomings our data demonstrate the overall progress made and the potential of the MIDTAL array. The case of Pseudochattonella — where two morphologically similar species impossible to separate by light microscopy were distinguished — in particular, underlines the added value of molecular methods such as microarrays in routine phytoplankton monitoring.     

Ground-Level Ozone in Eastern Canada: Seasonal Variations,Trends, and Occurrences of High Concentrations

Over the past few years, concern has increased in Canada over the health and environmental impacts of elevated concentrations of ground-level ozone. During the summer the most populated regions of Canada frequently record ozone concentrations that exceed the one-hour average maximum acceptable air quality objective of 32 parts per billion (ppb). In 1988 the Canadian Council of Ministers of the Environment agreed to develop a federal/provincial management plan to control nitrogen oxide and volatile organic compound emissions to reduce ozone concentrations in all affected regions of the country. In addition to the proposed interim control measures, the plan recommended that studies be undertaken to acquire the information necessary to develop sound control strategies. This report represents one of those studies and provides a summary of ground-level ozone measurements for eastern Canada for the 1980 to 1991 period with an emphasis on seasonal variations, trends, and occurrences of high concentrations.

Southwestern Ontario experiences the highest maximum hourly ozone concentrations and the greatest frequency of hours greater than the 82 ppb acceptable objective. Urban sites have the highest frequencies of ozone concentration measurements in the < 10 ppb range, while rural and remote sites show peaks in frequency distribution in the 20 to 30 ppb range. Trend analysis of summertime (May to September) average daily maximum ozone concentration showed no consistent pattern for eastern Canadian sites during 1980 to 1991. Sites in Montreal showed statistically insignificant downward trends while sites in Toronto showed small but statistically significant upward trends. These ozone-increasing trends are associated with reductions in nitric oxide concentrations. At all sites there was large year-to-year variability in peak ozone levels and in the frequency of hours with ozone concentrations above the maximum acceptable objective.     

A Comparison of Mass,Lead, Sulfate,and Nitrate Concentrations in a Field Study Using Dichotomous,Size-Selective,and Standard Hi-Vol Samplers

Air monitoring In the San Francisco Bay Area was carried out to measure outdoor community air concentrations of poly cyclic aromatic hydrocarbons (PAH) and mutagenlc activity (mutagenlclty) In participate organic matter (POM). Monitoring began In 1979 and Is currently conducted at six stations. PAH and mutagenlclty tests were performed on organic extracts prepared from high volume (hl-vol) filters composited every four months, by meteorological season. PAH were determined by high pressure liquid chromatography (HPLC) with fluorescence and ultraviolet detection. Mutagenlclty was measured In the Ames Salmonella bloas-say using strain TA98 with and without metabolic activation. The nine-year mean concentration of benzo(a)pyrene (BaP) was 0.4 ng/m³. The mutagenlcfty of this amount of BaP accounted for only about 0.2% of the observed mutagenicity In POM and other measured PAH accounted for even less. Concentrations of PAH and mutagenlclty were three to nine times higher during the winter than during other seasons. Year-to-year wintertime trends In several PAH were also seen. Early In the 1980s, winter concentrations of BaP and benzo (g,h,i)perylene Increased. However since the mld-1980’s, their concentrations have fallen. The decrease In PAH concentrations may be the result of an Increasing proportion of vehicles with relatively low organic emissions. In contrast to PAH, mutagenlcfty did not show significant year-to-year time trends.