Sample records for acid rain ph

  1. Acid Rain, pH & Acidity: A Common Misinterpretation.

    ERIC Educational Resources Information Center

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  2. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.

    1995-01-01

    Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

  3. Effects of acid rain on grapevines

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Forsline, P.L.; Musselman, R.C.; Dee, R.J.

    1983-01-01

    Mature vineyard-growing Concord grapevines were sprayed with simulated acid rain solutions ranging from pH 2.5 to 5.5 both as acute treatments at anthesis and chronically throughout the season in 1980 and 1981. In 1981, 8 additional varieties were also treated with simulated acid rain solutions at pH 2.75 and 3.25. With Concord in 1981, few foliar lesions on leaves were visible at pH 2.75. In contrast, many leaf lesions with decreased fruit soluble solids were observed at pH 2.5 in 1980. The relationship between acid-rain and oxidant stipple, chlorosis, and soluble solids in the absence of acid rain leaf lesionsmore » at pH>2.5 remains unclear. Acute sprays (pH2.75) at anthesis reduced pollen germination in four grape cultivars. However, fruit set was reduced in only one of these. Grape yields were not influenced by acid rain treatments. There was no evidence that acid-rain at ambient pH levels had negative effects on grape production or fruit quality.« less

  4. [Effects of simulated acid rain on respiration rate of cropland system with different soil pH].

    PubMed

    Zhu, Xue-zhu; Zhang, Gao-chuan; Li, Hui

    2009-10-15

    To evaluate the effects of acid rain on the respiration rate of cropland system, an outdoor pot experiment was conducted with paddy soils of pH 5.48 (S1), pH 6.70 (S1) and pH 8.18 (S3) during the 2005-2007 wheat-growing seasons. The cropland system was exposed to acid rain by spraying the wheat foliage and irrigating the soil with simulated rainwater of T1 (pH 6.0), T2 (pH 6.0, ionic concentration was twice as rainwater T1), and T3 (pH 4.4, ionic concentration was twice as rainwater T1), respectively. The static opaque chamber-gas chromatograph method was used to measure CO2 fluxes from cropland system. The results showed that acid rain affected the respiration rate of cropland system through crop plant, and the cropland system could adapt to acid rain. Acid rainwater significantly increased the average respiration rate in alkaline soil (S3) cropland system, while it had no significant effects on the average respiration rate in neutral soil (S2) and acidic soil (S1) cropland systems. During 2005-2006, after the alkaline soil cropland system was treated with rainwater T3, the average respiration rate was 23.6% and 27.6% higher than that of alkaline soil cropland system treated with rainwater T1 and T2, respectively. During March to April, the respiration rate was enhanced with the increase of rainwater ionic concentration, while it was dropped with the decrease of rainwater pH value in acidic soil cropland system. It was demonstrated that soil pH and crop plant played important roles on the respiration rate of cropland system.

  5. Effects of acid rain on grapevines

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Forsline, P.L.; Musselman, R.C.; Dee, R.J.

    1983-01-01

    Mature vineyard-growing Concord grapevines (Vitis labrusca, Bailey) were sprayed with simulated acid rain solutions ranging from pH 2.5 to pH 5.5 both as acute treatments at anthesis and chronically throughout the season in 1980 and 1981. In 1981, eight additional varieties were also treated with simulated acid rain solutions at pH 2.75 and pH 3.25. With Concord in 1981, few foliar lesions on leaves were visible at pH 2.75. In contrast, many leaf lesions with decreased fruit soluble solids in the absence of acid rain leaf lesions at pH>2.5 remains unclear. Acute sprays (pH 2.75) at anthesis reduced pollen germinationmore » in four grape cultivars. However, fruit set was reduced in only one of these. Only the cultivars de Chaunac and Ives had reduced berry soluble solids with chronic weekly sprays at pH 2.75. Reduction in soluble solids was not associated with increased oxidant stipple (ozone injury) in Concord and de Chaunac cultivars, but this association was observed in Ives. There was no evidence that acid rain in combination with ozone increased oxidant stipple as occurs when ozone and SO/sub 2/ are combined. Grape yields were not influenced by acid rain treatments. There was no evidence that acid rain at ambient pH levels had negative effects on grape production or fruit quality.« less

  6. The Acid Rain Reader.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  7. Influence of simulated acidic rain on root-infecting fungi

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shafer, S.R.

    1983-01-01

    Influences of the acidity of simulated rain on root-infecting fungi were investigated. Effects of rain acidity on Phytophthora cinnamomi were studied. Propagule densities in soil depended upon the acidity (pH 5.6, 4.0, 3.2, or 2.4) of simulated rain and soil depth (1, 2, 4, or 8 cm). Lowest densities occurred in 1 to 2 cm soil layers exposed to rains at pH 3.2 or 2.4. Sporangium production on radicles of Lupinus angustifolius in Lakeland sand moistened with rain solution at pH 2.4 was 47% less than production with solution at pH 5.6. A linear response to solution acidity was exhibited.more » Infection of L. angustifolius roots by zoospores demonstrated a linear response to acidity of rain. Approximately 44% fewer lesions occurred on roots of seedlings exposed to rain at pH 2.4 than on roots of seedlings exposed to rain at pH 5.6. The acidity (pH 5.6, 4.0, 3.2, or 2.4) of repeated rains had no consistent effect on disease progress among L. augustifolius seedlings planted in infested soil. The formation of ectomycorrhizae on Pinus taeda seedlings exhibited a quadratic response to acidity of repeated rains. The percentage of short roots that were ectomycorrhizal was greatest among seedlings exposed to rains at pH 2.4 and least among seedlings exposed to rains at pH 4.0. The density of Macrophomina phaseolina propagules in Lakeland sand exposed to repeated rains at pH 2.4 was an average of 20% less than densities associated with rains at pH 5.6, 4.0, or 3.2.« less

  8. Effect of acid rain pH on leaching behavior of cement stabilized lead-contaminated soil.

    PubMed

    Du, Yan-Jun; Wei, Ming-Li; Reddy, Krishna R; Liu, Zhao-Peng; Jin, Fei

    2014-04-30

    Cement stabilization is a practical approach to remediate soils contaminated with high levels of lead. However, the potential for leaching of lead out of these stabilized soils under variable acid rain pH conditions is a major environmental concern. This study investigates the effects of acid rain on the leaching characteristics of cement stabilized lead contaminated soil under different pH conditions. Clean kaolin clay and the same soil spiked with 2% lead contamination are stabilized with cement contents of 12 and 18% and then cured for 28 days. The soil samples are then subjected to a series of accelerated leaching tests (or semi-dynamic leaching tests) using a simulated acid rain leachant prepared at pH 2.0, 4.0 or 7.0. The results show that the strongly acidic leachant (pH ∼2.0) significantly altered the leaching behavior of lead as well as calcium present in the soil. However, the differences in the leaching behavior of the soil when the leachant was mildly acidic (pH ∼4.0) and neutral (pH ∼7.0) prove to be minor. In addition, it is observed that the lead contamination and cement content levels can have a considerable impact on the leaching behavior of the soils. Overall, the leachability of lead and calcium is attributed to the stability of the hydration products and their consequent influence on the soil buffering capacity and structure. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Rain pH estimation based on the particulate matter pollutants and wet deposition study.

    PubMed

    Singh, Shweta; Elumalai, Suresh Pandian; Pal, Asim Kumar

    2016-09-01

    In forecasting of rain pH, the changes caused by particulate matter (PM) are generally neglected. In regions of high PM concentration like Dhanbad, the role of PM in deciding the rain pH becomes important. Present work takes into account theoretical prediction of rain pH by two methods. First method considers only acid causing gases (ACG) like CO2, SO2 and NOx in pH estimation, whereas, second method additionally accounts for effect of PM (ACG-PM). In order to predict the rain pH, site specific deposited dust that represents local PM was studied experimentally for its impact on pH of neutral water. After incorporation of PM correction factor, it was found that, rain pH values estimated were more representative of the observed ones. Fractional bias (FB) for the ACG-PM method reduced to values of the order of 10(-2) from those with order of 10(-1) for the ACG method. The study confirms neutralization of rain acidity by PM. On account of this, rain pH was found in the slightly acidic to near neutral range, despite of the high sulfate flux found in rain water. Although, the safer range of rain pH blurs the severity of acid rain from the picture, yet huge flux of acidic and other ions get transferred to water bodies, soil and ultimately to the ground water system. Simple use of rain pH for rain water quality fails to address the issues of its increased ionic composition due to the interfering pollutants and thus undermines severity of pollutants transferred from air to rain water and then to water bodies and soil. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Acid Rain: An Educational Opportunity?

    ERIC Educational Resources Information Center

    Marion, James I.

    1984-01-01

    Deals with how educators can handle the subject of acid rain; illustrates suggestions with experiences of grade nine students visiting Frost Valley Environmental Education Center (Oliverea, New York) to learn scientific concepts through observation of outdoor phenomena, including a stream; and discusses acid rain, pH levels, and pollution control…

  11. [Relationship between simulated acid rain stress and leaf reflectance].

    PubMed

    Song, Xiao-dong; Jiang, Hong; Yu, Shu-quan; Zhou, Guo-mo; Jiang, Zi-shan

    2010-01-01

    Acid rain is a worldwide environmental problem. Serious acid rain pollution in subtropical China has constituted a potential threat to the health of the local forest. In the present paper, the changing properties of the chlorophyll concentration and spectral reflectance at the visible wavelengths for the six subtropical broad-leaved tree species leaves under simulated acid rain (SAR) treatment with different pH levels were studied. With the increasing strength of the SAR, the chlorophyll concentrations of the experimental species under pH 2.5 and pH 4.0 treatment were higher than that under pH 5.6; the spectral reflectance at the visible wavelengths for pH 2.5 and pH 4.0 were lower than that for pH 5.6 in general; while there weren't significant differences between pH 2.5 and pH 4.0. After the treatment with different levels of SAR, the differences in spectral reflectance at the visible wavelengths mainly focused around the green peak and red edge on the reflectance curve. The subtropical broad-leaved tree species studied were relatively not sensitive to acid rain stresses; some stronger acid rain may accelerate the growth of the tree species used here to some extent.

  12. Pyrite oxidation under simulated acid rain weathering conditions.

    PubMed

    Zheng, Kai; Li, Heping; Wang, Luying; Wen, Xiaoying; Liu, Qingyou

    2017-09-01

    We investigated the electrochemical corrosion behavior of pyrite in simulated acid rain with different acidities and at different temperatures. The cyclic voltammetry, polarization curve, and electrochemical impedance spectroscopy results showed that pyrite has the same electrochemical interaction mechanism under different simulated acid rain conditions, regardless of acidity or environmental temperature. Either stronger acid rain acidity or higher environmental temperature can accelerate pyrite corrosion. Compared with acid rain having a pH of 5.6 at 25 °C, the prompt efficiency of pyrite weathering reached 104.29% as the acid rain pH decreased to 3.6, and it reached 125.31% as environmental temperature increased to 45 °C. Increasing acidity dramatically decreases the charge transfer resistance, and increasing temperature dramatically decreases the passivation film resistance, when other conditions are held constant. Acid rain always causes lower acidity mine drainage, and stronger acidity or high environmental temperatures cause serious acid drainage. The natural parameters of latitude, elevation, and season have considerable influence on pyrite weathering, because temperature is an important influencing factor. These experimental results are of direct significance for the assessment and management of sulfide mineral acid drainage in regions receiving acid rain.

  13. SULFURIC ACID RAIN EFFECTS ON CROP YIELD AND FOLIAR INJURY

    EPA Science Inventory

    A study was undertaken to determine the relative sensitivity of major U.S. crops to sulfuric acid rain. Plants were grown under controlled environmental conditions and exposed to simulated acid rain of three sulfuric acid concentrations (pH 3.0, 3.5, 4.0) or to a control rain (pH...

  14. Acid Rain. LC Science Tracer Bullet.

    ERIC Educational Resources Information Center

    Hollmann, Pauline, Comp.

    The term "acid rain," also called "acid precipitation," generally refers to any precipitation having a pH value of less than 5.6. This guide to the literature on acid rain in the collections of the Library of Congress is not necessarily intended to be a comprehensive bibliography. It is designed to provide the reader with a set…

  15. Detecting Sulfuric and Nitric Acid Rain Stresses on Quercus glauca through Hyperspectral Responses

    PubMed Central

    Wang, Shanqian; Zhang, Xiuying; Ma, Yuandan; Li, Xinhui; Zhang, Xiaomin; Liu, Lei

    2018-01-01

    Acid rain, which has become one of the most severe global environmental issues, is detrimental to plant growth. However, effective methods for monitoring plant responses to acid rain stress are currently lacking. The hyperspectral technique provides a cost-effective and nondestructive way to diagnose acid rain stresses. Taking a widely distributed species (Quercus glauca) in Southern China as an example, this study aims to monitor the hyperspectral responses of Q. glauca to simulated sulfuric acid rain (SAR) and nitric acid rain (NAR). A total of 15 periods of leaf hyperspectral data under four pH levels of SAR and NAR were obtained during the experiment. The results showed that hyperspectral information could be used to distinguish plant responses under acid rain stress. An index (green peak area index, GPAI) was proposed to indicate acid rain stresses, based on the significantly variations in the region of 500–660 nm. Light acid rain (pH 4.5 SAR and NAR) promoted Q. glauca growth relative to the control groups (pH 5.6 SAR and NAR); moderate acid rain (pH 3.0 SAR) firstly promoted and then inhibited plant growth, while pH 3.0 NAR showed mild inhibitory effects during the experiment; and heavy acid rain (pH 2.0) significantly inhibited plant growth. Compared with NAR, SAR induced more serious damages to Q. glauca. These results could help monitor acid rain stress on plants on a regional scale using remote sensing techniques. PMID:29522488

  16. Detecting Sulfuric and Nitric Acid Rain Stresses on Quercus glauca through Hyperspectral Responses.

    PubMed

    Wang, Shanqian; Zhang, Xiuying; Ma, Yuandan; Li, Xinhui; Cheng, Min; Zhang, Xiaomin; Liu, Lei

    2018-03-09

    Acid rain, which has become one of the most severe global environmental issues, is detrimental to plant growth. However, effective methods for monitoring plant responses to acid rain stress are currently lacking. The hyperspectral technique provides a cost-effective and nondestructive way to diagnose acid rain stresses. Taking a widely distributed species ( Quercus glauca ) in Southern China as an example, this study aims to monitor the hyperspectral responses of Q. glauca to simulated sulfuric acid rain (SAR) and nitric acid rain (NAR). A total of 15 periods of leaf hyperspectral data under four pH levels of SAR and NAR were obtained during the experiment. The results showed that hyperspectral information could be used to distinguish plant responses under acid rain stress. An index (green peak area index, GPAI) was proposed to indicate acid rain stresses, based on the significantly variations in the region of 500-660 nm. Light acid rain (pH 4.5 SAR and NAR) promoted Q. glauca growth relative to the control groups (pH 5.6 SAR and NAR); moderate acid rain (pH 3.0 SAR) firstly promoted and then inhibited plant growth, while pH 3.0 NAR showed mild inhibitory effects during the experiment; and heavy acid rain (pH 2.0) significantly inhibited plant growth. Compared with NAR, SAR induced more serious damages to Q. glauca . These results could help monitor acid rain stress on plants on a regional scale using remote sensing techniques.

  17. [Effects of simulated acid rain on water physiological characteristics of Myrica rubra seedlings].

    PubMed

    Yaho, Zhao-bin; Jiang, Hong; Yu, Shu-quan; Lu, Mei-juan

    2011-08-01

    Taking the seedlings of typical subtropical economic tree species Myrica rubra in Zhejiang Province as test materials, a pot experiment was conducted to study their water physiological characteristics under effects of simulated acid rain (pH 2.5 and pH 4.0), with water (pH 5.6) as the control. Season, year, and acid rain all had significant effects on the photosynthetic rate (Pn). Among the treatments, the Pn had a greater difference in summer than in spring and autumn, and was higher in treatment acid rain (pH 4.0). Season, year, acid rain, and the interactions of season and year and of the three factors had significant effects on the stomata conductance (Gs), and also, the Gs had a greater difference among the treatments in summer than in spring and autumn. Acid rain had inhibitory effect on Gs. Season, year, acid rain, and the interactions of season and year and of season and acid rain affected the transpiration rate (Tr) significantly. Same as Pn and Gs, the Tr had a greater difference among the treatments in summer than in spring and autumn. Acid rain (pH 2.5) had the strongest inhibitory effect on Tr. Acid rain and the interactions of season and year and of season and acid rain had significant effects on the water use efficiency (WUE), and acid rain (pH 2.5) had definitely positive effect on the WUE.

  18. [Effects of simulated acid rain on Quercus glauca seedlings photosynthesis and chlorophyll fluorescence].

    PubMed

    Li, Jia; Jiang, Hong; Yu, Shu-quan; Jiang, Fu-wei; Yin, Xiu-min; Lu, Mei-juan

    2009-09-01

    Taking the seedlings of Quercus glauca, a dominant evergreen broadleaf tree species in subtropical area, as test materials, this paper studied their photosynthesis, chlorophyll fluorescence, and chlorophyll content under effects of simulated acid rain with pH 2.5, 4.0, and 5.6 (CK). After 2-year acid rain stress, the net photosynthetic rate of Q. glauca increased significantly with decreasing pH of acid rain. The acid rain with pH 2.5 and 4.0 increased the stomatal conductance and transpiration rate, and the effect was more significant under pH 2.5. The intercellular CO2 concentration decreased in the order of pH 2.5 > pH 5.6 > pH 4.0. The maximum photosynthetic rate, light compensation point, light saturation point, and dark respiration rate were significantly higher under pH 2.5 and 4.0 than under pH 5.6, while the apparent quantum yield was not sensitive to acid rain stress. The maximal photochemical efficiency of PS II and the potential activity of PS II under pH 2.5 and 4.0 were significantly higher than those under pH 5.6. The relative chlorophyll content was in the order of pH 2.5 > pH 5.6 > pH 4.0, and there was a significant difference between pH 2.5 and 4.0. All the results suggested that the photosynthesis and chlorophyll fluorescence of Q. glauca increased under the effects of acid rain with pH 2.5 and 4.0, and the acid rain with pH 2.5 had more obvious effects.

  19. CR@BaSO4: an acid rain-indicating material.

    PubMed

    Gao, Hong-Wen; Xu, Xin-Hui

    2011-12-28

    The CR@BaSO(4) hybrid was synthesized, characterized and used as an acid rain-indicating (ARI) material. A painted ARI umbrella was discolored after exposure to simulated acid rain of pH 5 or less and returned to the initial color after the rain stopped. Such a functionalized material may make acid rain visual to remind people in real-time. This journal is © The Royal Society of Chemistry 2011

  20. Acid rain and its ecological consequences.

    PubMed

    Singh, Anita; Agrawal, Madhoolika

    2008-01-01

    Acidification of rain-water is identified as one of the most serious environmental problems of transboundary nature. Acid rain is mainly a mixture of sulphuric and nitric acids depending upon the relative quantities of oxides of sulphur and nitrogen emissions. Due to the interaction of these acids with other constituents of the atmosphere, protons are released causing increase in the soil acidity Lowering of soil pH mobilizes and leaches away nutrient cations and increases availability of toxic heavy metals. Such changes in the soil chemical characteristics reduce the soil fertility which ultimately causes the negative impact on growth and productivity of forest trees and crop plants. Acidification of water bodies causes large scale negative impact on aquatic organisms including fishes. Acidification has some indirect effects on human health also. Acid rain affects each and every components of ecosystem. Acid rain also damages man-made materials and structures. By reducing the emission of the precursors of acid rain and to some extent by liming, the problem of acidification of terrestrial and aquatic ecosystem has been reduced during last two decades.

  1. [Effects of simulated acid rain on decomposition of soil organic carbon and crop straw].

    PubMed

    Zhu, Xue-Zhu; Huang, Yao; Yang, Xin-Zhong

    2009-02-01

    To evaluate the effects of acid rain on the organic carbon decomposition in different acidity soils, a 40-day incubation test was conducted with the paddy soils of pH 5.48, 6.70 and 8.18. The soils were amended with 0 and 15 g x kg(-1) of rice straw, adjusted to the moisture content of 400 g x kg(-1) air-dried soil by using simulated rain of pH 6.0, 4.5, and 3.0, and incubated at 20 degrees C. The results showed that straw, acid rain, and soil co-affected the CO2 emission from soil system. The amendment of straw increased the soil CO2 emission rate significantly. Acid rain had no significant effects on soil organic carbon decomposition, but significantly affected the straw decomposition in soil. When treated with pH 3.0 acid rain, the amount of decomposed straw over 40-day incubation in acid (pH 5.48) and alkaline (pH 8.18) soils was 8% higher, while that in neutral soil (pH 6.70) was 15% lower, compared to the treatment of pH 6.0 rain. In the treatment of pH 3.0 acid rain, the decomposition rate of soil organic C in acid (pH 5.48) soil was 43% and 50% (P < 0.05) higher than that in neutral (pH 6.70) and alkaline (pH 8.18) soils, while the decomposition rate of straw in neutral soil was 17% and 16% (P < 0.05) lower than that in acid and alkaline soils, respectively.

  2. Acid-rain induced changes in streamwater quality during storms on Catoctin Mountain, Maryland

    USGS Publications Warehouse

    Rice, Karen C.; Bricker, O.P.

    1992-01-01

    Catoctin Mountain receives some of the most acidic (lowest pH) rain in the United States. In 1990, the U.S. Geological Survey (USGS), in cooperation with the Maryland Department of the Environment (MDE) and the Maryland Department of Natural Resources (DNR), began a study of the effects of acid rain on the quality of streamwater on the part of Catoctin Mountain within Cunningham Falls State Park, Maryland (fig. 1). Samples of precipitation collected on the mountain by the USGS since 1982 have been analyzed for acidity and concentration of chemical constituents. During 1982-91, the volume-weighted average pH of precipitation was 4.2. (Volume weighting corrects for the effect of acids being washed out of the atmosphere at the beginning of rainfall). The pH value is measured on a logarithmic scale, which means that for each whole number change, the acidity changes by a factor of 10. Thus rain with a pH of 4.2 is more than 10 times as acidic as uncontaminated rain, which has a pH of about 5.6. The acidity of rain during several rainstorms on Catoctin Mountain was more than 100 times more acidic than uncontaminated rain.

  3. Acid rain stimulation of Lake Michigan phytoplankton growth

    USGS Publications Warehouse

    Manny, Bruce A.; Fahnenstiel, G.L.; Gardner, W.S.

    1987-01-01

    Three laboratory experiments demonstrated that additions of rainwater to epilimnetic lake water collected in southeastern Lake Michigan stimulated chlorophyll a production more than did additions of reagent-grade water during incubations of 12 to 20 d. Chlorophyll a production did not begin until 3–5 d after the rain and lake water were mixed. The stimulation caused by additions of rain acidified to pH 3.0 was greater than that caused by additions of untreated rain (pH 4.0–4.5). Our results support the following hypotheses: (1) Acid rain stimulates the growth of phytoplankton in lake water; (2) phosphorus in rain appears to be the factor causing this stimulation. We conclude that acid rain may accelerate the growth of epilimnetic phytoplankton in Lake Michigan (and other similar lakes) during stratification when other sources of bioavailable phosphorus to the epilimnion are limited

  4. Acid rain attack on outdoor sculpture in perspective

    NASA Astrophysics Data System (ADS)

    Livingston, Richard A.

    2016-12-01

    A major concern motivating research in acid rain materials effects has been the potential for damage to cultural heritage, particularly outdoor marble and bronze sculpture. However, a combination of field and laboratory studies has failed to show a correlation between rain pH and loss of materials. In order to understand this counterintuitive lack of acid rain effect, an aqueous geochemical modeling approach was used to analyze rain runoff chemistry for the relative importance of acid rain neutralization, dry deposition, and in the case of marble, natural carbonate dissolution. This approach involved the development of pH - SO42- phase diagrams for marble (calcium carbonate) and bronze (copper) under ambient environmental conditions. This then enabled reaction path modeling of the acid neutralization process using the pH range typically found in wet deposition (3.5-6). The results were for marble that the theoretical maximum amount of Ca2+ ion that could be lost due acid rain neutralization would be 0.158 mmol/l compared to 10.5 mmol/l by dry deposition, and for bronze, the Cu2+ ion losses would be 0.21 mmol/l and 47.3 mmol/l respectively. Consequently dry deposition effects on these materials have the potential to dominate over wet deposition effects. To test these predictions the geochemical models were applied to examples of data sets from mass balance (runoff vs rainfall) studies on a marble statue in New York City and some bronze memorial plaques at Gettysburg PA. Although these data sets were collected in the early 1980s they remain valid for demonstrating the mass balance method. For the marble statue, the mean Ca2+ losses by dry deposition was about 69% of the total compared 0.3% for acid rain neutralization, which was less than the natural carbonate dissolution losses of 0.8%. For the bronze, the mean Cu2+ losses were 70.6% by SO42- dry deposition and 23% by NO3- dry deposition compared to 6.4% by acid rain neutralization. Thus for both cases the wet

  5. Spread of acid rain over India

    NASA Astrophysics Data System (ADS)

    Khemani, L. T.; Momin, G. A.; Rao, P. S. Prakasa; Safai, P. D.; Singh, G.; Kapoor, R. K.

    Rain water and aerosol samples were collected at a few locations representative of urban and non-urban regions in India. Also, rain water samples were collected in and around a coal-fired power plant. All the rain water and aerosol samples were analyzed for major chemical components along with pH. The rain water at all the places of measurement, except near the industrial sources, has been found to be alkaline and was characterized by the presence of excess cations, particularly by Ca 2+. The acid rain near the industrial sources was associated with excess anions, especially SO 42-. The atmospheric aerosols at all the places of measurement were found rich with basic components, suggesting that the alkaline soil dust and fly ash are responsible at present for preventing the spread of acid rain in India.

  6. Study on the relationship between meteorological conditions and acid rain in mid-eastern Fujian.

    PubMed

    Lin, C C; Liu, J X; Cai, Y Y; Li, B L; Wang, Z L; Chen, B B

    2009-08-01

    Based on the acid rain observation data and the contemporaneous historical synoptic charts of Mid-Eastern Fujian during the period of 1991 to 2003, we analyzed the distribution characteristics of acid rain in different seasons, weather types, precipitation grades and wind directions. The results showed that the acid pollution in Mid-Eastern Fujian was still serious. In winter, the precipitation pH value was 4.79, and the acid rain frequency was 60.62% which was twice higher than that in summer. The pH value of warm shear-type precipitation at 850 hPa was 4.79. Nearly half of these precipitations had the problems of acid rain pollution. The acid rain frequency of the inverted trough type was only 26.11% which was the lowest one in all types. There was no marked difference of the acid rain distribution characteristics between ahead-of-trough and behind-the-trough. The precipitation pH values of the five grades were lower than 5.30 and the acid rain frequency changed as an inverted U shape with the increasing of the rainfall. The pH values of precipitations in the eight wind directions were generally below 5.20, and the acid rain frequencies were about 40%.

  7. Effects of simulated rain acidified with sulfuric acid on host-parasite interactions

    Treesearch

    D. S. Shriner

    1976-01-01

    Wind-blown rain, rain splash, and films of free moisture play important roles in the epidemiology of many plant diseases. The effects of simulated rain acidified with sulfuric acid were studied on several host-parasite systems. Plants were exposed, in greenhouse or field, to simulated rain of pH 3.2 ? 0.1 or pH 6.0 ? 0.2. Simulated "rain" of pH 3.2 resulted...

  8. Effects and mechanism of acid rain on plant chloroplast ATP synthase.

    PubMed

    Sun, Jingwen; Hu, Huiqing; Li, Yueli; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2016-09-01

    Acid rain can directly or indirectly affect plant physiological functions, especially photosynthesis. The enzyme ATP synthase is the key in photosynthetic energy conversion, and thus, it affects plant photosynthesis. To clarify the mechanism by which acid rain affects photosynthesis, we studied the effects of acid rain on plant growth, photosynthesis, chloroplast ATP synthase activity and gene expression, chloroplast ultrastructure, intracellular H(+) level, and water content of rice seedlings. Acid rain at pH 4.5 remained the chloroplast structure unchanged but increased the expression of six chloroplast ATP synthase subunits, promoted chloroplast ATP synthase activity, and increased photosynthesis and plant growth. Acid rain at pH 4.0 or less decreased leaf water content, destroyed chloroplast structure, inhibited the expression of six chloroplast ATP synthase subunits, decreased chloroplast ATP synthase activity, and reduced photosynthesis and plant growth. In conclusion, acid rain affected the chloroplast ultrastructure, chloroplast ATPase transcription and activity, and P n by changing the acidity in the cells, and thus influencing the plant growth and development. Finally, the effects of simulated acid rain on the test indices were found to be dose-dependent.

  9. Influence of acid rain upon water plumbosolvency.

    PubMed Central

    Moore, M R

    1985-01-01

    The West of Scotland has had particular problems in the past associated with soft acidic water supplies and uptake of lead from domestic plumbing systems by such water. As a consequence of this, health problems related to overexposure to lead have been identified. The current debate on acidification of ground waters by acid rain is therefore particularly pertinent to this area. Studies have shown that even a modest decrease in pH will result in very substantial increase in plumbosolvency. This was found to be of particular importance in the city of Glasgow and town of Ayr, where prior to water treatment, pH values were 6.3 and 5.4, respectively, and where, consequentially, large numbers of homes did not comply with lead in water standards. Closed-loop lime-dosing systems were introduced in both Glasgow and Ayr to increase the pH with immediate decrease in the lead content of the water and, subsequently, blood lead concentrations of the subjects living in these areas. Such closed-loop systems will compensate for any acidity in water supplies, whether of natural origin or originating from acid rain precipitation. However, when such treatment has not been applied, any increase in water acidity due to acid rain which is, in many cases, already unacceptable. which is, in many cases, already unacceptable. PMID:4076078

  10. Effects of sulfuric, nitric, and mixed acid rain on Chinese fir sapling growth in Southern China.

    PubMed

    Liu, Xin; Fu, Zhiyuan; Zhang, Bo; Zhai, Lu; Meng, Miaojing; Lin, Jie; Zhuang, Jiayao; Wang, G Geoff; Zhang, Jinchi

    2018-09-30

    The influence of acid rain on plant growth includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in root growth. In addition, the concentration of NO 3 - in acid rain increases along with the rapid growth of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO 4 2- /NO 3 - (S/N) ratios, which were 1:0, 5:1, 1:1, 1:5 and 0:1, on Chinese fir sapling growth from March 2015 to April 2016. Results showed that Chinese fir sapling height growth rate (HGR) and basal diameter growth rate (DGR) decreased as acid rain pH decreased, and also decreased as the percentage of NO 3 - increased in acid rain. Acid rain pH significantly decreased the Chlorophyll a (Chla) and Chlorophyll b (Chlb) content, and Chla and Chlb contents with acid rain S/N 1:5 were significantly lower than those with S/N 1:0 at pH 2.5. The chlorophyll fluorescence parameters, maximal efficiency of Photosystem II photochemistry (Fv/Fm) and non-photochemical quenching coefficient (NPQ), with most acid rain treatments were significantly lower than those with CK treatments. Root activities first increased and then decreased as acid rain pH decreased, when acid rain S/N ratios were 1:1, 1:5 and 0:1. Redundancy discriminant analysis (RDA) showed that the Chinese fir DGR and HGR had positive correlations with Chla, Chlb, Fv/Fm ratio, root activity, catalase and superoxide dismutase activities in roots under the stress of acid rain with different pH and S/N ratios. The structural equation modelling (SEM) results showed that acid rain NO 3 - concentration and pH had stronger direct effects on Chinese fir sapling HGR and DGR, and the direct effects of acid rain NO 3 - concentration and pH on HGR were lower than those on DGR. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect the sustainable development of monoculture Chinese fir plantations in southern China

  11. Differential Gene Expression of Longan Under Simulated Acid Rain Stress.

    PubMed

    Zheng, Shan; Pan, Tengfei; Ma, Cuilan; Qiu, Dongliang

    2017-05-01

    Differential gene expression profile was studied in Dimocarpus longan Lour. in response to treatments of simulated acid rain with pH 2.5, 3.5, and a control (pH 5.6) using differential display reverse transcription polymerase chain reaction (DDRT-PCR). Results showed that mRNA differential display conditions were optimized to find an expressed sequence tag (EST) related with acid rain stress. The potential encoding products had 80% similarity with a transcription initiation factor IIF of Gossypium raimondii and 81% similarity with a protein product of Theobroma cacao. This fragment is the transcription factor activated by second messenger substances in longan leaves after signal perception of acid rain.

  12. [Spatiotemporal trends and the impact factors of acid rain in Anhui Province].

    PubMed

    Shi, Chun-E; Qiu, Ming-Yan; Zhang, Ai-Min; Zhang, Hao; Zhang, Su; Wang, Zi-Fa

    2010-06-01

    The observational data of acid rain at seven stations in Anhui province operated by China Meteorological Administration (CMA), as well as the coal consumptions in Anhui and some surrounding provinces along with satellite measured tropospheric NO2 columns, were used to analyze the spatiotemporal trends of acid rain in Anhui and the potential reasons of the increasing occurrence frequency of acid rain. In addition, the technique of back-trajectory-cluster analysis was used to examine the impacts of transport patterns on the precipitation acidity in Anhui. The occurrence frequency shows the lowest in summer and the highest in autumn, with 3-year average pH < 5.6 during 2006-2008 at all stations, hereinto, pH values are between 5.0 and 4.5 in Hefei, Anqing, Maanshan and Bengbu. In spatial, acid rain were the most severe in southern to middle Anhui and mitigated to north. The distributions of pH were concentrative at Fuyang, Tongling and Huangshan, with more than 75% occurred between 6.00-7.50 (Fuyang), 5.00-6.00 (Tongling) and 5.00-6.50 (Huangshan); quite dispersive at other stations, with the maximum at 4.00-4.50 (Hefei and Anqing), 5.00-5.50 (Maanshan) and 5.50-6.00 (Bengbu). The occurrence frequencies of acid rain increased evidently at all stations comparing with those in the end of 1990s. The results of back-trajectories-cluster analysis show that the acid rain is closely related with the regional-range transport of acid rain precursors at each station. The air-masses from southeast and northeast, especially those passing through Jiangsu and Zhejiang, associated with the highest frequencies of acid rain with pH < 5.0, indicating that the industrial emissions in the economy developed areas of Yangtze Delta play key roles in acid rain in Anhui province. In addition, statistics shows that the occurrence frequency of acid rain in Hefei was highly correlated with the trends of the provincial coal consumptions in Anhui, Jiangsu and Zhejiang, also tropospheric NO2 column

  13. Selenium speciation in acidic environmental samples: application to acid rain-soil interaction at Mount Etna volcano.

    PubMed

    Floor, Geerke H; Iglesías, Mònica; Román-Ross, Gabriela; Corvini, Philippe F X; Lenz, Markus

    2011-09-01

    Speciation plays a crucial role in elemental mobility. However, trace level selenium (Se) speciation analyses in aqueous samples from acidic environments are hampered due to adsorption of the analytes (i.e. selenate, selenite) on precipitates. Such solid phases can form during pH adaptation up till now necessary for chromatographic separation. Thermodynamic calculations in this study predicted that a pH<4 is needed to prevent precipitation of Al and Fe phases. Therefore, a speciation method with a low pH eluent that matches the natural sample pH of acid rain-soil interaction samples from Etna volcano was developed. With a mobile phase containing 20mM ammonium citrate at pH 3, selenate and selenite could be separated in different acidic media (spiked water, rain, soil leachates) in <10 min with a LOQ of 0.2 μg L(-1) using (78)Se for detection. Applying this speciation analysis to study acid rain-soil interaction using synthetic rain based on H(2)SO(4) and soil samples collected at the flanks of Etna volcano demonstrated the dominance of selenate over selenite in leachates from samples collected close to the volcanic craters. This suggests that competitive behavior with sulfate present in acid rain might be a key factor in Se mobilization. The developed speciation method can significantly contribute to understand Se cycling in acidic, Al/Fe rich environments. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. EFFECTS OF ACID RAIN ON GRAPEVINES

    EPA Science Inventory

    Mature vineyard-growing Concord grapevines were sprayed with simulated acid rain solutions ranging from pH 2.5 to 5.5 both as acute treatments at anthesis and chronically throughout the season in 1980 and 1981. In 1981, 8 additional varieties were also treated with simulated acid...

  15. Non-linear direct effects of acid rain on leaf photosynthetic rate of terrestrial plants.

    PubMed

    Dong, Dan; Du, Enzai; Sun, Zhengzhong; Zeng, Xuetong; de Vries, Wim

    2017-12-01

    Anthropogenic emissions of acid precursors have enhanced global occurrence of acid rain, especially in East Asia. Acid rain directly suppresses leaf function by eroding surface waxes and cuticle and leaching base cations from mesophyll cells, while the simultaneous foliar uptake of nitrates in rainwater may directly benefit leaf photosynthesis and plant growth, suggesting a non-linear direct effect of acid rain. By synthesizing data from literature on acid rain exposure experiments, we assessed the direct effects of acid rain on leaf photosynthesis across 49 terrestrial plants in China. Our results show a non-linear direct effect of acid rain on leaf photosynthetic rate, including a neutral to positive effect above pH 5.0 and a negative effect below that pH level. The acid rain sensitivity of leaf photosynthesis showed no significant difference between herbs and woody species below pH 5.0, but the impacts above that pH level were strongly different, resulting in a significant increase in leaf photosynthetic rate of woody species and an insignificant effect on herbs. Our analysis also indicates a positive effect of the molar ratio of nitric versus sulfuric acid in the acid solution on leaf photosynthetic rate. These findings imply that rainwater acidity and the composition of acids both affect the response of leaf photosynthesis and therefore result in a non-linear direct effect. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Activity of earthworm in Latosol under simulated acid rain stress.

    PubMed

    Zhang, Jia-En; Yu, Jiayu; Ouyang, Ying

    2015-01-01

    Acid rain is still an issue of environmental concerns. This study investigated the impacts of simulated acid rain (SAR) upon earthworm activity from the Latosol (acidic red soil). Laboratory experiment was performed by leaching the soil columns grown with earthworms (Eisenia fetida) at the SAR pH levels ranged from 2.0 to 6.5 over a 34-day period. Results showed that earthworms tended to escape from the soil and eventually died for the SAR at pH = 2.0 as a result of acid toxicity. The catalase activity in the earthworms decreased with the SAR pH levels, whereas the superoxide dismutases activity in the earthworms showed a fluctuate pattern: decreasing from pH 6.5 to 5.0 and increasing from pH 5.0 to 4.0. Results implied that the growth of earthworms was retarded at the SAR pH ≤ 3.0.

  17. [Characteristics and the impact factors of acid rain in Fuzhou and Xiamen 1992-2012].

    PubMed

    Zheng, Qiu-Ping; Wang, Hong; Chen, Bin-Bin; Sui, Ping; Lin, Wen

    2014-10-01

    Based on the observed acid rain data, synoptic situations and mass concentrations of atmospheric pollutants data from 1992 to 2012, the temporal variation characteristics and the impact factors of acid rain were analyzed in Fuzhou and Xiamen. The results showed that acid rain and non-acid rain accounted for 38.1% and 61.9% respectively in Fuzhou, 40.6% and 59.4% respectively in Xiamen. The annual average pH was 4.1-5.5 in Fuzhou. Acid rain pollution alleviated after 2007 in Fuzhou, and alleviated after 2006 in Xiamen. Acid rain was more serious in winter and spring than in summer and autumn. Precipitation intensity could affect the acidity of rain. Acid rain was observed more serious in southeast, southwest, west and northwest wind in Fuzhou, and more serious in northeast, southwest, west and northwest wind in Xiamen. Acid rain was most severe under the condition of transformed surface cold high, while most light under the conditions of typhoon (intertropical convergence zone) and outside of typhoon (intertropical convergence zone). There was a negative correlation between the mass concentrations of atmospheric pollutants, such as SO2, NO2, PM10, and the pH of rain in Fuzhou.

  18. ACID RAIN AND SOIL MICROBIAL ACTIVITY: EFFECTS AND THEIR MECHANISMS

    EPA Science Inventory

    In the investigation, our aim was to determine if acid rain affects soil microbial activity and to identify possible mechanisms of observed effects. A Sierran forest soil (pH 6.4) planted with Ponderosa pine seedlings was exposed to simulated rain (pH 2.0, 3.0, 4.0 and 5.6) with ...

  19. Acid rain research program. Annual progress report, September 1975--June 1976

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Evans, L.S.; Raynor, G.S.

    1976-09-01

    The aims of the research program are: (a) to observe the minimum threshold dose of simulated acid rain to produce visual and histological effects on plant foliage, (b) approach threshold limits of simulated sulfate acid rain that affect plant growth and reproduction, and (c) to measure chemical and meteorological parameters of incident rain. Acute leaf injury to several plant species resulted from exposure of foliage to simulated sulfate acid rain of pH level 2.3 to 2.9. Only slight injury occurred at 3.1. Scanning electron micrographs showed that injury to upper leaf surfaces occurred mostly at the base of trichomes (leafmore » hairs) and near stomata. An association of lesion development near vascular tissue was also noted. Histologically, lesions are characterized by an initial collapse of the epidermis with eventual lysis and collapse of more internal leaf tissues on the upper leaf surface of pinto beans which complemented detailed descriptions of visual lesion development after daily exposures to simulated rain. Initial experiments with gametophytes of Pteridium aquilinum show that reproduction of this fern species is very sensitive to solutions of pH 5.2 while vegetative development is not affected at pH levels of 2.2. Initial rain samples from the sequential sampler have been obtained. Initial portions of rain events exhibit a pH near 3.0 in some cases. More complete chemical analyses are anticipated.« less

  20. Impacts of simulated acid rain on recalcitrance of two different soils.

    PubMed

    Dai, Zhongmin; Liu, Xingmei; Wu, Jianjun; Xu, Jianming

    2013-06-01

    Laboratory experiments were conducted to estimate the impacts of simulated acid rain (SAR) on recalcitrance in a Plinthudult and a Paleudalfs soil in south China, which were a variable and a permanent charge soil, respectively. Simulated acid rains were prepared at pH 2.0, 3.5, 5.0, and 6.0, by additions of different volumes of H2SO4 plus HNO3 at a ratio of 6 to 1. The leaching period was designed to represent 5 years of local annual rainfall (1,200 mm) with a 33 % surface runoff loss. Both soils underwent both acidification stages of (1) cation exchange and (2) mineral weathering at SAR pH 2.0, whereas only cation exchange occurred above SAR pH 3.5, i.e., weathering did not commence. The cation exchange stage was more easily changed into that of mineral weathering in the Plinthudult than in the Paleudalfs soil, and there were some K(+) and Mg(2+) ions released on the stages of mineral weathering in the Paleudalfs soil. During the leaching, the release of exchangeable base cations followed the order Ca(2+) >K(+) >Mg(2+) >Na(+) for the Plinthudult and Ca(2+) >Mg(2+) >Na(+) >K(+) for the Paleudalfs soil. The SARs above pH 3.5 did not decrease soil pH or pH buffering capacity, while the SAR at pH 2.0 decreased soil pH and the buffering capacity significantly. We conclude that acid rain, which always has a pH from 3.5 to 5.6, only makes a small contribution to the acidification of agricultural soils of south China in the short term of 5 years. Also, Paleudalfs soils are more resistant to acid rain than Plinthudult soils. The different abilities to prevent leaching by acid rain depend upon the parent materials, types of clay minerals, and soil development degrees.

  1. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  2. Response of plasma membrane H+-ATPase in rice (Oryza sativa) seedlings to simulated acid rain.

    PubMed

    Liang, Chanjuan; Ge, Yuqing; Su, Lei; Bu, Jinjin

    2015-01-01

    Understanding the adaptation of plants to acid rain is important to find feasible approaches to alleviate such damage to plants. We studied effects of acid rain on plasma membrane H(+)-ATPase activity and transcription, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate during stress and recovery periods. Simulated acid rain at pH 5.5 did not affect plasma membrane H(+)-ATPase activity, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate. Plasma membrane H(+)-ATPase activity and transcription in leaves treated with acid rain at pH 3.5 was increased to maintain ion homeostasis by transporting excessive H(+) out of cells. Then intracellular H(+) was close to the control after a 5-day recovery, alleviating damage on membrane and sustaining photosynthetic efficiency and growth. Simulated acid rain at pH 2.5 inhibited plasma membrane H(+)-ATPase activity by decreasing the expression of H(+)-ATPase at transcription level, resulting in membrane damage and abnormal intracellular H(+), and reduction in photosynthetic efficiency and relative growth rate. After a 5-day recovery, all parameters in leaves treated with pH 2.5 acid rain show alleviated damage, implying that the increased plasma membrane H(+)-ATPase activity and its high expression were involved in repairing process in acid rain-stressed plants. Our study suggests that plasma membrane H(+)-ATPase can play a role in adaptation to acid rain for rice seedlings.

  3. Influence of simulated acidic rain on bacterial speck of tomato. [Lycopersicon esculentum Mill var. 'Chico III', Pseudomonas tomato

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bisessar, S.; Palmer, K.T.; Kuja, A.L.

    Ambient rain in southern Ontario has a volume-weighted average pH of approximately 4.2. Tomato (Lycopersicon esculentum Mill var. 'Chico III') seedlings were exposed to simulated acidic rain in specially designed chambers. The inoculum of Pseudomonas tomato (Okabe) Alstatt, causal agent of bacterial speck, was sprayed on plants before or after exposure to acidic rain of pH 2.5, 3.5, and 4.5, as well as on plants not exposed to the simulated acidic rain. Speck symptoms (small, dark, brown spots with yellow halos) were found on all inoculated plants. Exposure of plants to simulted acidic rain inhibited speck development, but the inhibitionmore » was greater on plants exposed to acidic rain after inoculation. Spot necrosis, a typical response to acid rain, occurred on up to 15 to 20% of the leaf area on all tomato plants treated with acidic rain at pH 2.5. Plants alos showed a decrease in growth (height and fresh and dry weights) with an increase in rain acidity. Leaves injured by simulated acidic rain and examined histopathologically displayed cellular malformations including hyperplasia and hypertrophy. Pseudomonas tomato failed to grow on acidified King B medium or Difco nutrient broth adjusted to pH 3.5 or lower.« less

  4. Activity of earthworm in Latosol under simulated acid rain stress

    Treesearch

    Jia-En Zhang; Jiayu Yu; Ying Ouyang

    2015-01-01

    Acid rain is still an issue of environmental concerns. This study investigated the impacts of simulated acid rain (SAR) upon earthworm activity from the Latosol (acidic red soil). Laboratory experiment was performed by leaching the soil columns grown with earthworms (Eisenia fetida) at the SAR pH levels ranged from 2.0 to 6.5 over a 34-day period....

  5. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  6. Effects of simulated acid rain on soil fauna community composition and their ecological niches.

    PubMed

    Wei, Hui; Liu, Wen; Zhang, Jiaen; Qin, Zhong

    2017-01-01

    Acid rain is one of the severest environmental issues globally. Relative to other global changes (e.g., warming, elevated atmospheric [CO 2 ], and nitrogen deposition), however, acid rain has received less attention than its due. Soil fauna play important roles in multiple ecological processes, but how soil fauna community responds to acid rain remains less studied. This microcosm experiment was conducted using latosol with simulated acid rain (SAR) manipulations to observe potential changes in soil fauna community under acid rain stress. Four pH levels, i.e., pH 2.5, 3.5, 4.5, and 5.5, and a neutral control of pH 7.0 were set according to the current pH condition and acidification trend of precipitation in southern China. As expected, we observed that the SAR treatments induced changes in soil fauna community composition and their ecological niches in the tested soil; the treatment effects tended to increase as acidity increased. This could be attributable to the environmental stresses (such as acidity, porosity and oxygen supply) induced by the SAR treatments. In addition to direct acidity effect, we propose that potential changes in permeability and movability of water and oxygen in soils induced by acid rain could also give rise to the observed shifts in soil fauna community composition. These are most likely indirect pathways of acid rain to affect belowground community. Moreover, we found that nematodes, the dominating soil fauna group in this study, moved downwards to mitigate the stress of acid rain. This is probably detrimental to soil fauna in the long term, due to the relatively severer soil conditions in the deep than surface soil layer. Our results suggest that acid rain could change soil fauna community and the vertical distribution of soil fauna groups, consequently changing the underground ecosystem functions such as organic matter decomposition and greenhouse gas emissions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Direct effect of acid rain on leaf chlorophyll content of terrestrial plants in China.

    PubMed

    Du, Enzai; Dong, Dan; Zeng, Xuetong; Sun, Zhengzhong; Jiang, Xiaofei; de Vries, Wim

    2017-12-15

    Anthropogenic emissions of acid precursors in China have resulted in widespread acid rain since the 1980s. Although efforts have been made to assess the indirect, soil mediated ecological effects of acid rain, a systematic assessment of the direct foliage injury by acid rain across terrestrial plants is lacking. Leaf chlorophyll content is an important indicator of direct foliage damage and strongly related to plant productivity. We synthesized data from published literature on experiments of simulated acid rain, by directly exposing plants to acid solutions with varying pH levels, to assess the direct effect of acid rain on leaf chlorophyll content across 67 terrestrial plants in China. Our results indicate that acid rain substantially reduces leaf chlorophyll content by 6.71% per pH unit across the recorded plant species. The direct reduction of leaf chlorophyll content due to acid rain exposure showed no significant difference across calcicole, ubiquist or calcifuge species, implying that soil acidity preference does not influence the sensitivity to leaf injury by acid rain. On average, the direct effects of acid rain on leaf chlorophyll on trees, shrubs and herbs were comparable. The effects, however varied across functional groups and economic use types. Specifically, leaf chlorophyll content of deciduous species was more sensitive to acid rain in comparison to evergreen species. Moreover, vegetables and fruit trees were more sensitive to acid rain than other economically used plants. Our findings imply a potential production reduction and economic loss due to the direct foliage damage by acid rain. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. [Effects of simulated acid rain on seed germination and seedling growth of different type corn Zea mays].

    PubMed

    Zhang, Hai-Yan

    2013-06-01

    Taking normal corn, waxy corn, pop corn, and sweet corn as test materials, this paper studied their seed germination and seedling growth under effects of simulated acid rain (pH 6.0, 5.0, 4.0, 3.0, 2.0, and 1.0). Simulated acid rain at pH 2.0-5.0 had no significant effects on the seed germination and seedling growth, but at pH 1.0, the germination rate of normal corn, waxy corn, pop corn, and sweet corn was 91.3%, 68.7%, 27.5%, and 11.7%, respectively. As compared with those at pH 6.0 (CK), the germination rate, germination index, vigor index, germination velocity, shoot height, root length, shoot and root dry mass, and the transformation rate of stored substances at pH 1.0 had significant decrease, and the average germination time extended apparently. At pH 1.0, the effects of acid rain were greater at seedling growth stage than at germination stage, and greater on underground part than on aboveground part. Due to the differences in gene type, normal corn and waxy corn had the strongest capability against acid rain, followed by pop corn, and sweet corn. It was suggested that corn could be categorized as an acid rain-tolerant crop, the injury threshold value of acid rain was likely between pH 1.0 and pH 2.0, and normal corn and waxy corn would be prioritized for planting in acid rain-stricken area.

  9. Combined effects of lanthanum (III) chloride and acid rain on photosynthetic parameters in rice.

    PubMed

    Wang, Lihong; Wang, Wen; Zhou, Qing; Huang, Xiaohua

    2014-10-01

    Rare earth elements (REEs) pollution and acid rain are environmental issues, and their deleterious effects on plants attract worldwide attention. These two issues exist simultaneously in many regions, especially in some rice-growing areas. However, little is known about the combined effects of REEs and acid rain on plants. Here, the combined effects of lanthanum chloride (LaCl3), one type of REE salt, and acid rain on photosynthesis in rice were investigated. We showed that the combined treatment of 81.6 μM LaCl3 and acid rain at pH 4.5 increased net photosynthetic rate (Pn), stomatic conductance (Gs), intercellular CO2 concentration (Ci), Hill reaction activity (HRA), apparent quantum yield (AQY) and carboxylation efficiency (CE) in rice. The combined treatment of 81.6 μM LaCl3 and acid rain at pH 3.5 began to behave toxic effects on photosynthesis (decreasing Pn, Gs, HRA, AQY and CE, and increasing Ci), and the maximally toxic effects were observed in the combined treatment of 2449.0 μM LaCl3 and acid rain at pH 2.5. Moreover, the combined effects of LaCl3 and acid rain on photosynthesis in rice depended on the growth stage of rice, with the maximal effects occurring at the booting stage. Furthermore, the combined treatment of high-concentration LaCl3 and low-pH acid rain had more serious effects on photosynthesis in rice than LaCl3 or acid rain treatment alone. Finally, the combined effect of LaCl3 and acid rain on Pn in rice resulted from the changes in stomatic (Gs, Ci) and non-stomatic (HRA, AQY and CE) factors. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Antioxidant response of soybean seedlings to joint stress of lanthanum and acid rain.

    PubMed

    Liang, Chanjuan; Wang, Weimin

    2013-11-01

    Excess of rare earth elements in soil can be a serious environmental stress on plants, in particular when acid rain coexists. To understand how such a stress affects plants, we studied antioxidant response of soybean leaves and roots exposed to lanthanum (0.06, 0.18, and 0.85 mmol L(-1)) under acid rain conditions (pH 4.5 and 3.0). We found that low concentration of La3+ (0.06 mmol L(-1)) did not affect the activity of antioxidant enzymes (catalase and peroxidase) whereas high concentration of La3+ (≥0.18 mmol L(-1)) did. Compared to treatment with acid rain (pH 4.5 and pH 3.0) or La3+ alone, joint stress of La3+ and acid rain affected more severely the activity of catalase and peroxidase, and induced more H2O2 accumulation and lipid peroxidation. When treated with high level of La3+ (0.85 mmol L(-1)) alone or with acid rain (pH 4.5 and 3.0), roots were more affected than leaves regarding the inhibition of antioxidant enzymes, physiological function, and growth. The severity of oxidative damage and inhibition of growth caused by the joint stress associated positively with La3+ concentration and soil acidity. These results will help us understand plant response to joint stress, recognize the adverse environmental impact of rare earth elements in acidic soil, and develop measures to eliminate damage caused by such joint stress.

  11. Response of citrus and other selected plant species to simulated HCL - acid rain

    NASA Technical Reports Server (NTRS)

    Knott, W. M.; Heagle, A. S.

    1980-01-01

    Mature valencia orange trees were sprayed with hydrochloric acid solutions (pH 7.8, 2.0, 1.0, and 0.5) in the field at the full bloom stage and at one month after fruit set. Potted valencia orange and dwarf citrus trees, four species of plants native to Merritt Island, and four agronomic species were exposed to various pH levels of simulated acid rain under controlled conditions. The acid rain was generated from dilutions of hydrochloric acid solutions or by passing water through an exhaust generated by burning solid rocket fuel. The plants were injured severely at pH levels below 1.0, but showed only slight injury at pH levels of 2.0 and above. Threshold injury levels were between 2.0 and 3.0 pH. The sensitivity of the different plant species to acid solutions was similar. Foliar injury symptoms were representative of acid rain including necrosis of young tissue, isolated necrotic spots or patches, and leaf abscission. Mature valencia orange trees sprayed with concentrations of 1.0 pH and 0.5 pH in the field had reduced fruit yields for two harvests after the treatment. All experimental trees were back to full productivity by the third harvest after treatment.

  12. Response of soybean seed germination to cadmium and acid rain.

    PubMed

    Liu, Ting Ting; Wu, Peng; Wang, Li Hong; Zhou, Qing

    2011-12-01

    Cadmium (Cd) pollution and acid rain are the main environmental issues, and they often occur in the same agricultural region. Nevertheless, up to now, little information on the combined pollution of Cd(2+) and acid rain action on crops were presented. Here, we investigated the combined effect of Cd(2+) and acid rain on the seed germination of soybean. The results indicated that the single treatment with the low level of Cd(2+) (0.18, 1.0, 3.0 mg L(-1)) or acid rain (pH ≥3.0) could not affect the seed germination of soybean, which was resulted in the increased activities of peroxidase and catalase. The single treatment with the high concentration of Cd(2+) (>6 mg L(-1)) or acid rain at pH 2.5 decreased the activities of peroxidase and catalase, damaged the cell membrane and then decreased the seed germination of soybean. Meanwhile, the same toxic effect was observed in the combined treatment with Cd(2+) and acid rain, and the combined treatment had more toxic effect than the single treatment with Cd(2+) or acid rain. Thus, the combined pollution of Cd(2+) and acid rain had more potential threat to the seed germination of soybean than the single pollution of Cd(2+) or acid rain.

  13. Occurrence of acid rain in Baton Rouge, Louisiana, Summer 1981. The role of the catalytic converter

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Robinson, J.W.; Ghane, H.

    1982-01-01

    Between June and October 1981, acid rain falling in Baton Rouge, LA was studied. The acidity of the rain ranged for pH 3.9 to pH 5.8. Preliminary data showed that rain associated with thermal cumulo nimbus tended to be more acidic, but rain associated with active cold fronts were less acid. This may relate to dispersion and dilution of the acid aerosols by the cold front. It is proposed that exhaust from automobiles fitted with catalytic converters is a substantial contributor to the acid rain problem, and that their net value to the abatement of pollution must be questioned, particularlymore » in regions of the country where smog is not a problem. (JMT)« less

  14. Prolonged acid rain facilitates soil organic carbon accumulation in a mature forest in Southern China.

    PubMed

    Wu, Jianping; Liang, Guohua; Hui, Dafeng; Deng, Qi; Xiong, Xin; Qiu, Qingyan; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2016-02-15

    With the continuing increase in anthropogenic activities, acid rain remains a serious environmental threat, especially in the fast developing areas such as southern China. To detect how prolonged deposition of acid rain would influence soil organic carbon accumulation in mature subtropical forests, we conducted a field experiment with simulated acid rain (SAR) treatments in a monsoon evergreen broadleaf forest at Dinghushan National Nature Reserve in southern China. Four levels of SAR treatments were set by irrigating plants with water of different pH values: CK (the control, local lake water, pH ≈ 4.5), T1 (water pH=4.0), T2 (water pH=3.5), and T3 (water pH=3.0). Results showed reduced pH measurements in the topsoil exposed to simulated acid rains due to soil acidification. Soil respiration, soil microbial biomass and litter decomposition rates were significantly decreased by the SAR treatments. As a result, T3 treatment significantly increased the total organic carbon by 24.5% in the topsoil compared to the control. Furthermore, surface soil became more stable as more recalcitrant organic matter was generated under the SAR treatments. Our results suggest that prolonged acid rain exposure may have the potential to facilitate soil organic carbon accumulation in the subtropical forest in southern China. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. [Effects of acid rain stress on Eleocarpus glabripetalus seedlings leaf chlorophyll fluorescence characteristics and growth].

    PubMed

    Yin, Xiu-Min; Yu, Shu-Quan; Jiang, Hong; Liu, Mei-Hu

    2010-06-01

    A pot experiment was conducted to study the Eleocarpus glabripetalus seedlings leaf chlorophyll fluorescence characteristics and growth in different seasons under simulated acid rain stress (heavy, pH = 2. 5; moderate, pH = 4.0; and control, pH = 5.6). In the same treatments, the leaf relative chlorophyll content (SPAD), maximum PS II photochemical efficiency (F(v)/F(m)), actual PSII photochemical quantum yield (phi(PS II)), plant height, and stem diameter in different seasons were all in the order of October > July > April > January. In the same seasons, all the parameters were in the order of heavy acid rain > moderate acid rain > control. The interactions between different acid rain stress and seasons showed significant effects on the SPAD, F(v)/F(m), plant height, and stem diameter, but lesser effects on phi(PS II), qp and qN.

  16. USGS Tracks Acid Rain

    USGS Publications Warehouse

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  17. Time dependence of the pH of rain

    Treesearch

    John A. Kadlecek; Volkar A. Mohnen

    1976-01-01

    Standard procedures for determining the pH of rain samples usually involve substantial delays from the time of rainfall to the time of analysis. This assumes that no change in pH occurs during the storage period. We have found that this is not always true. We have determined that individual rain water samples possess a time dependent pH which can be correlated with the...

  18. Effects of simulated acid rain on pollen physiology and ultrastructure in the apple.

    PubMed

    Bellani, L M; Rinallo, C; Muccifora, S; Gori, P

    1997-01-01

    Viability, germination and tube length were investigated in pollen grains of field-grown 'Summerred' apple trees (Malus domestica Borkh) exposed to deionized water, rainfall or simulated acid rain at pH 5.6, 4.0 and 3.0. Pollen viability and germination significantly decreased with lower values of pH and with increasing number of treatments. The effects of pH 5.6 and natural rainfall were not significant. Electron microscope investigation of vegetative pollen cells of plants exposed to acid rain at pH 4.0 and 3.0 showed modified features in mitochondria, plastids and endoplasmic reticulum.

  19. Leaching Characteristics of Calcium and Strontium from Phosphogypsum Under Acid Rain.

    PubMed

    Wang, Mei; Luo, Houqiao; Chen, Yong; Yang, Jinyan

    2018-02-01

    Phosphogypsum (PG) stored close to phosphorus chemical plants has caused worldwide environmental problems. Column leaching experiments were conducted to evaluate Ca and Sr leaching from PG under simulated acid rain at pH levels typical for rain in the study region (Shifang, China). High concentrations of Ca and Sr in leachates in the first five leaching events could pollute the soil and groundwater around the PG. Leachates pH was lower than and had no correlation with simulated rain pH. No correlations between simulated rain pH and cumulative Ca and Sr content in leachates were noted. Around 2.0%-2.2% of Ca and 0.5%-0.6% of Sr were leached out from PG by the simulated summer rainfall in Shifang. Electrical conductivity values, Ca and Sr concentrations at bottom sections of PG columns were higher than those of top sections, while pH values showed a reverse trend. More precautions should be taken to protect the environment around PG stacks.

  20. Influence of long-term exposure to simulated acid rain on development, reproduction and acaricide susceptibility of the carmine spider mite, Tetranychus cinnabarinus

    PubMed Central

    Wang, Jin-Jun; Zhang, Jian-Ping; He, Lin; Zhao, Zhi-Mo

    2006-01-01

    Development, reproduction and acaricide susceptibility of Tetranychus cinnabarinus (Boisduvals) (Acari: Tetranychidae) were investigated after long-term (about 40 generations) exposure to various levels of acid rain; pH 2.5, 3.0, 4.0, and 5.6. Deionized water (pH 6.8) served as a control. The mites were reared on eggplant leaves at 28°C, 80%RH and a photoperiod of 14:10 (L:D) in the laboratory. The results showed that the duration of the immature stage was significantly affected by acid rain exposure. The shortest duration (8.90 days) was recorded for populations exposed to pH 5.6 acid rain, while the longest duration (9.37 days) occurred after exposure to pH 2.5 acid rain. Compared with the control population, adult longevity was shortened with an increase in acidity. Similarly, the oviposition duration was also shortened by an increase in acidity. Statistically, female fecundity did not differ significantly between pH 5.6, pH 4.0 and control populations, but did differ significantly between the control population and those exposed to pH 2.5 and pH 3.0 acid rain. This suggested that the mite suffered reproductive defects after long-term exposure to acid rain with higher acidity (pH 2.5 and 3.0). The intrinsic rate of increase among different populations was not significantly affected, but the net reproductive rate of populations exposed to pH 2.5 and 3.0 acid rain was significantly less than pH4.0, 5.6, and control populations. Bioassay results showed that after long-term exposure to acid rain, susceptibility of the mites to two acaricides, dichlorvos and fenpropathrin, did not change significantly. PMID:19537978

  1. Comparative effects of simulated acid rain of different ratios of SO42- to NO3- on fine root in subtropical plantation of China.

    PubMed

    Liu, Xin; Zhao, Wenrui; Meng, Miaojing; Fu, Zhiyuan; Xu, Linhao; Zha, Yan; Yue, Jianmin; Zhang, Shuifeng; Zhang, Jinchi

    2018-03-15

    The influence of acid rain on forest trees includes direct effects on foliage as well as indirect soil-mediated effects that cause a reduction in fine-root growth. In addition, the concentration of NO 3 - in acid rain increases with the rapidly growing of nitrogen deposition. In this study, we investigated the impact of simulated acid rain with different SO 4 2- /NO 3 - (S/N) ratios, which were 5:1 (S), 1:1 (SN) and 1:5 (N), on fine-root growth from March 2015 to February 2016. Results showed that fine roots were more sensitive to the effects of acid rain than soils in the short-term. Both soil pH and fine root biomass (FRB) significantly decreased as acid rain pH decreased, and also decreased with the percentage of NO 3 - increased in acid rain. Acid rain pH significantly influenced soil total carbon and available potassium in summer. Higher acidity level (pH=2.5), especially of the N treatments, had the strongest inhibitory impact on soil microbial activity after summer. The structural equation modelling results showed that acid rain S/N ratio and pH had stronger direct effects on FRB than indirect effects via changed soil and fine root properties. Fine-root element contents and antioxidant enzymes activities were significantly affected by acid rain S/N ratio and pH during most seasons. Fine-root Al ion content, Ca/Al, Mg/Al ratios and catalase activity were used as better indicators than soil parameters for evaluating the effects of different acid rain S/N ratios and pH on forests. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect fine-root growth in subtropical forests of China. Copyright © 2017. Published by Elsevier B.V.

  2. Pollution problem: acid rain and beekeeping

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Hayes, B.

    1979-11-01

    Some of the problems caused by acid rain are presented with emphasis on the effects on bees, especially in the Northeast. Scientists believe that rain east of the Mississippi is below 5.6 and average Northeastern rainfall is now down to pH 4. Trace minerals are being leached out of the soils and nectar that lacks calcium is being passed by when the bees forage. The first plants to show the effects will be the wild varieties of the legumes, such as clover. This leaves only plants on the extreme end of the acid scale such as the blueberry for beemore » forage. This leads to the side effect of the movement of calcium in nectar which will be restricted due to a lack of calcium-lime.« less

  3. Continued studies of acid rain and its effects on the Baton Rouge area

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Robinson, J.W.; Ghane, H.

    1983-01-01

    The acidity of rain water was measured in the Baton Rouge, Louisiana area from June 1981 to September 1982. Coordinated measurements were taken of the dissolved oxygen concentration in two local lakes before and after each rainfall. About 50% of the rainfall observed was quite acidic, with about 25% of the rain having a pH of 4 or less. Rain was more acidic during warm summers than in the winter weather. Rainfall during 1982 was, on a month to month comparison, more acidic than in 1981. Attempts were also made to discover any possible correlation of pH values with windmore » direction. The acidity of each of the two lakes increased over the time of the study. The dissolved oxygen content in each lake increased after periods of rain, probably due to a high concentration of oxygen in the rainwater. The buffering capacities of the lakes was measurable. However, it is noted that the larger lake was undergoing dredging at the time of the study and showed considerably less buffer capacity than the smaller lake. The smaller lake was far more affected by surface drainage and thus should have been more influenced by the acid rain. 7 references, 7 figures, 1 table.« less

  4. Acid Rain Analysis by Standard Addition Titration.

    ERIC Educational Resources Information Center

    Ophardt, Charles E.

    1985-01-01

    The standard addition titration is a precise and rapid method for the determination of the acidity in rain or snow samples. The method requires use of a standard buret, a pH meter, and Gran's plot to determine the equivalence point. Experimental procedures used and typical results obtained are presented. (JN)

  5. Acid Rain Study Guide.

    ERIC Educational Resources Information Center

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  6. Effects of intermittent acid rain on proline and antioxidant content on medicinal plant “Pereskia bleo”

    NASA Astrophysics Data System (ADS)

    Sulandjari; Dewi, W. S.

    2018-03-01

    Global warming due to CO2 and other greenhouse gas emissions from human activities have led to climate change and environmental degradation. The acid rain, with the pH of rainwater below 5.6, is a serious environmental problem. Arising from air pollution and potentially harmful to health, it can damage old buildings and distract the growth and physiological metabolism of sensitive plants. How does the influence of climate change on medicinal plants such as Pereskia bleo? The leaf of Pereskia bleo (Kunth) DC. contains high antioxidants with benefits for anti-cancer, anti-tumor, anti-rheumatic, and anti-inflammatory. This research aims to investigate the influence of acid rain on the proline level and antioxidant content of Pereskia bleo. Having been carried out from June to August in Jogjakarta, this study was conducted through the use of artificial acid rain with pH 5.8, 4.9, 3.7 and 2.9, by adding sulfate acid (H2SO4) to rainwater. The interval of intermittent watering acid rain to the plants is once a day, twice a day, and once in three days with three replications for six weeks. The results showed that Acid rain with a pH less than 4.9 and the intermittent interval of acid rain twice a day and once in three days significantly suppresses growth and chlorophyll content. In contrast, it increases the proline and antioxidant levels as a tolerant action of the plant.

  7. [Effects of simulated acid rain on oilseed rape (Brassica napus) physiological characteristics at flowering stage and yield].

    PubMed

    Cao, Chun-Xin; Zhou, Qin; Han, Liang-Liang; Zhang, Pei; Jiang, Hai-Dong

    2010-08-01

    A pot experiment was conducted to study the effects of different acidity simulated acid rain on the physiological characteristics at flowering stage and yield of oilseed rape (B. napus cv. Qinyou 9). Comparing with the control (pH 6.0), weak acidity (pH = 4.0-5.0) simulated acid rain stimulated the rape growth to some extent, but had less effects on the plant biomass, leaf chlorophyll content, photosynthetic characteristics, and yield. With the further increase of acid rain acidity, the plant biomass, leaf chlorophyll content, photosynthetic rate, antioxidative enzyme activities, and non-enzyme antioxidant contents all decreased gradually, while the leaf malonyldialdehyde (MDA) content and relative conductivity increased significantly. As the results, the pod number per plant, seed number per pod, seed weight, and actual yield decreased. However, different yield components showed different sensitivity to simulated acid rain. With the increasing acidity of simulated acid rain, the pod number per plant and the seed number per pod decreased significantly, while the seed weight was less affected.

  8. Effects of simulated acid rain on microbial characteristics in a lateritic red soil.

    PubMed

    Xu, Hua-qin; Zhang, Jia-en; Ouyang, Ying; Lin, Ling; Quan, Guo-ming; Zhao, Ben-liang; Yu, Jia-yu

    2015-11-01

    A laboratory experiment was performed to examine the impact of simulated acid rain (SAR) on nutrient leaching, microbial biomass, and microbial activities in a lateritic red soil in South China. The soil column leaching experiment was conducted over a 60-day period with the following six SAR pH treatments (levels): 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 and one control treatment (pH = 7). Compared with the control treatment, the concentrations of soil organic matter, total nitrogen, total phosphorus, total potassium, soil microbial biomass carbon (MBC), soil microbial biomass nitrogen (MBN), and average well color density (AWCD) in the Ecoplates were all significantly decreased by leaching with SAR at different pH levels. The decrease in MBC and MBN indicated that acid rain reduced the soil microbial population, while the decrease in AWCD revealed that acid rain had a negative effect on soil bacterial metabolic function. Soil basal respiration increased gradually from pH 4.0 to 7.0 but decreased dramatically from pH 2.5 to 3.0. The decrease in soil nutrient was the major reason for the change of soil microbial functions. A principal component analysis showed that the major carbon sources used by the bacteria were carbohydrates and carboxylic acids.

  9. The characteristics changes of pH and EC of atmospheric precipitation and analysis on the source of acid rain in the source area of the Yangtze River from 2010 to 2015

    NASA Astrophysics Data System (ADS)

    Zong-Jie, Li; Song, Ling-Ling; Jing-zhu, Ma; Li, Yong-ge

    2017-05-01

    Through the analysis of pH value, EC, precipitation and wind speed of 402 precipitation samples in the source region of the Yangtze River from January 1, 2010 to December 31, 2015, especially for the analysis of the 14 acid rain events. The results showed that: the acid rain in the source region of the Yangtze River was mainly affected by the southwest monsoon and the westerly circulation. The occurrence of acid rain mainly controlled by industrial pollution and other pollutants coming from India and other surrounding areas. And the other cause was that because of the Qinghai Tibet highway and the Qinghai Tibet railway, there were a lot of cars coming and going. And there were people in the summer to plateau tourism increased year by year, and more for self-driving travelling. This added additional pollutants (automobile exhaust) for the source of the Yangtze River. During the period of sampling, the variation range of pH value was from 4.0 to 8.57, with the mean was 6.37. And the range of EC was from 5.2 to 124.4 μs/cm, the average was 27.59 μs/cm. The order of conductivity in the four seasons was Spring > Winter > Summer > Autumn. And the order of pH in four seasons was Summer > Spring = Winter > Autumn. The results are also helpful for further understanding the acid rain in the Tibetan Plateau and providing scientific basis for the effective prevention and control of acid rain.

  10. Industrial ecotoxicology "acid rain".

    PubMed

    Astolfi, E; Gotelli, C; Higa, J

    1986-01-01

    The acid rain phenomenon was studied in the province of Cordoba, Argentina. This study, based on a previously outlined framework, determined the anthropogenic origin of the low pH due to the presence of industrial hydrochloric acid wastage. This industrial ecotoxicological phenomenon seriously affected the forest wealth, causing a great defoliation of trees and shrubs, with a lower effect on crops. A survey on its effects on human beings has not been carried out, but considering the corrosion caused to different metals and its denouncing biocide effect on plants and animals, we should expect to find some kind of harm to the health of the workers involved or others engaged in farming, and even to those who are far away from the polluting agent.

  11. A numerical study of the acid rain in northern Taiwan in winter season

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Ching-Sen; Deng, Zen-Sing

    1996-12-31

    Two-thirds of the land mass of Taiwan island is covered by mountains. In winter precipitation could occur in northern Taiwan when the prevailing wind was from northeastern direction. In northern Taiwan the acid rain (pH value less than 5.0) in winter time could contribute about 30 rain in the whole year. A three-dimensional numerical model with terrain following coordinated system was used to simulate the precipitation system and the characteristics of acid rain. A smooth terrain was assumed in the model. A mean sounding was used to initialize the numerical model when acid rain occurred in northern Taiwan during wintermore » time from 1991 to 1993. Investigations of the effect of pollutions from abroad on the acid rain in northern Taiwan in winter are considered for the future.« less

  12. EFFECTS OF ACID RAIN ON APPLE TREE PRODUCTIVITY AND FRUIT QUALITY

    EPA Science Inventory

    Mature 'McIntosh', 'Empire', and 'Golden Delicious' apple trees (Malus domestica) were sprayed with simulated acid rain solutions in the pH range of 2.5 to 5.5 at full bloom in 1980 and 1981. In 1981, weekly sprays were applied at pH 2.75 and pH 3.25. Necrotic lesions developed o...

  13. [Combined injured effects of acid rain and lanthanum on growth of soybean seedling].

    PubMed

    Liang, Chan-juan; Pan, Dan-yun; Xu, Qiu-rong; Zhou, Qing

    2010-07-01

    Combined effects of acid rain and lanthanum on growth of soybean seedling (Glycine max) and its inherent mechanism were studied in this paper. Compared with treatments by simulated acid rain (pH 3.0, 3.5, 4.5) or rare earth La(III) (60, 100 and 300 mg x L(-1)), the decrease degree of growth parameters in combined treatments was higher, indicating that there were a synergistic effects between acid rain and La. Moreover,the inhibition effects of acid rain and La(III) were more obvious when pH value of acid rain was lower or the concentration of La(III) was higher. The changes of photosynthetic parameters were similar to those of growth, but the decrease degree of each parameter was not same in the same treatment group. The decrease degree of optimal PSII photochemical efficiency (Fv/Fm) and chlorophyll content (Chl) were 9.35%-22.75% and 9.14%-24.53%, respectively, lower than that of photosynthetic rate Pn (22.78%-84.7%), Hill reaction rate (15.52%-73.38%) and Mg2+ -ATPase activity (14.51%-71.54%), showing that the sensitivity of photosynthetic parameters to the combined factors was different. Furthermore, relative analysis showed that the change of Pn were mainly affected by Hill reaction rate and Mg2+ -ATPase activity, and was less influenced by Chl and Fv/Fm. It indicates that the effect of acid rain and La on each reaction in photosynthesis was different, and the inhibition of combined treatments on photosynthesis in plants was one of the main factors affecting growth of plant.

  14. Acid rain phenomenon in niger delta region of Nigeria: economic, biodiversity, and public health concern.

    PubMed

    Nduka, J K C; Orisakwe, O E; Ezenweke, L O; Ezenwa, T E; Chendo, M N; Ezeabasili, N G

    2008-08-28

    Rain samples were collected from Warri and Port Harcourt, two major oil-producing cities of Nigeria in April-June, July-August, and September-October 2005 and 2006. Awka, a "non-oil" city was used as control. Samples were collected from three points, using clean plastic basins fastened to a table, 2 m above ground level and 115 m away from tall buildings and trees. Water samples were filtered and acidity determined using digital pH meter. The results show that the rain samples were acidic. The pH values for the 2 years under study show that the rainfall in Warri was more acidic than that of Port Harcourt. Oil exploration and other anthropogenic sources may be responsible for the acid rain in the Niger Delta region of Nigeria.

  15. [Influence of simulated acid rain on nitrogen and phosphorus contents and their stoichiome-tric ratios of tea organs in a red soil region, China].

    PubMed

    Zhang, Yu Fei; Fang, Xiang Min; Chen, Fu Sheng; Zong, Ying Ying; Gu, Han Jiao; Hu, Xiao Fei

    2017-04-18

    A 25-year-old tea plantation in a typical red soil region was selected for an in situ simulated acid rain experiment treated by pH 4.5, 3.5, 2.5 and water (control, CK). Roots with different functions, leaves and twigs with different ages were collected to measure nitrogen (N) and phosphorus (P) contents in the third year after simulated acid rain treatment. The N/P and acid rain sensitivity coefficient of tea plant organs were also calculated. The results indicated that with the increase of acid rain intensity, the soil pH, NO 3 - -N and available P decreased, while the absorption root N content increased. Compared with the control, the N content in absorption root was increased by 32.9% under the treatment of pH 2.5. The P content in storage root significantly decreased with enhanced acid rain intensity, and the acid rain treatment significantly enhanced N/P of absorption root. Young and mature leaf N, P contents were not sensitive to different intensities of acid rain, but the mature leaf N/P was significantly increased under pH 3.5 treatment compared with the control. The effects of acid rain treatments differed with tea twig ages. Compared with the control, low intensity acid treatment (pH 4.5) significantly increased young twig N content and N/P, while no signi-ficant differences in old twig N content and N/P were observed among four acid rain treatments. Acid rain sensitivity coefficients of absorption root, young leaf and twig N contents were higher than that of storage root, old leaf and twig, respectively. And the storage root and leaf P had higher acid rain sensitivity coefficient than other tea organs. In sum, tea organs N content was sensitive to acid rain treatment, and moderate acid rain could increase young organ N content and N/P, and change the cycle and balance of N and P in tea plantation.

  16. Pollen selection under acid rain stress

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhang, Y.

    To investigate whether acid rain stress induces pollen selection in nature, three different approaches were used, based on the assumption that the response of pollen grains to acid rain is controlled by an acid sensitive gene product. Germination of pollen from homozygous and heterozygous individuals under acid rain stress was examined to detect any differences in rate of germination between populations of homogeneous and heterogeneous pollen grains. In vitro and in vivo bulked segregant analysis using RAPDs was used to search for differences in DNA constitution between the survivors of acid rain stressed and non-acid rain stressed pollen populations inmore » vitro and between the progenies of acid rain stressed and non-acid rain stressed populations during pollination, respectively. No evidence for the pollen selection under acid rain stress was obtained in any of the test systems. Inhibition of protein synthesis using cycloheximide led to significant reduction of tube elongation at 4 hr and had no effect on pollen germination at any time interval tested. Total proteins extracted from control and acid rain stressed pollen grain populations exhibited no differences. The reduction of corn pollen germination in vitro under acid rain stress was mainly due to pollen rupture. The present data indicates the reduction of pollen germination and tube growth under acid rain stress may be a physiological response rather than a genetic response. A simple, nontoxic, and effective method to separate germinated from ungerminated pollen grains has been developed using pollen from corn (Zea mays, L. cv. Pioneer 3747). The separated germinated pollen grains retained viability and continued tube growth when placed in culture medium.« less

  17. Acidification and Acid Rain

    NASA Astrophysics Data System (ADS)

    Norton, S. A.; Veselã½, J.

    2003-12-01

    endangers the existing biota. Concerns about acid (or acidic) rain in its modern sense were publicized by the Swedish soil scientist Svante Odén (1968). He argued, initially in the Swedish press, that long-term increases in the atmospheric deposition of acid could lower the pH of surface waters, cause a decline in fish stocks, deplete soils of nutrients, and accelerate damage to materials. By the 1970s, acidification of surface waters was reported in many countries in Europe as well as in North America. The late twentieth-century rush to understand the impact of acid rain was driven by: (i) reports of damaged or threatened freshwater fisheries and (ii) damaged forests. Perhaps the earliest linkage between acidic surface water and damage to fish was made by Dahl (1921) in southern Norway. There, spring runoff was sufficiently acidic to kill trout. It was not until the 1970s that a strong link was established between depressed pH, mobilization of aluminum from soil, and fish status ( Schofield and Trojnar,1980). The relationship between acidification of soils and forest health started with hypotheses in the 1960s and has slowly developed. Acid rain enhances the availability of some nutrients (e.g., nitrogen), and may either enhance or diminish the availability of others (e.g., calcium, magnesium, potassium, and phosphorus). Damage to anthropogenic structures, human health, and visibility have also raised concerns. The history of these early developments was summarized by Cowling (1982). Since the 1970s, sulfur and nitrogen emissions to the atmosphere have been reduced by 50-85% and 0-30%, respectively, both in North America and Europe. The emission reductions have occurred as a consequence of knowledge gained and economic factors. While recovery of water quality is underway in some areas, problems of acidification persist, and are now complicated by the effects of climate change ( Schindler, 1997).

  18. Effects of acidic rain and ozone on nitrogen fixation and photosynthesis in the lichen lobaria pulmonaria (L. ) Hoffm

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sigal, L.L.; Johnston, J.W.

    1986-01-01

    The lichen Lobaria pulmonaria was subjected to ozone fumigations at 118, 235 and 353 mcg/cu m and simulated acidic rain at pH levels of 2.6, 4.2 and 5.6 for 5 days (M,W,F,M,W) during a 10-day period. Acidic rain at pH 2.6 caused significant reduction in nitrogen fixation and gross photosynthesis of 100 and 90%, respectively, and thallus bleaching was apparent. There were no significant differences between the pH 5.6 and 4.2 treatments in either gross photosynthesis or nitrogen fixation, and the color of the lichen thalli was unchanged. The effect of ozone on nitrogen fixation and photosynthesis over the rangemore » of concentrations used was not significant, but there was a trend toward reduced nitrogen fixation with increasing O/sub 3/ concentration. There were no significant ozone-acidic rain interactions. The threshold for response to rain acidity for L. pulmonaria lies between pH 2.6 and 4.2, and the acidity of wet deposition in parts of the United States may fall in the range.« less

  19. Effects of acid rain and sulfur dioxide on marble dissolution

    USGS Publications Warehouse

    Schuster, Paul F.; Reddy, Michael M.; Sherwood, Susan I.

    1994-01-01

    Acid precipitation and the dry deposition of sulfur dioxide (SO2) accelerate damage to carbonate-stone monuments and building materials. This study identified and quantified environmental damage to a sample of Vermont marble during storms and their preceding dry periods. Results from field experiments indicated the deposition of SO2 gas to the stone surface during dry periods and a twofold increase in marble dissolution during coincident episodes of low rain rate and decreased rainfall pH. The study is widely applicable to the analysis of carbonate-stone damage at locations affected by acid rain and air pollution.

  20. [Analysis of acid rain characteristics of Lin'an Regional Background Station using long-term observation data].

    PubMed

    Li, Zheng-Quan; Ma, Hao; Mao, Yu-Ding; Feng, Tao

    2014-02-01

    Using long-term observation data of acid rain at Lin'an Regional Background Station (Lin'an RBS), this paper studied the interannual and monthly variations of acid rain, the reasons for the variations, and the relationships between acid rain and meteorological factors. The results showed that interannual variation of acid rain at Lin'an RBS had a general increasing trend in which there were two obvious intensifying processes and two distinct weakening processes, during the period ranging from 1985 to 2012. In last two decades, the monthly variation of acid rain at Lin'an RBS indicated that rain acidity and frequency of severe acid rain were increasing but the frequency of weak acid rain was decreasing when moving towards bilateral side months of July. Acid rain occurrence was affected by rainfall intensity, wind speed and wind direction. High frequency of severe acid rain and low frequency of weak acid rain were on days with drizzle, but high frequency of weak acid rain and low frequency of severe acid rain occurred on rainstorm days. With wind speed upgrading, the frequency of acid rain and the proportion of severe acid rain were declining, the pH value of precipitation was reducing too. Another character is that daily dominant wind direction of weak acid rain majorly converged in S-W section ,however that of severe acid rain was more likely distributed in N-E section. The monthly variation of acid rain at Lin'an RBS was mainly attributed to precipitation variation, the increasing and decreasing of monthly incoming wind from SSE-WSW and NWN-ENE sections of wind direction. The interannual variation of acid rain could be due to the effects of energy consumption raising and significant green policies conducted in Zhejiang, Jiangsu and Shanghai.

  1. [Combined effects of copper and simulated acid rain on copper accumulation, growth, and antioxidant enzyme activities of Rumex acetosa].

    PubMed

    He, Shan-Ying; Gao, Yong-Jie; Shentu, Jia-Li; Chen, Kun-Bai

    2011-02-01

    A pot experiment was conducted to study the combined effects of Cu (0-1500 mg x kg(-1)) and simulated acid rain (pH 2.5-5.6) on the copper accumulation, growth, and antioxidant enzyme activities of Rumex acetosa. With the increasing concentration of soil Cu, the Cu accumulation in R. acetosa increased, being higher in root than in stem and leaf. The exposure to low pH acid rain promoted the Cu uptake by R. acetosa. With the increase of soil Cu concentration and/or of acid rain acidity, the biomass of R. acetosa decreased, leaf and root MDA contents increased and had good correlation with soil Cu concentration, and the SOD and POD activities in leaf and root displayed a decreasing trend after an initial increase. This study showed that R. acetosa had a strong adaptive ability to Cu and acid rain stress, exhibiting a high application potential in the remediation of Cu-contaminated soil in acid rain areas.

  2. The effect of simulated acid rain on the stabilization of cadmium in contaminated agricultural soils treated with stabilizing agents.

    PubMed

    Zhu, Hao; Wu, Chunfa; Wang, Jun; Zhang, Xumei

    2018-04-16

    Stabilization technology is one of widely used remediation technologies for cadmium (Cd)-contaminated agricultural soils, but stabilized Cd in soil may be activated again when external conditions such as acid rain occurred. Therefore, it is necessary to study the effect of acid rain on the performance of different stabilizing agents on Cd-polluted agriculture soils. In this study, Cd-contaminated soils were treated with mono-calcium phosphate (MCP), mono-ammonium phosphate (MAP), and artificial zeolite (AZ) respectively and incubated 3 months. These treatments were followed by two types of simulated acid rain (sulfuric acid rain and mixed acid rain) with three levels of acidity (pH = 3.0, 4.0, and 5.6). The chemical forms of Cd in the soils were determined by Tessier's sequential extraction procedure, and the leaching toxicities of Cd in the soils were assessed by toxicity characteristic leaching procedure (TCLP). The results show that the three stabilizing agents could decrease the mobility of Cd in soil to some degree with or without simulated acid rain (SAR) treatment. The stabilization performances followed the order of AZ < MAP < MCP. Acid rain soaking promoted the activation of Cd in stabilized soil, and both anion composition and pH of acid rain were two important factors that influenced the stabilization effect of Cd.

  3. What Is Acid Rain?

    ERIC Educational Resources Information Center

    Likens, Gene E.

    2004-01-01

    Acid rain is the collective term for any type of acidified precipitation: rain, snow, sleet, and hail, as well as the presence of acidifying gases, particles, cloud water, and fog in the atmosphere. The increased acidity, primarily from sulfuric and nitric acids, is generated as a by-product of the combustion of fossil fuels such as coal and oil.…

  4. Effects of silicon on Oryza sativa L. seedling roots under simulated acid rain stress.

    PubMed

    Ju, Shuming; Yin, Ningning; Wang, Liping; Zhang, Cuiying; Wang, Yukun

    2017-01-01

    Silicon (Si) has an important function in reducing the damage of environmental stress on plants. Acid rain is a serious abiotic stress factor, and Si can alleviate the stress induced by acid rain on plants. Based on these assumptions, we investigated the effects of silicon on the growth, root phenotype, mineral element contents, hydrogen peroxide (H2O2) and antioxidative enzymes of rice (Oryza sativa L.) seedling roots under simulated acid rain (SAR) stress. The results showed that the combined or single effects of Si and/or SAR on rice roots depend on the concentration of Si and the pH of the SAR. The combined or single effects of a low or moderate concentration of Si (1.0 or 2.0 mM) and light SAR (pH 4.0) enhanced the growth of rice roots, and the combined effects were stronger than those of the single treatment. A high concentration of Si (4.0 mM) or severe SAR (pH 2.0) exerted deleterious effects. The incorporation of Si (1.0, 2.0 or 4.0 mM) into SAR with pH 3.0 or 2.0 promoted the rice root growth, decreased the H2O2 content, increased the Si concentration and the superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) activities, maintained the balance of mineral element (K, Ca, Mg, Fe, Zn, and Cu) concentrations in the roots of rice seedlings compared with SAR alone. The alleviatory effects observed with a moderate concentration of Si (2.0 mM) were better than the effects obtained with a low or high concentration of Si (1.0 or 4.0 mM). The observed effects were due to disruptions in the absorption and utilization of mineral nutrients and impacts on the activity of antioxidant enzymes in roots, and this conclusion suggests that the degree of rice root damage caused by acid rain might be attributed to not only acid rain but also the level of Si in the soil.

  5. Effects of silicon on Oryza sativa L. seedling roots under simulated acid rain stress

    PubMed Central

    Wang, Liping; Zhang, Cuiying; Wang, Yukun

    2017-01-01

    Silicon (Si) has an important function in reducing the damage of environmental stress on plants. Acid rain is a serious abiotic stress factor, and Si can alleviate the stress induced by acid rain on plants. Based on these assumptions, we investigated the effects of silicon on the growth, root phenotype, mineral element contents, hydrogen peroxide (H2O2) and antioxidative enzymes of rice (Oryza sativa L.) seedling roots under simulated acid rain (SAR) stress. The results showed that the combined or single effects of Si and/or SAR on rice roots depend on the concentration of Si and the pH of the SAR. The combined or single effects of a low or moderate concentration of Si (1.0 or 2.0 mM) and light SAR (pH 4.0) enhanced the growth of rice roots, and the combined effects were stronger than those of the single treatment. A high concentration of Si (4.0 mM) or severe SAR (pH 2.0) exerted deleterious effects. The incorporation of Si (1.0, 2.0 or 4.0 mM) into SAR with pH 3.0 or 2.0 promoted the rice root growth, decreased the H2O2 content, increased the Si concentration and the superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) activities, maintained the balance of mineral element (K, Ca, Mg, Fe, Zn, and Cu) concentrations in the roots of rice seedlings compared with SAR alone. The alleviatory effects observed with a moderate concentration of Si (2.0 mM) were better than the effects obtained with a low or high concentration of Si (1.0 or 4.0 mM). The observed effects were due to disruptions in the absorption and utilization of mineral nutrients and impacts on the activity of antioxidant enzymes in roots, and this conclusion suggests that the degree of rice root damage caused by acid rain might be attributed to not only acid rain but also the level of Si in the soil. PMID:28291806

  6. Acid Rain: What We Must Do.

    ERIC Educational Resources Information Center

    Gorham, Eville

    1983-01-01

    Addresses questions about the nature, source, and history of acid rain. In addition, discusses the questions: Why is acid rain a problem? Is acid rain getting worse? What is the threat of further problems? Concludes that it is time to act on the problem and recommends an appropriate course of action. (JN)

  7. Characterizing the release of different composition of dissolved organic matter in soil under acid rain leaching using three-dimensional excitation-emission matrix spectroscopy.

    PubMed

    Liu, Li; Song, Cunyi; Yan, Zengguang; Li, Fasheng

    2009-09-01

    Although excitation-emission matrix spectroscopy (EEMS) has been widely used to characterize dissolved organic matter (DOM), there has no report that EEMS has been used to study the effects of acid rain on DOM and its composition in soil. In this work, we employed three-dimensional EEMS to characterize the compositions of DOM leached by simulated acid rain from red soil. The red soil was subjected to leaching of simulated acid rain of different acidity, and the leached DOM presented five main peaks in its EEMS: peak-A, related to humic acid-like (HA-like) material, at Ex/Em of 310-330/395-420nm; peak-B, related to UV fulvic acid-like (FA-like) material, at Ex/Em of 230-280/400-435nm; peak-C and peak-D, both related to microbial byproduct-like material, at Ex/Em of 250-280/335-355nm and 260-280/290-320nm, respectively; and peak-E, related to simple aromatic proteins, at Ex/Em of 210-240/290-340nm. EEMS analysis results indicated that most DOM could be lost from red soil in the early phase of acid rain leaching. In addition to the effects of the pH of acid rain, the loss of DOM also depended on the properties of its compositions and the solubility of their complexes with aluminum. HA-like and microbial byproduct-like materials could be more easily released from red soil by acid rain at both higher pH (4.5 and 5.6) and lower pH (2.5 and 3) than that at middle pH (3.5). On the contrary, FA-like material lost in a similar manner under the action of different acid rains with pH ranging from 2.5 to 5.6.

  8. A Demonstration of Acid Rain

    ERIC Educational Resources Information Center

    Fong, Man Wai

    2004-01-01

    A demonstration showing acid rain formation is described. Oxides of sulfur and nitrogen that result from the burning of fossil fuels are the major pollutants of acid rain. In this demonstration, SO[subscript 2] gas is produced by the burning of matches. An acid-base indicator will show that the dissolved gas turns an aqueous solution acidic.

  9. Acid rain at Kennedy Space Center, Florida - Recent observations

    NASA Technical Reports Server (NTRS)

    Madsen, B. C.

    1981-01-01

    During the period July, 1977 to September, 1979, rainfall was collected in the vicinity of the Kennedy Space Center and subjected to appropriate chemical analysis for purposes of characterization of general composition and acidity. Results obtained form the basis for future comparisons, should significant alteration of the chemical composition of rain occur during the space shuttle era. Acidity extremes calculated on a monthly basis from event samples collected from five sites within a 200 sq km area varied from pH 5.1 in November, 1977, and April, 1978 to pH 4.3 in July, 1978 and July, 1979. Weighted average pH for the entire period was 4.55. Acidity was due to the presence of sulfuric and nitric acids. The mole ratio of excess SO4(-2):NO3(-) was typically greater than one. Monthly weighted average Cl(-) concentrations ranged from 20-240 micromoles/liter. The Cl(-):Na(+) ratio was slightly lower than that present in sea water.

  10. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.

    1993-01-01

    Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H2SO4 and HNO3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition.Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

  11. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.; Dietrich, W.E.; Sposito, Garrison

    1997-01-01

    Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H2SO4 and HNO3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition.Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

  12. Acid Rain: What It Is -- How You Can Help!

    ERIC Educational Resources Information Center

    National Wildlife Federation, Washington, DC.

    This publication discusses the nature and consequences of acid precipitation (commonly called acid rain). Topic areas include: (1) the chemical nature of acid rain; (2) sources of acid rain; (3) geographic areas where acid rain is a problem; (4) effects of acid rain on lakes; (5) effect of acid rain on vegetation; (6) possible effects of acid rain…

  13. An Umbrella for Acid Rain.

    ERIC Educational Resources Information Center

    Randal, Judith

    1979-01-01

    The Environmental Protection Agency has awarded several grants to study effects of and possible solutions to the problem of "acid rain"; pollution from atmospheric nitric and sulfuric acids. The research program is administered through North Carolina State University at Raleigh and will focus on biological effects of acid rain. (JMF)

  14. Response of soil respiration to acid rain in forests of different maturity in southern China.

    PubMed

    Liang, Guohua; Liu, Xingzhao; Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

    2013-01-01

    The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types.

  15. Response of Soil Respiration to Acid Rain in Forests of Different Maturity in Southern China

    PubMed Central

    Chen, Xiaomei; Qiu, Qingyan; Zhang, Deqiang; Chu, Guowei; Liu, Juxiu; Liu, Shizhong; Zhou, Guoyi

    2013-01-01

    The response of soil respiration to acid rain in forests, especially in forests of different maturity, is poorly understood in southern China despite the fact that acid rain has become a serious environmental threat in this region in recent years. Here, we investigated this issue in three subtropical forests of different maturity [i.e. a young pine forest (PF), a transitional mixed conifer and broadleaf forest (MF) and an old-growth broadleaved forest (BF)] in southern China. Soil respiration was measured over two years under four simulated acid rain (SAR) treatments (CK, the local lake water, pH 4.5; T1, water pH 4.0; T2, water pH 3.5; and T3, water pH 3.0). Results indicated that SAR did not significantly affect soil respiration in the PF, whereas it significantly reduced soil respiration in the MF and the BF. The depressed effects on both forests occurred mostly in the warm-wet seasons and were correlated with a decrease in soil microbial activity and in fine root biomass caused by soil acidification under SAR. The sensitivity of the response of soil respiration to SAR showed an increasing trend with the progressive maturity of the three forests, which may result from their differences in acid buffering ability in soil and in litter layer. These results indicated that the depressed effect of acid rain on soil respiration in southern China may be more pronounced in the future in light of the projected change in forest maturity. However, due to the nature of this field study with chronosequence design and the related pseudoreplication for forest types, this inference should be read with caution. Further studies are needed to draw rigorous conclusions regarding the response differences among forests of different maturity using replicated forest types. PMID:23626790

  16. Efficient inhibition of heavy metal release from mine tailings against acid rain exposure by triethylenetetramine intercalated montmorillonite (TETA-Mt).

    PubMed

    Gong, Beini; Wu, Pingxiao; Huang, Zhujian; Li, Yuanyuan; Yang, Shanshan; Dang, Zhi; Ruan, Bo; Kang, Chunxi

    2016-11-15

    The potential application of triethylenetetramine intercalated montmorillonite (TETA-Mt) in mine tailings treatment and AMD (acid mine drainage) remediation was investigated with batch experiments. The structural and morphological characteristics of TETA-Mt were analyzed with XRD, FTIR, DTG-TG and SEM. The inhibition efficiencies of TETA-Mt against heavy metal release from mine tailings when exposed to acid rain leaching was examined and compared with that of triethylenetetramine (TETA) and Mt. Results showed that the overall inhibition by TETA-Mt surpassed that by TETA or Mt for various heavy metal ions over an acid rain pH range of 3-5.6 and a temperature range of 25-40°C. When mine tailings were exposed to acid rain of pH 4.8 (the average rain pH of the mining site where the mine tailings were from), TETA-Mt achieved an inhibition efficiency of over 90% for Cu(2+), Zn(2+), Cd(2+) and Mn(2+) release, and 70% for Pb(2+) at 25°C. It was shown that TETA-Mt has a strong buffering capacity. Moreover, TETA-Mt was able to adsorb heavy metal ions and the adsorption process was fast, suggesting that coordination was mainly responsible. These results showed the potential of TETA-Mt in AMD mitigation, especially in acid rain affected mining area. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Acid Thunder: Acid Rain and Ancient Mesoamerica

    ERIC Educational Resources Information Center

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  18. Acid Rain: What's the Forecast?

    ERIC Educational Resources Information Center

    Bybee, Rodger

    1984-01-01

    Discusses various types of acid rain, considered to be a century-old problem. Topics include: wet and dry deposition, effects on a variety of environments, ecosystems subject to detrimental effects, and possible solutions to the problem. A list of recommended resources on acid rain is provided. (BC)

  19. Effect of simulated acid rain on the mutualism between tall fescue (Festuca arundinacea) and an endophytic fungus (Acremonium coenophialum)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cheplick, G.P.

    Biotic interactions between plants and microorganisms have the potential to be affected by acidic precipitation. I examined the effect of simulated sulfuric acid rain on the mutualism between a perennial forage grass (Festuca arundinacea) and a fungal endophyte (Acremonium coenophialum). Acid water was supplied as mists sprayed onto leaf surfaces or as water added to the soil for two groups in a greenhouse: one group had high levels of endophyte infection, while the other was predominantly noninfected. Control plants received distilled water (pH 6), while others received sulfuric acid water at pH 4.5 or pH 3. Plants were harvested aftermore » 4, 6, 8, and 23 wk. Leaf endophyte infection intensity as measured by hyphal counts was not affected by acid water treatment. Root mass and root: shoot ratios generally decreased with increasing acidity of both foliar sprays and soil water, but shoot mass was mostly not affected. There was a significant pH x infection interaction for plants exposed to acidic foliar sprays for 4 wk; root and shoot mass decreased with acidity, but only for infected plants. It was found that acid rain may be deleterious to tall fescue growth at specific stages of development, but biomass production in response to acid rain is not likely to be influenced by fungal endophytes within mature plants. 55 refs., 2 figs., 3 tabs.« less

  20. Characterization of heavy metal desorption from road-deposited sediment under acid rain scenarios.

    PubMed

    Zhao, Bo; Liu, An; Wu, Guangxue; Li, Dunzhu; Guan, Yuntao

    2017-01-01

    Road-deposited sediments (RDS) on urban impervious surfaces are important carriers of heavy metals. Dissolved heavy metals that come from RDS influenced by acid rain, are more harmful to urban receiving water than particulate parts. RDS and its associated heavy metals were investigated at typical functional areas, including industrial, commercial and residential sites, in Guangdong, Southern China, which was an acid rain sensitive area. Total and dissolved heavy metals in five particle size fractions were analyzed using a shaking method under acid rain scenarios. Investigated heavy metals showed no difference in the proportion of dissolved fraction in the solution under different acid rain pHs above 3.0, regardless of land use. Dissolved loading of heavy metals related to organic carbon content were different in runoff from main traffic roads of three land use types. Coarse particles (>150μm) that could be efficiently removed by conventional street sweepers, accounted for 55.1%-47.1% of the total dissolved metal loading in runoff with pH3.0-5.6. The obtained findings provided a significant scientific basis to understand heavy metal release and influence of RDS grain-size distribution and land use in dissolved heavy metal pollution affected by acid rain. Copyright © 2016. Published by Elsevier B.V.

  1. Modeling estimates of the effect of acid rain on background radiation dose.

    PubMed Central

    Sheppard, S C; Sheppard, M I

    1988-01-01

    Acid rain causes accelerated mobilization of many materials in soils. Natural and anthropogenic radionuclides, especially 226Ra and 137Cs, are among these materials. Okamoto is apparently the only researcher to date who has attempted to quantify the effect of acid rain on the "background" radiation dose to man. He estimated an increase in dose by a factor of 1.3 following a decrease in soil pH of 1 unit. We reviewed literature that described the effects of changes in pH on mobility and plant uptake of Ra and Cs. Generally, a decrease in soil pH by 1 unit will increase mobility and plant uptake by factors of 2 to 7. Thus, Okamoto's dose estimate may be too low. We applied several simulation models to confirm Okamoto's ideas, with most emphasis on an atmospherically driven soil model that predicts water and nuclide flow through a soil profile. We modeled a typical, acid-rain sensitive soil using meteorological data from Geraldton, Ontario. The results, within the range of effects on the soil expected from acidification, showed essentially direct proportionality between the mobility of the nuclides and dose. This supports some of the assumptions invoked by Okamoto. We conclude that a decrease in pH of 1 unit may increase the mobility of Ra and Cs by a factor of 2 or more. Our models predict that this will lead to similar increases in plant uptake and radiological dose to man. Although health effects following such a small increase in dose have not been statistically demonstrated, any increase in dose is probably undesirable. PMID:3203639

  2. Effects of simulated acid rain and ozone on foliar chemistry of field-grown Pinus ponderosa seedlings and mature trees.

    PubMed

    Momen, B; Helms, J A

    1996-01-01

    We investigated the additive and interactive effects of simulated acid rain and elevated ozone on C and N contents, and the C:N ratio of one-year-old and current-year foliage of field-grown mature trees and their half-sib seedlings of a stress tolerant genotype of ponderosa pine. Acid rain levels (pH 5.1 and 3.0) were applied weekly to foliage only (no soil acidification or N addition), from January to April, 1992. Plants were exposed to two ozone levels (ambient and twice-ambient) during the day from September 1991 to November 1992. The sequential application of acid rain and elevated ozone mimicked the natural conditions. Twice-ambient ozone significantly decreased foliar N content (by 12-14%) and increased the C:N ratio of both one-year-old and current-year foliage of seedlings. Although similar ozone effects were also observed on one-year-old foliage of mature trees, the only statistically significant effect was an increased C:N ratio when twice-ambient ozone combined with pH 3.0 rain (acid rain by ozone interaction). Enhancing the effect of twice-ambient ozone in increasing the C:N ratio of one-year-old foliage of mature trees in June was the only significant effect of acid rain.

  3. Impact of simulated acid rain on trace metals and aluminum leaching in latosol from Guangdong Province, China

    Treesearch

    Jia-En Zhang; Jiayu Yu; Ying Ouyang; Huaqin Xu

    2014-01-01

    Acid rain is one of the most serious ecological and environmental problems worldwide. This study investigated the impacts of simulated acid rain (SAR) upon leaching of trace metals and aluminum (Al) from a soil. Soil pot leaching experiments were performed to investigate the impacts of SAR at five different pH levels (or treatments) over a 34-day period upon the...

  4. Comparative effects of sulfuric and nitric acid rain on litter decomposition and soil microbial community in subtropical plantation of Yangtze River Delta region.

    PubMed

    Liu, Xin; Zhang, Bo; Zhao, Wenrui; Wang, Ling; Xie, Dejin; Huo, Wentong; Wu, Yanwen; Zhang, Jinchi

    2017-12-01

    Acid rain is mainly caused by dissolution of sulfur dioxide and nitrogen oxides in the atmosphere, and has a significant negative effect on ecosystems. The relative composition of acid rain is changing gradually from sulfuric acid rain (SAR) to nitric acid rain (NAR) with the rapidly growing amount of nitrogen deposition. In this study, we investigated the impact of simulated SAR and NAR on litter decomposition and the soil microbial community over four seasons since March 2015. Results first showed that the effects of acid rain on litter decomposition and soil microbial were positive in the early period of the experiment, except for SAR on soil microbes. Second, soil pH with NAR decreased more rapidly with the amount of acid rain increased in summer than with SAR treatments. Only strongly acid rain (both SAR and NAR) was capable of depressing litter decomposition and its inhibitory effect was stronger on leaf than on fine root litter. Meanwhile, NAR had a higher inhibitory effect on litter decomposition than SAR. Third, in summer, autumn and winter, PLFAs were negatively impacted by the increased acidity level resulting from both SAR and NAR. However, higher acidity level of NAR (pH=2.5) had the strongest inhibitory impact on soil microbial activity, especially in summer. In addition, Gram-negative bacteria (cy19:0) and fungi (18:1ω9) were more sensitive to both SAR and NAR, and actinomycetes was more sensitive to SAR intensity. Finally, soil total carbon, total nitrogen and pH were the most important soil property factors affecting soil microbial activity, and high microbial indices (fungi/bacteria) with high soil pH. Our results suggest that the ratio of SO 4 2- to NO 3 - in acid rain is an important factor which could affect litter decomposition and soil microbial in subtropical forest of China. Copyright © 2017. Published by Elsevier B.V.

  5. Acid Rain: The Scientific Challenge.

    ERIC Educational Resources Information Center

    Godfrey, Paul J.

    1991-01-01

    Documents the workings and findings of the Massachusetts Acid Rain Monitoring Project, which has pooled the volunteer efforts of more than 1,000 amateur and professional scientists since 1983. Reports on the origins of air pollution, the prediction of acid rain, and its effects on both water life and land resources. (JJK)

  6. Effects of simulated acid rain on germination, seedling growth and oxidative metabolism of recalcitrant-seeded Trichilia dregeana grown in its natural seed bank.

    PubMed

    Ramlall, Chandika; Varghese, Boby; Ramdhani, Syd; Pammenter, Norman W; Bhatt, Arvind; Berjak, Patricia; Sershen

    2015-01-01

    Increased air pollution in a number of developing African countries, together with the reports of vegetation damage typically associated with acid precipitation in commercial forests in South Africa, has raised concerns over the potential impacts of acid rain on natural vegetation in these countries. Recalcitrant (i.e. desiccation sensitive) seeds of many indigenous African species, e.g. must germinate shortly after shedding and hence, may not be able to avoid exposure to acid rain in polluted areas. This study investigated the effects of simulated acid rain (rainwater with pH adjusted to pH 3.0 and 4.5 with 70:30, H2 SO4 :HNO3 ) on germination, seedling growth and oxidative metabolism in a recalcitrant-seeded African tree species Trichilia dregeana Sond., growing in its natural seed bank. The results suggest that acid rain did not compromise T. dregeana seed germination and seedling establishment significantly, relative to the control (non-acidified rainwater). However, pH 3.0 treated seedlings exhibited signs of stress typically associated with acid rain: leaf tip necrosis, abnormal bilobed leaf tips, leaf necrotic spots and chlorosis, reduced leaf chlorophyll concentration, increased stomatal density and indications of oxidative stress. This may explain why total and root biomass of pH 3.0 treated seedlings were significantly lower than the control. Acid rain also induced changes in the species composition and relative abundance of the different life forms emerging from T. dregeana's natural seed bank and in this way could indirectly impact on T. dregeana seedling establishment success. © 2014 Scandinavian Plant Physiology Society.

  7. Canada issues booklet describing acid rain

    NASA Astrophysics Data System (ADS)

    A booklet recently released by Environment Canada describes acid rain in terms easily understood by the general public. Although Acid Rain — The Facts tends somewhat to give the Canadian side of this intercountry controversial subject, it nevertheless presents some very interesting, simple statistics of interest to people in either the U.S. or Canada. Copies of the booklet can be obtained from Inquiry Environment Canada, Ottawa, Ontario K1A OH3, Canada, tel. 613-997-2800.The booklet points out that acid rain is caused by emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx). Once released into the atmosphere, these substances can be carried long distances by prevailing winds and return to Earth as acidic rain, snow, fog, or dust. The main sources of SO2 emissions in North America are coal-fired power generating stations and nonferrous ore smelters. The main sources of NOx emissions are vehicles and fuel combustion. From economical and environmental viewpoints, Canada believes acid rain is one of the most serious problems presently facing the country: increasing the acidity of more than 20% of Canada's 300,000 lakes to the point that aquatic life is depleted and acidity of soil water and shallow groundwater is increasing, causing decline in forest growth and water fowl populations, and eating away at buildings and monuments. Acid rain is endangering fisheries, tourism, agriculture, and forest resources in an area of 2.6 million km2 (one million square miles) of eastern Canada, about 8% of Canada's gross national product.

  8. The erosion of carbonate stone by acid rain: Laboratory and field investigations

    USGS Publications Warehouse

    Baedecker, P.A.; Reddy, M.M.

    1993-01-01

    One of the goals of research on the effects of acidic deposition on carbonate stone surfaces is to define the incremental impact of acidic deposition relative to natural weathering processes on the rate of carbonate stone erosion. If rain that impacts carbonate stone surfaces is resident on the surface long enough to approach chemical equilibrium, the incremental effect of hydrogen ion is expected to be small (i.e., 6% for a rain of pH 4.0). Under nonequilibrium (i.e., high flow rate) conditions, kinetic considerations suggest that the incremental effect of hydrogen ion deposition could be quite significant. Field run-off experiments involving the chemical analysis of rain collected from inclined stone slabs have been used to evaluate stone dissolution processes under ambient conditions of wet and dry deposition of acidic species. The stoichiometry of the reaction of stone with hydrogen ion is difficult to define from the field data due to scatter in the data attributed to hydrodynamic effects. Laboratory run-off experiments show that the stoichiometry is best defined by a reaction with H+ in which CO2 is released from the system. The baseline effect caused by water in equilibrium with atmospheric CO2 is identical in the field and in laboratory simulation. The experiments show that the solutions are close enough to equilibrium for the incremental effect of hydrogen ion to be minor (i.e., 24% for marble for a rain of pH 4.0) relative to dissolution due to water and carbonic acid reactions. Stone erosion rates based on physical measurement are approximately double the recession rates that are due to dissolution (estimated from the observed calcium content of the run-off solutions). The difference may reflect the loss of granular material not included in recession estimates based on the run-off data. Neither the field nor the laboratory run-off experiments indicate a pH dependence for the grain-removal process.

  9. Acid Rain: The Silent Environmental Threat.

    ERIC Educational Resources Information Center

    Zmud, Mia

    1992-01-01

    Describes the silent environmental threat posed by acid rain. Caused mainly by manmade pollutants, acid rain damages water and trees, decreases visibility, corrodes monuments, and threatens public health. The article includes guidelines for action. (SM)

  10. Alterations in cytosol free calcium in horseradish roots simultaneously exposed to lanthanum(III) and acid rain.

    PubMed

    Zhang, Xuanbo; Wang, Lihong; Zhou, Anhua; Zhou, Qing; Huang, Xiaohua

    2016-04-01

    The extensive use of rare earth elements (REEs) has increased their environmental levels. REE pollution concomitant with acid rain in many agricultural regions can affect crop growth. Cytosol free calcium ions (Ca(2+)) play an important role in almost all cellular activities. However, no data have been reported regarding the role of cytosol free Ca(2+) in plant roots simultaneously exposed to REE and acid rain. In this study, the effects of exposures to lanthanum(III) and acid rain, independently and in combination, on cytosol free Ca(2+) levels, root activity, metal contents, biomass, cytosol pH and La contents in horseradish roots were investigated. The simultaneous exposures to La(III) and acid rain increased or decreased the cytosol free Ca(2+) levels, depending on the concentration of La(III), and these effects were more evident than independent exposure to La(III) or acid rain. In combined exposures, cytosol free Ca(2+) played an important role in the regulation of root activity, metal contents and biomass. These roles were closely related to La(III) dose, acid rain strength and treatment mode (independent exposure or simultaneous exposure). A low concentration of La(III) (20 mg L(-1)) could alleviate the adverse effects on the roots caused by acid rain, and the combined exposures at higher concentrations of La(III) and acid rain had synergic effects on the roots. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Acid Rain Students Do Original Research.

    ERIC Educational Resources Information Center

    Outdoor Communicator, 1984

    1984-01-01

    At Park Senior High School (Cottage Grove, Minnesota), 46 juniors and seniors planted 384 red pine seedlings in connection with their original research on acid rain, with advice from Dr. Harriet Stubbs, director of the Acid Precipitation Awareness Program (West Saint Paul), which has been developing acid rain teaching materials. (MH)

  12. Nature in the Classroom: Acid Rain.

    ERIC Educational Resources Information Center

    Doyle, Charles

    1982-01-01

    As a lesson topic, acid rain is defined, its chemistry given, and its development since the 1950s described. The worldwide effects of acid rain are discussed along with the available technology for controlling the problem. (CM)

  13. Acid Rain Phenomenon in Niger Delta Region of Nigeria: Economic, Biodiversity, and Public Health Concern

    PubMed Central

    Nduka, J. K. C.; Orisakwe, O. E.; Ezenweke, L. O.; Ezenwa, T. E.; Chendo, M. N.; Ezeabasili, N. G.

    2008-01-01

    Rain samples were collected from Warri and Port Harcourt, two major oil-producing cities of Nigeria in April-June, July-August, and September-October 2005 and 2006. Awka, a “non-oil” city was used as control. Samples were collected from three points, using clean plastic basins fastened to a table, 2 m above ground level and 115 m away from tall buildings and trees. Water samples were filtered and acidity determined using digital pHmeter. The results show that the rain samples were acidic. The pH values for the 2 years under study show that the rainfall in Warri was more acidic than that of Port Harcourt. Oil exploration and other anthropogenic sources may be responsible for the acid rain in the Niger Delta region of Nigeria. PMID:18758657

  14. Effects of rare earth and acid rain pollution on plant chloroplast ATP synthase and element contents at different growth stages.

    PubMed

    Zhang, Fan; Hu, Huiqing; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2018-03-01

    Combined rare earth and acid rain pollution has become a new environmental problem, seriously affecting plant survival. The effects of these two kinds of pollutants on plant photosynthesis have been reported, but the micro mechanisms are not very clear. In this research, we studied the effects of lanthanum [La(III), 0.08, 1.20 and 2.40 mM] and acid rain (pH value = 2.5, 3.5 and 4.5) on the ATPase activity and gene transcription level and the functional element contents in rice leaf chloroplasts. The results showed that the combined 0.08 mM La(III) and pH 4.5 acid rain increased the ATPase activity and gene transcription level as well as contents of some functional elements. But other combined treatments of acid rain and La(III) reduced the ATPase activity and gene transcription level as well as functional element contents. The change magnitude of the above indexes at rice booting stage was greater than that in seedling stage or grain filling stage. These results reveal that effects of La(III) and acid rain on ATPase activity and functional element contents in rice leaf chloroplasts are related to the combination of La(III) dose and acid rain intensity and the plant growth stage. In addition, the changes in the ATPase activity were related to ATPase gene transcription level. This study would provide a reference for understanding the microcosmic mechanism of rare earth and acid rain pollution on plant photosynthesis and contribute to evaluate the possible environmental risks associated with combined La(III) and acid rain pollution. The effects of La(III) and acid rain on activity and gene transcription level of rice chloroplast ATPase and contents of functional elements were different at different growth stages. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Acid Rain: Activities for Science Teachers.

    ERIC Educational Resources Information Center

    Johnson, Eric; And Others

    1983-01-01

    Seven complete secondary/college level acid rain activities are provided. Activities include overview; background information and societal implications; major concepts; student objectives; vocabulary/material lists; procedures; instructional strategies; and questions/discussion and extension suggestions. Activities consider effects of acid rain on…

  16. Acid rain and sugar maple decline

    Treesearch

    Paul G. Schaberg

    2017-01-01

    Through the increased combustion of fossil fuels, humans have dramatically increased pollutant additions of sulfur and nitrogen into the atmosphere where it conbines with water to form sulfuric and nitric acids, creating acid rain (Driscoll et al. 2001). Incoming acid rain has various impacts on human and natural systems, including the accelerated degradation of built...

  17. Combined effects of simulated acid rain and lanthanum chloride on chloroplast structure and functional elements in rice.

    PubMed

    Hu, Huiqing; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2016-05-01

    Acid rain and rare earth element (REE) pollution exist simultaneously in many agricultural regions. However, how REE pollution and acid rain affect plant growth in combination remains largely unknown. In this study, the combined effects of simulated acid rain and lanthanum chloride (LaCl3) on chloroplast morphology, chloroplast ultrastructure, functional element contents, chlorophyll content, and the net photosynthetic rate (P n) in rice (Oryza sativa) were investigated by simulating acid rain and rare earth pollution. Under the combined treatment of simulated acid rain at pH 4.5 and 0.08 mM LaCl3, the chloroplast membrane was smooth, proteins on this membrane were uniform, chloroplast structure was integrated, and the thylakoids were orderly arranged, and simulated acid rain and LaCl3 exhibited a mild antagonistic effect; the Mg, Ca, Mn contents, the chlorophyll content, and the P n increased under this combined treatment, with a synergistic effect of simulated acid rain and LaCl3. Under other combined treatments of simulated acid rain and LaCl3, the chloroplast membrane surface was uneven, a clear "hole" was observed on the surface of chloroplasts, and the thylakoids were dissolved and loose; and the P n and contents of functional elements (P, Mg, K, Ca, Mn, Fe, Ni, Cu, Zn and Mo) and chlorophyll decreased. Under these combined treatments, simulated acid rain and LaCl3 exhibited a synergistic effect. Based on the above results, a model of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis was established in order to reveal the combined effects on plant photosynthesis, especially on the photosynthetic organelle-chloroplast. Our results would provide some references for further understanding the mechanism of the combined effects of simulated acid rain and LaCl3 on plant photosynthesis.

  18. Effect of simulated acid rain on nitrate and ammonium production in soils from three ecosystems of Camels Hump Mountain, Vermont

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Like, D.E.; Klein, R.M.

    1985-11-01

    The authors removed intact soil columns from the Harwood (550 to 790 m), Transition (790 to 1050 m), and Conifer (1050 to 1160 m) ecological zones of Camels Hump Mountain, Vermont, treated them with simulated acid rain (pH 4.0) or nonacidic (pH 5.6) rain, and examined the percolates for ammonium and nitrate ions. Nitrification in soils from all three ecosystems was unaffected by acidic treatments, but mineralization was stimulated by acidic treatment of soil from the Transition Zone. Irrespective of treatment, Conifer Zone soils released less nitrate than did either Transition or Hardwood Zone soils. Soil columns from the Hardwoodmore » Zone were treated with acidic or nonacidic simulated rainfall supplemented with nitrate, ammonium, or both N sources. NO3-N in percolates increased when acidic simulated rain was supplemented with ammonium ion or both ammonium and nitrate ions. Efflux of NH4-N was unaffected by supplementing precipitation with either ammonium or nitrate ions.« less

  19. Acid Rain: A Teaching Focus for the Intermediate Grades.

    ERIC Educational Resources Information Center

    Adams, Renee B.; Adams, Neil D.

    1992-01-01

    The study of acid rain provides ample opportunities for active, interdisciplinary learning. This article describes 12 hands-on activities designed to expand students' understanding of acid rain. Background information on acid rain is included. (LB)

  20. Leaching behavior of heavy metals and transformation of their speciation in polluted soil receiving simulated acid rain.

    PubMed

    Zheng, Shun-an; Zheng, Xiangqun; Chen, Chun

    2012-01-01

    Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects.

  1. Leaching Behavior of Heavy Metals and Transformation of Their Speciation in Polluted Soil Receiving Simulated Acid Rain

    PubMed Central

    Zheng, Shun-an; Zheng, Xiangqun; Chen, Chun

    2012-01-01

    Heavy metals that leach from contaminated soils under acid rain are of increasing concern. In this study, simulated acid rain (SAR) was pumped through columns of artificially contaminated purple soil. Column leaching tests and sequential extraction were conducted for the heavy metals Cu, Pb, Cd, and Zn to determine the extent of their leaching as well as to examine the transformation of their speciation in the artificially contaminated soil columns. Results showed that the maximum leachate concentrations of Cu, Pb, Cd, and Zn were less than those specified in the Chinese Quality Standards for Groundwater (Grade IV), thereby suggesting that the heavy metals that leached from the polluted purple soil receiving acid rain may not pose as risks to water quality. Most of the Pb and Cd leachate concentrations were below their detection limits. By contrast, higher Cu and Zn leachate concentrations were found because they were released by the soil in larger amounts as compared with those of Pb and Cd. The differences in the Cu and Zn leachate concentrations between the controls (SAR at pH 5.6) and the treatments (SAR at pH 3.0 and 4.5) were significant. Similar trends were observed in the total leached amounts of Cu and Zn. The proportions of Cu, Pb, Cd, and Zn in the EXC and OX fractions were generally increased after the leaching experiment at three pH levels, whereas those of the RES, OM, and CAR fractions were slightly decreased. Acid rain favors the leaching of heavy metals from the contaminated purple soil and makes the heavy metal fractions become more labile. Moreover, a pH decrease from 5.6 to 3.0 significantly enhanced such effects. PMID:23185399

  2. Experimental investigation of influence of acid rain on leaching and hydraulic characteristics of cement-based solidified/stabilized lead contaminated clay.

    PubMed

    Du, Yan-Jun; Jiang, Ning-Jun; Shen, Shui-Long; Jin, Fei

    2012-07-30

    Remediation of contaminated lands in China urban areas is of great concern. Degradation of construction facilities caused by acid rain is a serious environmental pollution issue in China. This paper presents an investigation of the effects of acid rain on leaching and hydraulic properties of cement-based solidified/stabilized lead contaminated soil. Laboratory tests including infiltration test and soaking test are conducted. It is found that the soil hydraulic conductivity decreases with increase in the pore volume of flow of permeant liquids (acid rain and distilled water). The decreasing rate in the case of the acid rain is lower than that in the case of the distilled water. The soaking test results show that pH and the presence of sulfate ions of acid rain have considerable influence on the leached concentrations and leaching rate of calcium. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. 40 CFR 76.3 - General Acid Rain Program provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

  4. 40 CFR 76.3 - General Acid Rain Program provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

  5. 40 CFR 76.3 - General Acid Rain Program provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

  6. 40 CFR 76.3 - General Acid Rain Program provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

  7. 40 CFR 76.3 - General Acid Rain Program provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false General Acid Rain Program provisions. 76.3 Section 76.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) ACID RAIN NITROGEN OXIDES EMISSION REDUCTION PROGRAM § 76.3 General Acid Rain Program provisions...

  8. Effects of lanthanum and acid rain stress on the bio-sequestration of lanthanum in phytoliths in germinated rice seeds

    PubMed Central

    Si, Yong; Wang, Lihong; Huang, Xiaohua

    2018-01-01

    REEs in the environment can be absorbed by plants and sequestered by plant phytoliths. Acid rain can directly or indirectly affect plant physiological functions. Currently, the effects of REEs and acid rain on phytolith-REEs complex in plants are not yet fully understood. In this study, a high-silicon accumulation crop, rice (Oryza sativa L.), was selected as a representative of plants, and orthogonal experiments were conducted under various levels of lanthanum [La(III)] and pH. The results showed that various La(III) concentrations could significantly improve the efficiency and sequestration of phytolith La(III) in germinated rice seeds. A pH of 4.5 promoted phytolith La(III) sequestration, while a pH of 3.5 inhibited sequestration. Compared with the single treatment with La(III), the combination of La(III) and acid rain inhibited the efficiency and sequestration of phytolith La(III). Correlation analysis showed that the efficiency of phytolith La(III) sequestration had no correlation with the production of phytolith but was closely correlated with the sequestration of phytolith La(III) and the physiological changes of germinated rice seeds. Phytolith morphology was an important factor affecting phytolith La(III) sequestration in germinated rice seeds, and the effect of tubes on sequestration was more significant than that of dumbbells. This study demonstrated that the formation of the phytolith and La(III) complex could be affected by exogenous La(III) and acid rain in germinated rice seeds. PMID:29763463

  9. Combined acid rain and lanthanum pollution and its potential ecological risk for nitrogen assimilation in soybean seedling roots.

    PubMed

    Zhang, Fan; Cheng, Mengzhu; Sun, Zhaoguo; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2017-12-01

    Rare earth elements (REEs) are used in various fields, resulting in their accumulation in the environment. This accumulation has affected the survival and distribution of crops in various ways. Acid rain is a serious global environmental problem. The combined effects on crops from these two types of pollution have been reported, but the effects on crop root nitrogen assimilation are rarely known. To explore the impact of combined contamination from these two pollutants on crop nitrogen assimilation, the soybean seedlings were treated with simulated environmental pollution from acid rain and a representative rare earth ion, lanthanum ion (La 3+ ), then the indexes related to plant nitrogen assimilation process in roots were determined. The results showed that combined treatment with pH 4.5 acid rain and 0.08 mM La 3+ promoted nitrogen assimilation synergistically, while the other combined treatments all showed inhibitory effects. Moreover, acid rain aggravated the inhibitory effect of 1.20 or 0.40 mM La 3+ on nitrogen assimilation in soybean seedling roots. Thus, the effects of acid rain and La 3+ on crops depended on the combination levels of acid rain intensity and La 3+ concentration. Acid rain increases the bioavailability of La 3+ , and the combined effects of these two pollutants were more serious than that of either pollutant alone. These results provide new evidence in favor of limiting overuse of REEs in agriculture. This work also provides a new framework for ecological risk assessment of combined acid rain and REEs pollution on soybean crops. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Acid Rain Investigations.

    ERIC Educational Resources Information Center

    Hugo, John C.

    1992-01-01

    Presents an activity in which students investigate the formation of solid ammonium chloride aerosol particles to help students better understand the concept of acid rain. Provides activity objectives, procedures, sample data, clean-up instructions, and questions and answers to help interpret the data. (MDH)

  11. Human Ecology: Acid Rain and Public Policy.

    ERIC Educational Resources Information Center

    Bybee, Rodger W.

    1983-01-01

    A connection between science and society can be seen in the human and ecological dimensions of one contemporary problem: acid rain. Introduces a human ecological theme and relationships between acid rain and public policy, considering scientific understanding and public awareness, scientific research and public policy, and national politics and…

  12. 40 CFR 72.31 - Information requirements for Acid Rain permit applications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Information requirements for Acid Rain... (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Permit Applications § 72.31 Information requirements for Acid Rain permit applications. A complete Acid Rain permit application shall include the...

  13. 40 CFR 72.31 - Information requirements for Acid Rain permit applications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Information requirements for Acid Rain... (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Permit Applications § 72.31 Information requirements for Acid Rain permit applications. A complete Acid Rain permit application shall include the...

  14. 40 CFR 72.31 - Information requirements for Acid Rain permit applications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Information requirements for Acid Rain... (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Permit Applications § 72.31 Information requirements for Acid Rain permit applications. A complete Acid Rain permit application shall include the...

  15. 40 CFR 72.31 - Information requirements for Acid Rain permit applications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Information requirements for Acid Rain... (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Permit Applications § 72.31 Information requirements for Acid Rain permit applications. A complete Acid Rain permit application shall include the...

  16. 40 CFR 72.31 - Information requirements for Acid Rain permit applications.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Information requirements for Acid Rain... (CONTINUED) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Permit Applications § 72.31 Information requirements for Acid Rain permit applications. A complete Acid Rain permit application shall include the...

  17. Analysis of the combined effects of lanthanum and acid rain, and their mechanisms, on nitrate reductase transcription in plants.

    PubMed

    Xia, Binxin; Sun, Zhaoguo; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2017-04-01

    Rare earth element (REE) pollution and acid rain are major global environmental concerns, and their spatial distributions overlap. Thus, both forms of pollution combine to act on plants. Nitrogen is important for plant growth, and nitrate reductase (NR) is a key plant enzyme that catalyzes nitrogen assimilation. Studying the combined effects of REEs and acid rain on plant nitrogen-based nutrients has important environmental significance. Here, soybean (Glycine max) plants, commonly used for toxicological studies, were exposed to lanthanum (La), a REE, and acid rain to study the NR activities and NR transcriptional levels in the roots. To explain how the pollution affected the NR transcriptional level, we simultaneously observed the contents of intracellular La and nutrient elements, protoplast morphology, membrane lipid peroxidation and intracellular pH. A combined treatment of 0.08mmol/L La and pH 4.5 acid rain increased the NR activity, decreased the NR transcriptional level, increased the intracellular nutrient elements' contents and caused deformations in membrane structures. Other combined treatments significantly decreased the aforementioned parameters and caused serious damage to the membrane structures. The variation in the amplitudes of combined treatments was greater than those of individual treatments. Compared with the control and individual treatments, combined treatments increased membrane permeability, the malondialdehyde content, and intracellular H + and La contents, and with an increasing La concentration or acid strength, the change in amplitude increased. Thus, the combined effects on NR gene transcription in soybean seedling roots were related to the intracellular nutrient elements' contents, protoplast morphology, membranous lipid peroxidation, intracellular pH and La content. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. The role of urban forest to reduce rain acid in urban industrial areas

    NASA Astrophysics Data System (ADS)

    Slamet, B.; Agustiarni, Y.; Hidayati; Basyuni, M.

    2018-03-01

    Urban forest has many functions mainly on improving the quality of the urban environment. One of the functions is to increase pH and reduce dangerous chemical content. The aim of the research is to find out the role of vegetation density of urban forest around the industrial area in reducing the acid rain. The condition of land cover was classified into four classes which are dense, medium, sparse and open area. The water of the throughfall and stemflow was taken from each type of land cover except in the open area. Parameters measured in this study are water acidity (pH), anion content (SO4 2- and NO3 -), cation content (Ca2+, Mg2+, and NH4 +) and electrical conductivity (EC). The results indicated that urban forest vegetation was able to increase the pH of rain water from 5.42 which is in an open area without vegetation to be 7.13 and 7.32 in dense and moderate vegetation cover by throughfall mechanism, respectively. Rain water acidity also decreased through stemflow mechanism with a pH ranged from 5.92 - 6.43. Urban forest vegetation decreased sulfate content (SO42-) from 528.67 mg/l in open area to 44 - 118 mg/l by throughfall mechanism and ranged from 90 to 366.67 mg/l through stemflow mechanism. Urban forest vegetation significantly decreased the rainwater nitrate content from 27 mg/l to 0.03 - 0.70 mg/l through the mechanism of throughfall and between 1.53 - 8.82 mg/l through the stemflow mechanism. Urban forest vegetation also increased the concentration of cations (NH4+, Ca2+, Mg2+, Na+) compared with open areas. Urban forest vegetation showed increased the electrical conductivity (EC) from 208.12 μmhos/cm to 344.67 - 902.17 μmhos/cm through the through fall mechanism and 937.67 - 1058.70 μmhos/cm through the stemflow mechanism. The study suggested that urban forests play a significant role in reducing rainwater acidity and improving the quality of rainwater that reached the soil surface.

  19. A meteorological potential forecast model for acid rain in Fujian Province, China.

    PubMed

    Cai, Yi Yong; Lin, Chang Cheng; Liu, Jing Xiong; Wu, De Hui; Lian, Dong Ying; Chen, Bin Bin

    2010-05-01

    Based on the acid rain and concurrent meteorological observational data during the past 10 years in Fujian Province, China, the dependence of distribution characteristics of acid rain on season, rain rate, weather pattern and dominant airflow in four regions of Fujian Province is analyzed. On the annual average, the acid rain frequency is the highest (above 40%) in the southern and mid-eastern regions, and the lowest (16.2%) in the western region. The acid rain occurs most frequently in spring and winter, and least frequent in summer. The acid rain frequency in general increases with the increase of precipitation. It also depend on the direction of dominant airflows at 850 hPa. In the mid-eastern region, more than 40% acid rains appear when the dominant wind directions are NW, W, SW, S and SE. In the southern region, high acid rain occurrence happens when the dominant wind directions are NW, W, SW and S. In the northern region, 41.8% acid rains occur when the southwesterly is pronounced. In the western region, the southwesterly is associated with a 17% acid rain rate. The examination of meteorological sounding conditions over Fuzhou, Xiamen and Shaowu cities shows that the acid rain frequency increases with increased inversion thickness. Based on the results above, a meteorological potential forecast model for acid rain is established and tested in 2007. The result is encouraging. The model provides an objective basis for the development of acid rain forecasting operation in the province.

  20. Acid Rain: A Teacher's Guide. Activities for Grades 4 to 12.

    ERIC Educational Resources Information Center

    National Wildlife Federation, Washington, DC.

    This guide on acid rain for elementary and secondary students is divided into three study areas: (1) What Causes Acid Rain; (2) What Problems Acid Rain Has Created; (3) How You and Your Students Can Help Combat Acid Rain. Each section presents background information and a series of lessons pertaining to the section topic. Activities include…

  1. Acid Rain. Activities for Grades 4 to 12. A Teacher's Guide.

    ERIC Educational Resources Information Center

    Wood, David; Bryant, Jeannette

    This teacher's guide on acid rain is divided into three study areas to explain: (1) what causes acid rain; (2) what problems acid rain has created; and (3) what teachers and students can do to help combat acid rain. Instructions for activities within the study areas include suggested grade levels, objectives, materials needed, and directions for…

  2. Responses of tropical legumes from the Brazilian Atlantic Rainforest to simulated acid rain.

    PubMed

    Andrade, Guilherme C; Silva, Luzimar C

    2017-07-01

    We investigated the morphological and anatomical effects of simulated acid rain on leaves of two species native to the Brazilian Atlantic Rainforest: Paubrasilia echinata and Libidibia ferrea var. leiostachya. Saplings were subjected to acid rain in a simulation chamber during 10 days for 15 min daily, using H 2 SO 4 solution pH 3.0 and, in the control, deionized water. At the end of the experiment, fragments from young and expanding leaves were anatomically analyzed. Although L. ferrea var. leiostachya leaves are more hydrophobic, rain droplets remained in contact with them for a longer time, as in the hydrophilic P. echinata leaves, droplets coalesce and rapidly run off. Visual symptomatology consisted in interveinal and marginal necrotic dots. Microscopic damage found included epicuticular wax flaking, turgor loss and epidermal cell shape alteration, hypertrophy of parenchymatous cells, and epidermal and mesophyll cell collapse. Formation of a wound tissue was observed in P. echinata, and it isolated the necrosis to the adaxial leaf surface. Acid rain increased thickness of all leaf tissues except spongy parenchyma in young leaves of L. ferrea var. leiostachya, and such thickness was maintained throughout leaf expansion. To our knowledge, this is the first report of acidity causing increase in leaf tissue thickness. This could represent the beginning of cell hypertrophy, which was seen in visually affected leaf regions. Paubrasilia echinata was more sensitive, showing earlier symptoms, but the anatomical damage in L. ferrea var. leiostachya was more severe, probably due to the higher time of contact with acid solution in this species.

  3. Modeled dosage-response relationship on the net photosynthetic rate for the sensitivity to acid rain of 21 plant species.

    PubMed

    Deng, Shihuai; Gou, Shuzhen; Sun, Baiye; Lv, Wenlin; Li, Yuanwei; Peng, Hong; Xiao, Hong; Yang, Gang; Wang, Yingjun

    2012-08-01

    This study investigated the sensitivity of plant species to acid rain based on the modeled dosage-response relationship on the net photosynthetic rate (P (N)) of 21 types of plant species, subjected to the exposure of simulated acid rain (SAR) for 5 times during a period of 50 days. Variable responses of P (N) to SAR occurred depending on the type of plant. A majority (13 species) of the dosage-response relationship could be described by an S-shaped curve and be fitted with the Boltzmann model. Model fitting allowed quantitative evaluation of the dosage-response relationship and an accurate estimation of the EC(10), termed as the pH of the acid rain resulting in a P (N) 10 % lower than the reference value. The top 9 species (Camellia sasanqua, Cinnamomum camphora, etc. EC(10) ≤ 3.0) are highly endurable to very acid rain. The rare, relict plant Metasequoia glyptostroboides was the most sensitive species (EC(10) = 5.1) recommended for protection.

  4. Difficult Decisions: Acid Rain.

    ERIC Educational Resources Information Center

    Miller, John A.; Slesnick, Irwin L.

    1989-01-01

    Discusses some of the contributing factors and chemical reactions involved in the production of acid rain, its effects, and political issues pertaining to who should pay for the clean up. Supplies questions for consideration and discussion. (RT)

  5. The Acid Rain Debate.

    ERIC Educational Resources Information Center

    Oates-Bockenstedt, Catherine

    1997-01-01

    Details an activity designed to motivate students by incorporating science-related issues into a classroom debate. Includes "The Acid Rain Bill" and "Position Guides" for student roles as committee members, consumers, governors, industry owners, tourism professionals, senators, and debate directors. (DKM)

  6. 40 CFR 72.69 - Issuance and effective date of acid rain permits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.69 Issuance and effective date of acid rain permits. (a) After the close of the public comment period, the Administrator will issue or deny an Acid Rain permit. The Administrator will serve a copy of any Acid Rain...

  7. 40 CFR 72.69 - Issuance and effective date of acid rain permits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.69 Issuance and effective date of acid rain permits. (a) After the close of the public comment period, the Administrator will issue or deny an Acid Rain permit. The Administrator will serve a copy of any Acid Rain...

  8. 40 CFR 72.69 - Issuance and effective date of acid rain permits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.69 Issuance and effective date of acid rain permits. (a) After the close of the public comment period, the Administrator will issue or deny an Acid Rain permit. The Administrator will serve a copy of any Acid Rain...

  9. 40 CFR 72.69 - Issuance and effective date of acid rain permits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.69 Issuance and effective date of acid rain permits. (a) After the close of the public comment period, the Administrator will issue or deny an Acid Rain permit. The Administrator will serve a copy of any Acid Rain...

  10. 40 CFR 72.69 - Issuance and effective date of acid rain permits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) AIR PROGRAMS (CONTINUED) PERMITS REGULATION Federal Acid Rain Permit Issuance Procedures § 72.69 Issuance and effective date of acid rain permits. (a) After the close of the public comment period, the Administrator will issue or deny an Acid Rain permit. The Administrator will serve a copy of any Acid Rain...

  11. Acid Rain Classroom Projects.

    ERIC Educational Resources Information Center

    Demchik, Michael J.

    2000-01-01

    Describes a curriculum plan in which students learn about acid rain through instructional media, research and class presentations, lab activities, simulations, design, and design implementation. Describes the simulation activity in detail and includes materials, procedures, instructions, examples, results, and discussion sections. (SAH)

  12. Structure of a microbial community in soil after prolonged addition of low levels of simulated acid rain

    PubMed

    Pennanen; Fritze; Vanhala; Kiikkila; Neuvonen; Baath

    1998-06-01

    Humus samples were collected 12 growing seasons after the start of a simulated acid rain experiment situated in the subarctic environment. The acid rain was simulated with H2SO4, a combination of H2SO4 and HNO3, and HNO3 at two levels of moderate acidic loads close to the natural anthropogenic pollution levels of southern Scandinavia. The higher levels of acid applications resulted in acidification, as defined by humus chemistry. The concentrations of base cations decreased, while the concentrations of exchangeable H+, Al, and Fe increased. Humus pH decreased from 3.83 to 3.65. Basal respiration decreased with decreasing humus pH, and total microbial biomass, measured by substrate-induced respiration and total amount of phospholipid fatty acids (PLFA), decreased slightly. An altered PLFA pattern indicated a change in the microbial community structure at the higher levels of acid applications. In general, branched fatty acids, typical of gram-positive bacteria, increased in the acid plots. PLFA analysis performed on the bacterial community growing on agar plates also showed that the relative amount of PLFA specific for gram-positive bacteria increased due to the acidification. The changed bacterial community was adapted to the more acidic environment in the acid-treated plots, even though bacterial growth rates, estimated by thymidine and leucine incorporation, decreased with pH. Fungal activity (measured as acetate incorporation into ergosterol) was not affected. This result indicates that bacteria were more affected than fungi by the acidification. The capacity of the bacterial community to utilize 95 different carbon sources was variable and only showed weak correlations to pH. Differences in the toxicities of H2SO4 and HNO3 for the microbial community were not found.

  13. 40 CFR 72.71 - Acceptance of State Acid Rain programs-general.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Acceptance of State Acid Rain programs... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.71 Acceptance of State Acid... State Acid Rain program meeting the requirements of §§ 72.72 and 72.73. (b) The Administrator will...

  14. 40 CFR 72.71 - Acceptance of State Acid Rain programs-general.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Acceptance of State Acid Rain programs... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.71 Acceptance of State Acid... State Acid Rain program meeting the requirements of §§ 72.72 and 72.73. (b) The Administrator will...

  15. 40 CFR 72.71 - Acceptance of State Acid Rain programs-general.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Acceptance of State Acid Rain programs... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.71 Acceptance of State Acid... State Acid Rain program meeting the requirements of §§ 72.72 and 72.73. (b) The Administrator will...

  16. 40 CFR 72.71 - Acceptance of State Acid Rain programs-general.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Acceptance of State Acid Rain programs... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.71 Acceptance of State Acid... State Acid Rain program meeting the requirements of §§ 72.72 and 72.73. (b) The Administrator will...

  17. 40 CFR 72.71 - Acceptance of State Acid Rain programs-general.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Acceptance of State Acid Rain programs... PROGRAMS (CONTINUED) PERMITS REGULATION Acid Rain Phase II Implementation § 72.71 Acceptance of State Acid... State Acid Rain program meeting the requirements of §§ 72.72 and 72.73. (b) The Administrator will...

  18. Effects of simulated acid rain on microbial characteristics in a lateritic red soil

    Treesearch

    Hua-qin Xu; Jia-en Zhang; Ying Ouyang; Ling Lin; Guo-ming Quan; Ben-liang Zhao; Jia-yu Yu

    2015-01-01

    A laboratory experiment was performed to examine the impact of simulated acid rain (SAR) on nutrient leaching, microbial biomass, and microbial activities in a lateritic red soil in South China. The soil column leaching experiment was conducted over a 60-day period with the following six SAR pH treatments (levels): 2.5, 3.0, 3.5, 4.0, 4.5, and 5.0 and one control...

  19. Effects of simulated acid rain on the morphology, phenology and dry biomass of a local variety of maize (Suwan-1) in Southwestern Nigeria.

    PubMed

    Macaulay, Babajide Milton; Enahoro, Gloria Ebarunosen

    2015-10-01

    Effects of acid rain on the morphology, phenology and dry biomass of maize (Suwan-1 variety) were investigated. The maize seedlings were subjected to different pH treatments (1.0, 2.0, 3.0, 4.0, 5.0 and 6.0) of simulated acid rain (SAR) with pH 7.0 as the control for a period of 90 days. The common morphological defects due to SAR application were necrosis and chlorosis. It was observed that necrosis increased in severity as the acidity increased whilst chlorosis was dominant as the acidity decreased. SAR encouraged rapid floral and cob growth but with the consequence of poor floral and cob development in pH 1.0 to 3.0 treatments. The result for the dry biomass indicates that pH treatments 2.0 to 7.0 for total plant biomass were not significantly different (P > 0.05) from one another, but were all significantly higher (P < 0.05) than pH 1.0. Therefore, it may be deduced that Suwan-1 has the potential to withstand acid rain but with pronounced morphological and phenological defects which, however, have the capacity to reduce drastically the market value of the crop. Therefore, it may be concluded that Suwan-1 tolerated acid rain in terms of the parameters studied at pH 4.0 to 7.0 which makes it a suitable crop in acid rain-stricken climes. This research could also serve as a good reference for further SAR studies on maize or other important cereals.

  20. [Effects of exogenous nitric oxide on physiological characteristics of longan (Dimocarpus longana) seedlings under acid rain stress].

    PubMed

    Liu, Jian-fu; Wang, Ming-yuan; Yang, Chen; Zhu, Ai-jun

    2013-08-01

    This paper studied the effects of exogenous nitric oxide donor sodium nitroprusside (SNP) on the chlorophyll content, antioxidant enzyme activities, and osmotic regulation substances of longan (Dimocarpus longana 'Fuyan') seedlings under acid rain (pH 3.0) stress. Under the acid rain stress, the seedling leaf superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities and chlorophyll, soluble protein and soluble sugar contents decreased obviously, while the leaf malondialdedyde content had a remarkable increase, suggesting the toxic effect of the acid rain on the seedlings. Exogenous nitric oxide had dual nature on the physiological characteristics of longan seedlings under acid rain stress. Applying 0.1-0.5 mmol x L(-1) of SNP improved the SOD, POD and CAT activities and the chlorophyll, soluble protein and soluble sugar contents significantly, and decreased the malondialdedyde content. Low concentrations SNP reduced the oxidative damage caused by the acid rain stress, and 0.5 mmol x L(-1) of SNP had the best effect. Under the application of 0.5 mmol x L(-1) of SNP, the total chlorophyll, soluble protein, and soluble sugar contents and the SOD, POD and CAT activities increased by 76.0%, 107.0%, 216.1%, 150. 0%, 350.9% and 97.1%, respectively, and the malondialdedyde content decreased by 46.4%. It was suggested that low concentration (0.1-0.5 mmol x L(-1)) SNP could alleviate the toxic effect of acid rain stress on longan seedlings via activating the leaf antioxidant enzyme activities and reducing oxidative stress, while high concentration SNP (1.0 mmol x L(-1)) lowered the mitigation effect.

  1. Effect of simulated acid rain on the litter decomposition of Quercus acutissima and Pinus massoniana in forest soil microcosms and the relationship with soil enzyme activities.

    PubMed

    Wang, Congyan; Guo, Peng; Han, Guomin; Feng, Xiaoguang; Zhang, Peng; Tian, Xingjun

    2010-06-01

    With the continuing increase in human activities, ecologists are increasingly interested in understanding the effects of acid rain on litter decomposition. Two dominant litters were chosen from Zijin Mountain in China: Quercus acutissima from a broad-leaved forest and Pinus massoniana from a coniferous forest. The litters were incubated in microcosms and treated with simulated acid rain (gradient pH levels). During a six-month incubation, changes in chemical composition (i.e., lignin, total carbohydrate, and nitrogen), litter mass losses, soil pH values, and activities of degradative enzymes were determined. Results showed that litter mass losses were depressed after exposure to acid rain and the effects of acid rain on the litter decomposition rates of needles were higher than on those of leaves. Results also revealed that simulated acid rain restrained the activities of cellulase, invertase, nitrate reductase, acid phosphatase, alkaline phosphatase, polyphenol oxidase, and urease, while it enhanced the activities of catalase in most cases during the six-month decomposition process. Catalase and polyphenol oxidase were primarily responsible for litter decomposition in the broad-leaved forest, while invertase, nitrate reductase, and urease were primarily responsible for litter decomposition in the coniferous forest. The results suggest acid rain-restrained litter decomposition may be due to the depressed enzymatic activities. According to the results of this study, soil carbon in subtropical forests would accumulate as a long-term consequence of continued acid rain. This may presumably alter the balance of ecosystem carbon flux, nutrient cycling, and humus formation, which may, in turn, have multiple effects on forest ecosystems. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  2. The Acid Rain Debate.

    ERIC Educational Resources Information Center

    Bybee, Rodger; And Others

    1984-01-01

    Describes an activity which provides opportunities for role-playing as industrialists, ecologists, and government officials. The activity involves forming an international commission on acid rain, taking testimony, and, based on the testimony, making recommendations to governments on specific ways to solve the problem. Includes suggestions for…

  3. Elementary Acid Rain Kit, Interdisciplinary, Grades 4-8.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.; And Others

    An interdisciplinary approach for teaching about acid rain is offered in this curriculum guide for teachers of grades 4-8. Skill and concept areas of science, math, social studies, art, and the language arts are developed in 12 activities which focus on the acid rain problems. A matrix of the activities and subject areas indicates the coverage…

  4. [THE EFFECT OF ACID RAIN ON ULTRASTRUCTURE AND FUNCTIONAL PARAMETERS OF PHOTOSYNTHETIC APPARATUS OF PEA LEAVES].

    PubMed

    Polishchuk, A V; Vodka, M V; Belyavskaya, N A; Khomochkin, A P; Zolotareva, E K

    2016-01-01

    The effects of simulated acid rain (SAR) on the ultrastructure and functional parameters of the photosynthetic apparatus were studied using 14-day-old pea leaves as test system. Pea plants were sprayed with an aqueous solution containing NaNO₃(0.2 mM) and Na₂SO₄(0.2 mM) (pH 5.6, a control variant), or with the same solution, which was acidified to pH 2.5 (acid variant). Functional characteristics were determined by chlorophyll fluorescence analysis. Acid rain application caused reduction in the efficiency of the photosynthetic electron transport by 25%, which was accompanied by an increase by 85% in the quantum yield of thermal dissipation of excess light quanta. Ultrastructural changes in chloroplast were registered by transmission electron microscopy (TEM) after two days of the SAR-treatment of pea leaves. In this case, the changes in the structure of grana, heterogeneity of thylakoids packaging in granum, namely, the increase of intra-thylakoid gaps and thickness of granal thylakoids compared to the control were found. The migration of protein complexes in thylakoid membranes of chloroplasts isolated from leaves treated with SAR was suppressed. It was shown also that carbonic anhydrase activity was inhibited in chloroplast preparations isolated from SAR-treated pea leaves. We proposed a hypothesis on the possible inactivation of thylakoid carbonic anhydrase under SAR and its involvement in the inhibition of photochemical activity of chloroplasts. The data obtained allows to suggest that acid rains negatively affect the photosynthetic apparatus disrupting the membrane system of chloroplast.

  5. Acid rain in Shenandoah National Park, Virginia

    USGS Publications Warehouse

    Rice, Karen C.; Deviney, Frank A.; Olson, Gordon

    2007-01-01

    Visitors to Shenandoah National Park (SNP) enjoy the animal and plant life and the scenery but may not realize how vulnerable these features are to various threats, such as invasion of exotic plants and insects, improper use of park resources by humans, and air and water pollution. The National Park Service strives to protect natural resources from such threats to ensure that the resources will be available for enjoyment now and in the future. Because SNP has limited influence over the air pollution that envelops the region, acidic deposition--commonly known as acid rain--is one of the more challenging threats facing park managers. With the help of U.S. Geological Survey (USGS) scientists, park managers can understand how acid rain interacts with ground- and surface-water resources, which enables them to explain why reductions in air pollution can help preserve park resources. Such understanding also provides essential insight into ecosystem processes, as managers strive to unravel and resolve other environmental problems that are interrelated to acid rain.

  6. 40 CFR 75.3 - General Acid Rain Program provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false General Acid Rain Program provisions. 75.3 Section 75.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING General § 75.3 General Acid Rain Program provisions. The...

  7. 40 CFR 75.3 - General Acid Rain Program provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false General Acid Rain Program provisions. 75.3 Section 75.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING General § 75.3 General Acid Rain Program provisions. The...

  8. 40 CFR 75.3 - General Acid Rain Program provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false General Acid Rain Program provisions. 75.3 Section 75.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING General § 75.3 General Acid Rain Program provisions. The...

  9. 40 CFR 75.3 - General Acid Rain Program provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false General Acid Rain Program provisions. 75.3 Section 75.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING General § 75.3 General Acid Rain Program provisions. The...

  10. 40 CFR 75.3 - General Acid Rain Program provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false General Acid Rain Program provisions. 75.3 Section 75.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING General § 75.3 General Acid Rain Program provisions. The...

  11. Acid rain and its environmental effects: Recent scientific advances

    NASA Astrophysics Data System (ADS)

    Burns, Douglas A.; Aherne, Julian; Gay, David A.; Lehmann, Christopher M. B.

    2016-12-01

    The term 'acid rain' refers to atmospheric deposition of acidic constituents that impact the earth as rain, snow, particulates, gases, and vapor. Acid rain was first recognized by Ducros (1845) and subsequently described by the English chemist Robert Angus Smith (Smith, 1852) whose pioneering studies linked the sources to industrial emissions and included early observations of deleterious environmental effects (Smith, 1872). Smith's work was largely forgotten until the mid-20th century when observations began to link air pollution to the deposition of atmospheric sulfate (SO42-) and other chemical constituents, first near the metal smelter at Sudbury, Ontario, Canada, and later at locations in Europe, North America, and Australia (Gorham, 1961). Our modern understanding of acid rain as an environmental problem caused largely by regional emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) stems from observations in the 1960s and early 1970s in Sweden by Svante Odén (Odén, 1976), and in North America by Gene Likens and colleagues (Likens and Bormann, 1974). These scientists and many who followed showed the link to emissions from coal-fired power plants and other industrial sources, and documented the environmental effects of acid rain such as the acidification of surface waters and toxic effects on vegetation, fish, and other biota.

  12. Effect of exogenous abscisic acid on morphology, growth and nutrient uptake of rice (Oryza sativa) roots under simulated acid rain stress.

    PubMed

    Liu, Hongyue; Ren, Xiaoqian; Zhu, Jiuzheng; Wu, Xi; Liang, Chanjuan

    2018-05-31

    Application of proper ABA can improve acid tolerance of rice roots by balancing endogenous hormones and promoting nutrient uptake. Abscisic acid (ABA) has an important signaling role in enhancing plant tolerance to environmental stress. To alleviate the inhibition on plant growth and productivity caused by acid rain, it is crucial to clarify the regulating mechanism of ABA on adaptation of plants to acid rain. Here, we studied the effects of exogenously applied ABA on nutrients uptake of rice roots under simulated acid rain (SAR) stress from physiological, biochemical and molecular aspects. Compared to the single SAR treatment (pH 4.5 or 3.5), exogenous 10 μM ABA alleviated the SAR-induced inhibition of root growth by balancing endogenous hormones (abscisic acid, indole-3-acetic acid, gibberellic acid and zeatin), promoting nutrient uptake (nitrate, P, K and Mg) in rice roots, and increasing the activity of the plasma membrane H + -ATPase by up-regulating expression levels of genes (OSA2, OSA4, OSA9 and OSA10). However, exogenous 100 μM ABA exacerbated the SAR-caused inhibition of root growth by disrupting the balance of endogenous hormones, and inhibiting nutrient uptake (nitrate, P, K, Ca and Mg) through decreasing the activity of the plasma membrane H + -ATPase. These results indicate that proper concentration of exogenous ABA could enhance tolerance of rice roots to SAR stress by promoting nutrients uptake and balancing endogenous hormones.

  13. An evaluation of the effects of acid rain on low conductivity headwater streams in Pennsylvania

    USGS Publications Warehouse

    Ritter, John R.; Brown, Ann E.

    1981-01-01

    Analyses of water collected at 32 sites on headwater streams in Pennsylvania during low-flow conditions in 1970-80 were compared to pre-1971 data to evaluate whether acid rain had changed the chemistry of the streams in the previous decade. Most pH, alkalinity, and sulfate values of the samples collected in 1970-80 fell within the ranges of values for samples collected before 1971. The limited data indicate, however, that pH may have increased and alkalinity and sulfate may have decreased with time.

  14. The Acid Rain Game.

    ERIC Educational Resources Information Center

    Rakow, Steven J.; Glenn, Allen

    1982-01-01

    Provides rationale for and description of an acid rain game (designed for two players), a problem-solving model for elementary students. Although complete instructions are provided, including a copy of the game board, the game is also available for Apple II microcomputers. Information for the computer program is available from the author.…

  15. Transport and fate of acid rains out of North America. Final report, April 14, 1982-April 13, 1983

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Knap, A.H.

    1983-06-01

    A program to determine the transport of acid rain has been undertaken at Bermuda. The results indicate that precipitation at Bermuda is acidified to a pH of 4.8 over a one-year period with a seasonal component of greater acidity (pH 4.4) corresponding to back trajectories of the North American air mass. A detailed study of the composition of Bermuda rainwater compared to a North American coastal site has been carried out as well as a shipboard collection program between eastern North America and Bermuda. The results indicate that the strong acid acidity is due to long-range transport of the Northmore » American air mass.« less

  16. Corrosion of 85-5-5-5 bronze in natural and synthetic acid rain

    NASA Astrophysics Data System (ADS)

    Morselli, L.; Bernardi, E.; Chiavari, C.; Brunoro, G.

    In order to investigate the decay of bronzes exposed to acid wet depositions, a comparative study has been performed by following the corrosion behaviour of different sets of bronze specimens exposed either to natural rain or to a similar solution, without organic compounds, artificially reproduced in laboratory. The as cast G85 bronze specimens were exposed to aggressive solutions for different periods through a wet-dry technique. The pH trend of the solutions and the amount of metals transferred into the solutions were periodically monitored. OM, SEM, XRD, RAMAN analyses and ac electrochemical measurements were performed on the artificially weathered specimens. Preliminary results, showing the difference between the ageing in natural and synthetic rain, suggest the influence of the organic components on the corrosion process. In particular, the growth of a more uniform protective layer of corrosion products on the metal surface exposed to the natural rain could be attributed to these components.

  17. [Responses of rhizosphere nitrogen and phosphorus transformations to different acid rain intensities in a hilly red soil tea plantation].

    PubMed

    Chen, Xi; Chen, Fu-sheng; Ye, Su-qiong; Yu, Su-qin; Fang, Xiang-min; Hu, Xiao-fei

    2015-01-01

    Tea (Camellia sinensis) plantation in hilly red soil region has been long impacted by acid deposition, however its effects on nitrogen (N) and phosphorus (P) transformations in rhizosphere soils remain unclear. A 25-year old tea plantation in a typical hilly red soil region was selected for an in situ simulation experiment treated by pH 4.5, pH 3.5, pH 2.5 and control. Rhizosihere and bulk soils were collected in the third year from the simulated acid deposition experiment. Soil mineral N, available P contents and major enzyme activities were analyzed using the chemical extraction and biochemical methods, and N and P mineralization rates were estimated using the indoor aerobic incubation methods. Our results showed that compared to the control, the treatments of pH 4.5, pH 3.5 and pH 2.5, respectively decreased 7.1%, 42.1% and 49.9% NO3(-)-N, 6.4%, 35.9% and 40.3% mineral N, 10.5%, 41.1% and 46.9% available P, 18.7%, 30.1% and 44.7% ammonification rate, 3.6%, 12.7% and 38.8% net N-mineralization rate, and 31.5%, 41.8% and 63.0% P mineralization rate in rhizosphere soils; however, among the 4 treatments, rhizosphere soil nitrification rate was not significantly different, the rhizosphere soil urease and acid phosphatase activities generally increased with the increasing intensity of acid rain (P<0.05). In bulk soil, compared with the control, the treatments of pH 4.5, pH 3.5 and pH 2.5 did not cause significant changes in NO3(-)-N, mineral N, available P as well as in the rates of nitrification, ammonification, net N-mineralization and P mineralization. With increasing the acid intensity, the rhizosphere effects of NH4+-N, NO3(-)-N, mineral N, ammonification and net N-mineralization rates were altered from positive to negative effects, those of urease and acid phosphatease showed the opposite trends, those of available P and P mineralization were negative and that of nitrification was positive. In sum, prolonged elevated acid rain could reduce N and P transformation

  18. Combined effects of lead and acid rain on photosynthesis in soybean seedlings.

    PubMed

    Hu, Huiqing; Wang, Lihong; Liao, Chenyu; Fan, Caixia; Zhou, Qing; Huang, Xiaohua

    2014-10-01

    To explore how lead (Pb) and acid rain simultaneously affect plants, the combined effects of Pb and acid rain on the chlorophyll content, chlorophyll fluorescence reaction, Hill reaction rate, and Mg(2+)-ATPase activity in soybean seedlings were investigated. The results indicated that, when soybean seedlings were treated with Pb or acid rain alone, the chlorophyll content, Hill reaction rate, Mg(2+)-ATPase activity, and maximal photochemical efficiency (F(v)/F(m)) were decreased, while the initial fluorescence (F 0) and maximum quantum yield (Y) were increased, compared with those of the control. The combined treatment with Pb and acid rain decreased the chlorophyll content, Hill reaction rate, Mg(2+)-ATPase activity, F(v)/F(m), and Y and increased F 0 in soybean seedlings. Under the combined treatment with Pb and acid rain, the two factors showed additive effects on the chlorophyll content in soybean seedlings and exhibited antagonistic effects on the Hill reaction rate. Under the combined treatment with high-concentration Pb and acid rain, the two factors exhibited synergistic effects on the Mg(2+)-ATPase activity, F 0, F v/F m, as well as Y. In summary, the inhibition of the photosynthetic process is an important physiological basis for the simultaneous actions of Pb and acid rain in soybean seedlings.

  19. [Seasonality and contribution to acid rain of the carbon abundance in rainwater].

    PubMed

    Xu, Tao; Song, Zhi-guang; Liu, Jun-feng; Wang, Cui-ping

    2008-02-01

    This paper reports the results from a study of the carbon abundance in rainwater of Guangzhou city, China. The determination of TOC, DOC, POC and PEC helps to study the seasonality of carbon abundance and its contribution to the acid rain. The results display the fact that the average contents of TOC, DOC, POC and PEC are 7.10 mg/L, 3.58 mg/L, 3.60 mg/L and 0.72 mg/L, respectively. These results confirm the deep effect of the organic pollutant to the rain. The seasonality exists in the carbon abundance of rainwater. The contents of TOC and DOC are up to the maximum in spring and the minimum in summer; the contribution of POC to TOC in summer is obviously higher than that in other seasons; and the relative content of POC is clearly higher in dry season than that in wet season. The seasonality reflects the more emission of the total pollutant in spring and the solid particle pollutant in summer than those in other seasons. Moreover, the emission of the organic pollutant from the mobile vehicles is more obvious in dry season than that in wet season. The contents of TOC and DOC have the negative correlation to the pH values, which confirms the contribution effect of the organic pollutant, such as vehicle emission, to the acid rain.

  20. Acid Rain Materials for Classroom Use.

    ERIC Educational Resources Information Center

    Factor, Lance; Kooser, Robert G.

    This booklet contains three separate papers suitable for use in an advanced high school or college chemistry course. The first paper provides background information on acids and bases. The second paper provides additional background information, focusing on certain aspects of atmospheric chemistry as it relates to the acid rain problem. An attempt…

  1. Sequestering CO(2) by mineral carbonation: stability against acid rain exposure.

    PubMed

    Allen, Daniel J; Brent, Geoff F

    2010-04-01

    Mineral carbonation is a potentially attractive alternative to storage of compressed CO(2) in underground repositories, known as geosequestration. Processes for the conversion of basic ores, such as magnesium silicates, to carbonates have been proposed by various researchers, with storage of the carbonate as backfill in the original mine representing a solid carbon sink. The stability of such carbon sinks against acid rain and other sources of strong acids is examined here. It is acknowledged that in the presence of strong acid, carbonates will dissolve and release carbon dioxide. A sensitivity analysis covering annual average rainfall and pH that may be encountered in industrialized areas of the United States, China, Europe, and Australia was conducted to determine maximum CO(2) rerelease rates from mineral carbonation carbon sinks. This analysis is based on a worst-case premise that is equivalent to assuming infinitely rapid kinetics of dissolution of the carbonate. The analysis shows that under any likely conditions of pH and rainfall, leakage rates of stored CO(2) are negligible. This is illustrated in a hypothetical case study under Australian conditions. It is thus proposed that sequestration by mineral carbonation can be considered to be permanent on practical human time scales. Other possible sources of acid have also been considered.

  2. Acid Rain: A Student's First Sourcebook.

    ERIC Educational Resources Information Center

    Kyle, Beth Ann; And Others

    The purpose of this guide is to help students better understand the science, citizen action, and research issues that are part of the acid rain problem. The guide is designed for students in grades 4-8 and their teachers. Following an introduction, the first seven sections are informative in nature. They include: (1) "Observations about Acidity";…

  3. THE ACID RAIN NOX PROGRAM

    EPA Science Inventory

    Between 350,000 and 400,000 tons of annual NOx emissions have been eliminated as a result of Phase I of the Acid Rain NOx Program. As expected. the utilities have chosen emissions averaging as the primary compliance option. This reflects that, in general, NO x reductions have ...

  4. Vermicompost and biochar as bio-conditioners to immobilize heavy metal and improve soil fertility on cadmium contaminated soil under acid rain stress.

    PubMed

    Wang, Ying; Xu, YongAn; Li, Dan; Tang, BiCong; Man, ShuLei; Jia, YiFan; Xu, Heng

    2018-04-15

    This experiment was conducted to investigate the remediation effects of bio-conditioners vermicompost (VC) and biochar (BC) on cadmium contaminated soil under the threat of acid rain, individually and associatively. With the application of soil conditioners, the percentages of HOAc-extractable Cd decreased 5.2-6.8%, 9.0-13.5% and 7.9-12.1% in the groups amended with VC, BC and VC combined BC, respectively. When the pH of rain decreased from 7.0 to 4.0, the activity of acid phosphatase decreased 2.0%, 12.3%, 3.2%, 14.8% in VC, BC, VC combined BC and control groups, individually. This study affirmed that with the application of soil conditioners, the threat of heavy metal along with bioavailability of Cd was depressed, and the properties of soil biochemical indictors were enhanced. Oppositely, the bioavailability of Cd was promoted, and soil microbial viability as well as nutrient contents was inhibited with the spraying of acid rain. The findings indicated that acid deposition played a restrain effect on soil remediation process. Meanwhile, soil conditioners showed potentials to improve soil fertilities and alleviate the stress of acid rain. Copyright © 2017. Published by Elsevier B.V.

  5. Acid rain and its environmental effects: Recent scientific advances

    USGS Publications Warehouse

    Burns, Douglas A.; Aherne, Julian; Gay, David A.; Lehmann, Christopher M.B.

    2016-01-01

    The term ‘acid rain’ refers to atmospheric deposition of acidic constituents that impact the earth as rain, snow, particulates, gases, and vapor. Acid rain was first recognized by Ducros (1845) and subsequently described by the English chemist Robert Angus Smith (Smith, 1852) whose pioneering studies linked the sources to industrial emissions and included early observations of deleterious environmental effects (Smith, 1872). Smith's work was largely forgotten until the mid-20th century when observations began to link air pollution to the deposition of atmospheric sulfate (SO42−) and other chemical constituents, first near the metal smelter at Sudbury, Ontario, Canada, and later at locations in Europe, North America, and Australia (Gorham, 1961). Our modern understanding of acid rain as an environmental problem caused largely by regional emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) stems from observations in the 1960s and early 1970s in Sweden by Svante Odén (Odén, 1976), and in North America by Gene Likens and colleagues (Likens and Bormann, 1974). These scientists and many who followed showed the link to emissions from coal-fired power plants and other industrial sources, and documented the environmental effects of acid rain such as the acidification of surface waters and toxic effects on vegetation, fish, and other biota.

  6. [Relationship between atmospheric particles and rain water chemistry character].

    PubMed

    Huo, Ming-Qun; Sun, Qian; Xie, Peng; Bai, Yu-Hua; Liu, Zhao-Rong; Li, Ji-Long; Lu, Si-Hua

    2009-11-01

    Rain and atmospheric particle samples were collected in the rural area of Taian and Shenzhen in 2007, respectively. Rain sampling was carried out during the precipitation process and several samples were got from the beginning of one precipitation to the end. The chemical character changes during precipitation and the changes of concentration of particles before and after rain were studied in this research to understand the contribution of particles on the rain chemical character and the rain-out effect for particles. The volume-weighted mean pH of rainwater in Taian was 5.97 and the total concentration of ions was 1 187.96 microeq x L(-1). The mass concentration of PM10 in Taian was 131.76 microg/m3 and that of PM2.5 was 103.84 microg/m3. The volume-weighted mean pH of rainwater in Shenzhen was 4.72 and the total concentration of ions was 175.89 microeq x L(-1). The mass concentration of PM10 in Shenzhen was 56.66 microg/m3 and that of PM2.5 was 41.52 microg/m3. During precipitation process pH and ion concentration of rain decrease and it is shown the neutralizing effect happens. The difference between rainwater of Taian and Shenzhen is due to cloud water acidity, atmospheric particles character and atmospheric acid-basic gases concentration. The clean-up effect of Na+ and Ca2+ by rain is high and which of NH4+ and NO3- is low. The clean-up effect for mass concentration, ions concentration and element concentration of particles by rain are significant.

  7. TECHNOLOGICAL OPTIONS FOR ACID RAIN CONTROL

    EPA Science Inventory

    Discussed are acid rain control options available to the electric utility industry. They include coal switching, flue gas desulfurization, and such emerging lower cost technologies as Limestone Injection Multistage Burners (LIMB) and Advanced Silicate (ADVACATE), both developed ...

  8. Leaf surface and histological perturbations of leaves of Phaseolus vulgaris and Helianthus annuus after exposure to simulated acid rain

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Evans, L.S.; Gmur, N.F.; Da Costa, F.

    1977-08-01

    Initial injury to adaxial leaf surfaces of Phaseolus vulgaris and Helianthus annuus occurred near trichomes and stomata after exposure to simulated sulfate acid rain. Lesion frequency was not correlated with density of either stomata or trichomes but was correlated with degree of leaf expansion. The number of lesions per unit area increased with total leaf area. Results suggest that characteristics of the leaf indumentum such as development of trichomes and guard cells and/or cuticle thickness near these structures may be involved in lesion development. Adaxial epidermal cell collapse was the first event in lesion development. Palisade cells and eventually spongymore » mesophyll cells collapsed after continued, daily exposure to simulated rain of low pH. Lesion development on Phaseolus vulgaris followed a specific course of events after exposure to simulated rain of known composition, application rate, drop size frequency, drop velocities, and frequency of exposures. These results allow development of further experiments to observe accurately other parameters, such as nutrient inputs and nutrient leaching from foliage, after exposure to simulated sulfate acid rain.« less

  9. Acid Rain: A Selective Bibliography. Second Edition. Bibliography Series Twenty-One.

    ERIC Educational Resources Information Center

    O'Neill, Gertrudis, Comp.

    Acid rain is a term for rain, snow, or other precipitation produced from water vapor in the air reacting with emissions from automobiles, factories, power plants, and other oil and coal burning sources. When these chemical compounds, composed of sulfur oxide and nitrogen oxide, react with water vapor, the result is sulfuric acid and nitric acid.…

  10. Acid rain

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Boyle, R.H.; Boyle, R.A.

    1983-01-01

    Acid rain, says Boyle is a chemical leprosy eating into the face of North America and Europe, perhaps the major ecological problem of our time. Boyle describes the causes and scope of the phenomenon; the effects on man, wildlife, water, and our cultural heritage. He probes the delays of politicians and the frequent self-serving arguments advanced by industry in the face of what scientists have proved. The solutions he offers are to strengthen the Clean Air Act and require emission reductions that can be accomplished by establishing emission standards on a regional or bubble basis, burn low-sulfur coal, install scrubbersmore » at critical plants, and invest in alternative energy sources. 73 references, 1 figure.« less

  11. Short-term effects of a simulated acid rain upon the growth and nutrient relations of Pinus strobus, L.

    Treesearch

    Tim Wood; F. H. Bormann

    1976-01-01

    Acidified precipitation may affect the productivity of forests by altering the availability of plant nutrients of by affecting the ability of trees to absorb and assimilate those nutrients. In this study, the short-term effects of simulated acid rain (pH range 5.6 - 2.3) upon the growth and nutrient relations of Eastern White Pine seedlings (Pinus strobus...

  12. Evidence for multiple hydrogen-ion donor systems in rain

    Treesearch

    Sagar V. Krupa; M. R., Jr. Coscio; F. A. Wood

    1976-01-01

    An integrated analytical system consisting of combined scanning electron microscopy and x-ray analysis, atomic absorption, colorimetry and coulometry was used to study rain water chemistry. The coulometry facilitated the determination in molarities of strong and non-volatile and volatile weak acids. The pH of individual rains in St. Paul - Minneapolis, Minnesota ranged...

  13. Effects of acid rain on plant microbial associations in California. Research report (final)

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Harris, D.; Paul, E.A.

    1984-04-13

    The effects of simulated acid rain of pH 5.6 to 3.0, with ionic composition similar to that found in California, on Trifolium repens, Lupinus densiflorus and L. benthamii grown in two soils were tested. The interactions of treatment intensity, soil type, phosphorus uptake and mycorrhizal influences on growth, carbon fixation and allocation and nitrogen fixation were determined. Acidic treatments generally decreased plant growth, nodulation and nitrogenase activity. The exposure of plants to a large number of simulated rainfall conditions of shorter duration did not result in the negative growth effects. Plants adequately supplied with P, either as fertilizer or bymore » mycorrhizal fungi, were much more resistant to conditions caused by acidic precipitation and in some cases growth increases were found.« less

  14. Acid Rain: Resource Materials for Schools.

    ERIC Educational Resources Information Center

    American Biology Teacher, 1983

    1983-01-01

    Provides listings of acid rain resource material groups under: (1) printed materials (pamphlets, books, articles); (2) audiovisuals (slide/tape presentations, tape, video-cassette); (3) miscellaneous (buttons, pocket lab, umbrella); (4) transparencies; (5) bibliographies; and (6) curriculum materials. Sources and prices (when applicable) are…

  15. Learning About Acid Rain: A Teacher's Guide for Grades 6 through 8

    EPA Pesticide Factsheets

    Find on this page a link to the Acid Rain Teacher's Guide for Students Grades 6-8. This guide contains information, class discussions and experiments teachers can use to teach students about acid rain.

  16. Effects of acidic precipitation on host-parasite interactions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Shriner, D.S.

    1974-01-01

    During the past decade, the average acidity of rain and snow increased by 1-2 pH units in many parts of Europe and North America. Little is known of the effects of acid rain resulting from dissolution of sulfur dioxide on biological systems. The effects of simulated sulfuric acid rain on four host-pathogen system were studied. Plants were exposed in greenhouse and field to simulated rain of pH 3.2 or pH 6.0 in amounts and intervals common to weather patterns of the eastern United States. Simulated acid rain resulted in: (1) an 86% inhibition in telia production of Cronartium fusiforme onmore » willow oak (Quercus phellos); (2) a 66% inhibition in the production of root-knot nematodes (Meloidogyne hapla) on field grown kidney beans (Phaseolus vulgaris Red Kidney); (3) a 20% decrease in the severity of Uromyces phaseoli infection of field grown kidney beans; and (4) either stimulated or inhibited development of halo blight on kidney bean (caused by Pseudomonas phaseolicola) depending upon the segment of the disease cycle in which the stress occurred: (a) simulated acid rain before inoculation stimulated disease development; (b) suspension of inoculum in acid rain decreased inoculum potential; and (c) acid rain after infection inhibited disease development. Results suggest that the pH of rain is a new environmental parameter of concern to plant pathologists.« less

  17. 40 CFR 74.3 - Relationship to the Acid Rain program requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Relationship to the Acid Rain program requirements. 74.3 Section 74.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Background and Summary § 74.3 Relationship to the Acid Rain...

  18. 40 CFR 74.3 - Relationship to the Acid Rain program requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Relationship to the Acid Rain program requirements. 74.3 Section 74.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Background and Summary § 74.3 Relationship to the Acid Rain...

  19. 40 CFR 74.3 - Relationship to the Acid Rain program requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Relationship to the Acid Rain program requirements. 74.3 Section 74.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Background and Summary § 74.3 Relationship to the Acid Rain...

  20. 40 CFR 74.3 - Relationship to the Acid Rain program requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Relationship to the Acid Rain program requirements. 74.3 Section 74.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Background and Summary § 74.3 Relationship to the Acid Rain...

  1. 40 CFR 74.3 - Relationship to the Acid Rain program requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Relationship to the Acid Rain program requirements. 74.3 Section 74.3 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) SULFUR DIOXIDE OPT-INS Background and Summary § 74.3 Relationship to the Acid Rain...

  2. TECHNOLOGICAL OPTIONS FOR ACID RAIN CONTROL

    EPA Science Inventory

    The paper discusses technological options for acid rain control. Compliance with Title IV of the Clean Air Act Amendments of 1990 will require careful scrutiny of a number of issues before selecting control options to reduce sulfur dioxide (SO2) and nitrogen oxide (NOx) emissions...

  3. Further emissions cuts needed for speedier acid rain recovery

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    Some people may have thought that the problem of acid deposition, commonly referred to as acid rain, had been solved in the United States with the passage of the Acid Deposition Control Program under Title IV of the 1990 Clean Air Act Amendments (CAAA).Although that legislation has helped to dramatically limit emissions of sulfur dioxide and nitrogen oxide—gases that can react in the atmosphere and form acidic compounds, including fine particles of sulfates and nitrates— much steeper cuts are needed for a quicker recovery from acid rain in the north-eastern United States, according to a new scientific appraisal of the effectiveness of measures called for in that law. The appraisal was issued on March 26 and is entitled “Acidic Deposition in the Northeastern United States: Sources and Inputs, Ecosystem Effects, and Management Strategies.”

  4. Comparative proteomic analysis of differentially expressed proteins in β-aminobutyric acid enhanced Arabidopsis thaliana tolerance to simulated acid rain.

    PubMed

    Liu, Tingwu; Jiang, Xinwu; Shi, Wuliang; Chen, Juan; Pei, Zhenming; Zheng, Hailei

    2011-05-01

    Acid rain is a worldwide environmental issue that has seriously destroyed forest ecosystems. As a highly effective and broad-spectrum plant resistance-inducing agent, β-aminobutyric acid could elevate the tolerance of Arabidopsis when subjected to simulated acid rain. Using comparative proteomic strategies, we analyzed 203 significantly varied proteins of which 175 proteins were identified responding to β-aminobutyric acid in the absence and presence of simulated acid rain. They could be divided into ten groups according to their biological functions. Among them, the majority was cell rescue, development and defense-related proteins, followed by transcription, protein synthesis, folding, modification and destination-associated proteins. Our conclusion is β-aminobutyric acid can lead to a large-scale primary metabolism change and simultaneously activate antioxidant system and salicylic acid, jasmonic acid, abscisic acid signaling pathways. In addition, β-aminobutyric acid can reinforce physical barriers to defend simulated acid rain stress. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Acid Rain Education and Its Implications for Curricular Development: A Teacher Survey.

    ERIC Educational Resources Information Center

    Barrow, Lloyd H.; Germann, Paul

    1987-01-01

    Describes a survey which was designed to obtain information on acid rain education. Reviews results pertaining to instructional time, instructional topics, use of labs from a common resource guide, and preference of materials related to acid rain education. (ML)

  6. Effects of simple rain-shelter cultivation on fatty acid and amino acid accumulation in 'Chardonnay' grape berries.

    PubMed

    Meng, Nan; Ren, Zhi-Yuan; Yang, Xiao-Fan; Pan, Qiu-Hong

    2018-02-01

    Fatty acids and amino acids are the precursors of aliphatic and aromatic volatile compounds, higher alcohols and esters. They are also nutrition for yeast metabolism during fermentation. However, few reports have been concerned about the effect of viticulture practices on the accumulation of fatty acids and amino acids in wine grapes. This study aimed to explore the accumulation of these compounds in developing Vitis vinifera L. cv. Chardonnay grape berries under two vintages, and compare the influences of the rain-shelter cultivation and open-field cultivation. Fifteen fatty acids and 21 amino acids were detected in total. The rain-shelter cultivation led to an increase in the total concentration of fatty acids, and a decrease in the total concentration of amino acids compared with the open-field cultivation in 2012, while no significant difference was observed between two cultivation modes in 2013 vintage. Concentrations of palmitoleic acid, isoleucine and cysteine were significantly promoted in the rain-shelter grape berries, whereas those of tyrosine and ornithine were markedly reduced in both vintages. The rain-shelter cultivation of wine grapes in the rainy region is beneficial for improving grape quality and fermentation activity by influence on the concentration of fatty acids and amino acids. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  7. Photosynthesis and oxidative stress in the restinga plant species Eugenia uniflora L. exposed to simulated acid rain and iron ore dust deposition: potential use in environmental risk assessment.

    PubMed

    Neves, Natália Rust; Oliva, Marco Antonio; da Cruz Centeno, Danilo; Costa, Alan Carlos; Ribas, Rogério Ferreira; Pereira, Eduardo Gusmão

    2009-06-01

    The Brazilian sandy coastal plain named restinga is frequently subjected to particulate and gaseous emissions from iron ore factories. These gases may come into contact with atmospheric moisture and produce acid rain. The effects of the acid rain on vegetation, combined with iron excess in the soil, can lead to the disappearance of sensitive species and decrease restinga biodiversity. The effects of iron ore dust deposition and simulated acid rain on photosynthesis and on antioxidant enzymes were investigated in Eugenia uniflora, a representative shrub species of the restinga. This study aimed to determine the possible utility of this species in environmental risk assessment. After the application of iron ore dust as iron solid particulate matter (SPM(Fe)) and simulated acid rain (pH 3.1), the 18-month old plants displayed brown spots and necrosis, typical symptoms of iron toxicity and injuries caused by acid rain, respectively. The acidity of the rain intensified leaf iron accumulation, which reached phytotoxic levels, mainly in plants exposed to iron ore dust. These plants showed the lowest values for net photosynthesis, stomatal conductance, transpiration, chlorophyll a content and electron transport rate through photosystem II (PSII). Catalase and superoxide dismutase activities were decreased by simulated acid rain. Peroxidase activity and membrane injury increased following exposure to acid rain and simultaneous SPM(Fe) application. Eugenia uniflora exhibited impaired photosynthetic and antioxidative metabolism in response to combined iron and acid rain stresses. This species could become a valuable tool in environmental risk assessment in restinga areas near iron ore pelletizing factories. Non-invasive evaluations of visual injuries, photosynthesis and chlorophyll a fluorescence, as well as invasive biochemical analysis could be used as markers.

  8. EFFECT OF SIMULATED SULFURIC ACID RAIN ON THE CHEMISTRY OF A SULFATE-ADSORBING FOREST SOIL

    EPA Science Inventory

    Simulated H2SO4 rain (pH 3.0, 3.5, 4.0) or control rain (pH 5.6) was applied for 3.5 yr to large lysimeter boxes containing a sulfate-adsorbing forest soil and either red alder (Alnus rubra) or sugar maple (Acer saccharum) seedlings. After removal of the plants and the litter lay...

  9. Effects of simulated acid rain on soil respiration and its components in a subtropical mixed conifer and broadleaf forest in southern China.

    PubMed

    Liang, Guohua; Hui, Dafeng; Wu, Xiaoying; Wu, Jianping; Liu, Juxiu; Zhou, Guoyi; Zhang, Deqiang

    2016-02-01

    Soil respiration is a major pathway in the global carbon cycle and its response to environmental changes is an increasing concern. Here we explored how total soil respiration (RT) and its components respond to elevated acid rain in a mixed conifer and broadleaf forest, one of the major forest types in southern China. RT was measured twice a month in the first year under four treatment levels of simulated acid rain (SAR: CK, the local lake water, pH 4.7; T1, water pH 4.0; T2, water pH 3.25; and T3, water pH 2.5), and in the second year, RT, litter-free soil respiration (RS), and litter respiration (RL) were measured simultaneously. The results indicated that the mean rate of RT was 2.84 ± 0.20 μmol CO2 m(-2) s(-1) in the CK plots, and RS and RL contributed 60.7% and 39.3% to RT, respectively. SAR marginally reduced (P = 0.08) RT in the first year, but significantly reduced RT and its two components in the second year (P < 0.05). The negative effects were correlated with the decrease in soil microbial biomass and fine root biomass due to soil acidification under the SAR. The temperature coefficients (Q10) of RT and its two components generally decreased with increasing levels of the SAR, but only the decrease of RT and RL was significant (P < 0.05). In addition, the contribution of RL to RT decreased significantly under the SAR, indicating that RL was more sensitive to the SAR than RS. In the context of elevated acid rain, the decline trend of RT in the forests in southern China appears to be attributable to the decline of soil respiration in the litter layer.

  10. 76 FR 71559 - Acid Rain Program: Notice of Annual Adjustment Factors for Excess Emissions Penalty

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-18

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9494-6] Acid Rain Program: Notice of Annual Adjustment... annual adjustment factors for excess emissions penalty. SUMMARY: The Acid Rain Program under title IV of... emissions for sources that do not meet their annual Acid Rain emissions limitations. This notice states the...

  11. 78 FR 64496 - Acid Rain Program: Notice of Annual Adjustment Factors for Excess Emissions Penalty

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-29

    ... ENVIRONMENTAL PROTECTION AGENCY [FRL-9902-14-OAR] Acid Rain Program: Notice of Annual Adjustment... annual adjustment factors for excess emissions penalty. SUMMARY: The Acid Rain Program under title IV of... emissions for sources that do not meet their annual Acid Rain emissions limitations. This notice states the...

  12. STATE ACID RAIN RESEARCH AND SCREENING SYSTEM - VERSION 1.0 USER'S MANUAL

    EPA Science Inventory

    The report is a user's manual that describes Version 1.0 of EPA's STate Acid Rain Research and Screening System (STARRSS), developed to assist utility regulatory commissions in reviewing utility acid rain compliance plans. It is a screening tool that is based on scenario analysis...

  13. Acid Rain. Teacher's Guide. LHS GEMS.

    ERIC Educational Resources Information Center

    Hocking, Colin; Barber, Jacqueline; Coonrod, Jan

    This teacher's guide presents a unit on acid rain and introduces hands-on activities for sixth through eighth grade students. In each unit, students act as real scientists and gather evidence by using science process skills such as observing, measuring and recording data, classifying, role playing, problem solving, critical thinking, synthesizing…

  14. Acid Rain: A Resource Guide for Classroom, Laboratory, Field, and Debate Topics.

    ERIC Educational Resources Information Center

    Stoss, Frederick W.

    1987-01-01

    Provides a partially annotated bibliography of journals and book chapters which deal with acid rain. Includes selections which provide background information, ideas for introducing acid rain into science or social studies curricula, inventories of audio-visual aids, and non-print media to supplement classroom, laboratory, and field instruction.…

  15. [Effects of simulating acid rain on photosynthesis and chlorophyll fluorescence parameters of Quercus glauca Quercus glauca].

    PubMed

    Wang, Sai; Yi, Li-Ta; Yu, Shu-Quan; Zhang, Chao; Shi, Jing-Jing

    2014-08-01

    At three levels of simulated acid rainfall intensities with pH values of 2.5 (severe), 40 (medium) and 5.6 (light) respectively, the responses of chlorophyll fluorescence and photosynthetic parameters of Quercus glauca seedlings were studied in three acid rainfall treatments, i. e. only the aboveground of seedlings exposed to acid rain (T1), both of the seedlings and soil exposed to acid rain (T2), only the soil exposed to acid rain (T3) compared with blank control (CK). Under the severe acid rainfall, T1 significantly inhibited chlorophyll synthesis, and thus reduced the primary photochemical efficiency of PS II ( F(v)/F(m)), potential activity of PS II (F(v)/F(o)) , apparent quantum (Y), net photosynthetic rate (P(n)), and transpiration rate (T(r)), but increased the light compensation point (LCP) and dark respiration rate (R(d)) of Q. glauca seedlings. T2 inhibited, but T3 played a little enhancement on the aforementioned parameters of Q. glauca seedlings. Under the conditions of medium and light acid rainfall intensities, the above parameters in the three treatments were higher than that of CK, except with lower R(d). The chlorophyll fluorescence and photosynthetic parameters showed a similar tendency in the three treatments, i. e. T2>T3 >T1. It indicated that T1 had the strongest inhibition on seedlings in condition of the severe acid rainfall, while T2 had the most dramatic facilitating effect on seedlings under the medium and light acid rainfall. Intensity of acid rainfall had significant influences on SPAD, F(v)/F(m), F(v)/F(o), Y, P(n), T(r), and maximum photosynthetic rate (A(max)), whereas treatments of acid rainfall affected SPAD, F(v)/F(m), Y, P(n), T(r), A(max) and light saturation point (LSP). The interaction of acid rainfall intensities and treatments played significant effects on SPAD, F(v)/F(m), Y, P(n) and A(max).

  16. Interactive effects of cadmium and acid rain on photosynthetic light reaction in soybean seedlings.

    PubMed

    Sun, Zhaoguo; Wang, Lihong; Chen, Minmin; Wang, Lei; Liang, Chanjuan; Zhou, Qing; Huang, Xiaohua

    2012-05-01

    Interactive effects of cadmium (Cd(2+)) and acid rain on photosynthetic light reaction in soybean seedlings were investigated under hydroponic conditions. Single treatment with Cd(2+) or acid rain and the combined treatment decreased the content of chlorophyll, Hill reaction rate, the activity of Mg(2+)-ATPase, maximal photochemical efficiency and maximal quantum yield, increased initial fluorescence and damaged the chloroplast structure in soybean seedlings. In the combined treatment, the change in the photosynthetic parameters and the damage of chloroplast structure were stronger than those of any single pollution. Meanwhile, Cd(2+) and acid rain had the interactive effects on the test indices in soybean seedlings. The results indicated that the combined pollution of Cd(2+) and acid rain aggravated the toxic effect of the single pollution of Cd(2+) or acid rain on the photosynthetic parameters due to the serious damage to the chloroplast structure. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Acid rain controls through the back door

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Not Available

    The paper briefly discusses the regulatory policy changes being proposed for acid rain control. Court rulings requiring the EPA to order reductions of sulfur dioxide emissions from power plants are described. Costs to utilities, and ultimately consumers, are also considered.

  18. A Demonstration of Acid Rain and Lake Acidification: Wet Deposition of Sulfur Dioxide.

    ERIC Educational Resources Information Center

    Goss, Lisa M.

    2003-01-01

    Introduces a science demonstration on the dissolution of sulfuric oxide emphasizing the concept of acid rain which is an environmental problem. Demonstrates the acidification from acid rain on two lake environments, limestone and granite. Includes safety information. (YDS)

  19. Sex Differences in Environmental Concern and Knowledge: The Case of Acid Rain.

    ERIC Educational Resources Information Center

    Arcury, Thomas A.; And Others

    1987-01-01

    Presents results of a telephone survey of 516 adults which focused on sex differences in concern and knowledge about one environmental issue, acid rain. The findings contradict predictions that women are more concerned about environmental issues: if there is a sex difference, men are found to be more concerned and knowledgeable about acid rain.…

  20. Characterization and Evaluation of Acid Rain in East Central Florida from 1978 to 1995 and Evaluation of Some Chromatographic/Spectroscopic Results from Leachate Samples from CELSS

    NASA Technical Reports Server (NTRS)

    Madsen, Brooks C.

    1996-01-01

    The results of monitoring the chemical composition of rain in east-central Florida have shown that the rain is moderately acid. The measured acidity of rain is less than that observed in other regions of the U. S., however, it does suggest that the level of acidity is substantial. The annual chemical composition of rain at UCF and at KSC has shown moderate variability. Extreme daily and monthly variations are observed, however these variations are not addressed here. The total ionic composition of rain collected at FL99 is greater than that for rain collected at UCF, however this can be accounted for by site proximity to the ocean with the accompanying marine influence. Difference in acidity data collected from the UCF and FL99 sites which are separated by 50 km may be due in part to the differences that have been observed between laboratory and field pH measurements. Trend assessment for precipitation composition requires evaluation of data that covers some minimum time period. In fact, the subdivision of the multi-year UCF record into individual 10 year records as described above can lead to the conclusion that a significant increase, a significant decrease or no trend exists for acidity depending upon the time period chosen for evaluation. Trend evaluation has also been accomplished by linear and nonlinear regression analysis using monthly volume weighted average concentrations and deposition using the UCF data set and some of the Florida NADP data set.

  1. Correlation between microstructural characteristics and weight loss of natural stones exposed to simulated acid rain.

    PubMed

    Franzoni, Elisa; Sassoni, Enrico

    2011-12-15

    The correlation between stone microstructural characteristics and material degradation (in terms of weight loss), in given environmental conditions, was investigated. Seven lithotypes, having very different microstructural characteristics, were used. Four acidic aqueous solutions were prepared to simulate acid rain (two adding H(2)SO(4) and two adding HNO(3) to deionized water, in order to reach, for each acid, pH values of 5.0 and 4.0), and deionized water at pH=5.6 was used to simulate clean rain. Stone samples were then immersed in such aqueous solutions, the surface alteration being periodically inspected and the weight loss periodically measured. After 14 days of immersion, a good correlation was found between weight loss and the product of carbonate content and specific surface area in the starting materials. This was explained considering that this product accounts for the weight loss owing to the sample's fraction actually composed of calcite (the most soluble fraction) and the effective surface area exposed to dissolving solution (which depends on stone porosity and pore size distribution). Such correlation between stone microstructure and degradation may be useful for comparing the durability of different lithotypes, in given environmental conditions, and quantitatively predicting the weight loss of a lithotype, compared to another one. Hence, the correlation found in this study may be used to specifically tailor to various stone types, with different microstructural characteristics, some results that have been calculated in literature for specific stone types and then proposed as possibly representative for a broad category of stones with similar characteristics. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Biochemical responses of the mycorrhizae in Pinus massoniana to combined effects of Al, Ca and low pH.

    PubMed

    Kong, F X; Liu, Y; Hu, W; Shen, P P; Zhou, C L; Wang, L S

    2000-02-01

    Biochemical responses of Pinus massoniana, with and without the inoculation mycorrhizal fungus Pisolithus tinctorius at the root, to artificial acid rain (pH 2.0) and various Ca/Al ratios were investigated. Some enzymes associated with the nutritive metabolism, such as acid phosphatase, alkaline phosphatase, nitrate reductase, mannitol dehydrogenase and trehalase, in the roots, stems and leaves of plant were obviously inhibited by the artificial acid rain and Al. After treatment with pH 2.0 + Ca/Al (0/1 or 1/10) artificial acid rain, the protein content in the organs was decreased. However, the activities of superoxide dismutase (SOD) and peroxidase (POD) and glutathione (GSH) concentrations were induced. It demonstrated that acid rain and Al could induce oxygen radicals in plant. Compared with the treatments with lower pH or Al, respectively, the combination of lower pH and Al concentration was more toxic to P. massoniana. Al toxicity could be ameliorated by the addition of Ca and the amelioration was the most when the ratio was 1/1 among the various Ca/Al ratio. Infection with mycorrhizal fungus P. tinctorius at the root of P. massoniana increased the ability of the plant to resist the toxicity of artificial acid rain and Al stress.

  3. EFFECTS OF SIMULATED ACIDIC RAIN APPLIED ALONE AND IN COMBINATION WITH AMBIENT RAIN ON GROWTH AND YIELD OF FIELD-GROWN SNAP BEAN

    EPA Science Inventory

    Field-grown snap bean plants were treated with simulated acidic rain applied either alone or in combination with ambient rain and the effects on growth and yield were determined. In plots where ambient rain was excluded, a retractable canopy was activated to shield the crop. Four...

  4. Protective effect of Mn(III)-desferrioxamine B upon oxidative stress caused by ozone and acid rain in the Brazilian soybean cultivar Glycine max "Sambaiba".

    PubMed

    Esposito, Jéssica Bordotti Nobre; Esposito, Breno Pannia; Azevedo, Ricardo Antunes; Cruz, Luciano Soares; da Silva, Luzimar Campos; de Souza, Silvia Ribeiro

    2015-04-01

    This study aimed to investigate the effects of the Mn complex (Mn(III)-desferrioxamine B (MnDFB)) on oxidative stress in the Brazilian soybean cultivar Glycine max "Sambaiba" following exposure to ozone and acid rain. We determined the suitable dose of MnDFB to apply to G. max seedlings using a dose-response curve. The highest superoxide dismutase (SOD) activity and Mn content in leaves were found upon the application of 8 μM MnDFB. Thus, G. max seedlings pretreated with 8 μM MnDFB were individually exposed to ozone and acid rain simulated. Pretreatment with MnDFB reduced lipid peroxidation upon ozone exposure and increased SOD activity in leaves; it did not alter the metal content in any part of the plant. Conversely, following acid rain exposure, neither the metal content in leaves nor SOD enzyme activity were directly affected by MnDFB, unlike pH. Our findings demonstrated that exogenous MnDFB application before ozone exposure may modulate the MnSOD, Cu/ZnSOD, and FeSOD activities to combat the ROS excess in the cell. Here, we demonstrated that the applied dose of MnDFB enhances antioxidative defenses in soybean following exposure to acid rain and especially to ozone.

  5. Effects of simulated acid rain on soil and soil solution chemistry in a monsoon evergreen broad-leaved forest in southern China.

    PubMed

    Qiu, Qingyan; Wu, Jianping; Liang, Guohua; Liu, Juxiu; Chu, Guowei; Zhou, Guoyi; Zhang, Deqiang

    2015-05-01

    Acid rain is an environmental problem of increasing concern in China. In this study, a laboratory leaching column experiment with acid forest soil was set up to investigate the responses of soil and soil solution chemistry to simulated acid rain (SAR). Five pH levels of SAR were set: 2.5, 3.0, 3.5, 4.0, and 4.5 (as a control, CK). The results showed that soil acidification would occur when the pH of SAR was ≤3.5. The concentrations of NO₃(-)and Ca(2+) in the soil increased significantly when the pH of SAR fell 3.5. The concentration of SO₄(2-) in the soil increased significantly when the pH of SAR was <4.0. The effects of SAR on soil solution chemistry became increasingly apparent as the experiment proceeded (except for Na(+) and dissolved organic carbon (DOC)). The net exports of NO₃(-), SO₄(2-), Mg(2+), and Ca(2+) increased about 42-86% under pH 2.5 treatment as compared to CK. The Ca(2+) was sensitive to SAR, and the soil could release Ca(2+) through mineral weathering to mitigate soil acidification. The concentration of exchangeable Al(3+) in the soil increased with increasing the acidity of SAR. The releases of soluble Al and Fe were SAR pH dependent, and their net exports under pH 2.5 treatment were 19.6 and 5.5 times, respectively, higher than that under CK. The net export of DOC was reduced by 12-29% under SAR treatments as compared to CK. Our results indicate the chemical constituents in the soil are more sensitive to SAR than those in the soil solution, and the effects of SAR on soil solution chemistry depend not only on the intensity of SAR but also on the duration of SAR addition. The soil and soil solution chemistry in this region may not be affected by current precipitation (pH≈4.5) in short term, but the soil and soil leachate chemistry may change dramatically if the pH of precipitation were below 3.5 and 3.0, respectively.

  6. Variation in pH optima of hydrolytic enzyme activities in tropical rain forest soils.

    PubMed

    Turner, Benjamin L

    2010-10-01

    Extracellular enzymes synthesized by soil microbes play a central role in the biogeochemical cycling of nutrients in the environment. The pH optima of eight hydrolytic enzymes involved in the cycles of carbon, nitrogen, phosphorus, and sulfur, were assessed in a series of tropical forest soils of contrasting pH values from the Republic of Panama. Assays were conducted using 4-methylumbelliferone-linked fluorogenic substrates in modified universal buffer. Optimum pH values differed markedly among enzymes and soils. Enzymes were grouped into three classes based on their pH optima: (i) enzymes with acidic pH optima that were consistent among soils (cellobiohydrolase, β-xylanase, and arylsulfatase), (ii) enzymes with acidic pH optima that varied systematically with soil pH, with the most acidic pH optima in the most acidic soils (α-glucosidase, β-glucosidase, and N-acetyl-β-glucosaminidase), and (iii) enzymes with an optimum pH in either the acid range or the alkaline range depending on soil pH (phosphomonoesterase and phosphodiesterase). The optimum pH values of phosphomonoesterase were consistent among soils, being 4 to 5 for acid phosphomonoesterase and 10 to 11 for alkaline phosphomonoesterase. In contrast, the optimum pH for phosphodiesterase activity varied systematically with soil pH, with the most acidic pH optima (3.0) in the most acidic soils and the most alkaline pH optima (pH 10) in near-neutral soils. Arylsulfatase activity had a very acidic optimum pH in all soils (pH ≤3.0) irrespective of soil pH. The differences in pH optima may be linked to the origins of the enzymes and/or the degree of stabilization on solid surfaces. The results have important implications for the interpretation of hydrolytic enzyme assays using fluorogenic substrates.

  7. Acid Rain: A Description of Bilingual Friesland.

    ERIC Educational Resources Information Center

    Zondag, Koen

    1984-01-01

    Using acid rain as a metaphor, discusses the status of the Frisian language and culture as one which, though apparently thriving, is really threatened. Examines the sources of this threat, i.e., the education system, the church, mass communication and transportation, and the demise of the Frisian village community. (SED)

  8. European views on controlling acid rain. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Fay, J.A.

    The National Governors Association (NGA) will be considering a plan for alleviating acid rain effects by reduction of emissions of sulfur and nitrogen oxides. This plan, in some respects similar to current legislative proposals in Congress, was formulated by the northeastern governors with administrative support from the Commonwealth of Massachusetts. Lt. Governor John Kerry has undertaken to prepare this plan for consideration by the NGA. In order to provide a better understanding of how other industrialized nations are dealing with the acid rain problem, the office of Lt. Gov. Kerry arranged for a tour of European countries during the weekmore » beginning 10 January 1984. Norway, Sweden, the Federal Republic of Germany (FRG), Belgium and the United Kingdom (UK) were visited, as well as the Commission of the European Communities (EEC) in Brussels.« less

  9. Combined effects of lanthanum ion and acid rain on growth, photosynthesis and chloroplast ultrastructure in soybean seedlings.

    PubMed

    Wen, Kejia; Liang, Chanjuan; Wang, Lihong; Hu, Gang; Zhou, Qing

    2011-07-01

    Rare earth elements (REEs) have been accumulated in the agricultural environment. Acid rain is a serious environmental issue. In the present work, the effects of lanthanum ion (La(3+)) and acid rain on the growth, photosynthesis and chloroplast ultrastructure in soybean seedlings were investigated using the gas exchange measurements system, chlorophyll fluorometer, transmission electron microscopy and some biochemical techniques. It was found that although the growth and photosynthesis of soybean seedlings treated with the low concentration of La(3+) was improved, the growth and photosynthesis of soybean seedlings were obviously inhibited in the combined treatment with the low concentration of La(3+) and acid rain. At the same time, the chloroplast ultrastructure in the cell of soybean seedlings was destroyed. Under the combined treatment with the high concentration of La(3+) and acid rain, the chloroplast ultrastructure in the cell of soybean seedlings was seriously destroyed, and the growth and of photosynthesis were greatly decreased compared with those of the control, the single treatment with the high concentration of La(3+) and the single treatment with acid rain, respectively. The degree of decrease and destruction on chloroplast ultrastructure depended on the increases in the concentration of La(3+) and acid rain (H(+)). In conclusion, the combined pollution of La(3+) and acid rain obviously destroyed the chloroplast ultrastructure of cell and aggravated the harmful effect of the single La(3+) and acid rain on soybean seedlings. As a new combined pollutant, the harmful effect of REEs ions and acid rain on plant should be paid attention to. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. A Gaming Approach to the Acid Rain Problem.

    ERIC Educational Resources Information Center

    Baba, Norio; And Others

    1984-01-01

    Describes an educational microcomputer gaming system for dealing with the acid rain problem in Western Europe and discusses its objectives, rules, problems, and future perspectives. Usefulness of gaming as an operational aid in formulating appropriate energy policies worldwide is emphasized. (MBR)

  11. The combined effects of urea application and simulated acid rain on soil acidification and microbial community structure.

    PubMed

    Liu, Xingmei; Zhou, Jian; Li, Wanlu; Xu, Jianming; Brookes, Philip C

    2014-05-01

    Our aim was to test the effects of simulated acid rain (SAR) at different pHs, when applied to fertilized and unfertilized soils, on the leaching of soil cations (K, Ca, Mg, Na) and Al. Their effects on soil pH, exchangeable H(+) and Al(3+) and microbial community structure were also determined. A Paleudalfs soil was incubated for 30 days, with and without an initial application of urea (200 mg N kg(-1)soil) as nitrogen (N) fertilizer. The soil was held in columns and leached with SAR at three pH levels. Six treatments were tested: SAR of pH 2.5, 4.0 and 5.6 leaching on unfertilized soil (T1, T2 and T3), and on soils fertilized with urea (T4, T5 and T6). Increasing acid inputs proportionally increased cation leaching in both unfertilized and fertilized soils. Urea application increased the initial Ca and Mg leaching, but had no effect on the total concentrations of Ca, Mg and K leached. There was no significant difference for the amount of Na leached between the different treatments. The SAR pH and urea application had significant effects on soil pH, exchangeable H(+) and Al(3+). Urea application, SAR treated with various pH, and the interactions between them all had significant impacts on total phospholipid fatty acids (PLFAs). The highest concentration of total PLFAs occurred in fertilized soils with SAR pH5.6 and the lowest in soils leached with the lowest SAR pH. Soils pretreated with urea then leached with SARs of pH 4.0 and 5.6 had larger total PLFA concentrations than soil without urea. Bacterial, fungal, actinomycete, Gram-negative and Gram-positive bacterial PLFAs had generally similar trends to total PLFAs.

  12. Gypsy moth (Lepidoptera: Lymantriidae) consumption and utilization of northern red oak and white oak foliage exposed to simulated acid rain and ozone

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Cannon, W.N. Jr.

    1993-06-01

    Two-year-old seedlings of white oak, Quercus alba L., and red oak, Q. rubra L., were exposed to ozone (O[sub 3]) fumigations in four continuously stirred tank reactor chambers in the greenhouse for 8 h/d, 3 d/wk for 6 wk. Fumigation treatments were charcoal-filtered air (CFA) and CFA + 0.15 ppm O[sub 3]. Two simulated rain treatments, pH 4.2 and pH 3.0, of-1.25 cm were applied once each week in rain-simulation chambers. Gypsy moth, Lymantria dispar (L.), third instars were allowed to feed on leaf disks from treated seedlings for 24 h. Leaf area consumed, food assimilated, weight gain, and relativemore » growth rate (RGR) were examined. Overall, larvae fed white oak foliage consumed more foliage and gained more weight than those fed red oak foliage. Response to the fumigation and rain treatments was different for each oak species. On white oak foliage, larvae consumed significantly less foliage treated with CFA + pH 3.0 rain, but the lowest RGR occurred with the 0.15 ppm O[sub 3] + pH 4.2 rain treatment. The most food assimilated, greatest weight gain, and highest RGR occurred with the CFA + pH 4.2 rain control. Red oak foliage consumed was equivalent for all treatments, but foliage exposed to CFA + pH 3.0 rain resulted in more food assimilated, greater weight gain, and higher RGR for that species.« less

  13. Calcium affecting protein expression in longan under simulated acid rain stress.

    PubMed

    Pan, Tengfei; Li, Yongyu; Ma, Cuilan; Qiu, Dongliang

    2015-08-01

    Longan (Dimocarpus longana Lour. cv. Wulongling) of uniform one-aged seedlings grown in pots were selected to study specific proteins expressed in leaves under simulated acid rain (SiAR) stress and exogenous Ca(2+) regulation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results showed that there was a protein band specifically expressed under SiAR of pH 2.5 stress for 15 days with its molecular weight of about 23 kD. A 17 kD protein band specifically expressed after SiAR stress 5 days. Compared with pH 2.5, the pH 3.5 of SiAR made a less influence to protein expression. Two-dimensional electrophoresis (2-DE) results showed that six new specific proteins including C4 (20.2 kD pI 6.0), F (24 kD pI 6.35), B3 (22.3 kD pI 6.35), B4 (23.5 kD pI 6.5), C5 (21.8 kD pI 5.6), and C6 (20.2 kD pI 5.6) specifically expressed. C4 always expressed during SiAR stress. F expressed under the stress of pH 2.5 for 15 days and expressed in all pH SiAR stress for 20 days. The expression of proteins including B3, C5, and C6 was related to pH value and stress intensity of SiAR. The expression of B4 resulted from synergistic effects of SiAR and Ca. The expression of G1 (Mr 19.3 kD, pI 4.5), G2 (Mr 17.8 kD, pI 4.65), G3 (Mr 16.6 kD, pI 4.6), and G4 (Mr 14.7 kD, pI 4.4) enhanced under the treatment of 5 mM ethylene glycol tetraacetic acid (EGTA) and 2 mM chlorpromazine (CPZ). These proteins showed antagonistic effects and might be relative to the Ca-calmodulin (Ca-CaM) system of longan in response to SiAR stress.

  14. Acid Rain: Science Projects.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.

    1989-01-01

    Presented is a science activity designed to help students monitor the pH of rainfall. Materials, procedures and follow-up activities are listed. A list of domestic and foreign sources of information is provided. Topics which relate to acid precipitation are outlined. (CW)

  15. Acid rain impacts on calcium nutrition and forest health

    Treesearch

    Donald H. DeHayes; Paul G. Schaberg; Gary J. Hawley; G. Richard Strimbeck

    1999-01-01

    Forest ecosystems throughout the world are exposed to acid rain, a complex solution consisting largely of H+, SO42-, NH4+, and NO3- pollutant ions derived from sulfur and nitrogen oxides. Although the public in...

  16. A Simulation of the Interaction of Acid Rain with Soil Minerals

    ERIC Educational Resources Information Center

    Schilling, Amber L.; Hess, Kenneth R.; Leber, Phyllis A.; Yoder, Claude H.

    2004-01-01

    The atmospheric issue of acid rains is subjected to a five-part laboratory experiment by concentrating on the chemistry of the infiltration process of acid rainwater through soils. This procedure of quantitative scrutiny helps students realize the efficacy of soil minerals in the consumption of surplus acidity in rainwater.

  17. Acid loading test (pH)

    MedlinePlus

    ... medlineplus.gov/ency/article/003615.htm Acid loading test (pH) To use the sharing features on this page, please enable JavaScript. The acid loading test (pH) measures the ability of the kidneys to send ...

  18. Desorption of 137Cs from Brachythecium mildeanum moss using acid solutions with pH 4.60-6.50

    NASA Astrophysics Data System (ADS)

    Čučulović, Ana; Veselinović, Dragan

    2015-12-01

    The desorption of 137Cs from the moss Brachythecium mildeanum (Schimp.) was performed using the following solutions: H2SO4 ( I), HNO3 ( II), H2SO4 + HNO3 ( III) with pH values of 4.60, 5.15, and 5.75, respectively, as well as distilled water (D) with pH 6.50. After five successive desorptions, each lasting 24 h, 20.5-37.6% 137Cs was desorbed from the moss using these solutions, while 30.7% of the starting content was desorbed using distilled water. The first desorption removed the highest percent of the original content of 137Cs in the moss (11.3-18.4%). This was determined by measuring 137Cs activity. If the current results are compared with those obtained earlier it may be concluded that 137Cs desorption from mosses is not species-dependent. The obtained results indicate the necessity of investigating the influence of acid rain, or rather, of H+ ions, on desorption of other ions from biological systems, i.e., the role of H+ ions in spreading other polluting compounds and thus producing secondary environmental pollution. From the results of this study it follows that acid rain will lead, through H+ ion action, to a similar increasing pollution of fallout waters with other ionic compounds which may not be present in the water before the contact with the plants and thus enable the pollution spreading. In the investigated system, the replacement of H+ ions from acid rains by more dangerous radioactive ions occured, increasing the concentration of the radioactive ions in the water, which demonstrates that the same process takes place in fallout water.

  19. Effects and mechanisms of the combined pollution of lanthanum and acid rain on the root phenotype of soybean seedlings.

    PubMed

    Sun, Zhaoguo; Wang, Lihong; Zhou, Qing; Huang, Xiaohua

    2013-09-01

    Rare earth pollution and acid rain pollution are both important environmental issues worldwide. In regions which simultaneously occur, the combined pollution of rare earth and acid rain becomes a new environmental issue, and the relevant research is rarely reported. Accordingly, we investigated the combined effects and mechanisms of lanthanum ion (La(3+)) and acid rain on the root phenotype of soybean seedlings. The combined pollution of low-concentration La(3+) and acid rain exerted deleterious effects on the phenotype and growth of roots, which were aggravated by the combined pollution of high-concentration La(3+) and acid rain. The deleterious effects of the combined pollution were stronger than those of single La(3+) or acid rain pollution. These stronger deleterious effects on the root phenotype and growth of roots were due to the increased disturbance of absorption and utilization of mineral nutrients in roots. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Effect of simulated acid rain on fluorine mobility and the bacterial community of phosphogypsum.

    PubMed

    Wang, Mei; Tang, Ya; Anderson, Christopher W N; Jeyakumar, Paramsothy; Yang, Jinyan

    2018-06-01

    Contamination of soil and water with fluorine (F) leached from phosphogypsum (PG) stacks is a global environmental issue. Millions of tons of PG is produced each year as a by-product of fertilizer manufacture, and in China, weathering is exacerbated by acid rain. In this work, column leaching experiments using simulated acid rain were run to evaluate the mobility of F and the impact of weathering on native bacterial community composition in PG. After a simulated summer rainfall, 2.42-3.05 wt% of the total F content of PG was leached and the F concentration in leachate was above the quality standard for surface water and groundwater in China. Acid rain had no significant effect on the movement of F in PG. A higher concentration of F was observed at the bottom than the top section of PG columns suggesting mobility and reprecipitation of F. Throughout the simulation, the PG was environmentally safe according the TCLP testing. The dominant bacteria in PG were from the Enterococcus and Bacillus genus. Bacterial community composition in PG leached by simulated acid rain (pH 3.03) was more abundant than at pH 6.88. Information on F mobility and bacterial community in PG under conditions of simulated rain is relevant to management of environmental risk in stockpiled PG waste.

  1. Acid rain, air pollution, and tree growth in southeastern New York

    USGS Publications Warehouse

    Puckett, L.J.

    1982-01-01

    Whether dendroecological analyses could be used to detect changes in the relationship of tree growth to climate that might have resulted from chronic exposure to components of the acid rain-air pollution complex was determined. Tree-ring indices of white pine (Pinus strobus L.), eastern hemlock (Tsuga canadensis (L.) Cart.), pitch pine (Pinus rigida Mill.), and chestnut oak (Quercus prinus L.) were regressed against orthogonally transformed values of temperature and precipitation in order to derive a response-function relationship. Results of the regression analyses for three time periods, 1901–1920, 1926–1945, and 1954–1973 suggest that the relationship of tree growth to climate has been altered. Statistical tests of the temperature and precipitation data suggest that this change was nonclimatic. Temporally, the shift in growth response appears to correspond with the suspected increase in acid rain and air pollution in the Shawangunk Mountain area of southeastern New York in the early 1950's. This change could be the result of physiological stress induced by components of the acid rain-air pollution complex, causing climatic conditions to be more limiting to tree growth.

  2. Spatial characterization of acid rain stress in Canadian Shield Lakes

    NASA Technical Reports Server (NTRS)

    Tanis, Fred J.

    1987-01-01

    The acidification of lake waters from airborne pollution is of continental proportions both in North America and Europe. A major concern of the acid rain problem is the cumulative ecosystem damage to lakes and forest. The number of lakes affected in northeastern U.S. and on the Canadian Shield is though to be enormous. How seasonal changes in lake transparency are related to annual acidic load was examined. The relationship between variations in lake acidification and ecophysical units was also examined. The utility of Thematic Mapper based observations to measure seasonal changes in the optical transparency in acid lakes was investigated. The potential for this optical response is related to a number of local ecophysical factors with bedrock geology being, perhaps, the most important. Other factors include sulfate deposition, vegetative cover, and terrain drainage/relief. The area of southern Ontario contains a wide variety of geologies from the most acid rain sensitive granite quartzite types to the least sensitive limestone dolomite sediments. Annual sulfate deposition ranges from 1.0 to 4.0 grams/sq m.

  3. Acid Rain - This cloud has no silver lining

    Treesearch

    Gail Michaels

    2000-01-01

    Twenty years ago, acid rain was the environmental cause du jour, a symptom of all that was wrong with humans and their relationship to the environment. Its discovery was accidental, ironic for what turned out to be such a wide-ranging problem. "Hub" Vogelman, a University of Vermont botanist, noticed something troubling in the precipitation data he and his...

  4. Acid Rain: Federal Policy Action 1983-1985. A Guide to Government Documents and Commercial Sources.

    ERIC Educational Resources Information Center

    Lovenburg, Susan, Comp.

    The problems associated with acid rain as well as strategies on what to do and how to do it are addressed in this resource guide. The first section identifies and describes the U.S. agencies and congressional committees which play a role in acid rain research, legislation, and regulation. Actions already taken by the executive and legislative…

  5. The role of calcium in improving photosynthesis and related physiological and biochemical attributes of spring wheat subjected to simulated acid rain.

    PubMed

    Dolatabadian, Aria; Sanavy, Seyed Ali Mohammad Modarres; Gholamhoseini, Majid; Joghan, Aydin Khodaei; Majdi, Mohammad; Kashkooli, Arman Beyraghdar

    2013-04-01

    The response of photosynthesis parameters, catalase, superoxide dismutase and peroxidase activity, malondialdehyde, proline, chlorophyll, yield and yield components to foliar application of calcium and simulated acid rain in wheat were investigated. Foliar treatment of calcium led to significant increases in the photosynthesis rate, transpiration rate, stomatal conductance, proline, chlorophyll, yield and yield components in plants subjected to acid rain. Antioxidant enzyme activity and lipid peroxidation in the wheat leaves decreased because of calcium foliar application. Calcium hindered degradation of the rubisco subunits under acid rain treatment compared with water-treated plants. Results suggest that acid rain induces the production of free radicals resulting in lipid peroxidation of the cell membrane so that significant increase in antioxidant enzyme activity was observed. In addition, photosynthetic parameters i.e. photosynthesis rate, transpiration rate and stomatal conductance were drastically suppressed by acid rain. The cellular damage caused by free radicals might be reduced or prevented by a protective metabolism including antioxidative enzymes and calcium. We report that foliar application of calcium before acid rain may ameliorate the adverse effects of acid rain in wheat plants.

  6. Urban dew and rain in Paris, France: Occurrence and physico-chemical characteristics

    NASA Astrophysics Data System (ADS)

    Beysens, D.; Mongruel, A.; Acker, K.

    2017-06-01

    This paper summarizes one year (April 2011 to March 2012) measurements on planar condensing surfaces of dew and rain events and related physico-chemical characteristics in the urban environment of Paris (city center). Yearly collected water was 3.48 mm for dew (63 events) and 593 mm for rain (146 events). The latter value compares well with rain data (547 mm and 107 events) collected within 12 km at Paris-Orly airport. An estimation of dew yield based on meteo data gives 2.35 mm and 74 events, to be compared with 17.11 mm and 196 events at Paris-Orly. These differences highlight the large reduction in dew events and dew yields in an urban area as compared to a close rural-like area. This reduction is not due to a sky view reduction but to heat island that increases air temperature and decreases relative humidity. Analysis of dew (34) and rain (77) samples were done concerning pH, electrical conductivity (EC), major anions and cations as well as selected trace metals and other minor ions. Mean pH values are found similar for both, dew (6.5) and rain (6.1), rain being slightly more acidic than dew. The mean dew total ionic content (TIC 1.8 meq/l) and EC value (124 μS/cm) are about four times that of rain (0.45 meq/l; 35 μS/cm), meaning that total dissolved solids in dew is nearly four times that in rain. Sulfate and nitrate are the most acidifying components, calcium the most neutralizing constituent with ratio of mean total acidity/total alkalinity comparable for dew and rain ( 0.9). Sulfate and nitrate have mainly anthropogenic sources, whereas chloride and magnesium are mostly connected with marine air masses. Dew is a considerable factor of wet deposition of pollutants; dew and rain ion concentrations, however, meet the WHO requirements for drinking water.

  7. Acid Precipitation Awareness Curriculum Materials in the Life Sciences.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.

    1983-01-01

    Provides an outline of course content for acid precipitation and two acid rain activities (introduction to pH and effects of acid rain on an organism). Information for obtaining 20 additional activities as well as an information packet containing booklets, pamphlets, and articles are also provided. (JN)

  8. Is There Scientific Consensus on Acid Rain? -- Excerpts from Six Governmental Reports.

    ERIC Educational Resources Information Center

    Environmental Education Report and Newsletter, 1986

    1986-01-01

    Compiles a series of direct quotations from six governmental reports that reflect a scientific consensus on major aspects of acid deposition. Presents the statements in a question and answer format. Also reviews the sources, extent, and effects of acid rain. (ML)

  9. Alleviatory effects of silicon on the foliar micromorphology and anatomy of rice (Oryza sativa L.) seedlings under simulated acid rain

    PubMed Central

    Ju, Shuming; Wang, Liping; Zhang, Cuiying; Yin, Tingchao; Shao, Siliang

    2017-01-01

    Silicon (Si) is a macroelement in plants. The biological effects and mitigation mechanisms of silicon under environmental stress have become hot topics. The main objectives of this study were to elucidate the roles of Si in alleviating the effects on the phenotype, micromorphology and anatomy of the leaves of rice seedlings under acid rain stress. The results indicated that the combined or single effects of Si and simulated acid rain (SAR) stress on rice roots depended on the concentration of Si and the intensity of the SAR stress. The combined or single effects of the moderate concentration of Si (2.0 mM) and light SAR (pH 4.0) enhanced the growth of the rice leaves and the development of the mesophyll cells, and the combined effects were stronger than those of the single treatments. The high concentration of Si (4.0 mM) and severe SAR (pH 3.0 or 2.0) exerted deleterious effects. The incorporation of Si (2.0 or 4.0 mM) into SAR at pH values of 3.0 or 2.0 promoted rice leaf growth, decreased necrosis spots, maintained the structure and function of the mesophyll cells, increased the epicuticular wax content and wart-like protuberance (WP) density, and improved the stomatal characteristics of the leaves of rice seedlings more than the SAR only treatments. The alleviatory effects observed with a moderate concentration of Si (2.0 mM) were better than the effects obtained with the high concentration of Si (4.0 mM). The alleviatory effects were due to the enhancement of the mechanical barriers in the leaf epidermis. PMID:29065171

  10. Alleviatory effects of silicon on the foliar micromorphology and anatomy of rice (Oryza sativa L.) seedlings under simulated acid rain.

    PubMed

    Ju, Shuming; Wang, Liping; Zhang, Cuiying; Yin, Tingchao; Shao, Siliang

    2017-01-01

    Silicon (Si) is a macroelement in plants. The biological effects and mitigation mechanisms of silicon under environmental stress have become hot topics. The main objectives of this study were to elucidate the roles of Si in alleviating the effects on the phenotype, micromorphology and anatomy of the leaves of rice seedlings under acid rain stress. The results indicated that the combined or single effects of Si and simulated acid rain (SAR) stress on rice roots depended on the concentration of Si and the intensity of the SAR stress. The combined or single effects of the moderate concentration of Si (2.0 mM) and light SAR (pH 4.0) enhanced the growth of the rice leaves and the development of the mesophyll cells, and the combined effects were stronger than those of the single treatments. The high concentration of Si (4.0 mM) and severe SAR (pH 3.0 or 2.0) exerted deleterious effects. The incorporation of Si (2.0 or 4.0 mM) into SAR at pH values of 3.0 or 2.0 promoted rice leaf growth, decreased necrosis spots, maintained the structure and function of the mesophyll cells, increased the epicuticular wax content and wart-like protuberance (WP) density, and improved the stomatal characteristics of the leaves of rice seedlings more than the SAR only treatments. The alleviatory effects observed with a moderate concentration of Si (2.0 mM) were better than the effects obtained with the high concentration of Si (4.0 mM). The alleviatory effects were due to the enhancement of the mechanical barriers in the leaf epidermis.

  11. Chemistry For Kids: Pre-Chemistry Acid Rain Activities for Kids.

    ERIC Educational Resources Information Center

    Barrow, Lloyd H.

    1985-01-01

    Presents two activities on acid rain for students in intermediate grades. Materials needed and procedures used are included. Also describes "chemical magic" shows performed by high school students for sixth-grade students in seven elementary schools in Altus, Oklahoma. (JN)

  12. Direct damage to vegetation caused by acid rain and polluted cloud: definition of critical levels for forest trees.

    PubMed

    Cape, J N

    1993-01-01

    The concept of critical levels was developed in order to define short-term and long-term average concentrations of gaseous pollutants above which plants may be damaged. Although the usual way in which pollutants in precipitation (wet deposition) influence vegetation is by affecting soil processes, plant foliage exposed to fog and cloud, which often contain much greater concentrations of pollutant ions than rain, may be damaged directly. The idea of a critical level has been extended to define concentrations of pollutants in wet deposition above which direct damage to plants is likely. Concentrations of acidity and sulphate measured in mountain and coastal cloud are summarised. Vegetation at risk of injury is identified as montane forest growing close to the cloud base, where ion concentrations are highest. The direct effects of acidic precipitation on trees are reviewed, based on experimental exposure of plants to simulated acidic rain, fog or mist. Although most experiments have reported results in terms of pH (H(+) concentration), the accompanying anion is important, with sulphate being more damaging than nitrate. Both conifers and broadleaved tree seedlings showing subtle changes in the structural characteristics of leaf surfaces after exposure to mist or rain at or about pH 3.5, or sulphate concentration of 150 micromol litre(-1). Visible lesions on leaf surfaces occur at around pH 3 (500 micromol litre(-1) sulphate), broadleaved species tending to be more sensitive than conifers. Effects on photosynthesis and water relations, and interactions with other stresses (e.g. frost), have usually been observed only for treatments which have also caused visible injury to the leaf surface. Few experiments on the direct effects of polluted cloud have been conducted under field conditions with mature trees, which unlike seedlings in controlled conditions, may suffer a growth reduction in the absence of visible injury. Although leaching of cations (Ca(2+), Mg(2+), K(+)) is

  13. Analysis of Natural Buffer Systems and the Impact of Acid Rain

    ERIC Educational Resources Information Center

    Powers, David C.; Yoder, Claude H.; Higgs, Andrew T.; Obley, Matt L.; Hess, Kenneth R.; Leber, Phyllis A.

    2005-01-01

    The environmental significance of acid rain on water systems of different buffer capacities is discussed. The most prevalent natural buffer system is created by the equilibrium between carbonate ions and carbon dioxide.

  14. Elution of lead from lead zirconate titanate ceramics to acid rain

    NASA Astrophysics Data System (ADS)

    Tsurumi, Takaaki; Takezawa, Shuhei; Hoshina, Takuya; Takeda, Hiroaki

    2017-10-01

    The amount of lead that eluted from lead zirconate titanate (PZT) ceramics to artificial acid rain was evaluated. Four kinds of PZT ceramics, namely, pure PZT at MPB composition, CuO-added PZT, PZT with 10 mol % substitution of Ba for Pb, and CuO-added PZT with 10 mol % substitution of Ba for Pb, were used as samples of the elution test. These PZT ceramics of 8 mm2 and 1.1-1.2 mm thickness were suspended in 300 ml of H2SO4 solution of pH 4.0. The concentration of lead eluted from PZT was in the range from 0.2 to 0.8 ppm. It was found that both liquid phase formation by the addition of CuO and the substitution of Ba for Pb were effective to reduce the amount of lead that eluted. By fitting the leaching out curve with a classical equation, a master curve assuming no sampling effect was obtained. The lead concentration evaluated from the amount of lead that eluted from a commercial PZT plate to H2SO4 solution of pH 5.3 was almost the same as the limit in city water. It is concluded that PZT is not harmful to health and the environment and the amount of lead that eluted from PZT can be controlled by modifying PZT composition.

  15. Spatial characterization of acid rain stress in Canadian Shield lakes

    NASA Technical Reports Server (NTRS)

    Tanis, Fred J.

    1986-01-01

    A major concern of the acid rain problem is the cumulative ecosystem damage to lakes and forests. The number of lakes affected in northeastern United States and on the Canadian Shield is thought to be enormous. Seasonal changes in lake transparency are examined relative to annual acidic load. The relationship between variations in lake acidification and ecophysical units is being examined. Finally, the utility of Thematic Mapper (TM) based observations is being used to measure seasonal changes in the optical transparency in acid lakes.

  16. Comparative Analysis of Nitrate Levels in Pensacola Area Rain Water

    NASA Astrophysics Data System (ADS)

    Jacobs, J.; Caffrey, J. M.; Maestre, A.; Landing, W. M.

    2017-12-01

    Nitrate is an important constituent of acid rain and often correlated with atmospheric NOx levels. This link between air and water quality was tested over a course of summer 2017 and compared to data from 2005-2012. Rain water samples collected from late May through early July of 2017 were tested for pH and nitrate concentrations. These months were among the stormiest on record for the Northwest Florida region with a total rainfall of 648 mm. The data analyzed from these rain events was compared to previous data to show the trends of nitrate and pH levels in the rainwater. Median pH for this study was 5.2, higher than the medians between 2015-2012 which ranged from 4.2 to 5.0, while nitrate concentrations for this study were 15.2 µM. This contrasts with a significant drop in nitrate concentrations from 41 µM in 2005 and 2006 to around 12 µM between 2007 and 2012. The drop between 2006-7 was suspected to be a result of implementation of NOx controls at Plant Crist coal fired power plant and other Clean Air Act requirements. These inputs of nitrate and H+ ions from rainwater can have a significant influence water quality throughout the region.

  17. Simulated acid rain alters litter decomposition and enhances the allelopathic potential of the invasive plant Wedelia trilobata (Creeping Daisy)

    USDA-ARS?s Scientific Manuscript database

    Invasive species and acid rain cause global environmental problems. Limited information exists, however, concerning the effects of acid rain on the invasiveness of these plants. For example, creeping daisy, an invasive exotic allelopathic weed, has caused great damage in southern China where acid ra...

  18. Acid Rain Effects on Adirondack Streams - Results from the 2003-05 Western Adirondack Stream Survey (the WASS Project)

    USGS Publications Warehouse

    Lawrence, Gregory B.; Roy, Karen M.; Baldigo, Barry P.; Simonin, Howard A.; Passy, Sophia I.; Bode, Robert W.; Capone, Susan B.

    2009-01-01

    Traditionally lakes have been the focus of acid rain assessments in the Adirondack region of New York. However, there is a growing recognition of the importance of streams as environmental indicators. Streams, like lakes, also provide important aquatic habitat, but streams more closely reflect acid rain effects on soils and forests and are more prone to acidification than lakes. Therefore, a large-scale assessment of streams was undertaken in the drainage basins of the Oswegatchie and Black Rivers; an area of 4,585 km2 in the western Adirondack region where acid rain levels tend to be highest in New York State.

  19. Learning about Acid Rain: A Teacher's Guide for Grades 6 through 8. EPA 430-F-08-002

    ERIC Educational Resources Information Center

    US Environmental Protection Agency, 2008

    2008-01-01

    Acid rain is a complex environmental problem which affects the United States and many other countries around the world. The United States Environmental Protection Agency (EPA) was established in 1970 to address environmental issues, such as acid rain. Through its programs, EPA works to protect human health and the environment in the United States…

  20. Assessing acid rain and climate effects on the temporal variation of dissolved organic matter in the unsaturated zone of a karstic system from southern China

    NASA Astrophysics Data System (ADS)

    Liao, Jin; Hu, Chaoyong; Wang, Miao; Li, Xiuli; Ruan, Jiaoyang; Zhu, Ying; Fairchild, Ian J.; Hartland, Adam

    2018-01-01

    Acid rain has the potential to significantly impact the quantity and quality of dissolved organic matter (DOM) leached from soil to groundwater. Yet, to date, the effects of acid rain have not been investigated in karstic systems, which are expected to strongly buffer the pH of atmospheric rainfall. This study presents a nine-year DOM fluorescence dataset from a karst unsaturated zone collected from two drip sites (HS4, HS6) in Heshang Cave, southern China between 2005 and 2014. Cross-correlograms show that fluorescence intensity of both dripwaters lagged behind rainfall by ∼1 year (∼11 months lag for HS4, and ∼13 months for HS6), whereas drip rates responded quite quickly to rainfall (0 months lag for HS4, and ∼3 months for HS6), based on optimal correlation coefficients. The rapid response of drip rates to rainfall is related to the change of reservoir head pressure in summer, associated with higher rainfall. In winter, low rainfall has a limited effect on head pressure, and drip rates gradually slow to a constant value associated with base flow from the overlying reservoir- this effect being most evident on inter-annual timescales (R2 = 0.80 for HS4 and R2 = 0.86 for HS6, n = 9, p < 0.01). We ascribed the ∼1 year lag of fluorescence intensity to the effect of the soil moisture deficit and the karst process on delaying water and solute transport. After eliminating the one year lag, the congruent seasonal pacing and amplitude between fluorescence intensity and rainfall observed suggests that the seasonality of fluorescence intensity was mainly controlled by the monsoonal rains which can govern the output of DOM from the soil, as well as the residence time of water in the unsaturated zone. On inter-annual timescales, a robust linear relationship between fluorescence intensity and annual (effective) precipitation amount (R2 = 0.86 for HS4 and R2 = 0.77 for HS6, n = 9, p < 0.01) was identified, implying that annual (effective) precipitation is the main

  1. Soil-calcium depletion linked to acid rain and forest growth in the eastern United States

    USGS Publications Warehouse

    Lawrence, Gregory B.; Huntington, T.G.

    1999-01-01

    Since the discovery of acid rain in the 1970's, scientists have been concerned that deposition of acids could cause depletion of calcium in forest soils. Research in the 1980's showed that the amount of calcium in forest soils is controlled by several factors that are difficult to measure. Further research in the 1990's, including several studies by the U.S. Geological Survey, has shown that (1) calcium in forest soils has decreased at locations in the northeastern and southeastern U.S., and (2) acid rain and forest growth (uptake of calcium from the soil by roots) are both factors contributing to calcium depletion.

  2. The influence of SO4 and NO3 to the acidity (pH) of rainwater using minimum variance quadratic unbiased estimation (MIVQUE) and maximum likelihood methods

    NASA Astrophysics Data System (ADS)

    Dilla, Shintia Ulfa; Andriyana, Yudhie; Sudartianto

    2017-03-01

    Acid rain causes many bad effects in life. It is formed by two strong acids, sulfuric acid (H2SO4) and nitric acid (HNO3), where sulfuric acid is derived from SO2 and nitric acid from NOx {x=1,2}. The purpose of the research is to find out the influence of So4 and NO3 levels contained in the rain to the acidity (pH) of rainwater. The data are incomplete panel data with two-way error component model. The panel data is a collection of some of the observations that observed from time to time. It is said incomplete if each individual has a different amount of observation. The model used in this research is in the form of random effects model (REM). Minimum variance quadratic unbiased estimation (MIVQUE) is used to estimate the variance error components, while maximum likelihood estimation is used to estimate the parameters. As a result, we obtain the following model: Ŷ* = 0.41276446 - 0.00107302X1 + 0.00215470X2.

  3. Spatial characterization of acid rain stress in Canadian Shield lakes

    NASA Technical Reports Server (NTRS)

    Tanis, Fred J.

    1986-01-01

    The acidification of lake waters from airborne pollutants is of continental proportions both in North America and Europe. A major concern of the acid rain problem is the cumulative ecosystem damage to lakes and forest. The number of lakes affected in northeastern United States and on the Canadian Shield is though to be enormous. The principle objective is to examine how seasonal changes in lake water transparency are related to annual acidic load. Further, the relationship between variations in lake acidification and ecophysical units is being examined. Finally, the utility of Thematic Mapper (TM) based observations to measure seasonal changes in the optical transparency in acid lakes is being investigated.

  4. Environmental Externalities in Electric Power Markets: Acid Rain, Urban Ozone, and Climate Change

    EIA Publications

    1995-01-01

    This article discusses the emissions resulting from the generation of electricity by utilities and their role in contributing to the environmental problems of acid rain, urban ozone, and climate change.

  5. Impacts of acid precipitation on coniferous forest ecosystems

    Treesearch

    Gunnar Abrahamsen; Richard Horntvedt; Bjorn Tveite

    1976-01-01

    This paper summarizes the results from current studies in Norway. One main approach is the application of artificial acid "rain" and of lime to field plots and lysimeters. Application during two growth seasons of 50 mm per month of "rain water" of pH 3 to a podzol soil increased the acidity of the humus and decreased the base saturation. The...

  6. Why Isn't My Rain as Acidic as Yours?

    ERIC Educational Resources Information Center

    Zajicek, O. T.

    1985-01-01

    Discusses three topics that have been improperly applied to the acidic precipitation issue. They are: (1) use of the pH scale; (2) acidity; and (3) solution equilibria of strong and weak acids. Implications for instruction are considered. (JN)

  7. Source tagging modeling study of regional contributions to acid rain in summer over Liaoning Province, Northeastern China.

    PubMed

    Gbaguidi, Alex E; Wang, Zifa; Wang, Wei; Yang, Ting; Chen, Huan-Sheng

    2018-04-01

    Strong acid rain was recently observed over Northeastern China, particularly in summer in Liaoning Province where alkaline dust largely neutralized acids in the past. This seems to be related to the regional transboundary pollution and poses new challenges in acid rain control scheme in China. In order to delve into the regional transport impact, and quantify its potential contributions to such an "eruption" of acid rain over Liaoning, this paper employs an online source tagging model in coupling with the Nested Air Quality Prediction Modeling System (NAQPMS). Validation of predictions shows the model capability in reproducing key meteorological and chemical features. Acid concentration over Liaoning is more pronounced in August (average of 0.087 mg/m 3 ) with strong pollutant import from regional sources against significant depletion of basic species. Seasonal mean contributions from regional sources are assessed at both lower and upper boundary layers to elucidate the main pathways of the impact of regional sources on acid concentration over Liaoning. At the upper layer (1.2 km), regional sources contribute to acid concentration over Liaoning by 67%, mainly from Shandong (16%), Hebei (13%), Tianjin (11%) and Korean Peninsula (9%). Identified main city-receptors in Liaoning are Dandong, Dalian, Chaohu, Yingkou, Liaoyang, Jinfu, Shengyang, Panjin, Tieling, Benxi, Anshan and Fushun. At lower layer (120 m) where Liaoning local contribution is dominant (58%), regional sources account for 39% in acid concentration. However, inter-municipal acid exchanges are prominent at this layer and many cities in Liaoning are revealed as important sources of local acid production. Seasonal acid contribution average within 1.2 km-120 m attains 55%, suggesting dominance of vertical pollutant transport from regional sources towards lower boundary layer in Liaoning. As direct environmental implication, this study provides policy makers with a perspective of regulating the

  8. Acid rain and deterioration of monuments: How old is the phenomenon?

    NASA Astrophysics Data System (ADS)

    Camuffo, Dario

    The first known articles on acid rain appeared when atmospheric pollution reached high levels in the industrial towns of England. Research was carried out to ascertain and interpret earlier documentation, mainly written or printed in Italy, that could throw new light on both the environmental history and the relationship between present-day pollution and weathering of monuments. Very important discussions on dispersion and transport of airborne pollutants, atmospheric scavenging, acid rain, as well as descriptions of effects on fruit, monuments and people, were found in scientific treatises of the 1600s and 1700s. The cause of acidification can be found in volcanic activity, especially that of Stromboli, Vulcano, Vesuvius and Etna, which increased in the 17th and 18th century. Although in the past some pollutants may have reached higher concentrations locally than at present, nowadays air pollution has become a global problem; there are many new species of pollutants and catalysts, and their combined action has increased impressively the environmental risk and the deterioration rate of historic buildings and monuments.

  9. A transcriptomic study reveals differentially expressed genes and pathways respond to simulated acid rain in Arabidopsis thaliana.

    PubMed

    Liu, Ting-Wu; Niu, Li; Fu, Bin; Chen, Juan; Wu, Fei-Hua; Chen, Juan; Wang, Wen-Hua; Hu, Wen-Jun; He, Jun-Xian; Zheng, Hai-Lei

    2013-01-01

    Acid rain, as a worldwide environmental issue, can cause serious damage to plants. In this study, we provided the first case study on the systematic responses of arabidopsis (Arabidopsis thaliana (L.) Heynh.) to simulated acid rain (SiAR) by transcriptome approach. Transcriptomic analysis revealed that the expression of a set of genes related to primary metabolisms, including nitrogen, sulfur, amino acid, photosynthesis, and reactive oxygen species metabolism, were altered under SiAR. In addition, transport and signal transduction related pathways, especially calcium-related signaling pathways, were found to play important roles in the response of arabidopsis to SiAR stress. Further, we compared our data set with previously published data sets on arabidopsis transcriptome subjected to various stresses, including wound, salt, light, heavy metal, karrikin, temperature, osmosis, etc. The results showed that many genes were overlapped in several stresses, suggesting that plant response to SiAR is a complex process, which may require the participation of multiple defense-signaling pathways. The results of this study will help us gain further insights into the response mechanisms of plants to acid rain stress.

  10. [Characteristics of precipitation pH and conductivity at Mt. Huang].

    PubMed

    Shi, Chun-e; Deng, Xue-liang; Wu, Bi-wen; Hong, Jie; Zhang, Su; Yang, Yuan-jian

    2013-05-01

    To understand the general characteristics of pH distribution and pollution in precipitation at Mt. Huang, statistical analyses were conducted for the routine measurements of pH and conductivity (K) at Mt. Huang during 2006-2011. The results showed that: (1) Over the period of study, the annual volume weighted mean (VWM) precipitation pH varied from 4.81 to 5.57, with precipitation acidity strengthening before 2009 and weakening thereafter. The precipitation acidity showed evident seasonal variations, with the VWM pH lowest in winter (4.78), and highest in summer (5.33). The occurrence frequency of acid rain was 46% , accounting for 45% of total rainfalls and with the most frequent pH falling into weak acid to neutral rain. (2) The annual VWM K varied from 16.91 to 27.84 microS x cm(-1), with no evident trend. As for ions pollution, the precipitation was relatively clean at Mt. Huang, with the most frequent K range being below 15 microS x cm(-1), followed by 15-25 microS x cm(-1). From February 2010 to December 2011, precipitation samples were collected on daily basis for ions analysis, as well as pH and K measurement in lab. Detailed comparisons were conducted between the two sets of pH and K, one set from field measurement and the other from lab measurement. The results indicated: (1) The lab measured pH (K) was highly correlated with the field pH (K); however, the lab pH tended to move towards neutral comparing with the corresponding field pH, and the shift range was closely correlated with the field pH and rainfall. The shift range of K from field to lab was highly correlated with the total ion concentration of precipitation. The field K showed evident negative correlation with the field pH with a correlation coefficient of -0.51. (2) When sampling with nylon-polyethylene bags, the statistics showed smaller bias between two sets of pH, with higher correlation coefficient between two sets of K. Furthermore, the lab K also showed evident negative correlation with

  11. Predicting recovery from acid rain using the micro-spatial heterogeneity of soil columns downhill the infiltration zone of beech stemflow: introduction of a hypothesis.

    PubMed

    Berger, Torsten W; Muras, Alexander

    Release of stored sulfur may delay the recovery of soil pH from Acid Rain. It is hypothesized that analyzing the micro-spatial heterogeneity of soil columns downhill of a beech stem enables predictions of soil recovery as a function of historic acid loads and time. We demonstrated in a very simplified approach, how these two different factors may be untangled from each other using synthetic data. Thereafter, we evaluated the stated hypothesis based upon chemical soil data with increasing distance from the stem of beech trees. It is predicted that the top soil will recover from acid deposition, as already recorded in the infiltration zone of stemflow near the base of the stem. However, in the between trees areas and especially in deeper soil horizons recovery may be highly delayed.

  12. From the Fur Trade to Acid Rain: A Study of Canadian Natural Resources.

    ERIC Educational Resources Information Center

    Winans, Linda

    1988-01-01

    Presents a teaching module for upper elementary students that devotes eight class periods of study to Canadian resources. Includes study of the Canadian fur trade, fishing industry, forestry, and the problems caused by acid rain. Includes the unit evaluation. (DB)

  13. Environmental Policy-Making and Their Impacts in the Case of Acid Rain Abatement.

    ERIC Educational Resources Information Center

    Boehmer-Christiansen, Sonja

    1992-01-01

    Great Britain and Germany accepted European Community acid rain reduction directives. Discusses the differences in the amount of reduction required from each country, the strategies adopted to attain those reductions, and the levels of emission reductions already achieved.(52 references) (MDH)

  14. ACID PRECIPITATION IN HISTORICAL PERSPECTIVE: AWARENESS OF THE ACID RAIN PROBLEM HAS DEVELOPED IN MANY COUNTRIES OVER MORE THAN A CENTURY

    EPA Science Inventory

    Awareness of the acid rain problem has developed in many countries over more than a century. This brief article is an attempt to illuminate some of the questions, such as, why did it take so long for acid precipitation to be recognized as an important environmental problem. What ...

  15. Lots of data, how do we use it? Strengths and inaccuracies of utility acid rain electronic data reports

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schott, J.

    1996-12-31

    Entergy Corporation is a Phase II utility with a fossil generation base composed primarily natural gas and low sulfur coal. This paper presents an analysis of a large Phase II utility`s continuous emissions monitoring data reported to EPA under Title IV Acid Rain. Electric utilities currently report hourly emissions of NOx, SO{sub 2}, CO{sub 2}, fuel use, and generation through electronic data reports to EPA. This paper describes strengths and weaknesses of the data reported to EPA as determined through an analysis of 1995 data. Emissions reported by this company tinder acid rain for SO{sub 2} and NOx are verymore » different from emissions reported to state agencies for annual emission inventory purposes in past years and will represent a significant break with historic trends. A comparison of emissions has been made of 1995 emissions reported under Electronic Data Reports to the emissions that would have been reported using emission factors and fuel data in past years. In addition, the paper examines the impacts of 40 CFR Part 75 Acid Rain requirements such as missing data substitution and monitor bias adjustments. Measurement system errors including stack flow measurement and false NOx Lb/MMBtu readings at very low loads are discussed. This paper describes the implications for public policy, compliance, emissions inventories, and business decisions of Part 75 acid rain monitoring and reporting requirements.« less

  16. Complex toxic effects of Cd2+, Zn2+, and acid rain on growth of kidney bean (Phaseolus vulgaris L).

    PubMed

    Liao, Bo-han; Liu, Hong-yu; Zeng, Qing-ru; Yu, Ping-zhong; Probst, Anne; Probst, Jean-Luc

    2005-08-01

    Complex toxic effects of Cd2+, Zn2+, and acid rain on growth of kidney bean (Phaseolus vulgaris L) were studied in a pot experiment by measurement of fresh weights of the plants, determination of surperoxide dismutase (SOD), peroxidase (POD), and lipid peroxidation (MDA) in the plant organs, and observation of injury symptoms. The experimental results demonstrated that all treatments of Cd2+, Zn2+, and/or acid rain significantly decreased fresh weights of kidney bean and caused toxic effects on growth of the plants, especially higher amounts of Cd2+ and Zn2+ and higher acidity of acid rain. Combination of these three pollutant factors resulted in more serious toxic effects than any single pollutant and than combinations of any two pollutants. SOD, POD, and MDA in the plant organs changed with different pollution levels, but MDA content in the leaves showed the best relationship between the pollution levels and toxic effects.

  17. Student Teacher Understanding of the Greenhouse Effect, Ozone Layer Depletion, and Acid Rain.

    ERIC Educational Resources Information Center

    Dove, Jane

    1996-01-01

    Describes the results of a survey designed to ascertain details of student teachers' knowledge and misconceptions about the greenhouse effect, acid rain, and ozone layer depletion. Results indicate familiarity with the issues but little understanding of the concepts involved and many commonly held misconceptions. (JRH)

  18. Effect of nanohydroxyapatite on cadmium leaching and environmental risks under simulated acid rain.

    PubMed

    Zhao, Chenchen; Ren, Shuxia; Zuo, Qingqing; Wang, Shutao; Zhou, Yapeng; Liu, Wei; Liang, Shuxuan

    2018-06-15

    Cadmium (Cd) contamination in soil is a global environmental pollution issue. Nanohydroxyapatite (NHAP) has been used in soil remediation to immobilize cadmium in contaminated soils. However, the effect of acid rain on the export of cadmium from topsoil and its behavior in deep soil and leachate is unclear. In this study, column experiments and development of parsimonious model were performed to estimate Cd leaching behavior from topsoil and environmental risk of groundwater after 0.5% NHAP remediation. Four leaching events were performed and total Cd, different fractions of Cd determined by sequential extraction procedure and pH were determined for each leaching. The results show that with the export of Cd in topsoil, the total Cd concentration in soil at different depths had the following vertical distributions: 0-5 cm > 5-10 cm > 10-15 cm > 15-20 cm. NHAP treatment increased the soil pH and decreased Cd leaching loss by 56.45% compared to the control, and the results fit the parabolic diffusion model. With sequential extraction it was observed that NHAP application increased the residual fraction of cadmium in soil. After leaching, there was a positive correlation between soil pH and Cd concentration with regards to the exchangeable, reducible, oxidizable and residual Cd fractions. The parabolic diffusion model showed that Cd-contaminated soil with NHAP remediation is harmless to humans after sufficient remediation duration, whereas the resultant concentrations from the CK treatment could be toxic. The results indicate that nanohydroxyapatite could significantly reduce the bioavailability of cadmium and the environmental risk. However, the release of Ca and P from the dissolution of NHAP should be carefully studied as this will impact the mobilization of Cd or colloid Cd, and high leaching of P may result in P-induced eutrophication risk. Copyright © 2018 Elsevier B.V. All rights reserved.

  19. Red herring in acid rain research

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Havas, M.; Hutchinson, T.C.; Likens, G.E.

    1984-06-01

    Five common misconceptions, red herrings, regarding the effects of acid deposition on aquatic ecosystems are described in an attempt to clarify some of the confusion they have created. These misconceptions are the following: Bog lakes have been acidic for thousands of years; thus the acidification of lakes is not a recent phenomenon. The early methods for measuring pH are in error; therfore, no statements can be made regarding historical trends. Acidification of lakes and streams results from changed land use practices (forestry, agriculture, animal husbandry) and not acid deposition. The decrease in fish populations is caused by overfishing, disease, andmore » water pollution, not acidification. Because lakes that receive identical rainfall can have considerable different pHs, regional lake acidification cannot be due to acid precipitation. It is easy to suggest a whole series of alternative, and often unlikely, explanations of the causes and consequences of acid deposition. These keep scientists busy for years assembling and examining data only to conclude that the explanation is not valid. These tactics cause, and perhaps are designed to cause, continuous delay in remedial action. They fail to take into account the large body of information that deals with the sources of the acid deposition and the seriousness of its effects.« less

  20. Rain water chemistry in Ankara, Turkey

    NASA Astrophysics Data System (ADS)

    Tuncel, Semra G.; Ungör, Sevgi

    Samples of rain water were collected in Ankara for the period between September 1989 and May 1990, by using wet-only sampler. Concentrations of major cations (H +, Na + K + Ca 2+ and NH 4+) and major anions (Cl -, NO 3- and SO 42-) were determined for the first time in Turkey. The rain water was not acidic owing to high concentrations of alkaline soil particles in the atmosphere. However, the concentrations of acid forming ions, such as SO 4- and N03, were higher than the concentrations expected in a typical urban atmosphere. Most of the SO 4- in rain water was in the form of CaSO 4. Rain-aerosol coupling were examined by simultaneous sampling of aerosols with rain. The ions most efficiently scavenged from the atmosphere were found to be SO 42- and Ca 2+.

  1. Titratable acidity of beverages influences salivary pH recovery.

    PubMed

    Tenuta, Livia Maria Andaló; Fernández, Constanza Estefany; Brandão, Ana Carolina Siqueira; Cury, Jaime Aparecido

    2015-01-01

    A low pH and a high titratable acidity of juices and cola-based beverages are relevant factors that contribute to dental erosion, but the relative importance of these properties to maintain salivary pH at demineralizing levels for long periods of time after drinking is unknown. In this crossover study conducted in vivo, orange juice, a cola-based soft drink, and a 10% sucrose solution (negative control) were tested. These drinks differ in terms of their pH (3.5 ± 0.04, 2.5 ± 0.05, and 5.9 ± 0.1, respectively) and titratable acidity (3.17 ± 0.06, 0.57 ± 0.04 and < 0.005 mmols OH- to reach pH 5.5, respectively). Eight volunteers with a normal salivary flow rate and buffering capacity kept 15 mL of each beverage in their mouth for 10 s, expectorated it, and their saliva was collected after 15, 30, 45, 60, 90, and 120 s. The salivary pH, determined using a mini pH electrode, returned to the baseline value at 30 s after expectoration of the cola-based soft drink, but only at 90 s after expectoration of the orange juice. The salivary pH increased to greater than 5.5 at 15 s after expectoration of the cola drink and at 30 s after expectoration of the orange juice. These findings suggest that the titratable acidity of a beverage influences salivary pH values after drinking acidic beverages more than the beverage pH.

  2. Acidic pH promotes intervertebral disc degeneration: Acid-sensing ion channel -3 as a potential therapeutic target.

    PubMed

    Gilbert, Hamish T J; Hodson, Nathan; Baird, Pauline; Richardson, Stephen M; Hoyland, Judith A

    2016-11-17

    The aetiology of intervertebral disc (IVD) degeneration remains poorly understood. Painful IVD degeneration is associated with an acidic intradiscal pH but the response of NP cells to this aberrant microenvironmental factor remains to be fully characterised. The aim here was to address the hypothesis that acidic pH, similar to that found in degenerate IVDs, leads to the altered cell/functional phenotype observed during IVD degeneration, and to investigate the involvement of acid-sensing ion channel (ASIC) -3 in the response. Human NP cells were treated with a range of pH, from that of a non-degenerate (pH 7.4 and 7.1) through to mildly degenerate (pH 6.8) and severely degenerate IVD (pH 6.5 and 6.2). Increasing acidity of pH caused a decrease in cell proliferation and viability, a shift towards matrix catabolism and increased expression of proinflammatory cytokines and pain-related factors. Acidic pH resulted in an increase in ASIC-3 expression. Importantly, inhibition of ASIC-3 prevented the acidic pH induced proinflammatory and pain-related phenotype in NP cells. Acidic pH causes a catabolic and degenerate phenotype in NP cells which is inhibited by blocking ASIC-3 activity, suggesting that this may be a useful therapeutic target for treatment of IVD degeneration.

  3. Effects of simulated acid rain on the allelopathic potential of invasive weed Wedelia trilobata

    USDA-ARS?s Scientific Manuscript database

    Acid rain continues to pose a major threat to natural ecosystems in rapidly-developing industrialized regions such as southern China. Despite the significant environmental impact of this phenomenon, relatively little is known concerning its effects on important aspects of ecosystem dynamics such as ...

  4. Acidic pH modulation of Na+ channels in trigeminal mesencephalic nucleus neurons.

    PubMed

    Kang, In-Sik; Cho, Jin-Hwa; Choi, In-Sun; Kim, Do-Yeon; Jang, Il-Sung

    2016-12-07

    Cell bodies of trigeminal mesencephalic nucleus (Vmes) neurons are located within the central nervous system, and therefore, peripheral as well as central acidosis can modulate the excitability of Vmes neurons. Here, we report the effect of acidic pH on voltage-gated Na channels in acutely isolated rat Vmes neurons using a conventional whole-cell patch clamp technique. Acidic pH (pH 6.0) slightly but significantly shifted both the activation and steady-state fast inactivation relationships toward depolarized potentials. However, acidic pH (pH 6.0) had a minor effect on the inactivation kinetics of voltage-gated Na channels. Less sensitivity of voltage-gated Na channels to acidic pH may allow Vmes neurons to transduce the precise proprioceptive information even under acidic pH conditions.

  5. Silicon alleviates simulated acid rain stress of Oryza sativa L. seedlings by adjusting physiology activity and mineral nutrients.

    PubMed

    Ju, Shuming; Wang, Liping; Yin, Ningning; Li, Dan; Wang, Yukun; Zhang, Cuiying

    2017-11-01

    Silicon (Si) has been a modulator in plants under abiotic stresses, such as acid rain. To understand how silicon made an effect on rice (Oryza sativa L.) exposed to simulated acid rain (SAR) stress, the growth, physiologic activity, and mineral nutrient content in leaves of rice were investigated. The results showed that combined treatments with Si (1.0, 2.0, or 4.0 mM) and SAR (pH 4.0, 3.0, or 2.0) obviously improved the rice growth compared with the single treatment with SAR. Incorporation of Si into SAR treatment decreased malondialdehyde (MDA) content; increased soluble protein and proline contents; promoted CAT, POD, SOD, and APX activity; and maintained the K, Ca, Mg, Fe, Zn, Cu content balance in leaves of rice seedlings under SAR stress. The moderate concentration of Si (2.0 mM) was better than the low and high concentration of Si (1.0 and 4.0 mM). Therefore, application of Si could be a better strategy for maintaining the crop productivity in acid rain regions.

  6. The Influence of a Collaborative Learning Environment on Primary Students' Conceptions about Acid Rain.

    ERIC Educational Resources Information Center

    Marinopoulos, Dimitrios; Stavridou, Heleni

    2002-01-01

    Investigates primary students' conceptions of acid rain formation and its consequences to people and the environment before and after a 10-hour constructivist teaching intervention. Reports improvement in conceptions of physical and chemical phenomena among the experimental group participants. (Contains 23 references.) (Author/YDS)

  7. Neutralizing salivary pH by mouthwashes after an acidic challenge.

    PubMed

    Dehghan, Mojdeh; Tantbirojn, Daranee; Kymer-Davis, Emily; Stewart, Colette W; Zhang, Yanhui H; Versluis, Antheunis; Garcia-Godoy, Franklin

    2017-05-01

    The aim of the present study was to test the neutralizing effect of mouthwashes on salivary pH after an acidic challenge. Twelve participants were recruited for three visits, one morning per week. Resting saliva was collected at baseline and after 2-min swishing with 20 mL orange juice as an acidic challenge. Participants then rinsed their mouth for 30 s with 20 mL water (control), an over-the-counter mouthwash (Listerine), or a two-step mouthwash, randomly assigned for each visit. Saliva was collected immediately, 15, and 45 min after rinsing. The pH values of the collected saliva were measured and analyzed with anova, followed by Student-Newman-Keuls post-hoc test (significance level: 0.05). Orange juice significantly lowered salivary pH. Immediately after rinsing, Listerine and water brought pH back to baseline values, with the pH significantly higher in the Listerine group. The two-step mouthwash raised pH significantly higher than Listerine and water, and higher than the baseline value. Salivary pH returned to baseline and was not significantly different among groups at 15 and 45 min post-rinsing. Mouth rinsing after an acidic challenge increased salivary pH. The tested mouthwashes raised pH higher than water. Mouthwashes with a neutralizing effect can potentially reduce tooth erosion from acid exposure. © 2015 Wiley Publishing Asia Pty Ltd.

  8. Physiological responses of root-less epiphytic plants to acid rain.

    PubMed

    Kováčik, Jozef; Klejdus, Bořivoj; Bačkor, Martin; Stork, František; Hedbavny, Josef

    2011-03-01

    Selected physiological responses of Tillandsia albida (Bromeliaceae) and two lichens (Hypogymnia physodes and Xanthoria parietina) exposed to simulated acid rain (AR) over 3 months were studied. Pigments were depressed in all species being affected the most in Tillandsia. Amounts of hydrogen peroxide and superoxide were elevated and soluble proteins decreased only in AR-exposed Hypogymnia. Free amino acids were slightly affected among species and only glutamate sharply decreased in AR-exposed Xanthoria. Slight increase in soluble phenols but decrease in flavonoids in almost all species suggests that the latter are not essential for tolerance to AR. Almost all phenolic acids in Tillandsia leaves decreased in response to AR and activities of selected enzymes (phenylalanine ammonia-lyase, polyphenol oxidase, ascorbate- and guaiacol-peroxidase) were enhanced by AR. In lichens, considerable increase in metabolites (physodalic acid, atranorin and parietin) in response to AR was found but amount of ergosterol was unchanged. Macronutrients (K, Ca, Mg) decreased more pronouncedly in comparison with micronutrients in all species. Xanthoria showed higher tolerance in comparison with Hypogymnia, suggesting that could be useful for long-term biomonitoring.

  9. The effects of acid rain on nitrogen fixation in Western Washington coniferous forests

    Treesearch

    Robert Denison; Bruce Caldwell; Bernard Bormann; Lindell Eldred; Cynthia Swanberg; Steven Anderson

    1976-01-01

    We investigated both the current status of nitrogen fixation in Western Washington forests, and the potential effects of acid rain on this vital process. Even the low concentrations of sulfur dioxide presently found in the Northwest are thought to have an adverse effect on nitrogen fixation by limiting the distribution of the epiphytic nitrogen-fixing lichen, ...

  10. [Degradation kinetics of chlorogenic acid, cryptochlorogenic acid, and neochlorogenic acid at neutral and alkaline pH values].

    PubMed

    Zhu, Peng; Miao, Xiao-lei; Chen, Yong

    2016-01-01

    The degradation kinetics of chlorogenic acid (5-CQA), cryptochlorogenic acid (4-CQA), and neochlorogenic acid (3-CQA) in aqueous solution at 37 degrees C and different pH values (7.05, 7.96, 9.25) were investigated in the present work. The results indicated that 3-, 4- and 5-CQA tended to remain stable in acidic pH circumstance, and unstable in neutral and alkaline pH circumstance. With the increase of the alkalinity, the degradation of 3-, 4- and 5-CQA was increased leading to a less amount of total CQA and was satisfactorily described by the Weibull equation. Meanwhile, caffeic acid was not detected after the degradation of CQA. Moreover, the degradation of 3-CQA and 5-CQA tended to be converted to 4-CQA, and the degradation of 4-CQA tended to be converted to 3-CQA rather than 5-CQA. The comparison of the degradation kinetics parameters of 3-, 4- and 5-CQA at neutral and alkaline pH values showed that the orders of the rate constant (k) values were 4-CQA > 3-CQA > 5-CQA, while the orders of the degradation half life (t½) values were 4-CQA < 3-CQA < 5-CQA, indicating the orders of the stabilities of 3-, 4- and 5-CQA at 37 degrees C and neutral and alkaline pH values were 4-CQA < 3-CQA < 5-CQA.

  11. Embedded micro-sensor for monitoring pH in concrete structures

    NASA Astrophysics Data System (ADS)

    Srinivasan, Rengaswamy; Phillips, Terry E.; Bargeron, C. Brent; Carlson, Micah A.; Schemm, Elizabeth R.; Saffarian, Hassan M.

    2000-04-01

    Three major causes of corrosion of steel in concrete are chloride ions (Cl-), temperature (T) and acidity (pH). Under normal operating temperatures and with pH above 13, steel does not undergo pitting corrosion. In presence of Cl-, if the pH decreases below 12, the probability of pitting increases. Acid rain and atmospheric carbon dioxide cause the pH to drop in concrete, often leading to corrosion of the structure with the concomitant cost of repair or replacement. Currently, the pH level in concrete is estimated through destructive testing of the structures. Glass ISFET, and other pH sensors that need maintenance and calibration cannot be embedded in concrete. In this paper, we describe an inexpensive solid state pH sensor that can be embedded in concrete, to detect pH changes at the early stages. It employs a chemical reagent, trinitrobenzenesulfonic acid (TNBS) that exhibits changes in optical properties in the 12 - 14 pH range, and is held in a film of a sol-gel/TNBS composite on an optically transparent surface. A simple LED/filter/photodiode transducer monitors pH-induced changes in TNBS. Such a device needs no periodic calibration or maintenance. The optical window, the light-source and sensor can be easily housed and encapsulated in a chemically inert structure, and embedded in concrete.

  12. A Fresh Look at the Benefits and Costs of the US Acid Rain Program

    EPA Science Inventory

    The US Acid Rain Program (Title IV of the 1990 Clean Air Act Amendments) has achieved substantial reductions in emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx) from power plants in the United States. We compare new estimates of the benefits and costs of Title IV to th...

  13. Acidic Extracellular pH Promotes Activation of Integrin αvβ3

    PubMed Central

    Paradise, Ranjani K.; Lauffenburger, Douglas A.; Van Vliet, Krystyn J.

    2011-01-01

    Acidic extracellular pH is characteristic of the cell microenvironment in several important physiological and pathological contexts. Although it is well established that acidic extracellular pH can have profound effects on processes such as cell adhesion and migration, the underlying molecular mechanisms are largely unknown. Integrin receptors physically connect cells to the extracellular matrix, and are thus likely to modulate cell responses to extracellular conditions. Here, we examine the role of acidic extracellular pH in regulating activation of integrin αvβ3. Through computational molecular dynamics simulations, we find that acidic extracellular pH promotes opening of the αvβ3 headpiece, indicating that acidic pH can thereby facilitate integrin activation. This prediction is consistent with our flow cytometry and atomic force microscope-mediated force spectroscopy assays of integrin αvβ3 on live cells, which both demonstrate that acidic pH promotes activation at the intact cell surface. Finally, quantification of cell morphology and migration measurements shows that acidic extracellular pH affects cell behavior in a manner that is consistent with increased integrin activation. Taken together, these computational and experimental results suggest a new and complementary mechanism of integrin activation regulation, with associated implications for cell adhesion and migration in regions of altered pH that are relevant to wound healing and cancer. PMID:21283814

  14. Putting the pH into phosphatidic acid signaling

    PubMed Central

    2011-01-01

    The lipid phosphatidic acid (PA) has important roles in cell signaling and metabolic regulation in all organisms. New evidence indicates that PA also has an unprecedented role as a pH biosensor, coupling changes in pH to intracellular signaling pathways. pH sensing is a property of the phosphomonoester headgroup of PA. A number of other potent signaling lipids also contain headgroups with phosphomonoesters, implying that pH sensing by lipids may be widespread in biology. PMID:22136116

  15. Micro - ring resonator with variety of gap width for acid rain sensing application: preliminary study

    NASA Astrophysics Data System (ADS)

    Mulyanti, B.; Ramza, H.; Pawinanto, R. E.; Rahman, J. A.; Ab-Rahman, M. S.; Putro, W. S.; Hasanah, L.; Pantjawati, A. B.

    2017-05-01

    The acid rain is an environmental disaster that it will be intimidates human life. The development micro-ring resonator sensor created from SOI (Silicon on insulator) and it used to detect acid rain index. In this study, the LUMERICAL software was used to simulate SOI material micro-ring resonator. The result shows the optimum values of fixed parameters from ring resonator have dependent variable in gap width. The layers under ring resonator with silicone (Si) and wafer layer of silicone material (Si) were added to seen three conditions of capability model. Model - 3 is an additional of bottom layer that gives the significant effect on the factor of quality. The optimum value is a peak value that given by the FSR calculation. FSR = 0, it means that is not shows the light propagation in the ring resonator and none of the light coming out on the bus - line.

  16. Acid rain effects on aluminum mobilization clarified by inclusion of strong organic acids.

    PubMed

    Lawrence, G B; Sutherland, J W; Boylen, C W; Nierzwicki-Bauer, S W; Momen, B; Baldigo, B P; Simonin, H A

    2007-01-01

    Assessments of acidic deposition effects on aquatic ecosystems have often been hindered by complications from naturally occurring organic acidity. Measurements of pH and ANCG, the most commonly used indicators of chemical effects, can be substantially influenced by the presence of organic acids. Relationships between pH and inorganic Al, which is toxic to many forms of aquatic biota, are also altered by organic acids. However, when inorganic Al concentrations are plotted against ANC (the sum of Ca2+, Mg2+, Na+, and K+, minus S042-, N03-, and Cl-), a distinct threshold for Al mobilization becomes apparent. If the concentration of strong organic anions is included as a negative component of ANC, the threshold occurs at an ANC value of approximately zero, the value expected from theoretical charge balance constraints. This adjusted ANC is termed the base-cation surplus. The threshold relationship between the base-cation surplus and Al was shown with data from approximately 200 streams in the Adirondack region of New York, during periods with low and high dissolved organic carbon concentrations, and for an additional stream from the Catskill region of New York. These results indicate that (1) strong organic anions can contribute to the mobilization of inorganic Al in combination with SO42- and N03-, and (2) the presence of inorganic Al in surface waters is an unambiguous indication of acidic deposition effects.

  17. A novel acidic pH fluorescent probe based on a benzothiazole derivative

    NASA Astrophysics Data System (ADS)

    Ma, Qiujuan; Li, Xian; Feng, Suxiang; Liang, Beibei; Zhou, Tiqiang; Xu, Min; Ma, Zhuoyi

    2017-04-01

    A novel acidic pH fluorescent probe 1 based on a benzothiazole derivative has been designed, synthesized and developed. The linear response range covers the acidic pH range from 3.44 to 6.46, which is valuable for pH researches in acidic environment. The evaluated pKa value of the probe 1 is 4.23. The fluorescence enhancement of the studied probe 1 with an increase in hydrogen ions concentration is based on the hindering of enhanced photo-induced electron transfer (PET) process. Moreover, the pH sensor possesses a highly selective response to H+ in the presence of metal ions, anions and other bioactive small molecules which would be interfere with its fluorescent pH response. Furthermore, the probe 1 responds to acidic pH with short response time that was less than 1 min. The probe 1 has been successfully applied to confocal fluorescence imaging in live HeLa cells and can selectively stain lysosomes. All of such good properties prove it can be used to monitoring pH fluctuations in acidic environment with high sensitivity, pH dependence and short response time.

  18. Nestedness in Arbuscular Mycorrhizal Fungal Communities along Soil pH Gradients in Early Primary Succession: Acid-Tolerant Fungi Are pH Generalists

    PubMed Central

    Kawahara, Ai; An, Gi-Hong; Miyakawa, Sachie; Sonoda, Jun

    2016-01-01

    Soil acidity is a major constraint on plant productivity. Arbuscular mycorrhizal (AM) fungi support plant colonization in acidic soil, but soil acidity also constrains fungal growth and diversity. Fungi in extreme environments generally evolve towards specialists, suggesting that AM fungi in acidic soil are acidic-soil specialists. In our previous surveys, however, some AM fungi detected in strongly acidic soils could also be detected in a soil with moderate pH, which raised a hypothesis that the fungi in acidic soils are pH generalists. To test the hypothesis, we conducted a pH-manipulation experiment and also analyzed AM fungal distribution along a pH gradient in the field using a synthesized dataset of the previous and recent surveys. Rhizosphere soils of the generalist plant Miscanthus sinensis were collected both from a neutral soil and an acidic soil, and M. sinensis seedlings were grown at three different pH. For the analysis of field communities, rhizosphere soils of M. sinensis were collected from six field sites across Japan, which covered a soil pH range of 3.0–7.4, and subjected to soil trap culture. AM fungal community compositions were determined based on LSU rDNA sequences. In the pH-manipulation experiment the acidification of medium had a significant impact on the compositions of the community from the neutral soil, but the neutralization of the medium had no effect on those of the community from the acidic soil. Furthermore, the communities in lower -pH soils were subsets of (nested in) those in higher-pH soils. In the field communities a significant nestedness pattern was observed along the pH gradient. These observations suggest that the fungi in strongly acidic soils are pH generalists that occur not only in acidic soil but also in wide ranges of soil pH. Nestedness in AM fungal community along pH gradients may have important implications for plant community resilience and early primary succession after disturbance in acidic soils. PMID

  19. Nestedness in Arbuscular Mycorrhizal Fungal Communities along Soil pH Gradients in Early Primary Succession: Acid-Tolerant Fungi Are pH Generalists.

    PubMed

    Kawahara, Ai; An, Gi-Hong; Miyakawa, Sachie; Sonoda, Jun; Ezawa, Tatsuhiro

    2016-01-01

    Soil acidity is a major constraint on plant productivity. Arbuscular mycorrhizal (AM) fungi support plant colonization in acidic soil, but soil acidity also constrains fungal growth and diversity. Fungi in extreme environments generally evolve towards specialists, suggesting that AM fungi in acidic soil are acidic-soil specialists. In our previous surveys, however, some AM fungi detected in strongly acidic soils could also be detected in a soil with moderate pH, which raised a hypothesis that the fungi in acidic soils are pH generalists. To test the hypothesis, we conducted a pH-manipulation experiment and also analyzed AM fungal distribution along a pH gradient in the field using a synthesized dataset of the previous and recent surveys. Rhizosphere soils of the generalist plant Miscanthus sinensis were collected both from a neutral soil and an acidic soil, and M. sinensis seedlings were grown at three different pH. For the analysis of field communities, rhizosphere soils of M. sinensis were collected from six field sites across Japan, which covered a soil pH range of 3.0-7.4, and subjected to soil trap culture. AM fungal community compositions were determined based on LSU rDNA sequences. In the pH-manipulation experiment the acidification of medium had a significant impact on the compositions of the community from the neutral soil, but the neutralization of the medium had no effect on those of the community from the acidic soil. Furthermore, the communities in lower -pH soils were subsets of (nested in) those in higher-pH soils. In the field communities a significant nestedness pattern was observed along the pH gradient. These observations suggest that the fungi in strongly acidic soils are pH generalists that occur not only in acidic soil but also in wide ranges of soil pH. Nestedness in AM fungal community along pH gradients may have important implications for plant community resilience and early primary succession after disturbance in acidic soils.

  20. Acid rain effects on aluminum mobilization clarified by inclusion of strong organic acids

    USGS Publications Warehouse

    Lawrence, G.B.; Sutherland, J.W.; Boylen, C.W.; Nierzwicki-Bauer, S. W.; Momen, B.; Baldigo, Barry P.; Simonin, H.A.

    2007-01-01

    Assessments of acidic deposition effects on aquatic ecosystems have often been hindered by complications from naturally occurring organic acidity. Measurements of pH and ANCG, the most commonly used indicators of chemical effects, can be substantially influenced by the presence of organic acids. Relationships between pH and inorganic Al, which is toxic to many forms of aquatic biota, are also altered by organic acids. However, when inorganic Al concentrations are plotted against ANC (the sum of Ca2+, Mg 2+, Na+, and K+, minus SO42-, NO3-, and Cl-), a distinct threshold for Al mobilization becomes apparent. If the concentration of strong organic anions is included as a negative component of ANC, the threshold occurs at an ANC value of approximately zero, the value expected from theoretical charge balance constraints. This adjusted ANC is termed the base-cation surplus. The threshold relationship between the base-cation surplus and Al was shown with data from approximately 200 streams in the Adirondack region of New York, during periods with low and high dissolved organic carbon concentrations, and for an additional stream from the Catskill region of New York. These results indicate that (1) strong organic anions can contribute to the mobilization of inorganic Al in combination with SO42- and NO 3-, and (2) the presence of inorganic Al in surface waters is an unambiguous indication of acidic deposition effects. ?? 2007 American Chemical Society.

  1. Exogenous Melatonin Mitigates Acid Rain Stress to Tomato Plants through Modulation of Leaf Ultrastructure, Photosynthesis and Antioxidant Potential.

    PubMed

    Debnath, Biswojit; Hussain, Mubasher; Irshad, Muhammad; Mitra, Sangeeta; Li, Min; Liu, Shuang; Qiu, Dongliang

    2018-02-11

    Acid rain (AR) is a serious global environmental issue causing physio-morphological changes in plants. Melatonin, as an indoleamine molecule, has been known to mediate many physiological processes in plants under different kinds of environmental stress. However, the role of melatonin in acid rain stress tolerance remains inexpressible. This study investigated the possible role of melatonin on different physiological responses involving reactive oxygen species (ROS) metabolism in tomato plants under simulated acid rain (SAR) stress. SAR stress caused the inhibition of growth, damaged the grana lamella of the chloroplast, photosynthesis, and increased accumulation of ROS and lipid peroxidation in tomato plants. To cope the detrimental effect of SAR stress, plants under SAR condition had increased both enzymatic and nonenzymatic antioxidant substances compared with control plants. But such an increase in the antioxidant activities were incapable of inhibiting the destructive effect of SAR stress. Meanwhile, melatonin treatment increased SAR-stress tolerance by repairing the grana lamella of the chloroplast, improving photosynthesis and antioxidant activities compared with those in SAR-stressed plants. However, these possible effects of melatonin are dependent on concentration. Moreover, our study suggests that 100-μM melatonin treatment improved the SAR-stress tolerance by increasing photosynthesis and ROS scavenging antioxidant activities in tomato plants.

  2. Contributions of acid rain research to the forest science-policy interface: learning from the national acid precipitation assessment program.

    Treesearch

    Charles E. Peterson; David S. Shriner

    2004-01-01

    During the 1970s, there was growing concern by scientists, policy officials and the general public in the USA over the possible effects of acid rain on human health and the environment (crops, forests, water, etc.). The lack of science-based information needed for policy and regulatory decisions led Congress to create an interagency task force in 1980 called the...

  3. Effects of simulated acid rain, EDTA, or their combination, on migration and chemical fraction distribution of extraneous metals in Ferrosol.

    PubMed

    Wen, Fang; Hou, Hong; Yao, Na; Yan, Zengguang; Bai, Liping; Li, Fasheng

    2013-01-01

    A laboratory repacked soil-leaching column experiment was conducted to study the effects of simulated acid rain or EDTA by themselves or in combination, on migration and chemical speciation distribution of Pb and its alternative rare metals including Ag, Bi, In, Sb, and Sn. Experimental results demonstrate that leaching with simulated acid rain promoted the migration of Bi, In and Pb, and their migration reached down to 8 cm in the soil profile, no enhancement of Sb, Ag or Sn migration was observed. Addition of EDTA significantly enhanced the migration of all six metals, especially Bi, In and Pb. The migration of metals was in the order Pb>Bi>In>Sb>Sn>Ag. The individual and combined effects of acid rain and EDTA increased the environmental risk of metals, by increasing the soluble content of metals in soil solutions and the relative distribution of the exchangeable fraction. Leaching risks of Bi, In and Pb were higher than other three metals. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Extracellular Acidic pH Inhibits Oligodendrocyte Precursor Viability, Migration, and Differentiation

    PubMed Central

    Jagielska, Anna; Wilhite, Kristen D.; Van Vliet, Krystyn J.

    2013-01-01

    Axon remyelination in the central nervous system requires oligodendrocytes that produce myelin. Failure of this repair process is characteristic of neurodegeneration in demyelinating diseases such as multiple sclerosis, and it remains unclear how the lesion microenvironment contributes to decreased remyelination potential of oligodendrocytes. Here, we show that acidic extracellular pH, which is characteristic of demyelinating lesions, decreases the migration, proliferation, and survival of oligodendrocyte precursor cells (OPCs), and reduces their differentiation into oligodendrocytes. Further, OPCs exhibit directional migration along pH gradients toward acidic pH. These in vitro findings support a possible in vivo scenario whereby pH gradients attract OPCs toward acidic lesions, but resulting reduction in OPC survival and motility in acid decreases progress toward demyelinated axons and is further compounded by decreased differentiation into myelin-producing oligodendrocytes. As these processes are integral to OPC response to nerve demyelination, our results suggest that lesion acidity could contribute to decreased remyelination. PMID:24098762

  5. Acidity of Lakes and Impoundments in North-Central Minnesota

    Treesearch

    Elon S. Verry

    1981-01-01

    Measurements of lake and impoundment pH for several years, intensive sampling within years, and pH-calcium plots verify normal pH levels and do not show evidence of changes due to acid precipitation. These data in comparison with general lake data narrow the northern Lake States area in which rain or snow may cause lake acidification.

  6. Acid rain publications by the U.S. Fish and Wildlife Service, 1979-1989

    USGS Publications Warehouse

    Villella, Rita F.

    1989-01-01

    Pollution of aquatic and terrestrial ecosystems has been a concern to society since the burning of fossil fuels began in the industrial revolution. In the past decade or so, this concern has been heightened by evidence that chemical transformation in the atmosphere of combustion by-products and subsequent long-range transport can cause environmental damage in remote areas. The extent of this damage and the rates of ecological recovery were largely unknown. "Acid rain" became the environmental issue of the 1980's. To address the increasing concerns of the public, in 1980 the Federal government initiated a 10-year interagency research program to develop information that could be used by the President and the Congress in making decisions for emission controls. The U.S. Fish and Wildlife Service has been an active participant in acid precipitation research. The Service provided support to a number of scientific conferences and forums, including the Action Seminar on Acid Precipitation held in Toronto, Canada, in 1979, an international symposium on Acidic Precipitation and Fishery Impacts in Northeastern North America in 1981, and a symposium on Acidic Precipitation and Atmospheric Deposition: A Western Perspective in 1982. These meetings as well as the growing involvement with the government's National Acidic Precipitation Assessment Program placed the Service in the lead in research on the biological effects of acidic deposition. Research projects have encompassed water chemistry, aquatic invertebrates, amphibians, fish, and waterfowl. Water quality surveys have been conducted to help determine the extent of acid precipitation effects in the northeast, Middle Atlantic, and Rocky Mountain regions. In addition to lake and stream studies, research in wetland and some terrestrial habitats has also been conducted. Specific projects have addressed important sport species such as brook trout (Salvelinus fontinalis), Atlantic salmon (Salmo salar), and striped bass (Morone

  7. Acid rain recovery may help to mitigate the impacts of climate change on thermally sensitive fish in lakes across eastern North America.

    PubMed

    Warren, Dana R; Kraft, Clifford E; Josephson, Daniel C; Driscoll, Charles T

    2017-06-01

    From the 1970s to 1990s, more stringent air quality regulations were implemented across North America and Europe to reduce chemical emissions that contribute to acid rain. Surface water pH slowly increased during the following decades, but biological recovery lagged behind chemical recovery. Fortunately, this situation is changing. In the past few years, northeastern US fish populations have begun to recover in lakes that were historically incapable of sustaining wild fish due to acidic conditions. As lake ecosystems across the eastern United States recover from acid deposition, the stress to the most susceptible populations of native coldwater fish appears to be shifting from acidification effects to thermal impacts associated with changing climate. Extreme summer temperature events - which are expected to occur with increasing frequency in the coming century - can stress and ultimately kill native coldwater fish in lakes where thermal stratification is absent or highly limited. Based on data from northeastern North America, we argue that recovery from acid deposition has the potential to improve the resilience of coldwater fish populations in some lakes to impacts of climate change. This will occur as the amount of dissolved organic carbon (DOC) in the water increases with increasing lake pH. Increased DOC will reduce water clarity and lead to shallower and more persistent lake thermoclines that can provide larger areas of coldwater thermal refuge habitat. Recovery from acidification will not eliminate the threat of climate change to coldwater fish, but secondary effects of acid recovery may improve the resistance of coldwater fish populations in lakes to the effects of elevated summer temperatures in historically acidified ecosystems. This analysis highlights the importance of considering the legacy of past ecosystem impacts and how recovery or persistence of those effects may interact with climate change impacts on biota in the coming decades. © 2016 John

  8. Primordial soup or vinaigrette: did the RNA world evolve at acidic pH?

    PubMed Central

    2012-01-01

    Background The RNA world concept has wide, though certainly not unanimous, support within the origin-of-life scientific community. One view is that life may have emerged as early as the Hadean Eon 4.3-3.8 billion years ago with an atmosphere of high CO2 producing an acidic ocean of the order of pH 3.5-6. Compatible with this scenario is the intriguing proposal that life arose within alkaline (pH 9-11) deep-sea hydrothermal vents like those of the 'Lost City', with the interface with the acidic ocean creating a proton gradient sufficient to drive the first metabolism. However, RNA is most stable at pH 4-5 and is unstable at alkaline pH, raising the possibility that RNA may have first arisen in the acidic ocean itself (possibly near an acidic hydrothermal vent), acidic volcanic lake or comet pond. As the Hadean Eon progressed, the ocean pH is inferred to have gradually risen to near neutral as atmospheric CO2 levels decreased. Presentation of the hypothesis We propose that RNA is well suited for a world evolving at acidic pH. This is supported by the enhanced stability at acidic pH of not only the RNA phosphodiester bond but also of the aminoacyl-(t)RNA and peptide bonds. Examples of in vitro-selected ribozymes with activities at acid pH have recently been documented. The subsequent transition to a DNA genome could have been partly driven by the gradual rise in ocean pH, since DNA has greater stability than RNA at alkaline pH, but not at acidic pH. Testing the hypothesis We have proposed mechanisms for two key RNA world activities that are compatible with an acidic milieu: (i) non-enzymatic RNA replication of a hemi-protonated cytosine-rich oligonucleotide, and (ii) specific aminoacylation of tRNA/hairpins through triple helix interactions between the helical aminoacyl stem and a single-stranded aminoacylating ribozyme. Implications of the hypothesis Our hypothesis casts doubt on the hypothesis that RNA evolved in the vicinity of alkaline hydrothermal vents. The

  9. The chemistry of the severe acidic precipitation in Shanghai, China

    NASA Astrophysics Data System (ADS)

    Huang, Kan; Zhuang, Guoshun; Xu, Chang; Wang, Ying; Tang, Aohan

    2008-07-01

    Seventy-six rain samples from forty-seven rain events and TSP aerosol samples throughout the entire year of 2005 were collected in Shanghai, China. The annual mean pH in rain was 4.49 with the lowest pH of 2.95, and the frequency of acid rain was 71% in 2005. The acidity of rain increased more than 15 times in the past 8 years compared to 1997. The volume-weighted mean ionic concentrations of the acidic ions, SO 42- and NO 3- in rainwater were 199.59 and 49.80 μeq/L with maximum of 832.67 and 236.59 μeq/L, respectively. The concentration of SO 42- was higher than the most polluted cities abroad, indicating Shanghai has been a severe polluted city over the world. The high coal/fuel consumption from urbanization and the rapid increase of vehicles resulted in the high emission of SO 2 and NO x, the precursor of the high concentration of acidic ions, SO 42- and NO 3-, which were the main reason of the severe acid rain in Shanghai. The major ions showed clear temporal variations with higher concentrations of SO 42-, NO 3-, NH 4+, and Ca 2+ in spring/winter, of Na +, Cl -, K +, and Mg 2+ in autumn, and the lowest of all the ions in summer. SO 42- and NO 3- were mainly in the form of CaSO 4 and Ca(NO 3) 2, which showed the dominant neutralization effect of Ca 2+ over NH 4+. Source identification indicated that SO 42-, NO 3-, NH 4+ and most Ca 2+ derived from anthropogenic sources, K +, Mg 2+ and partial Ca 2+ originated from mineral, and almost all the Cl - and Na + from the sea. The chemistry of precipitation in Shanghai was under the influence of local pollution sources and the long- and moderate-range transport through back trajectory analysis.

  10. Effects of acid deposition on dissolution of carbonate stone during summer storms in the Adirondack Mountains, New York, 1987-89

    USGS Publications Warehouse

    Schuster, Paul F.; Reddy, Michael M.; Sherwood, S.I.

    1994-01-01

    This study is part of a long-term research program designed to identify and quantify acid rain damage to carbonate stone. Acidic deposition accelerates the dissolution of carbonate-stone monuments and building materials. Sequential sampling of runoff from carbonate-stone (marble) and glass (reference) microcatchments in the Adirondack Mountains in New York State provided a detailed record of the episodic fluctuations in rain rate and runoff chemistry during individual summer storms. Rain rate and chemical concentrations from carbonate-stone and glass runoff fluctuated three to tenfold during storms. Net calcium-ion concentrations from the carbonatestone runoff, a measure of stone dissolution, typically fluctuated twofold during these storms. High net sulfate and net calcium concentrations in the first effective runoff at the start of a storm indicated that atmospheric pollutants deposited on the stone surface during dry periods formed calcium sulfate minerals, an important process in carbonate stone dissolution. Dissolution of the carbonate stone generally increased up to twofold during coincident episodes of low rain rate (less than 5 millimeters per hour) and decreased rainfall (glass runoff) pH (less than 4.0); episodes of high rain rate (cloudbursts) were coincident with a rapid increase in rainfall pH and also a rapid decrease in the dissolution of carbonate-stone. During a storm, it seems the most important factors causing increased dissolution of carbonate stone are coincident periods of low rain rate and decreased rainfall pH. Dissolution of the carbonate stone decreased slightly as the rain rate exceeded about 5 millimeters per hour, probably in response to rapidly increasing rainfall pH during episodes of high rain rate and shorter contact time between the runoff and the stone surface. High runoff rates resulting from cloudbursts remove calcium sulfate minerals formed during dry periods prior to storms and also remove dissolution products formed in large

  11. [Spatiotemporal variation of soil pH in Guangdong Province of China in past 30 years].

    PubMed

    Guo, Zhi-Xing; Wang, Jing; Chai, Min; Chen, Ze-Peng; Zhan, Zhen-Shou; Zheng, Wu-Ping; Wei, Xiu-Guo

    2011-02-01

    Based on the 1980s' soil inventory data and the 2002-2007 soil pH data of Guangdong Province, the spatiotemporal variation of soil pH in the Province in past 30 years was studied. In the study period, the spatial distribution pattern of soil pH in the Province had less change (mainly acidic), except that in Pearl River Delta and parts of Qingyuan and Shaoguan (weak alkaline). The overall variation of soil pH was represented as acidification, with the average pH value changed from 5.70 to 5.44. Among the soil types in the Province, alluvial soil had an increased pH, lateritic red soil, paddy soil, and red soil had a large decrement of pH value, and lime soil was most obvious in the decrease of pH value and its area percentage. The soil acidification was mainly induced by soil characteristics, some natural factors such as acid rain, and human factors such as unreasonable fertilization and urbanization. In addition, industrialization and mining increased the soil pH in some areas.

  12. The Fugitive Literature of Acid Rain: Making Use of Nonconventional Information Sources in a Vertical File.

    ERIC Educational Resources Information Center

    Lovenburg, Susan L.; Stoss, Frederick W.

    1988-01-01

    Discusses the advantages of vertical file collections for nonconventional literature, and describes the classification scheme used for fugitive literature by the Acid Rain Information Clearinghouse at the Center for Environmental Information. An annotated list of organizations and examples of titles they offer is provided. (8 notes with…

  13. Acidic pH sensing in the bacterial cytoplasm is required for Salmonella virulence.

    PubMed

    Choi, Jeongjoon; Groisman, Eduardo A

    2016-09-01

    pH regulates gene expression, biochemical activities and cellular behaviors. A mildly acidic pH activates the master virulence regulatory system PhoP/PhoQ in the facultative intracellular pathogen Salmonella enterica serovar Typhimurium. The sensor PhoQ harbors an extracytoplasmic domain implicated in signal sensing, and a cytoplasmic domain controlling activation of the regulator PhoP. We now report that, surprisingly, a decrease in Salmonella's own cytoplasmic pH induces transcription of PhoP-activated genes even when the extracytoplasmic pH remains neutral. Amino acid substitutions in PhoQ's cytoplasmic domain hindered activation by acidic pH and attenuated virulence in mice, but did not abolish activation by low Mg(2+) or the antimicrobial peptide C18G. Conversely, removal of PhoQ's extracytoplasmic domains prevented the response to the latter PhoQ-activating signals but not to acidic pH. PhoP-dependent genes were minimally induced by acidic pH in the non-pathogenic species Salmonella bongori but were activated by low Mg(2+) and C18G as in pathogenic S. enterica. Our findings indicate that the sensor PhoQ enables S. enterica to respond to both host- and bacterial-derived signals that alter its cytoplasmic pH. © 2016 John Wiley & Sons Ltd.

  14. The future of emissions trading in light of the acid rain experience

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    McLean, B.J.; Rico, R.

    1995-12-31

    The idea of emissions trading was developed more than two decades ago by environmental economists eager to provide new ideas for how to improve the efficiency of environmental protection. However, early emissions trading efforts were built on the historical {open_quotes}command and control{close_quotes} infrastructure which has dominated U.S. environmental protection until today. The {open_quotes}command and control{close_quotes} model initially had advantages that were of a very pragmatic character: it assured large pollution reductions in a time when large, cheap reductions were available and necessary; and it did not require a sophisticated government infrastructure. Within the last five years, large-scale emission trading programsmore » have been successfully designed and started that are fundamentally different from the earlier efforts, creating a new paradigm for environmental control just when our understanding of environmental problems is changing as well. The purpose of this paper is to focus on the largest national-scale program--the Acid Rain Program--and from that experience, forecast when emission trading programs may be headed based on our understanding of the factors currently influencing environmental management. The first section of this paper will briefly review the history of emissions trading programs, followed by a summary of the features of the Acid Rain Program, highlighting those features that distinguish it from previous efforts. The last section addresses the opportunities for emissions trading (and its probable future directions).« less

  15. Acid Rain Data System: Progressive application of information technology for operation of a market-based environmental program

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Price, D.A.

    1995-12-31

    Under the Acid Rain Program, by statute and regulation, affected utility units are allocated annual allowances. Each allowance permits a unit to emit one ton of SO{sub 2} during or after a specified year. At year end, utilities must hold allowances equal to or greater than the cumulative SO{sub 2} emissions throughout the year from their affected units. The program has been developing, on a staged basis, two major computer-based information systems: the Allowance Tracking System (ATS) for tracking creation, transfer, and ultimate use of allowances; and the Emissions Tracking System (ETS) for transmission, receipt, processing, and inventory of continuousmore » emissions monitoring (CEM) data. The systems collectively form a logical Acid Rain Data System (ARDS). ARDS will be the largest information system ever used to operate and evaluate an environmental program. The paper describes the progressive software engineering approach the Acid Rain Program has been using to develop ARDS. Iterative software version releases, keyed to critical program deadlines, add the functionality required to support specific statutory and regulatory provisions. Each software release also incorporates continual improvements for efficiency, user-friendliness, and lower life-cycle costs. The program is migrating the independent ATS and ETS systems into a logically coordinated True-Up processing model, to support the end-of-year reconciliation for balancing allowance holdings against annual emissions and compliance plans for Phase 1 affected utility units. The paper provides specific examples and data to illustrate exciting applications of today`s information technology in ARDS.« less

  16. Economic, Environmental, and Coal Market Impacts of Sulfur Dioxide Emissions Trading under Alternative Acid Rain Control Proposals (1989)

    EPA Pesticide Factsheets

    This report examines the ramifications of diferent levels of emissions trading in the context of tro representative electric utility sulfur dioxide emisson reduction proposals designed to control acid rain, and in the absence of any new control program.

  17. Anthropogenic and volcanic emission impacts on SO2 dynamics and acid rain profiles. Numerical study using WRF-Chem in a high-resolution modeling

    NASA Astrophysics Data System (ADS)

    Vela, A. V.; González, C. M.; Ynoue, R.; Rojas, N. Y.; Aristizábal, B. H.; Wahl, M.

    2017-12-01

    Eulerian 3-D chemistry transport models (CTM) have been widely used for the study of air quality in urban environments, becoming an essential tool for studying the impacts and dynamics of gases and aerosols on air quality. However, their use in Colombia is scarce, especially in medium-sized cities, which are experimenting a fast urban growth, increasing the risk associated with possible air pollution episodes. In the densely populated medium-sized Andean city of Manizales, Colombia - a city located on the western slopes of the central range of the Andes (urban population 368000; 2150 m.a.s.l), there is an influence of the active Nevado del Ruiz volcano, located 28 km to the southwest. This natural source emits daily gas and particle fluxes, which could influence the atmospheric chemistry of the city and neighboring towns. Hence, the zone presents a unique combination of anthropogenic and volcanic sulfur gas emissions, which affects SO2 dynamics in the urban area, influencing also in the formation of acid rain phenomenon in the city. Therefore, studies analyzing the relative contribution of anthropogenic and volcanic emission could contribute with a deep understanding about causes and dynamics of both acid rain phenomenon and ambient SO2 levels in Manizales. This work aimed to analyze the influence of anthropogenic (on-road vehicular and industrial point-sources) and volcanic sulfur emissions in SO2 atmospheric chemistry dynamics, evaluating its possible effects on acid rain profiles. Ambient SO2 levels and day-night rain samples were measured and used to analyze results obtained from the application of the fully-coupled on-line WRF-Chem model. Two high-resolution simulations were performed during two dry and wet one-week periods in 2015. Analysis of SO2 dispersion patterns and comparison with SO2 observations in the urban area were performed for three different scenarios in which natural and anthropogenic emissions were simulated separately. Results suggest that

  18. Average rainwater pH, concepts of atmospheric acidity, and buffering in open systems

    NASA Astrophysics Data System (ADS)

    Liljestrand, Howard M.

    The system of water equilibrated with a constant partial pressure of CO 2, as a reference point for pH acidity-alkalinity relationships, has nonvolatile acidity and alkalinity components as conservative quantities, but not [H +]. Simple algorithms are presented for the determination of the average pH for combinations of samples both above and below pH 5.6. Averaging the nonconservative quantity [H +] yields erroneously low mean pH values. To extend the open CO 2 system to include other volatile atmospheric acids and bases distributed among the gas, liquid and particulate matter phases, a theoretical framework for atmospheric acidity is presented. Within certain oxidation-reduction limitations, the total atmospheric acidity (but not free acidity) is a conservative quantity. The concept of atmospheric acidity is applied to air-water systems approximating aerosols, fogwater, cloudwater and rainwater. The buffer intensity in hydrometeors is described as a function of net strong acidity, partial pressures of acid and base gases and the water to air ratio. For high liquid to air volume ratios, the equilibrium partial pressures of trace acid and base gases are set by the pH or net acidity controlled by the nonvolatile acid and base concentrations. For low water to air volume ratios as well as stationary state systems such as precipitation scavenging with continuous emissions, the partial pressures of trace gases (NH 3, HCl, HNO 3, SO 2 and CH 3COOH) appear to be of greater or equal importance as carbonate species as buffers in the aqueous phase.

  19. Towards control of aggregational behaviour of alpha-lactalbumin at acidic pH.

    PubMed

    Pedersen, Jane B; Fojan, Peter; Sorensen, John; Petersen, Steffen B

    2006-07-01

    alpha-Lactalbumin (alpha-La) undergoes considerable structural changes upon loss of bound Ca2+ at acidic pH, leaving alpha-La in a molten globule structure. Using fluorescence the present work provides more insight into the structural transition of alpha-La at acidic pH leading to protein aggregation, most likely caused by a combination of hydrophobic and electrostatic interactions. The rate of aggregation is determined by the protein concentration and temperature applied. Availability of Ca2+ stabilises the protein, and thus prevent aggregation at pH values as low as pH 2.9. In contrast, presence of Cu2+ induces a destabilisation of the protein, which can be explained by a binding to the Zn2+ binding site in alpha-La, possibly resulting in structural alterations of the protein. In general, presence of anions destabilize alpha-La at pH values below pI, with SO4(2-) exhibiting the strongest effect on the protein stability, thus correlating well with the Hofmeister series. At more acidic pH values far from pI, alpha-La becomes more stable towards ion induced aggregation, since higher ion activity is required to efficiently screen the charges on the protein surface. The results presented in this paper provide detailed knowledge on the external parameters leading to aggregation of alpha-La at acidic pH, thus permitting rational design of the aggregation process.

  20. An evaluation of rain chemistry data for the John F. Kennedy Space Center, Florida and the University of Central Florida, Orlando

    NASA Technical Reports Server (NTRS)

    Madsen, Brooks C.; Dreschel, Thomas W.; Hinkle, C. Ross

    1986-01-01

    Concern over the effects of Space Shuttle launches prompted the initiation of a rather intense environmental monitoring program. The program included a precipitation monitoring network with 13 precipitation collection sites which were operated for various time periods to baseline precipitation chemistry at the John F. Kennedy Space Center (KSC). One additional site was also established as a remote background site on the Univ. of Central Florida (UCF) campus. One of the 13 sites was converted to a National Atmospheric Deposition Program (NADP) station. Collections and analyses of samples were performed using a number of methodologies during the monitoring period. An evaluation of the data for comparability and utility for acid rain research was performed using the anion/cation, measured conductivity, calculated conductivity, Cl/Na, and Mg/Na ratios. Data collected at all KSC sites between 1977 and 1981, from 1983 to 1985 at the NADP site and at UCF to 1985 are comparable and appropriate for determining acid rain trends. Examination of those comparable data showed a fairly stable pH between 1977 and 1982 and an increase of 0.2 pH units which was observed as an incremental increase between 1982 and 1983 at KSC and UCF.

  1. Interaction of melanin with proteins--the importance of an acidic intramelanosomal pH.

    PubMed

    Mani, I; Sharma, V; Tamboli, I; Raman, G

    2001-06-01

    Melanin is a highly irregular heteropolymer consisting of monomeric units derived from the enzymatic oxidation of the amino acid tyrosine. The process of melanin formation takes place in specialized acidic organelles (melanosomes) in melanocytes. The process of melanin polymerization requires an alkaline pH in vitro, and therefore, the purpose of an acidic environment in vivo remains a mystery. It is known that melanin is always bound to protein in vivo. It is also seen that polymerization in vitro at an acidic pH necessarily requires the presence of proteins. The effect of various model proteins on melanin synthesis and their interaction with melanin was studied. It was seen that many proteins could increase melanin synthesis at an acidic pH, and that different proteins resulted in the formation of different states of melanin, i.e., a precipitate or a soluble, protein-bound form. We also present evidence to show that soluble protein-bound melanin is present in vivo (in B16 cells as well as in B16 melanoma tissue). An acidic pH appeared to be necessary to ensure the formation of a uniform, very high molecular weight melano-protein complex. The interaction between melanin and proteins appears to be largely charge-dependent as evidenced by zeta potential measurements, and this interaction is also increased in an acidic pH. Thus, it appears that an acidic intramelanosomal pH is essential to ensure maximum interaction between protein and melanin, and also to ensure that all the melanin formed is protein-bound.

  2. Imaging of pH in vivo using hyperpolarized 13C-labelled zymonic acid

    PubMed Central

    Düwel, Stephan; Hundshammer, Christian; Gersch, Malte; Feuerecker, Benedikt; Steiger, Katja; Buck, Achim; Walch, Axel; Haase, Axel; Glaser, Steffen J.; Schwaiger, Markus; Schilling, Franz

    2017-01-01

    Natural pH regulatory mechanisms can be overruled during several pathologies such as cancer, inflammation and ischaemia, leading to local pH changes in the human body. Here we demonstrate that 13C-labelled zymonic acid (ZA) can be used as hyperpolarized magnetic resonance pH imaging sensor. ZA is synthesized from [1-13C]pyruvic acid and its 13C resonance frequencies shift up to 3.0 p.p.m. per pH unit in the physiological pH range. The long lifetime of the hyperpolarized signal enhancement enables monitoring of pH, independent of concentration, temperature, ionic strength and protein concentration. We show in vivo pH maps within rat kidneys and subcutaneously inoculated tumours derived from a mammary adenocarcinoma cell line and characterize ZA as non-toxic compound predominantly present in the extracellular space. We suggest that ZA represents a reliable and non-invasive extracellular imaging sensor to localize and quantify pH, with the potential to improve understanding, diagnosis and therapy of diseases characterized by aberrant acid-base balance. PMID:28492229

  3. Influence of sodium chloride, pH, and lactic acid bacteria on anaerobic lactic acid utilization during fermented cucumber spoilage.

    PubMed

    Johanningsmeier, Suzanne D; Franco, Wendy; Perez-Diaz, Ilenys; McFeeters, Roger F

    2012-07-01

    Cucumbers are preserved commercially by natural fermentations in 5% to 8% sodium chloride (NaCl) brines. Occasionally, fermented cucumbers spoil after the primary fermentation is complete. This spoilage has been characterized by decreases in lactic acid and a rise in brine pH caused by microbial instability. Objectives of this study were to determine the combined effects of NaCl and pH on fermented cucumber spoilage and to determine the ability of lactic acid bacteria (LAB) spoilage isolates to initiate lactic acid degradation in fermented cucumbers. Cucumbers fermented with 0%, 2%, 4%, and 6% NaCl were blended into slurries (FCS) and adjusted to pH 3.2, 3.8, 4.3, and 5.0 prior to centrifugation, sterile-filtration, and inoculation with spoilage organisms. Organic acids and pH were measured initially and after 3 wk, 2, 6, 12, and 18 mo anaerobic incubation at 25 °C. Anaerobic lactic acid degradation occurred in FCS at pH 3.8, 4.3, and 5.0 regardless of NaCl concentration. At pH 3.2, reduced NaCl concentrations resulted in increased susceptibility to spoilage, indicating that the pH limit for lactic acid utilization in reduced NaCl fermented cucumbers is 3.2 or lower. Over 18 mo incubation, only cucumbers fermented with 6% NaCl to pH 3.2 prevented anaerobic lactic acid degradation by spoilage bacteria. Among several LAB species isolated from fermented cucumber spoilage, Lactobacillus buchneri was unique in its ability to metabolize lactic acid in FCS with concurrent increases in acetic acid and 1,2-propanediol. Therefore, L. buchneri may be one of multiple organisms that contribute to development of fermented cucumber spoilage. Microbial spoilage of fermented cucumbers during bulk storage causes economic losses for producers. Current knowledge is insufficient to predict or control these losses. This study demonstrated that in the absence of oxygen, cucumbers fermented with 6% sodium chloride to pH 3.2 were not subject to spoilage. However, lactic acid was degraded

  4. Acid rain mitigation experiment shifts a forested watershed from a net sink to a net source of nitrogen

    PubMed Central

    Rosi-Marshall, Emma J.; Bernhardt, Emily S.; Buso, Donald C.; Driscoll, Charles T.; Likens, Gene E.

    2016-01-01

    Decades of acid rain have acidified forest soils and freshwaters throughout montane forests of the northeastern United States; the resulting loss of soil base cations is hypothesized to be responsible for limiting rates of forest growth throughout the region. In 1999, an experiment was conducted that reversed the long-term trend of soil base cation depletion and tested the hypothesis that calcium limits forest growth in acidified soils. Researchers added 1,189 kg Ca2+ ha−1 as the pelletized mineral wollastonite (CaSiO3) to a 12-ha forested watershed within the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire. Significant increases in the pH and acid-neutralizing capacity of soils and streamwater resulted, and the predicted increase in forest growth occurred. An unanticipated consequence of this acidification mitigation experiment began to emerge a decade later, with marked increases in dissolved inorganic nitrogen (DIN) exports in streamwater from the treated watershed. By 2013, 30-times greater DIN was exported from this base-treated watershed than from adjacent reference watersheds, and DIN exports resulting from this experiment match or exceed earlier reports of inorganic N losses after severe ice-storm damage within the study watershed. The discovery that CaSiO3 enrichment can convert a watershed from a sink to a source of N suggests that numerous potential mechanisms drive watershed N dynamics and provides new insights into the influence of acid deposition mitigation strategies for both carbon cycling and watershed N export. PMID:27335456

  5. Acid rain mitigation experiment shifts a forested watershed from a net sink to a net source of nitrogen.

    PubMed

    Rosi-Marshall, Emma J; Bernhardt, Emily S; Buso, Donald C; Driscoll, Charles T; Likens, Gene E

    2016-07-05

    Decades of acid rain have acidified forest soils and freshwaters throughout montane forests of the northeastern United States; the resulting loss of soil base cations is hypothesized to be responsible for limiting rates of forest growth throughout the region. In 1999, an experiment was conducted that reversed the long-term trend of soil base cation depletion and tested the hypothesis that calcium limits forest growth in acidified soils. Researchers added 1,189 kg Ca(2+) ha(-1) as the pelletized mineral wollastonite (CaSiO3) to a 12-ha forested watershed within the Hubbard Brook Experimental Forest in the White Mountains of New Hampshire. Significant increases in the pH and acid-neutralizing capacity of soils and streamwater resulted, and the predicted increase in forest growth occurred. An unanticipated consequence of this acidification mitigation experiment began to emerge a decade later, with marked increases in dissolved inorganic nitrogen (DIN) exports in streamwater from the treated watershed. By 2013, 30-times greater DIN was exported from this base-treated watershed than from adjacent reference watersheds, and DIN exports resulting from this experiment match or exceed earlier reports of inorganic N losses after severe ice-storm damage within the study watershed. The discovery that CaSiO3 enrichment can convert a watershed from a sink to a source of N suggests that numerous potential mechanisms drive watershed N dynamics and provides new insights into the influence of acid deposition mitigation strategies for both carbon cycling and watershed N export.

  6. Hyperpolarized Amino Acid Derivatives as Multivalent Magnetic Resonance pH Sensor Molecules.

    PubMed

    Hundshammer, Christian; Düwel, Stephan; Ruseckas, David; Topping, Geoffrey; Dzien, Piotr; Müller, Christoph; Feuerecker, Benedikt; Hövener, Jan B; Haase, Axel; Schwaiger, Markus; Glaser, Steffen J; Schilling, Franz

    2018-02-15

    pH is a tightly regulated physiological parameter that is often altered in diseased states like cancer. The development of biosensors that can be used to non-invasively image pH with hyperpolarized (HP) magnetic resonance spectroscopic imaging has therefore recently gained tremendous interest. However, most of the known HP-sensors have only individually and not comprehensively been analyzed for their biocompatibility, their pH sensitivity under physiological conditions, and the effects of chemical derivatization on their logarithmic acid dissociation constant (p K a ). Proteinogenic amino acids are biocompatible, can be hyperpolarized and have at least two pH sensitive moieties. However, they do not exhibit a pH sensitivity in the physiologically relevant pH range. Here, we developed a systematic approach to tailor the p K a of molecules using modifications of carbon chain length and derivatization rendering these molecules interesting for pH biosensing. Notably, we identified several derivatives such as [1- 13 C]serine amide and [1- 13 C]-2,3-diaminopropionic acid as novel pH sensors. They bear several spin-1/2 nuclei ( 13 C, 15 N, 31 P) with high sensitivity up to 4.8 ppm/pH and we show that 13 C spins can be hyperpolarized with dissolution dynamic polarization (DNP). Our findings elucidate the molecular mechanisms of chemical shift pH sensors that might help to design tailored probes for specific pH in vivo imaging applications.

  7. Separating analysis from politics: Acid rain in Europe

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Patt, A.

    Over the last twenty years, policy-makers in Europe have attempted to solve the problem of acid rain using detailed analysis grounded in natural science and economics. The results are impressive, as Europeans have successfully implemented a number of international agreements to reduce pollution emissions, agreements that in theory achieve the greatest environmental benefit at the lowest aggregate cost across Europe. This article examines the analysis on which these policies were based. First, it finds a pattern of investigating the use of cost-benefit analysis, together with a lack of usefulness associated with the actual results of such analysis. Second, it findsmore » that the analytic framework that came to replace cost-benefit analysis--critical loads--contained many of the same uncertainties and political decisions that plagued cost-benefit analysis. Nevertheless, critical loads analysis was seen as less value-laden and more reliable, and contributed significantly to policy development. Desire for rapid action led policy-makers to ignore or overlook the politics and uncertainties inherent in efforts at scientific assessment and modeling.« less

  8. Effects of simulated acid rain, ozone and sulfur dioxide on suitability of elms for elm leaf beetle

    Treesearch

    Richard W. Hall; Jack H. Barger; Alden M. Townsend

    1988-01-01

    Cuttings from two clonally propagated elm hybrids ('Pioneer' and 'Homestead') were treated with ozone (03), sulfur dioxide (S02), simulated acid rain or left untreated. Fumigants were applied 7 hours per day, 5 days per week for 9 weeks in open-top chambers. Fumigation treatments were: 0.1 ppm 0

  9. Enhancing tolerance of rice (Oryza sativa) to simulated acid rain by exogenous abscisic acid.

    PubMed

    Wu, Xi; Liang, Chanjuan

    2017-02-01

    Abscisic acid (ABA) regulates much important plant physiological and biochemical processes and induces tolerance to different stresses. Here, we studied the regulation of exogenous ABA on adaptation of rice seedlings to simulated acid rain (SAR) stress by measuring biomass dry weight, stomatal conductance, net photosynthesis rate, nutrient elements, and endogenous hormones. The application of 10 μM ABA alleviated the SAR-induced inhibition on growth, stomatal conductance, net photosynthesis rate, and decreases in contents of nutrient (K, Mg, N, and P) and hormone (auxin, gibberellins, and zeatin). Moreover, 10 μM ABA could stimulate the Ca content as signaling molecules under SAR stress. Contrarily, the application of 100 μM ABA aggravated the SAR-induced inhibition on growth, stomatal conductance, net photosynthesis rate, and contents of nutrient and hormone. The results got after a 5-day recovery (without SAR) show that exogenous 10 μM ABA can promote self-restoration process in rice whereas 100 μM ABA hindered the restoration by increasing deficiency of nutrients and disturbing the balance of hormones. These results confirmed that exogenous ABA at proper concentration could enhance the tolerance of rice to SAR stress.

  10. Monascus ruber as cell factory for lactic acid production at low pH.

    PubMed

    Weusthuis, Ruud A; Mars, Astrid E; Springer, Jan; Wolbert, Emil Jh; van der Wal, Hetty; de Vrije, Truus G; Levisson, Mark; Leprince, Audrey; Houweling-Tan, G Bwee; Pha Moers, Antoine; Hendriks, Sjon Na; Mendes, Odette; Griekspoor, Yvonne; Werten, Marc Wt; Schaap, Peter J; van der Oost, John; Eggink, Gerrit

    2017-07-01

    A Monascus ruber strain was isolated that was able to grow on mineral medium at high sugar concentrations and 175g/l lactic acid at pH 2.8. Its genome and transcriptomes were sequenced and annotated. Genes encoding lactate dehydrogenase (LDH) were introduced to accomplish lactic acid production and two genes encoding pyruvate decarboxylase (PDC) were knocked out to subdue ethanol formation. The strain preferred lactic acid to glucose as carbon source, which hampered glucose consumption and therefore also lactic acid production. Lactic acid consumption was stopped by knocking out 4 cytochrome-dependent LDH (CLDH) genes, and evolutionary engineering was used to increase the glucose consumption rate. Application of this strain in a fed-batch fermentation resulted in a maximum lactic acid titer of 190g/l at pH 3.8 and 129g/l at pH 2.8, respectively 1.7 and 2.2 times higher than reported in literature before. Yield and productivity were on par with the best strains described in literature for lactic acid production at low pH. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  11. Is Your Drinking Water Acidic? A Comparison of the Varied pH of Popular Bottled Waters.

    PubMed

    Wright, Kellie F

    2015-06-01

    Dental professionals continually educate patients on the dangers of consuming acidic foods and beverages due to their potential to contribute to dental erosion and tooth decay. Excess acid in the diet can also lead to acidosis, which causes negative systemic side effects. However, water is not typically categorized as acidic. The purpose of this in-vitro study was to investigate the pH levels of several popular brands of bottled water and compare them to various other acidic beverages. Two different brands of marketed alkaline water (with a pH of 8.8 or higher) were also studied, tested for acidity and described. A pilot in-vitro study was conducted to determine the pH levels of a convenience sample of popular brands of bottled water, tap water and other known acidic beverages in comparison with the pH values reported on the respective manufacturers' website. Each beverage was tested in a laboratory using a calibrated Corning pH meter model 240, and waters were compared to the corresponding company's testified pH value. Waters were also compared and contrasted based on their process of purification. The data was then compiled and analyzed descriptively. The pH values for the tested beverages and bottled waters were found to be predominantly acidic. Ten out of the 14 beverages tested were acidic (pH<7), 2 municipal (or "tap") waters were neutral (pH=7) and 2 bottled waters were alkaline (pH>7). The majority of waters tested had a more acidic pH when tested in the lab than the value listed in their water quality reports. It is beneficial for the health care provider to be aware of the potential acidity of popular bottled drinking waters and educate patients accordingly. Copyright © 2015 The American Dental Hygienists’ Association.

  12. [Relationships between soil moisture and needle-fall in Masson pine forests in acid rain region of Chongqing, Southwest China].

    PubMed

    Wang, Yi-Hao; Wang, Yan-Hui; Li, Zhen-Hua; Yu, Peng-Tao; Xiong, Wei; Hao, Jia; Duan, Jian

    2012-10-01

    From March 2009 to November 2011, an investigation was conducted on the spatiotemporal variation of soil moisture and its effects on the needle-fall in Masson pine (Pinus massoniana) forests in acid rain region of Chongqing, Southeast China, with the corresponding soil moisture thresholds determined. No matter the annual precipitation was abundant, normal or less than average, the seasonal variation of soil moisture in the forests could be obviously divided into four periods, i.e., sufficient (before May), descending (from June to July), drought (from August to September), and recovering (from October to November). With increasing soil depth, the soil moisture content increased after an initial decrease, but the difference of the soil moisture content among different soil layers decreased with decreasing annual precipitation. The amount of monthly needle-fall in the forests in growth season was significantly correlated with the water storage in root zone (0-60 cm soil layer), especially in the main root zone (20-50 cm soil layer). Soil field capacity (or capillary porosity) and 82% of field capacity (or 80% of capillary porosity) were the main soil moisture thresholds affecting the litter-fall. It was suggested that in acid rain region, Masson pine forest was easily to suffer from water deficit stress, especially in dry-summer period. The water deficit stress, together with already existed acid rain stress, would further threaten the health of the Masson forest.

  13. Health risks from acid rain: a Canadian perspective.

    PubMed

    Franklin, C A; Burnett, R T; Paolini, R J; Raizenne, M E

    1985-11-01

    Acidic deposition, commonly referred to as acid rain, is causing serious environmental damage in eastern Canada. The revenues from forest products, tourism and sport fishing are estimated to account for about 8% of the gross national product. The impact on human health is not as clearcut and a multi-department program on the Long-Range Transport of Airborne Pollutants (LRTAP) was approved by the federal government in June 1980. The objectives of the LRTAP program are to reduce wet sulfate deposition to less than 20 kg/ha per year in order to protect moderately sensitive areas. This will require a 50% reduction in Canadian SO2 emissions east of the Saskatchewan/Manitoba border and concomitant reductions in the eastern U.S.A. The objectives of the health sector of the program are to assess the risk to health posed by airborne pollutants which are subjected to long-range transport and to monitor the influence of abatement programs. Two major epidemiology studies were undertaken in 1983, one in which the health effects related to acute exposure to transported air pollutants were studied in asthmatic and nonasthmatic children, and another in which the effects of chronic exposure to these pollutants were studied in school children living in towns with high and low levels of pollutants. Preliminary analysis of the data do not indicate major health effects, but definitive conclusions must await final analysis. Studies on the indirect effects of acid deposition on water quality have shown that acidified lake water left standing in the plumbing system can adversely affect water quality and that federally set guidelines for copper and lead are exceeded. Flushing of the system before using the water rectifies the situation. Additional studies are planned to further delineate the magnitude of the health effects of acidified lake water.

  14. Health risks from acid rain: a Canadian perspective.

    PubMed Central

    Franklin, C A; Burnett, R T; Paolini, R J; Raizenne, M E

    1985-01-01

    Acidic deposition, commonly referred to as acid rain, is causing serious environmental damage in eastern Canada. The revenues from forest products, tourism and sport fishing are estimated to account for about 8% of the gross national product. The impact on human health is not as clearcut and a multi-department program on the Long-Range Transport of Airborne Pollutants (LRTAP) was approved by the federal government in June 1980. The objectives of the LRTAP program are to reduce wet sulfate deposition to less than 20 kg/ha per year in order to protect moderately sensitive areas. This will require a 50% reduction in Canadian SO2 emissions east of the Saskatchewan/Manitoba border and concomitant reductions in the eastern U.S.A. The objectives of the health sector of the program are to assess the risk to health posed by airborne pollutants which are subjected to long-range transport and to monitor the influence of abatement programs. Two major epidemiology studies were undertaken in 1983, one in which the health effects related to acute exposure to transported air pollutants were studied in asthmatic and nonasthmatic children, and another in which the effects of chronic exposure to these pollutants were studied in school children living in towns with high and low levels of pollutants. Preliminary analysis of the data do not indicate major health effects, but definitive conclusions must await final analysis. Studies on the indirect effects of acid deposition on water quality have shown that acidified lake water left standing in the plumbing system can adversely affect water quality and that federally set guidelines for copper and lead are exceeded. Flushing of the system before using the water rectifies the situation. Additional studies are planned to further delineate the magnitude of the health effects of acidified lake water. Images FIGURE 1. FIGURE 2. PMID:4076081

  15. Influence of polysorbate 80 and cyclopropane fatty acid synthase activity on lactic acid production by Lactobacillus casei ATCC 334 at low pH.

    PubMed

    Broadbent, J R; Oberg, T S; Hughes, J E; Ward, R E; Brighton, C; Welker, D L; Steele, J L

    2014-03-01

    Lactic acid is an important industrial chemical commonly produced through microbial fermentation. The efficiency of acid extraction is increased at or below the acid's pKa (pH 3.86), so there is interest in factors that allow for a reduced fermentation pH. We explored the role of cyclopropane synthase (Cfa) and polysorbate (Tween) 80 on acid production and membrane lipid composition in Lactobacillus casei ATCC 334 at low pH. Cells from wild-type and an ATCC 334 cfa knockout mutant were incubated in APT broth medium containing 3 % glucose plus 0.02 or 0.2 % Tween 80. The cultures were allowed to acidify the medium until it reached a target pH (4.5, 4.0, or 3.8), and then the pH was maintained by automatic addition of NH₄OH. Cells were collected at the midpoint of the fermentation for membrane lipid analysis, and media samples were analyzed for lactic and acetic acids when acid production had ceased. There were no significant differences in the quantity of lactic acid produced at different pH values by wild-type or mutant cells grown in APT, but the rate of acid production was reduced as pH declined. APT supplementation with 0.2 % Tween 80 significantly increased the amount of lactic acid produced by wild-type cells at pH 3.8, and the rate of acid production was modestly improved. This effect was not observed with the cfa mutant, which indicated Cfa activity and Tween 80 supplementation were each involved in the significant increase in lactic acid yield observed with wild-type L. casei at pH 3.8.

  16. Selection, procurement and description of Salem Limestone samples used to study the effects of acid rain

    NASA Astrophysics Data System (ADS)

    Ross, M.; Knab, L.

    1984-07-01

    The selection, procurement, and description of the Salem Limestone to be used in field exposure tests to assess the effects of acid rain on building stone are described. The rationale for choosing Salem Limestone is given and a brief geological description of the stone is provided. Preparation of the stone samples for field exposure, including cutting, surface finishing and labelling is presented.

  17. Intracellular pH Response to Weak Acid Stress in Individual Vegetative Bacillus subtilis Cells.

    PubMed

    Pandey, Rachna; Vischer, Norbert O E; Smelt, Jan P P M; van Beilen, Johan W A; Ter Beek, Alexander; De Vos, Winnok H; Brul, Stanley; Manders, Erik M M

    2016-11-01

    Intracellular pH (pH i ) critically affects bacterial cell physiology. Hence, a variety of food preservation strategies are aimed at perturbing pH i homeostasis. Unfortunately, accurate pH i quantification with existing methods is suboptimal, since measurements are averages across populations of cells, not taking into account interindividual heterogeneity. Yet, physiological heterogeneity in isogenic populations is well known to be responsible for differences in growth and division kinetics of cells in response to external stressors. To assess in this context the behavior of intracellular acidity, we have developed a robust method to quantify pH i at single-cell levels in Bacillus subtilis Bacilli spoil food, cause disease, and are well known for their ability to form highly stress-resistant spores. Using an improved version of the genetically encoded ratiometric pHluorin (IpHluorin), we have quantified pH i in individual B. subtilis cells, cultured at an external pH of 6.4, in the absence or presence of weak acid stresses. In the presence of 3 mM potassium sorbate, a decrease in pH i and an increase in the generation time of growing cells were observed. Similar effects were observed when cells were stressed with 25 mM potassium acetate. Time-resolved analysis of individual bacteria in growing colonies shows that after a transient pH decrease, long-term pH evolution is highly cell dependent. The heterogeneity at the single-cell level shows the existence of subpopulations that might be more resistant and contribute to population survival. Our approach contributes to an understanding of pH i regulation in individual bacteria and may help scrutinizing effects of existing and novel food preservation strategies. This study shows how the physiological response to commonly used weak organic acid food preservatives, such as sorbic and acetic acids, can be measured at the single-cell level. These data are key to coupling often-observed single-cell heterogeneous growth

  18. Environmental responsiveness of polygalacturonic acid-based multilayers to variation of pH.

    PubMed

    Westwood, Marta; Noel, Timothy R; Parker, Roger

    2011-02-14

    The effect of pH on the stability of layer-by-layer deposited polygalacturonic acid (PGalA)-based multilayer films prepared with the polycations poly-L-lysine, chitosan, and lysozyme is studied. The response was characterized using a quartz crystal microbalance, dual polarization interferometry, and Fourier transform infrared spectroscopy which probe multilayer thickness, density, polymer mass (composition and speciation), and hydration. All multilayers showed irreversible changes in response to pH change becoming thinner due to the partial disassembly. Preferential loss of the polycation (50-80% w/w) and relative small losses of PGaLA (10-35% w/w) occurred. The charge density on the polycation has a strong influence on the response to the acid cycle. Most of the disassembly takes place at the pH lower that pK(a) of PGaLA, indicating that this factor was crucial in determining the stability of the films. The pH challenge also revealed a polycation-dependent shift to acid pH in the PGaLA pK(a).

  19. The effect of pH on the toxicity of fatty acids and fatty acid amides to rainbow trout gill cells.

    PubMed

    Bertin, Matthew J; Voronca, Delia C; Chapman, Robert W; Moeller, Peter D R

    2014-01-01

    Harmful algal blooms (HABs) expose aquatic organisms to multiple physical and chemical stressors during an acute time period. Algal toxins themselves may be altered by water chemistry parameters affecting their bioavailability and resultant toxicity. The purpose of this study was to determine the effects of two abiotic parameters (pH, inorganic metal salts) on the toxicity of fatty acid amides and fatty acids, two classes of lipids produced by harmful algae, including the golden alga, Prymnesium parvum, that are toxic to aquatic organisms. Rainbow trout gill cells were used as a model of the fish gill and exposed to single compounds and mixtures of compounds along with variations in pH level and concentration of inorganic metal salts. We employed artificial neural networks (ANNs) and standard ANOVA statistical analysis to examine and predict the effects of these abiotic parameters on the toxicity of fatty acid amides and fatty acids. Our results demonstrate that increasing pH levels increases the toxicity of fatty acid amides and inhibits the toxicity of fatty acids. This phenomenon is reversed at lower pH levels. Exposing gill cells to complex mixtures of chemical factors resulted in dramatic increases in toxicity compared to tests of single compounds for both the fatty acid amides and fatty acids. These findings highlight the potential of physicochemical factors to affect the toxicity of chemicals released during algal blooms and demonstrate drastic differences in the effect of pH on fatty acid amides and fatty acids. Published by Elsevier B.V.

  20. Global Survey of Submicron Aerosol Acidity (pH)

    NASA Astrophysics Data System (ADS)

    Nault, B.; Day, D. A.; Campuzano Jost, P.; Hu, W.; Schroder, J. C.; Bian, H.; Chin, M.; Clegg, S. L.; Colarco, P. R.; Dibb, J. E.; Kim, M. J.; Kodros, J.; Marais, E. A.; Pierce, J. R.; Scheuer, E. M.; Wennberg, P. O.; Jimenez, J. L.

    2017-12-01

    Aerosol acidity (H+, often expressed as "pH" defined in various ways) is an important property that influences uptake and partitioning of gases, and homogeneous and surface aqueous reactions of key inorganic and organic compounds. As there is currently no rapid method to measure ambient aerosol acidity, a thermodynamic model, constrained by both inorganic aerosol species (e.g., NH4, NO3, SO4, Cl) and at least one inorganic gas (HNO3, NH3, or HCl), are currently understood to lead to the most reliable estimates of aerosol acidity. In this study, we calculated submicron (less than PM1) aerosol pH from the NASA ATom, "pole-to-pole," flights that covers both the Pacific and Atlantic ocean basins. The E-AIM thermodynamic model was used with measurements by an Aerodyne high-resolution time-of-flight aerosol-mass-spectrometer (HR-ToF-AMS) of inorganic aerosol species, along with inorganic gas measurements from other mass spectrometers and ion chromatography. We compare the results with those for the NASA KORUS-AQ, SEAC4RS, DC3, and ARCTAS campaigns, as well as several ground-based campaigns and recently-published studies. This provides an opportunity to compare the aerosol acidity in urban, rural, and remote regions, by season, and between the boundary layer and free troposphere. In addition, we compare the submicron aerosol acidity from these various localities with results from global models, such as GEOS-Chem, in order to investigate the ability of the global models to simulate aerosol acidity, and the processes it affects, such as nitrate, ammonium, and MSA partitioning.

  1. Organic acids in cloud water and rainwater at a mountain site in acid rain areas of South China.

    PubMed

    Sun, Xiao; Wang, Yan; Li, Haiyan; Yang, Xueqiao; Sun, Lei; Wang, Xinfeng; Wang, Tao; Wang, Wenxing

    2016-05-01

    To investigate the chemical characteristics of organic acids and to identify their source, cloud water and rainwater samples were collected at Mount Lu, a mountain site located in the acid rain-affected area of south China, from August to September of 2011 and March to May of 2012. The volume-weighted mean (VWM) concentration of organic acids in cloud water was 38.42 μeq/L, ranging from 7.45 to 111.46 μeq/L, contributing to 2.50 % of acidity. In rainwater samples, organic acid concentrations varied from 12.39 to 68.97 μeq/L (VWM of 33.39 μeq/L). Organic acids contributed significant acidity to rainwater, with a value of 17.66 %. Formic acid, acetic acid, and oxalic acid were the most common organic acids in both cloud water and rainwater. Organic acids had an obviously higher concentration in summer than in spring in cloud water, whereas there was much less discrimination in rainwater between the two seasons. The contribution of organic acids to acidity was lower during summer than during spring in both cloud water (2.20 % in summer vs 2.83 % in spring) and rainwater (12.24 % in summer vs 19.89 % in spring). The formic-to-acetic acid ratio (F/A) showed that organic acids were dominated by primary emissions in 71.31 % of the cloud water samples and whole rainwater samples. Positive matrix factorization (PMF) analysis determined four factors as the sources of organic acids in cloud water, including biogenic emissions (61.8 %), anthropogenic emissions (15.28 %), marine emissions (15.07 %) and soil emissions (7.85 %). The findings from this study imply an indispensable role of organic acids in wet deposition, but organic acids may have a limited capacity to increase ecological risks in local environments.

  2. Microenvironmental pH measurement during sodium naproxenate dissolution in acidic medium by UV/vis imaging.

    PubMed

    Østergaard, Jesper; Jensen, Henrik; Larsen, Susan W; Larsen, Claus; Lenke, Jim

    2014-11-01

    Variable dissolution from sodium salts of drugs containing a carboxylic acid group after passing the acidic environment of the stomach may affect oral bioavailability. The aim of the present proof of concept study was to investigate pH effects in relation to the dissolution of sodium naproxenate in 0.01M hydrochloric acid. For this purpose a UV/vis imaging-based approach capable of measuring microenvironmental pH in the vicinity of the solid drug compact as well as monitoring drug dissolution was developed. Using a pH indicating dye real-time spatially resolved measurement of pH was achieved. Sodium naproxenate, can significantly alter the local pH of the dissolution medium, is eventually neutralized and precipitates as the acidic species naproxen. The developed approach is considered useful for detailed studies of pH dependent dissolution phenomena in dissolution testing. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Change of pH during excess sludge fermentation under alkaline, acidic and neutral conditions.

    PubMed

    Yuan, Yue; Peng, Yongzhen; Liu, Ye; Jin, Baodan; Wang, Bo; Wang, Shuying

    2014-12-01

    The change in pH during excess sludge (ES) fermentation of varying sludge concentrations was investigated in a series of reactors at alkaline, acidic, and neutral pHs. The results showed that the changes were significantly affected by fermentative conditions. Under different conditions, pH exhibited changing profiles. When ES was fermented under alkaline conditions, pH decreased in a range of (10±1). At the beginning of alkaline fermentation, pH dropped significantly, at intervals of 4h, 4h, and 5h with sludge concentrations of 8665.6mg/L, 6498.8mg/L, and 4332.5mg/L, then it would become moderate. However, under acidic conditions, pH increased from 4 to 5. Finally, under neutral conditions pH exhibited a decrease then an increase throughout entire fermentation process. Further study showed short-chain fatty acids (SCFAs), ammonia nitrogen and cations contributed to pH change under various fermentation conditions. This study presents a novel strategy based on pH change to predict whether SCFAs reach their stable stage. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Acidic extracellular pH neutralizes the autophagy-inhibiting activity of chloroquine: implications for cancer therapies.

    PubMed

    Pellegrini, Paola; Strambi, Angela; Zipoli, Chiara; Hägg-Olofsson, Maria; Buoncervello, Maria; Linder, Stig; De Milito, Angelo

    2014-04-01

    Acidic pH is an important feature of tumor microenvironment and a major determinant of tumor progression. We reported that cancer cells upregulate autophagy as a survival mechanism to acidic stress. Inhibition of autophagy by administration of chloroquine (CQ) in combination anticancer therapies is currently evaluated in clinical trials. We observed in 3 different human cancer cell lines cultured at acidic pH that autophagic flux is not blocked by CQ. This was consistent with a complete resistance to CQ toxicity in cells cultured in acidic conditions. Conversely, the autophagy-inhibiting activity of Lys-01, a novel CQ derivative, was still detectable at low pH. The lack of CQ activity was likely dependent on a dramatically reduced cellular uptake at acidic pH. Using cell lines stably adapted to chronic acidosis we could confirm that CQ lack of activity was merely caused by acidic pH. Moreover, unlike CQ, Lys-01 was able to kill low pH-adapted cell lines, although higher concentrations were required as compared with cells cultured at normal pH conditions. Notably, buffering medium pH in low pH-adapted cell lines reverted CQ resistance. In vivo analysis of tumors treated with CQ showed that accumulation of strong LC3 signals was observed only in normoxic areas but not in hypoxic/acidic regions. Our observations suggest that targeting autophagy in the tumor environment by CQ may be limited to well-perfused regions but not achieved in acidic regions, predicting possible limitations in efficacy of CQ in antitumor therapies.

  5. Navigational choice between reversal and curve during acidic pH avoidance behavior in Caenorhabditis elegans.

    PubMed

    Wakabayashi, Tokumitsu; Sakata, Kazumi; Togashi, Takuya; Itoi, Hiroaki; Shinohe, Sayaka; Watanabe, Miwa; Shingai, Ryuzo

    2015-11-19

    Under experimental conditions, virtually all behaviors of Caenorhabditis elegans are achieved by combinations of simple locomotion, including forward, reversal movement, turning by deep body bending, and gradual shallow turning. To study how worms regulate these locomotion in response to sensory information, acidic pH avoidance behavior was analyzed by using worm tracking system. In the acidic pH avoidance, we characterized two types of behavioral maneuvers that have similar behavioral sequences in chemotaxis and thermotaxis. A stereotypic reversal-turn-forward sequence of reversal avoidance caused an abrupt random reorientation, and a shallow gradual turn in curve avoidance caused non-random reorientation in a less acidic direction to avoid the acidic pH. Our results suggest that these two maneuvers were each triggered by a distinct threshold pH. A simulation study using the two-distinct-threshold model reproduced the avoidance behavior of the real worm, supporting the presence of the threshold. Threshold pH for both reversal and curve avoidance was altered in mutants with reduced or enhanced glutamatergic signaling from acid-sensing neurons. C. elegans employ two behavioral maneuvers, reversal (klinokinesis) and curve (klinotaxis) to avoid acidic pH. Unlike the chemotaxis in C. elegans, reversal and curve avoidances were triggered by absolute pH rather than temporal derivative of stimulus concentration in this behavior. The pH threshold is different between reversal and curve avoidance. Mutant studies suggested that the difference results from a differential amount of glutamate released from ASH and ASK chemosensory neurons.

  6. Acid rain monitoring in East-Central Florida from 1977 to present

    NASA Technical Reports Server (NTRS)

    Madsen, B. C.; Kheoh, T.; Hinkle, C. R.; Dreschel, T. W.

    1990-01-01

    Rainfall has been collected on the University of Central Florida campus and at the Kennedy Space Center over a 12 year period. The chemical composition has been determined and summarized by monthly, annual periods, and for the entire 12 year period at both locations. The weighted average pH at each site is 4.58; however, annual weighted average pH has been equal to or above the 12 year average during six of the past eight years. Nitrate concentrations have increased slightly during recent years while excess sulfate concentrations have remained below the 12 year weighted average during six of the past seven years. Stepwise regression suggests that sulfate, nitrate, ammonium ion and calcium play major roles in the description of rainwater acidity. Annual acid deposition and annual rainfall have varied from 20 to 50 meg/(m(exp 2) year) and 100 to 180 cm/year, respectively. Sea salt comprises at least 25 percent of the total ionic composition.

  7. Evaluating Potential Bias in Media Coverage of the Public Debate over Acid Rain and Chlorofluorocarbons in the 1980s

    ERIC Educational Resources Information Center

    Williams, Tiffany Dawn; Moore, Rebecca; Markewitz, Daniel

    2012-01-01

    This study evaluates media coverage of two important environmental issues from the 1980s (acid rain and chlorofluorocarbons), providing historical context for current media coverage analysis. Focusing on popular magazine articles, this study identifies key characteristics of content and presentation. Content-related characteristics are inclusion…

  8. Vaginal pH and Microbicidal Lactic Acid When Lactobacilli Dominate the Microbiota

    PubMed Central

    O’Hanlon, Deirdre E.; Moench, Thomas R.; Cone, Richard A.

    2013-01-01

    Lactic acid at sufficiently acidic pH is a potent microbicide, and lactic acid produced by vaginal lactobacilli may help protect against reproductive tract infections. However, previous observations likely underestimated healthy vaginal acidity and total lactate concentration since they failed to exclude women without a lactobacillus-dominated vaginal microbiota, and also did not account for the high carbon dioxide, low oxygen environment of the vagina. Fifty-six women with low (0-3) Nugent scores (indicating a lactobacillus-dominated vaginal microbiota) and no symptoms of reproductive tract disease or infection, provided a total of 64 cervicovaginal fluid samples using a collection method that avoided the need for sample dilution and rigorously minimized aerobic exposure. The pH of samples was measured by microelectrode immediately after collection and under a physiological vaginal concentration of CO2. Commercial enzymatic assays of total lactate and total acetate concentrations were validated for use in CVF, and compared to the more usual HPLC method. The average pH of the CVF samples was 3.5 ± 0.3 (mean ± SD), range 2.8-4.2, and the average total lactate was 1.0% ± 0.2% w/v; this is a five-fold higher average hydrogen ion concentration (lower pH) and a fivefold higher total lactate concentration than in the prior literature. The microbicidal form of lactic acid (protonated lactic acid) was therefore eleven-fold more concentrated, and a markedly more potent microbicide, than indicated by prior research. This suggests that when lactobacilli dominate the vaginal microbiota, women have significantly more lactic acid-mediated protection against infections than currently believed. Our results invite further evaluations of the prophylactic and therapeutic actions of vaginal lactic acid, whether provided in situ by endogenous lactobacilli, by probiotic lactobacilli, or by products that reinforce vaginal lactic acid. PMID:24223212

  9. Vaginal pH and microbicidal lactic acid when lactobacilli dominate the microbiota.

    PubMed

    O'Hanlon, Deirdre E; Moench, Thomas R; Cone, Richard A

    2013-01-01

    Lactic acid at sufficiently acidic pH is a potent microbicide, and lactic acid produced by vaginal lactobacilli may help protect against reproductive tract infections. However, previous observations likely underestimated healthy vaginal acidity and total lactate concentration since they failed to exclude women without a lactobacillus-dominated vaginal microbiota, and also did not account for the high carbon dioxide, low oxygen environment of the vagina. Fifty-six women with low (0-3) Nugent scores (indicating a lactobacillus-dominated vaginal microbiota) and no symptoms of reproductive tract disease or infection, provided a total of 64 cervicovaginal fluid samples using a collection method that avoided the need for sample dilution and rigorously minimized aerobic exposure. The pH of samples was measured by microelectrode immediately after collection and under a physiological vaginal concentration of CO2. Commercial enzymatic assays of total lactate and total acetate concentrations were validated for use in CVF, and compared to the more usual HPLC method. The average pH of the CVF samples was 3.5 ± 0.3 (mean ± SD), range 2.8-4.2, and the average total lactate was 1.0% ± 0.2% w/v; this is a five-fold higher average hydrogen ion concentration (lower pH) and a fivefold higher total lactate concentration than in the prior literature. The microbicidal form of lactic acid (protonated lactic acid) was therefore eleven-fold more concentrated, and a markedly more potent microbicide, than indicated by prior research. This suggests that when lactobacilli dominate the vaginal microbiota, women have significantly more lactic acid-mediated protection against infections than currently believed. Our results invite further evaluations of the prophylactic and therapeutic actions of vaginal lactic acid, whether provided in situ by endogenous lactobacilli, by probiotic lactobacilli, or by products that reinforce vaginal lactic acid.

  10. The rain of terror

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zern, E.

    The problem of acid rain as it effects fish populations in the United States and Canada is briefly reviewed. The emphasis of the article is on the future of fishing in acid precipitation areas. The author concludes with a recommendation that fishermen write their Congressman urging support of Congressman Henry A. Waxman's House Bill 555. The bill would require a ten-year program to reduce sulfur-dioxide emisions in Central and Eastern states by approximately one-third. (JMT)

  11. Effects of acidic pH on voltage-gated ion channels in rat trigeminal mesencephalic nucleus neurons.

    PubMed

    Han, Jin-Eon; Cho, Jin-Hwa; Choi, In-Sun; Kim, Do-Yeon; Jang, Il-Sung

    2017-03-01

    The effects of acidic pH on several voltage-dependent ion channels, such as voltage-dependent K + and Ca 2+ channels, and hyperpolarization-gated and cyclic nucleotide-activated cation (HCN) channels, were examined using a whole-cell patch clamp technique on mechanically isolated rat mesencephalic trigeminal nucleus neurons. The application of a pH 6.5 solution had no effect on the peak amplitude of voltage-dependent K + currents. A pH 6.0 solution slightly, but significantly inhibited the peak amplitude of voltage-dependent K + currents. The pH 6.0 also shifted both the current-voltage and conductance-voltage relationships to the depolarization range. The application of a pH 6.5 solution scarcely affected the peak amplitude of membrane currents mediated by HCN channels, which were profoundly inhibited by the general HCN channel blocker Cs + (1 mM). However, the pH 6.0 solution slightly, but significantly inhibited the peak amplitude of HCN-mediated currents. Although the pH 6.0 solution showed complex modulation of the current-voltage and conductance-voltage relationships, the midpoint voltages for the activation of HCN channels were not changed by acidic pH. On the other hand, voltage-dependent Ca 2+ channels were significantly inhibited by an acidic pH. The application of an acidic pH solution significantly shifted the current-voltage and conductance-voltage relationships to the depolarization range. The modulation of several voltage-dependent ion channels by an acidic pH might affect the excitability of mesencephalic trigeminal nucleus neurons, and thus physiological functions mediated by the mesencephalic trigeminal nucleus could be affected in acidic pH conditions.

  12. Acid precipitation and reproductive success of Ambystoma salamanders

    Treesearch

    F. Harvey Pough; Richard E. Wilson

    1976-01-01

    The two species of mole salamander that occur in the Ithaca, New York, region (Ambystoma maculatum and A. jeffersonianum) breed in temporary ponds that are formed by accumulation of melted snow and spring rains. Water in many of these pools during the breeding season is acid; pH values as low as 3.5 have been measured. In...

  13. Differential gene expression in tomato fruit and Colletotrichum gloeosporioides during colonization of the RNAi-SlPH tomato line with reduced fruit acidity and higher pH.

    PubMed

    Barad, Shiri; Sela, Noa; Dubey, Amit K; Kumar, Dilip; Luria, Neta; Ment, Dana; Cohen, Shahar; Schaffer, Arthur A; Prusky, Dov

    2017-08-04

    The destructive phytopathogen Colletotrichum gloeosporioides causes anthracnose disease in fruit. During host colonization, it secretes ammonia, which modulates environmental pH and regulates gene expression, contributing to pathogenicity. However, the effect of host pH environment on pathogen colonization has never been evaluated. Development of an isogenic tomato line with reduced expression of the gene for acidity, SlPH (Solyc10g074790.1.1), enabled this analysis. Total RNA from C. gloeosporioides colonizing wild-type (WT) and RNAi-SlPH tomato lines was sequenced and gene-expression patterns were compared. C. gloeosporioides inoculation of the RNAi-SlPH line with pH 5.96 compared to the WT line with pH 4.2 showed 30% higher colonization and reduced ammonia accumulation. Large-scale comparative transcriptome analysis of the colonized RNAi-SlPH and WT lines revealed their different mechanisms of colonization-pattern activation: whereas the WT tomato upregulated 13-LOX (lipoxygenase), jasmonic acid and glutamate biosynthesis pathways, it downregulated processes related to chlorogenic acid biosynthesis II, phenylpropanoid biosynthesis and hydroxycinnamic acid tyramine amide biosynthesis; the RNAi-SlPH line upregulated UDP-D-galacturonate biosynthesis I and free phenylpropanoid acid biosynthesis, but mainly downregulated pathways related to sugar metabolism, such as the glyoxylate cycle and L-arabinose degradation II. Comparison of C. gloeosporioides gene expression during colonization of the WT and RNAi-SlPH lines showed that the fungus upregulates ammonia and nitrogen transport and the gamma-aminobutyric acid metabolic process during colonization of the WT, while on the RNAi-SlPH tomato, it mainly upregulates the nitrate metabolic process. Modulation of tomato acidity and pH had significant phenotypic effects on C. gloeosporioides development. The fungus showed increased colonization on the neutral RNAi-SlPH fruit, and limited colonization on the WT acidic fruit

  14. Sensing and adaptation to low pH mediated by inducible amino acid decarboxylases in Salmonella.

    PubMed

    Viala, Julie P M; Méresse, Stéphane; Pocachard, Bérengère; Guilhon, Aude-Agnès; Aussel, Laurent; Barras, Frédéric

    2011-01-01

    During the course of infection, Salmonella enterica serovar Typhimurium must successively survive the harsh acid stress of the stomach and multiply into a mild acidic compartment within macrophages. Inducible amino acid decarboxylases are known to promote adaptation to acidic environments. Three low pH inducible amino acid decarboxylases were annotated in the genome of S. Typhimurium, AdiA, CadA and SpeF, which are specific for arginine, lysine and ornithine, respectively. In this study, we characterized and compared the contributions of those enzymes in response to acidic challenges. Individual mutants as well as a strain deleted for the three genes were tested for their ability (i) to survive an extreme acid shock, (ii) to grow at mild acidic pH and (iii) to infect the mouse animal model. We showed that the lysine decarboxylase CadA had the broadest range of activity since it both had the capacity to promote survival at pH 2.3 and growth at pH 4.5. The arginine decarboxylase AdiA was the most performant in protecting S. Typhimurium from a shock at pH 2.3 and the ornithine decarboxylase SpeF conferred the best growth advantage under anaerobiosis conditions at pH 4.5. We developed a GFP-based gene reporter to monitor the pH of the environment as perceived by S. Typhimurium. Results showed that activities of the lysine and ornithine decarboxylases at mild acidic pH did modify the local surrounding of S. Typhimurium both in culture medium and in macrophages. Finally, we tested the contribution of decarboxylases to virulence and found that these enzymes were dispensable for S. Typhimurium virulence during systemic infection. In the light of this result, we examined the genomes of Salmonella spp. normally responsible of systemic infection and observed that the genes encoding these enzymes were not well conserved, supporting the idea that these enzymes may be not required during systemic infection.

  15. Dispelling the North American acid rain clouds: Developing a framework for political consensus through the identification of elite viewpoints

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bhatti, N.

    1988-01-01

    Acidic deposition has simultaneously been referred to as an environmental curiosity and as an ecological holocaust. This polarization of opinion on this pollutant has resulted in the policy stalemate in Congress over this issue and is responsible for the major part of the friction which currently besets Canada-United States relations. This study identified the distinctive viewpoints which characterize opposing attitudes. In addition, the specific areas of consensus and disagreement among these elite groups were determined. All of these objectives were carried out using the results of the Q-sort technique and interviews with members of the acid rain elite in bothmore » Canada and the United States (i.e. politicians, scientists, regulators, environmental/advocacy groups, and industry/utility personnel). Furthermore, a comprehensive, in-depth review of the scientific, legal, economic, social and political aspects of this tissue was conducted. Results show that implementation of the Acid Rain Experimental Control Program (ARECP) and the Clean Coal Technology project has the potential to break the existing stalemates over this issue and, at the same, could avert damage to many ecosystems, man-made structures and human health.« less

  16. Elevated nitrogen metabolism and nitric oxide production are involved in Arabidopsis resistance to acid rain.

    PubMed

    Qiao, Fang; Zhang, Xi-Min; Liu, Xiang; Chen, Juan; Hu, Wen-Jun; Liu, Ting-Wu; Liu, Ji-Yun; Zhu, Chun-Quan; Ghoto, Kabir; Zhu, Xue-Yi; Zheng, Hai-Lei

    2018-06-01

    Acid rain (AR) can induce great damages to plants and could be classified into different types according to the different SO 4 2- /NO 3 - ratio. However, the mechanism of plants' responding to different types of AR has not been elucidated clearly. Here, we found that nitric-rich simulated AR (N-SiAR) induced less leaves injury as lower necrosis percentage, better physiological parameters and reduced oxidative damage in the leaves of N-SiAR treated Arabidopsis thaliana compared with sulfate and nitrate mixed (SN-SiAR) or sulfuric-rich (S-SiAR) simulated AR treated ones. Of these three types of SiAR, N-SiAR treated Arabidopsis maintained the highest of nitrogen (N) content, nitrate reductase (NR) and nitrite reductase (NiR) activity as well as N metabolism related genes expression level. Nitric oxide (NO) content showed that N-SiAR treated seedlings had a higher NO level compared to SN-SiAR or S-SiAR treated ones. A series of NO production and elimination related reagents and three NO production-related mutants were used to further confirm the role of NO in regulating acid rain resistance in N-SiAR treated Arabidopsis seedlings. Taken together, we concluded that an elevated N metabolism and enhanced NO production are involved in the tolerance to different types of AR in Arabidopsis. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  17. Effect of pH on fecal recovery of energy derived from volatile fatty acids.

    PubMed

    Kien, C L; Liechty, E A

    1987-01-01

    We assessed the effect of pH on volatilization of short-chain fatty acids during lyophilization. Acetic, propionic, valeric, and butyric acids were added to a fecal homogenate in amounts sufficient to raise the energy density by 18-27%. Fecal homogenate samples were either acidified (pH 2.8-3.2), alkalinized (pH 7.9-8.7), or left unchanged (4.0-4.8) prior to lyophilization and subsequent bomb calorimetry. Alkalinizing the fecal samples prevented the 20% loss of energy derived from each of these volatile fatty acids observed in samples either acidified or without pH adjustment. These data suggest that in energy balance studies involving subjects with active colonic fermentation, fecal samples should be alkalinized prior to lyophilization and bomb calorimetry.

  18. Chemical characterization of fog and rain water collected at the eastern Andes cordillera

    NASA Astrophysics Data System (ADS)

    Beiderwieden, E.; Wrzesinsky, T.; Klemm, O.

    2005-09-01

    During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the "El Tiro" site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl-, NO3-, PO43-, and SO42- were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 μS cm-1 for the fog and 6 μS cm-1 for the rain. The continent samples exhibit higher concentrations of most ions as compared to the pacific samples, but these differences could not be detected statistically.

  19. The impacts of ;urban-induced heavy rains; on the distribution of deposition fluxes of inorganic acidic substances in the Tokyo metropolitan area in summer

    NASA Astrophysics Data System (ADS)

    Uchiyama, Ryunosuke; Okochi, Hiroshi; Kamiya, Junichi; Asai, Daisuke; Kaneko, Chiho; Ogata, Hiroko; Katsumi, Naoya

    2018-02-01

    We analyzed the trends in rainfall amounts and the number of heavy rain events with hourly rainfall amounts over 30 mm at the inland section of the 23-ward Tokyo metropolitan area (nine wards and ten sites) in the warm season (July to September) from 1978 to 2008. Heavy rain events in the Nerima Ward occurred nine times during decade I (1978-1987; 0.90 times/yr), 13 times during decade II (1988-1997; 1.3 times/yr), and 23 times during decade III (1998-2008; 2.1 times/yr). The annual average number of heavy rain events was 1.43 times/yr in Nerima from 1978 to 2008, while it was 0.98 times/yr on average at nine locations excluding Nerima. The frequency of extremely strong heavy rain events with hourly rainfall amounts greater than 50 mm during decade III was the highest in Nerima (six times) among ten sites. These data suggest that the frequency of heavy rain events has increased at Nerima during the past 30 years. Bulk precipitation data were collected biweekly by filtration-type collectors at 14 sites around Nerima from 2008 to 2010 to determine the impacts of urban-induced heavy rains (hereafter UHR), defined as a heavy rain event other than typhoons and frontal heavy rains, on the distribution of deposition fluxes of inorganic acidic substances. The NO3- and nss-SO42 - concentrations in bulk precipitation were higher during the periods including UHR than those not including UHR. The deposition fluxes of NO3- and SO42 - showed clear differences at the center of UHR (NO3-: 231 μeq/m2/d, SO42 -: 234 μeq/m2/d) and its surrounding area (NO3-: 76.4 μeq/m2/d, SO42 -: 86.1 μeq/m2/d). Our results suggest that large amounts of inorganic acidic substances are deposited locally by UHR in urban areas in summer.

  20. Estimating Rain Rates from Tipping-Bucket Rain Gauge Measurements

    NASA Technical Reports Server (NTRS)

    Wang, Jianxin; Fisher, Brad L.; Wolff, David B.

    2007-01-01

    This paper describes the cubic spline based operational system for the generation of the TRMM one-minute rain rate product 2A-56 from Tipping Bucket (TB) gauge measurements. Methodological issues associated with applying the cubic spline to the TB gauge rain rate estimation are closely examined. A simulated TB gauge from a Joss-Waldvogel (JW) disdrometer is employed to evaluate effects of time scales and rain event definitions on errors of the rain rate estimation. The comparison between rain rates measured from the JW disdrometer and those estimated from the simulated TB gauge shows good overall agreement; however, the TB gauge suffers sampling problems, resulting in errors in the rain rate estimation. These errors are very sensitive to the time scale of rain rates. One-minute rain rates suffer substantial errors, especially at low rain rates. When one minute rain rates are averaged to 4-7 minute or longer time scales, the errors dramatically reduce. The rain event duration is very sensitive to the event definition but the event rain total is rather insensitive, provided that the events with less than 1 millimeter rain totals are excluded. Estimated lower rain rates are sensitive to the event definition whereas the higher rates are not. The median relative absolute errors are about 22% and 32% for 1-minute TB rain rates higher and lower than 3 mm per hour, respectively. These errors decrease to 5% and 14% when TB rain rates are used at 7-minute scale. The radar reflectivity-rainrate (Ze-R) distributions drawn from large amount of 7-minute TB rain rates and radar reflectivity data are mostly insensitive to the event definition.

  1. Drivers of spatio-temporal changes in paddy soil pH in Jiangxi Province, China from 1980 to 2010.

    PubMed

    Guo, Xi; Li, Hongyi; Yu, Huimin; Li, Weifeng; Ye, Yingcong; Biswas, Asim

    2018-02-09

    The spatio-temporal distribution soil pH is critical for understanding the productivity and long-term sustainability of our agri-ecosystem. This study quantified the spatio-temporal distribution of paddy soil pH in Jiangxi province, China, and the potential driver of the change between 1980 and 2010. Data from the Soil Survey Information of Jiangxi province (1980s) and Jiangxi Soil Testing and Fertilizer Recommendation study (2010s) were collected and categorized into six pH ranges from strongly-acidic to strongly-alkaline with unit pH differences. Changes were calculated from the maps developed using the Pedological Knowledge base for 1980s data (without geolocation) and geostatistical methods for the 2010s data (geolocated). An overall 0.6-unit decrease and a major shift of soil pH from weakly-acidic (54% → 18%) to acidic (35% → 74%) was observed over the province in a scattered fashion with concentration in the central part and the Poyang Lake area. About half of the area under paddy cultivation went through acidification by at least one pH unit and 7% by at least 2 pH units, while 40% of the area remained unchanged. Excessive fertilizer application and acid-rain intensity contributed to the acidification. Thus, a more knowledge-based and comprehensive fertilizer management should be adopted to make paddy production sustainable in the province.

  2. Fast-growing Acer rubrum differs from slow-growing Quercus alba in leaf, xylem and hydraulic trait coordination responses to simulated acid rain.

    PubMed

    Medeiros, Juliana S; Tomeo, Nicholas J; Hewins, Charlotte R; Rosenthal, David M

    2016-08-01

    We investigated the effects of historic soil chemistry changes associated with acid rain, i.e., reduced soil pH and a shift from nitrogen (N)- to phosphorus (P)-limitation, on the coordination of leaf water demand and xylem hydraulic supply traits in two co-occurring temperate tree species differing in growth rate. Using a full-factorial design (N × P × pH), we measured leaf nutrient content, water relations, leaf-level and canopy-level gas exchange, total biomass and allocation, as well as stem xylem anatomy and hydraulic function for greenhouse-grown saplings of fast-growing Acer rubrum (L.) and slow-growing Quercus alba (L.). We used principle component analysis to characterize trait coordination. We found that N-limitation, but not P-limitation, had a significant impact on plant water relations and hydraulic coordination of both species. Fast-growing A. rubrum made hydraulic adjustments in response to N-limitation, but trait coordination was variable within treatments and did not fully compensate for changing allocation across N-availability. For slow-growing Q. alba, N-limitation engendered more strict coordination of leaf and xylem traits, resulting in similar leaf water content and hydraulic function across all treatments. Finally, low pH reduced the propensity of both species to adjust leaf water relations and xylem anatomical traits in response to nutrient manipulations. Our data suggest that a shift from N- to P-limitation has had a negative impact on the water relations and hydraulic function of A. rubrum to a greater extent than for Q. alba We suggest that current expansion of A. rubrum populations could be tempered by acidic N-deposition, which may restrict it to more mesic microsites. The disruption of hydraulic acclimation and coordination at low pH is emphasized as an interesting area of future study. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Acid precipitation effects on soil pH and base saturation of exchange sites

    Treesearch

    W. W. McFee; J. M. Kelly; R. H. Beck

    1976-01-01

    The typical values and probable ranges of acid-precipitation are evaluated in terms of their theoretical effects on pH and cation exchange equilibrium of soils characteristic of the humid temperature region. The extent of probable change in soil pH and the time required to cause such a change are calculated for a range of common soils. Hydrogen ion input by acid...

  4. Lower pH values of weakly acidic refluxes as determinants of heartburn perception in gastroesophageal reflux disease patients with normal esophageal acid exposure.

    PubMed

    de Bortoli, N; Martinucci, I; Savarino, E; Franchi, R; Bertani, L; Russo, S; Ceccarelli, L; Costa, F; Bellini, M; Blandizzi, C; Savarino, V; Marchi, S

    2016-01-01

    Multichannel impedance pH monitoring has shown that weakly acidic refluxes are able to generate heartburn. However, data on the role of different pH values, ranging between 4 and 7, in the generation of them are lacking. The aim of this study was to evaluate whether different pH values of weakly acidic refluxes play a differential role in provoking reflux symptoms in endoscopy-negative patients with physiological esophageal acid exposure time and positive symptom index and symptom association probability for weakly acidic refluxes. One hundred and forty-three consecutive patients with gastroesophageal reflux disease, nonresponders to proton pump inhibitors (PPIs), were allowed a washout from PPIs before undergoing: upper endoscopy, esophageal manometry, and multichannel impedance pH monitoring. In patients with both symptom index and symptom association probability positive for weakly acidic reflux, each weakly acidic reflux was evaluated considering exact pH value, extension, physical characteristics, and correlation with heartburn. Forty-five patients with normal acid exposure time and positive symptom association probability for weakly acidic reflux were identified. The number of refluxes not heartburn related was higher than those heartburn related. In all distal and proximal liquid refluxes, as well as in distal mixed refluxes, the mean pH value of reflux events associated with heartburn was significantly lower than that not associated. This condition was not confirmed for proximal mixed refluxes. Overall, a low pH of weakly acidic reflux represents a determinant factor in provoking heartburn. This observation contributes to better understand the pathophysiology of symptoms generated by weakly acidic refluxes, paving the way toward the search for different therapeutic approaches to this peculiar condition of esophageal hypersensitivity. © 2014 International Society for Diseases of the Esophagus.

  5. Effects of pH adjustment and sodium ions on sour taste intensity of organic acids

    USDA-ARS?s Scientific Manuscript database

    Protonated organic acid species have been shown to be the primary stimuli responsible for sour taste of organic acids. However, we have observed that sour taste may be modulated when the pH of acid solutions is raised using sodium hydroxide. Objectives were to evaluate the effect of pH adjustment on...

  6. Influence of Acidic pH on Hydrogen and Acetate Production by an Electrosynthetic Microbiome

    PubMed Central

    LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; May, Harold D.

    2014-01-01

    Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (∼5). Hydrogen production by biocathodes poised at −600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ∼5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ∼6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at −765 mV (0.065 mA/cm2 sterile control at −800 mV) by the Acetobacterium-dominated community. Supplying −800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (≈2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate ( = 4.7 kg CO2 captured). PMID:25333313

  7. Influence of acidic pH on hydrogen and acetate production by an electrosynthetic microbiome

    DOE PAGES

    LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; ...

    2014-10-15

    Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (~5). Hydrogen production by biocathodes poised at -600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ~5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ~6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm 2 at -765 mV (0.065 mA/cm 2 sterile control at -800 mV) bymore » the Acetobacterium-dominated community. Supplying -800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m 3/day hydrogen (≈2.6 gallons gasoline equivalent), 0.7 kg/m 3/day formate, and 3.1 kg/m 3/day acetate ( = 4.7 kg CO 2 captured).« less

  8. Acidic Food pH Increases Palatability and Consumption and Extends Drosophila Lifespan.

    PubMed

    Deshpande, Sonali A; Yamada, Ryuichi; Mak, Christine M; Hunter, Brooke; Soto Obando, Alina; Hoxha, Sany; Ja, William W

    2015-12-01

    Despite the prevalent use of Drosophila as a model in studies of nutrition, the effects of fundamental food properties, such as pH, on animal health and behavior are not well known. We examined the effect of food pH on adult Drosophila lifespan, feeding behavior, and microbiota composition and tested the hypothesis that pH-mediated changes in palatability and total consumption are required for modulating longevity. We measured the effect of buffered food (pH 5, 7, or 9) on male gustatory responses (proboscis extension), total food intake, and male and female lifespan. The effect of food pH on germfree male lifespan was also assessed. Changes in fly-associated microbial composition as a result of food pH were determined by 16S ribosomal RNA gene sequencing. Male gustatory responses, total consumption, and male and female longevity were additionally measured in the taste-defective Pox neuro (Poxn) mutant and its transgenic rescue control. An acidic diet increased Drosophila gustatory responses (40-230%) and food intake (5-50%) and extended survival (10-160% longer median lifespan) compared with flies on either neutral or alkaline pH food. Alkaline food pH shifted the composition of fly-associated bacteria and resulted in greater lifespan extension (260% longer median survival) after microbes were eliminated compared with flies on an acidic (50%) or neutral (130%) diet. However, germfree flies lived longer on an acidic diet (5-20% longer median lifespan) compared with those on either neutral or alkaline pH food. Gustatory responses, total consumption, and longevity were unaffected by food pH in Poxn mutant flies. Food pH can directly influence palatability and feeding behavior and affect parameters such as microbial growth to ultimately affect Drosophila lifespan. Fundamental food properties altered by dietary or drug interventions may therefore contribute to changes in animal physiology, metabolism, and survival. © 2015 American Society for Nutrition.

  9. Identification of Extracellular Domain Residues Required for Epithelial Na+ Channel Activation by Acidic pH

    PubMed Central

    Collier, Daniel M.; Peterson, Zerubbabel J.; Blokhin, Ilya O.; Benson, Christopher J.; Snyder, Peter M.

    2012-01-01

    A growing body of evidence suggests that the extracellular domain of the epithelial Na+ channel (ENaC) functions as a sensor that fine tunes channel activity in response to changes in the extracellular environment. We previously found that acidic pH increases the activity of human ENaC, which results from a decrease in Na+ self-inhibition. In the current work, we identified extracellular domain residues responsible for this regulation. We found that rat ENaC is less sensitive to pH than human ENaC, an effect mediated in part by the γ subunit. We identified a group of seven residues in the extracellular domain of γENaC (Asp-164, Gln-165, Asp-166, Glu-292, Asp-335, His-439, and Glu-455) that, when individually mutated to Ala, decreased proton activation of ENaC. γE455 is conserved in βENaC (Glu-446); mutation of this residue to neutral amino acids (Ala, Cys) reduced ENaC stimulation by acidic pH, whereas reintroduction of a negative charge (by MTSES modification of Cys) restored pH regulation. Combination of the seven γENaC mutations with βE446A generated a channel that was not activated by acidic pH, but inhibition by alkaline pH was intact. Moreover, these mutations reduced the effect of pH on Na+ self-inhibition. Together, the data identify eight extracellular domain residues in human β- and γENaC that are required for regulation by acidic pH. PMID:23060445

  10. Geochemical and stable isotope characteristics of urban heavy rain in the downtown of Tokyo, Japan

    NASA Astrophysics Data System (ADS)

    Uchiyama, Ryunosuke; Okochi, Hiroshi; Ogata, Hiroko; Katsumi, Naoya; Asai, Daisuke; Nakano, Takanori

    2017-09-01

    In order to make clear the impact of air pollution on the formation of sudden and locally-distributed heavy rain in urban area (hereafter Urban Heavy Rain: UHR), we analyzed inorganic ion concentration and stable isotope ratio of water (δD and δ18O) in rainwater. Rainwater samples were collected in Shinjuku, which is a representative downtown of Tokyo, Japan, during four years from October 2012 to December 2015. The concentration and wet deposition fluxes of acidic components (H+, NH4+, NO3-, and nss-SO42 -) in UHR were especially higher than those in other types of rain events, i.e. normal rain, typhoon heavy rain, and frontal heavy rain. UHR had distinctly lower stable isotope ratios than those in other urban rains with same rainfall amount and summer precipitation systems. There was a high negative correlation between δ18O and the distances from the sampling point to the formation area of UHR within 10 km, while there were high positive correlations between δ18O and the concentration of acidic components in UHR. These findings indicate that UHR could effectively scavenge acidic substances within cloud and suggest the use of stable isotope ratios as tracers of an urban heavy rain's water and in-cloud scavenging process.

  11. The Cytosolic pH of Individual Saccharomyces cerevisiae Cells Is a Key Factor in Acetic Acid Tolerance

    PubMed Central

    Fernández-Niño, Miguel; Marquina, Maribel; Swinnen, Steve; Rodríguez-Porrata, Boris

    2015-01-01

    It was shown recently that individual cells of an isogenic Saccharomyces cerevisiae population show variability in acetic acid tolerance, and this variability affects the quantitative manifestation of the trait at the population level. In the current study, we investigated whether cell-to-cell variability in acetic acid tolerance could be explained by the observed differences in the cytosolic pHs of individual cells immediately before exposure to the acid. Results obtained with cells of the strain CEN.PK113-7D in synthetic medium containing 96 mM acetic acid (pH 4.5) showed a direct correlation between the initial cytosolic pH and the cytosolic pH drop after exposure to the acid. Moreover, only cells with a low initial cytosolic pH, which experienced a less severe drop in cytosolic pH, were able to proliferate. A similar correlation between initial cytosolic pH and cytosolic pH drop was also observed in the more acid-tolerant strain MUCL 11987-9. Interestingly, a fraction of cells in the MUCL 11987-9 population showed initial cytosolic pH values below the minimal cytosolic pH detected in cells of the strain CEN.PK113-7D; consequently, these cells experienced less severe drops in cytosolic pH. Although this might explain in part the difference between the two strains with regard to the number of cells that resumed proliferation, it was observed that all cells from strain MUCL 11987-9 were able to proliferate, independently of their initial cytosolic pH. Therefore, other factors must also be involved in the greater ability of MUCL 11987-9 cells to endure strong drops in cytosolic pH. PMID:26341199

  12. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Forsline, P.L.; Musselman, R.C.; Kender, W.J.

    Mature 'McIntosh', 'Empire', and 'Golden Delicious' apple trees (Malus domestica Borkh.) were sprayed with simulated acid rain solutions in the pH range of 2.5 to 5.5 at full bloom in 1980 and in 1981. In 1981, weekly sprays were applied at pH 2.75 and pH 3.25. Necrotic lesions developed on apple petals at pH 2.5 with slight injury appearing at pH 3.0 and pH 3.5. Apple foliage had no acid rain lesions at any of the pH levels tested. Pollen germination was reduced at ph 2.5 in 'Empire'. Slight fruit set reduction at pH 2.5 was observed in 'McIntosh'. Themore » incidence of russetting on 'Golden Delicious' fruits was ameliorated by the presence of rain-exclusion chambers but was not affected by acid rain. With season-long sprays at pH 2.75, there was a slight delay in maturity and lower weight of 'McIntosh' apples. Even at the lowest pH levels no detrimental effects of simulated acid rain were found on apple tree productivity and fruit quality when measured as fruit set, seed number per fruit, and fruit size and appearance.« less

  13. History of blood gas analysis. II. pH and acid-base balance measurements.

    PubMed

    Severinghaus, J W; Astrup, P B

    1985-10-01

    Electrometric measurement of the hydrogen ion concentration was discovered by Wilhelm Ostwald in Leipzig about 1890 and described thermodynamically by his student Walther Nernst, using the van't Hoff concept of osmotic pressure as a kind of gas pressure, and the Arrhenius concept of ionization of acids, both of which had been formalized in 1887. Hasselbalch, after adapting the pH nomenclature of Sørensen to the carbonic-acid mass equation of Henderson, made the first actual blood pH measurements (with a hydrogen electrode) and proposed that metabolic acid-base imbalance be quantified as the "reduced" pH of blood after equilibration to a carbon dioxide tension (PCO2) of 40 mm Hg. This good idea, coming 40 years before simple blood pH measurements at 37 degrees C became widely available, was never adopted. Instead, Van Slyke developed a concept of acid-base chemistry that depended on measuring plasma CO2 content with his manometric apparatus, a standard method until the 1960s, when it was displaced by the three-electrode method of blood gas analysis. The 1952 polio epidemic in Copenhagen stimulated Astrup to develop a glass electrode in which pH could be measured in blood at 37 degrees C before and after equilibration with known PCO2. He introduced the interpolative measurement of PCO2 and bicarbonate level (later base excess) using only pH measurements and, with Siggaard-Andersen, developed clinical acid-base chemistry. Controversy arose when blood base excess was noted to be altered by acute changes in PCO2 and when abnormalities of base excess were called metabolic acidosis or alkalosis, even when they represented compensation for respiratory abnormalities in PCO2. In the 1970s it became clear that "in-vivo" or "extracellular fluid" base excess (measured at an average extracellular fluid hemoglobin concentration of 5 g) eliminated the error caused by acute changes in PCO2. Base excess is now almost universally used as the index of nonrespiratory acid

  14. Air quality monitor and acid rain networks

    NASA Technical Reports Server (NTRS)

    Rudolph, H.

    1980-01-01

    The air quality monitor program which consists of two permanent air monitor stations (PAMS's) and four mobile shuttle pollutant air monitor stations (SPAMS's) is evaluated. The PAMS measures SO sub X, NO sub X particulates, CO, O3, and nonmethane hydrocarbons. The SPAMS measures O3, SO2, HCl, and particulates. The collection and analysis of data in the rain monitor program are discussed.

  15. The cell transmembrane pH gradient in tumors enhances cytotoxicity of specific weak acid chemotherapeutics.

    PubMed

    Kozin, S V; Shkarin, P; Gerweck, L E

    2001-06-15

    The extracellular pH is lower in tumor than in normal tissue, whereas their intracellular pH is similar. In this study, we show that the tumor-specific pH gradient may be exploited for the treatment of cancer by weak acid chemotherapeutics. i.v.-injected glucose substantially decreased the electrode estimated extracellular pH in a xenografted human tumor while its intracellular pH, evaluated by (31)P magnetic resonance spectroscopy, remained virtually unchanged. The resulting increase in the average cell pH gradient caused a parallel increase in tumor growth delay by the weak acid chlorambucil (CHL). Regardless of glucose administration, the effect of CHL was significantly greater in tumors preirradiated with a large dose of ionizing radiation. This suggests that CHL was especially pronounced in radioresistant hypoxic cells possessing a larger transmembrane pH gradient. These results indicate that the naturally occurring cell pH gradient difference between tumor and normal tissue is a major and exploitable determinant of the uptake of weak acids in the complex tumor microenvironment. The use of such drugs may be especially effective in combination with radiation.

  16. Effect of acidic pH on the stability of α-synuclein dimers.

    PubMed

    Lv, Zhengjian; Krasnoslobodtsev, Alexey V; Zhang, Yuliang; Ysselstein, Daniel; Rochet, Jean Christophe; Blanchard, Scott C; Lyubchenko, Yuri L

    2016-10-01

    Environmental factors, such as acidic pH, facilitate the assembly of α-synuclein (α-Syn) in aggregates, but the impact of pH on the very first step of α-Syn aggregation remains elusive. Recently, we developed a single-molecule approach that enabled us to measure directly the stability of α-Syn dimers. Unlabeled α-Syn monomers were immobilized on a substrate, and fluorophore-labeled monomers were added to the solution to allow them to form dimers with immobilized α-Syn monomers. The dimer lifetimes were measured directly from the fluorescence bursts on the time trajectories. Herein, we applied the single-molecule tethered approach for probing of intermolecular interaction to characterize the effect of acidic pH on the lifetimes of α-Syn dimers. The experiments were performed at pH 5 and 7 for wild-type α-Syn and for two mutants containing familial type mutations E46K and A53T. We demonstrate that a decrease of pH resulted in more than threefold increase in the α-Syn dimers lifetimes with some variability between the α-Syn species. We hypothesize that the stabilization effect is explained by neutralization of residues 96-140 of α-Syn and this electrostatic effect facilitates the association of the two monomers. Given that dimerization is the first step of α-Syn aggregation, we posit that the electrostatic effect thereby contributes to accelerating α-Syn aggregation at acidic pH. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 715-724, 2016. © 2016 Wiley Periodicals, Inc.

  17. Development and Implementation of a Simple, Engaging Acid Rain Neutralization Experiment and Corresponding Animated Instructional Video for Introductory Chemistry Students

    ERIC Educational Resources Information Center

    Rand, Danielle; Yennie, Craig J.; Lynch, Patrick; Lowry, Gregory; Budarz, James; Zhu, Wenlei; Wang, Li-Qiong

    2016-01-01

    Here we describe an acid rain neutralization laboratory experiment and its corresponding instructional video. This experiment has been developed and implemented for use in the teaching laboratory of a large introductory chemistry course at Brown University. It provides a contextually relevant example to introduce beginner-level students with…

  18. Mode of de-esterification of alkaline and acidic pectin methyl esterases at different pH conditions.

    PubMed

    Duvetter, Thomas; Fraeye, Ilse; Sila, Daniel N; Verlent, Isabel; Smout, Chantal; Hendrickx, Marc; Van Loey, Ann

    2006-10-04

    Highly esterified citrus pectin was de-esterified at pH 4.5 and 8.0 by a fungal pectin methyl esterase (PME) that was shown to have an acidic isoelectric pH (pI) and an acidic pH optimum and by a plant PME that was characterized by an alkaline pI and an alkaline pH optimum. Interchain and intrachain de-esterification patterns were studied by digestion of the pectin products with endo-polygalacturonase and subsequent analysis using size exclusion and anion-exchange chromatography. No effect of pH was observed on the de-esterification mode of either of the two enzymes. Acidic, fungal PME converted pectin according to a multiple-chain mechanism, with a limited degree of multiple attack at the intrachain level, both at pH 4.5 and at pH 8.0. A multiple-attack mechanism, with a high degree of multiple attack, was more appropriate to describe the action mode of alkaline, plant PME, both at pH 4.5 and at pH 8.0.

  19. Relationship of Cell Sap pH to Organic Acid Change During Ion Uptake 1

    PubMed Central

    Hiatt, A. J.

    1967-01-01

    Excised roots of barley (Hordeum vulgare, var. Campana) were incubated in KCl, K2SO4, CaCl2, and NaCl solutions at concentrations of 10−5 to 10−2 n. Changes in substrate solution pH, cell sap pH, and organic acid content of the roots were related to differences in cation and anion absorption. The pH of expressed sap of roots increased when cations were absorbed in excess of anions and decreased when anions were absorbed in excess of cations. The pH of the cell sap shifted in response to imbalances in cation and anion uptake in salt solutions as dilute as 10−5 n. Changes in cell sap pH were detectable within 15 minutes after the roots were placed in 10−3 n K2SO4. Organic acid changes in the roots were proportional to expressed sap pH changes induced by unbalanced ion uptake. Changes in organic acid content in response to differential cation and anion uptake appear to be associated with the low-salt component of ion uptake. PMID:16656506

  20. The Cytosolic pH of Individual Saccharomyces cerevisiae Cells Is a Key Factor in Acetic Acid Tolerance.

    PubMed

    Fernández-Niño, Miguel; Marquina, Maribel; Swinnen, Steve; Rodríguez-Porrata, Boris; Nevoigt, Elke; Ariño, Joaquín

    2015-11-01

    It was shown recently that individual cells of an isogenic Saccharomyces cerevisiae population show variability in acetic acid tolerance, and this variability affects the quantitative manifestation of the trait at the population level. In the current study, we investigated whether cell-to-cell variability in acetic acid tolerance could be explained by the observed differences in the cytosolic pHs of individual cells immediately before exposure to the acid. Results obtained with cells of the strain CEN.PK113-7D in synthetic medium containing 96 mM acetic acid (pH 4.5) showed a direct correlation between the initial cytosolic pH and the cytosolic pH drop after exposure to the acid. Moreover, only cells with a low initial cytosolic pH, which experienced a less severe drop in cytosolic pH, were able to proliferate. A similar correlation between initial cytosolic pH and cytosolic pH drop was also observed in the more acid-tolerant strain MUCL 11987-9. Interestingly, a fraction of cells in the MUCL 11987-9 population showed initial cytosolic pH values below the minimal cytosolic pH detected in cells of the strain CEN.PK113-7D; consequently, these cells experienced less severe drops in cytosolic pH. Although this might explain in part the difference between the two strains with regard to the number of cells that resumed proliferation, it was observed that all cells from strain MUCL 11987-9 were able to proliferate, independently of their initial cytosolic pH. Therefore, other factors must also be involved in the greater ability of MUCL 11987-9 cells to endure strong drops in cytosolic pH. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Changes in composition and enamel demineralization inhibition activities of gallic acid at different pH values.

    PubMed

    Zhang, Jingyang; Huang, Xuelian; Huang, Shengbin; Deng, Meng; Xie, Xincheng; Liu, Mingdong; Liu, Hongling; Zhou, Xuedong; Li, Jiyao; Ten Cate, Jacob Martien

    2015-01-01

    Gallic acid (GA) has been shown to inhibit demineralization and enhance remineralization of enamel; however, GA solution is highly acidic. This study was to investigate the stability of GA solutions at various pH and to examine the resultant effects on enamel demineralization. The stability of GA in H2O or in phosphate buffer at pH 5.5, pH 7.0 and pH 10.0 was evaluated qualitatively by ultraviolet absorption spectra and quantified by high performance liquid chromatography with diode array detection (HPLC-DAD). Then, bovine enamel blocks were subjected to a pH-cycling regime of 12 cycles. Each cycle included 5 min applications with one of the following treatments: 1 g/L NaF (positive control), 4 g/L GA in H2O or buffered at pH 5.5, pH 7.0 and pH 10.0 and buffers without GA at the same pH (negative control), followed by a 60 min application with pH 5.0 acidic buffers and a 5 min application with neutral buffers. The acidic buffers were analysed for dissolved calcium. GA was stable in pure water and acidic condition, but was unstable in neutral and alkaline conditions, in which ultraviolet spectra changed and HPLC-DAD analysis revealed that most of the GA was degraded. All the GA groups significantly inhibited demineralization (p < 0.05) and there was no significant difference of the inhibition efficacy among different GA groups (p > 0.05). GA could inhibit enamel demineralization and the inhibition effect is not influenced by pH. GA could be a useful source as an anti-cariogenic agent for broad practical application.

  2. Isoelectric focusing of dansylated amino acids in immobilized pH gradients

    NASA Technical Reports Server (NTRS)

    Bianchi-Bosisio, Adriana; Righetti, Pier Giorgio; Egen, Ned B.; Bier, Milan

    1986-01-01

    The 21 free amino acids commonly encountered in proteins have been transformed into 'carrier ampholyte' species by reacting their primary amino groups with dansyl chloride. These derivatives can thus be focused in an immobilized pH gradient covering the pH interval 3.1 to 4.1, except for arginine, which still retains a pI of 8.8. Due to their inherent fluorescence, the dansyl derivatives are revealed in UV light, with a sensitivity of the order of 2-4 ng/sq mm. All nearest neighbors are separated except for the following couples: Asn-Gln, Gly-Thr, Val-Ile and Cys-Cys2, with a resolving power, in a Delta(pI) scale, of the order of 0.0018 pH units. Except for a few cases (notably the aromatic amino acids), the order of pI values is well correlated with the pK values of carboxyl groups, suggesting that the latter are not altered by dansylation. From the set of pK(COOH)-pI values of the different amino acids, the pK of the tertiary amino group in the dansyl label has been calculated to be 5.11 + or - 0.06. Knowing the pK of the amino-dansyl and the pI of the excess, free dansyl label (pI = 3.34), a pK of 1.57 is derived for its sulfonic acid group.

  3. Initial pH of medium affects organic acids production but do not affect phosphate solubilization.

    PubMed

    Marra, Leandro M; de Oliveira-Longatti, Silvia M; Soares, Cláudio R F S; de Lima, José M; Olivares, Fabio L; Moreira, Fatima M S

    2015-06-01

    The pH of the culture medium directly influences the growth of microorganisms and the chemical processes that they perform. The aim of this study was to assess the influence of the initial pH of the culture medium on the production of 11 low-molecular-weight organic acids and on the solubilization of calcium phosphate by bacteria in growth medium (NBRIP). The following strains isolated from cowpea nodules were studied: UFLA03-08 (Rhizobium tropici), UFLA03-09 (Acinetobacter sp.), UFLA03-10 (Paenibacillus kribbensis), UFLA03-106 (Paenibacillus kribbensis) and UFLA03-116 (Paenibacillus sp.). The strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 solubilized Ca3(PO4)2 in liquid medium regardless of the initial pH, although without a significant difference between the treatments. The production of organic acids by these strains was assessed for all of the initial pH values investigated, and differences between the treatments were observed. Strains UFLA03-09 and UFLA03-10 produced the same acids at different initial pH values in the culture medium. There was no correlation between phosphorus solubilized from Ca3(PO4)2 in NBRIP liquid medium and the concentration of total organic acids at the different initial pH values. Therefore, the initial pH of the culture medium influences the production of organic acids by the strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 but it does not affect calcium phosphate solubilization.

  4. Effects of urea and acetic acid on the heme axial ligation structure of ferric myoglobin at very acidic pH.

    PubMed

    Droghetti, Enrica; Sumithran, Suganya; Sono, Masanori; Antalík, Marián; Fedurco, Milan; Dawson, John H; Smulevich, Giulietta

    2009-09-01

    The heme iron coordination of ferric myoglobin (Mb) in the presence of 9.0M urea and 8.0M acetic acid at acidic pH values has been probed by electronic absorption, magnetic circular dichroism and resonance Raman spectroscopic techniques. Unlike Mb at pH 2.0, where heme is not released from the protein despite the acid denaturation and the loss of the axial ligand, upon increasing the concentration of either urea or acetic acid, a spin state change is observed, and a novel, non-native six-coordinated high-spin species prevails, where heme is released from the protein.

  5. A single pH fluorescent probe for biosensing and imaging of extreme acidity and extreme alkalinity.

    PubMed

    Chao, Jian-Bin; Wang, Hui-Juan; Zhang, Yong-Bin; Li, Zhi-Qing; Liu, Yu-Hong; Huo, Fang-Jun; Yin, Cai-Xia; Shi, Ya-Wei; Wang, Juan-Juan

    2017-07-04

    A simple tailor-made pH fluorescent probe 2-benzothiazole (N-ethylcarbazole-3-yl) hydrazone (Probe) is facilely synthesized by the condensation reaction of 2-hydrazinobenzothiazole with N-ethylcarbazole-3-formaldehyde, which is a useful fluorescent probe for monitoring extremely acidic and alkaline pH, quantitatively. The pH titrations indicate that Probe displays a remarkable emission enhancement with a pK a of 2.73 and responds linearly to minor pH fluctuations within the extremely acidic range of 2.21-3.30. Interestingly, Probe also exhibits strong pH-dependent characteristics with pK a 11.28 and linear response to extreme-alkalinity range of 10.41-12.43. In addition, Probe shows a large Stokes shift of 84 nm under extremely acidic and alkaline conditions, high selectivity, excellent sensitivity, good water-solubility and fine stability, all of which are favorable for intracellular pH imaging. The probe is further successfully applied to image extremely acidic and alkaline pH values fluctuations in E. coli cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Polyamine/salt-assembled microspheres coated with hyaluronic acid for targeting and pH sensing.

    PubMed

    Zhang, Pan; Yang, Hui; Wang, Guojun; Tong, Weijun; Gao, Changyou

    2016-06-01

    The poly(allylamine hydrochloride)/trisodium citrate aggregates were fabricated and further covalently crosslinked via the coupling reaction of carboxylic sites on trisodium citrate with the amine groups on polyamine, onto which poly-L-lysine and hyaluronic acid were sequentially assembled, forming stable microspheres. The pH sensitive dye and pH insensitive dye were further labeled to enable the microspheres with pH sensing property. Moreover, these microspheres could be specifically targeted to HeLa tumor cells, since hyaluronic acid can specifically recognize and bind to CD44, a receptor overexpressed on many tumor cells. Quantitative pH measurement by confocal laser scanning microscopy demonstrated that the microspheres were internalized into HeLa cells, and accumulated in acidic compartments. By contrast, only a few microspheres were adhered on the NIH 3T3 cells surface. The microspheres with combined pH sensing property and targeting ability can enhance the insight understanding of the targeted drug vehicles trafficking after cellular internalization. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Alteration of chemical behavior of L-ascorbic acid in combination with nickel sulfate at different pH solutions in vitro

    PubMed Central

    Maniyar, Shaheen A; Jargar, Jameel G; Das, Swastika N; Dhundasi, Salim A; Das, Kusal K

    2012-01-01

    Objective To evaluate the alteration of chemical behavior of L-ascorbic acid (vitamin C) with metal ion (nickel) at different pH solutions in vitro. Methods Spectra of pure aqueous solution of L-ascorbic acid (E mark) compound and NiSO4 (H2O) (sigma USA) were evaluated by UV visible spectrophotometer. Spectral analysis of L-ascorbic acid and nickel at various pH (2.0, 7.0, 7.4 and 8.6) at room temperature of 29 °C was recorded. In this special analysis, combined solution of L-ascorbic acid and nickel sulfate at different pH was also recorded. Results The result revealed that λmax (peak wavelength of spectra) of L-ascorbic acid at pH 2.0 was 289.0 nm whereas at neutral pH 7.0, λmax was 295.4 nm. In alkaline pH 8.6, λmax was 295.4 nm and at pH 7.4 the λmax of L-ascorbic acid remained the same as 295.4 nm. Nickel solution at acidic pH 2.0 was 394.5 nm, whereas at neutral pH 7.0 and pH 7.4 were the same as 394.5 nm. But at alkaline pH 8.6, λmax value of nickel sulfate became 392.0 nm. The combined solution of L-ascorbic acid and nickel sulfate (6 mg/mL each) at pH 2.0 showed 292.5 nm and 392.5 nm, respectively whereas at pH 7.0, L-ascorbic acid showed 296.5 nm and nickel sulfate showed 391.5 nm. At pH 7.4, L-ascorbic acid showed 297.0 nm and nickel sulfate showed 394.0 nm in the combined solution whereas at pH 8.6 (alkaline) L-ascorbic acid and nickel sulfate were showing 297.0 and 393.5 nm, respectively. Conclusions Results clearly indicate an altered chemical behavior of L-ascorbic acid either alone or in combination with nickel sulfate in vitro at different pH. Perhaps oxidation of L-ascorbic acid to L-dehydro ascorbic acid via the free radical (HSc*) generation from the reaction of H2ASc + Ni (II) is the cause of such alteration of λmax value of L-ascorbic acid in the presence of metal nickel. PMID:23569901

  8. Effects of acidity on tree Pollen germination and tube growth. Final report

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Van Ryn, D.M.; Jacobson, J.S.

    Most of the northeastern hardwood forests in North America are exposed repeatedly to acidic rainfall at pH values below 5.0. Pollen germination, tube growth and fertilization, important parts of the reproductive process, are sensitive to changes in their chemical environment. Accordingly, the authors investigated the effects of acidity on pollen germination and tube elongation of four northeastern tree species: flowering dogwood, black birch, yellow birch, and sugar maple. Pollen was collected and germinated in a growth medium acidified to pH values ranging from 5.0 to 2.6. Pollen was found to be sensitive to acidification of the germination medium to belowmore » pH 4.2. These results suggest that acidic rain that now occurs in eastern North America may influence reproductive processes that are necessary for seed set and regeneration in northern hardwood forests.« less

  9. Electric Utility Phase I Acid Rain Compliance Strategies for the Clean Air Act Amendments of 1990

    EIA Publications

    1994-01-01

    The Acid Rain Program is divided into two time periods; Phase I, from 1995 through 1999, and Phase II, starting in 2000. Phase I mostly affects power plants that are the largest sources of SO2 and NOx . Phase II affects virtually all electric power producers, including utilities and nonutilities. This report is a study of the effects of compliance with Phase I regulations on the costs and operations of electric utilities, but does not address any Phase II impacts.

  10. Net acidity indicates the whole effluent toxicity of pH and dissolved metals in metalliferous saline waters.

    PubMed

    Degens, Bradley P; Krassoi, Rick; Galvin, Lynette; Reynolds, Brad; Micevska, Tina

    2018-05-01

    Measurements of potential acidity in water are used to manage aquatic toxicity risks of discharge from acid sulfate soils or acid mine drainage. Net acidity calculated from pH, dissolved metals and alkalinity is a common measurement of potential acidity but the relevance of current risk thresholds to aquatic organisms are unclear. Aquatic toxicity testing was carried out using four halophytic organisms with water from four saline sources in southern Western Australia (3 acidic drains and one alkaline river; 39-40 g TDS/L) where acidity was varied by adjusting pH to 4.5-6.5. The test species were brine shrimps (Artemia salina), locally sourced ostracods (Platycypris baueri), microalgae (Dunaliella salina) and amphipods (Allorchestes compressa). Testing found the EC 10 and IC 10 of net acidity ranged from -7.8 to 10.5 mg CaCO 3 /L with no survival or growth of any species at >47 mg CaCO 3 /L. Reduced net acidity indicated reduced whole effluent toxicity more reliably than increased pH alone with organisms tolerating pH up to 1.1 units lower in the absence of dissolved metals. Variation in toxicity indicated by net acidity was mostly attributed to reduced concentrations of dissolved Al and Fe combined with higher pH and alkalinity and some changes in speciation of Al and Fe with pH. These results indicate that rapid in-field assessments of net acidity in acidic, Al dominated waters may be an indicator of potential acute and sub-chronic impacts on aquatic organisms. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  11. Bolide impacts, acid rain, and biospheric traumas at the Cretaceous-Tertiary boundary

    NASA Technical Reports Server (NTRS)

    Prinn, Ronald G.; Fegley, Bruce, Jr.

    1987-01-01

    Two plausible projectiles are considered: an ice-rich long-period comet and a much smaller rock-metal asteroid. In the framework of a proposal addressed by Lewis et al. (1982), it is shown that, while the impact projectiles themselves do not shock-heat the atmosphere very extensively, the supersonic plume of water vapor and rock produced on impact does shock the atmosphere up to global scales and the shock is of sufficient intensity to produce abundant nitric oxide. For example, an ice-rich long-period comet with a mass of 1.25 x 10 to the 16th kg and a velocity of 65 km/s striking the earth would produce about 7 x 10 to the 40th molecules NO through shock-heating of the atmosphere by the high-velocity ejecta plume fragments. Specific attention is given to the fraction of the atmosphere shock-heated, the global circulation of the nitrogen oxides, the effects of the ejecta plume water on acid rain (AR) predictions, the effects of AR on continental soils, the relationship between AR production rates and the total amount of acid needed to acidify the surface oceans, and the longevity of the oceanic acidity event and the exhaled CO2 event and their implications for the environment in the first millenia or so after the impact.

  12. pH regulation of mitochondrial branch chain alpha-keto acid transport and oxidation in rat heart mitochondria.

    PubMed

    Hutson, S M

    1987-07-15

    The kinetics of branched chain alpha-keto acid uptake and efflux were studied as a function of varied external and matrix pH. Matrix pH was determined by the distribution of 5,5'-dimethyloxazolidine-2,4-dione. When rat heart mitochondria were incubated under transport conditions at pH 7.0 with succinate as respiratory substrate, the matrix pH was significantly greater than 8.0. Matrix pH remained greater than or equal to 8.0 when the medium pH was varied from 6.3 to 8.3, and it was lowered below 8.0 by addition of 5 mM phosphate or uncoupler. No pH gradient was detectable when mitochondria were incubated in the presence of valinomycin and uncoupler. Efflux of alpha-ketoisocaproate or alpha-ketoisovalerate from rat heart mitochondria obeyed first order kinetics. Varying the external pH from 6.6 to 8.3 had no significant effect on efflux, and at an external pH of 7.0, the first order rate constant for efflux was not affected by decreasing the matrix pH. On the other hand, exchange was sensitive to changes in medium but not matrix pH. The K0.5 for external branched chain alpha-keto acid was lowered by changing the medium pH from 7.6 to 6.3. At medium pH values greater than or equal to 8.0 both K0.5 and Vmax were affected. Uptake was determined either by measuring initial rates or was calculated after measuring the first order approach to a final equilibrium value. Unlike efflux, uptake was sensitive to changes in both external and matrix pH. The rate of branched chain alpha-keto acid uptake was stimulated by decreasing the medium pH from 8.3 to 6.3 and by alkalinization of the mitochondrial matrix. The estimated external pK for proton binding was 6.9. The data indicate that the branched chain alpha-keto acid transporter is asymmetric, that is, binding sites for substrate on the inside and outside of the mitochondrial membrane are not identical. alpha-Ketoisocaproate oxidation was measured at 37 degrees C in isolated mitochondria over the pH range of 6.6 to 8

  13. Sensitive detection of strong acidic condition by a novel rhodamine-based fluorescent pH chemosensor.

    PubMed

    Tan, Jia-Lian; Yang, Ting-Ting; Liu, Yu; Zhang, Xue; Cheng, Shu-Jin; Zuo, Hua; He, Huawei

    2016-05-01

    A novel rhodamine-based fluorescent pH probe responding to extremely low pH values has been synthesized and characterized. This probe showed an excellent photophysical response to pH on the basis that the colorless spirocyclic structure under basic conditions opened to a colored and highly fluorescent form under extreme acidity. The quantitative relationship between fluorescence intensity and pH value (1.75-2.62) was consistent with the equilibrium equation pH = pKa + log[(Imax - I)/(I - Imin)]. This sensitive pH probe was also characterized with good reversibility and no interaction with interfering metal ions, and was successfully applied to image Escherichia coli under strong acidity. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Acidic Food pH Increases Palatability and Consumption and Extends Drosophila Lifespan12

    PubMed Central

    Deshpande, Sonali A; Yamada, Ryuichi; Mak, Christine M; Hunter, Brooke; Obando, Alina Soto; Hoxha, Sany; Ja, William W

    2015-01-01

    Background: Despite the prevalent use of Drosophila as a model in studies of nutrition, the effects of fundamental food properties, such as pH, on animal health and behavior are not well known. Objectives: We examined the effect of food pH on adult Drosophila lifespan, feeding behavior, and microbiota composition and tested the hypothesis that pH-mediated changes in palatability and total consumption are required for modulating longevity. Methods: We measured the effect of buffered food (pH 5, 7, or 9) on male gustatory responses (proboscis extension), total food intake, and male and female lifespan. The effect of food pH on germfree male lifespan was also assessed. Changes in fly-associated microbial composition as a result of food pH were determined by 16S ribosomal RNA gene sequencing. Male gustatory responses, total consumption, and male and female longevity were additionally measured in the taste-defective Pox neuro (Poxn) mutant and its transgenic rescue control. Results: An acidic diet increased Drosophila gustatory responses (40–230%) and food intake (5–50%) and extended survival (10–160% longer median lifespan) compared with flies on either neutral or alkaline pH food. Alkaline food pH shifted the composition of fly-associated bacteria and resulted in greater lifespan extension (260% longer median survival) after microbes were eliminated compared with flies on an acidic (50%) or neutral (130%) diet. However, germfree flies lived longer on an acidic diet (5–20% longer median lifespan) compared with those on either neutral or alkaline pH food. Gustatory responses, total consumption, and longevity were unaffected by food pH in Poxn mutant flies. Conclusions: Food pH can directly influence palatability and feeding behavior and affect parameters such as microbial growth to ultimately affect Drosophila lifespan. Fundamental food properties altered by dietary or drug interventions may therefore contribute to changes in animal physiology, metabolism, and

  15. Does simulated acid rain increase the leaching of cadmium from wood ash to toxic levels to coniferous forest humus microbes?

    PubMed

    Perkiömäki, Jonna; Fritze, Hannu

    2003-05-01

    Abstract Wood ash contains Cd in concentrations not permitted for fertilization use in agriculture (>3 mg kg(-1)). It has been shown that spiking ash with Cd to concentrations of 1000 mg kg(-1) induced no further changes in humus microbial activity and community structure as ash alone. To accelerate the weathering process and thus to liberate the spiked Cd from the ash, three treatments - wood ash (A), Cd spiked wood ash (ACd, 1000 mg Cd kg(-1) ash), both applied at a fertilization rate of 5000 kg ha(-1), together with a control (C) - were performed in microcosms and incubated in field condition under two types of irrigation - water and simulated acid rain. During the incubation period of one growing season the simulated acid rain plots received a sulfur load of 3.64 g S m(-2), which was 15 times more than the S deposition on the water irrigated plots. The treatments resulted in a mean Cd increase of the humus from 0.23 mg kg(-1) of the C treatment to 0.52 and 39.5 mg kg(-1) of the A and ACd treatments, respectively. The irrigation had no further effect on the result. The microbial activity, measured as soil basal respiration, and the microbial community structure, measured as humus phospholipid fatty acid and 16S and 18S polymerase chain reaction/denaturing gradient gel electrophoresis patterns, changed only due to the ash (A and ACd treatments) fertilization irrespective of the irrigation. The bacterial biosensor, emitting light in the presence of bioavailable Cd, did not react to any of the treatments. This result shows that Cd in ash was not leached into the humus due to increased deposition of acidified rain.

  16. Temporal and spatial variability of rainfall pH

    Treesearch

    Richard G. Semonin

    1977-01-01

    The distribution of average rainwater pH over an area of 1,800 km² containing 81 collectors was determined from 25 storm events. The areal average of the data was pH 4.9, with a range of values from 4.3 to 6.8. A single storm event was studied to determine the change of pH as a function of time. The initial rain was pH 7.1, decreasing to 4.1. An excellent...

  17. The influence of an endomycorrhizal symbiosis on nitrogen movement through soil columns under regimes of artificial throughfall and artificial acid rain

    Treesearch

    Bruce Haines; George Ronnie Best

    1976-01-01

    The effect of artificial acid rain on nitrogen uptake by a fungus [Glomus mosseae (Nicol. & Gerd. ) Gerd. & Trappe] endomycorrhizal with roots of sweetgum tree seedlings (Liquidambar styraciflua L.) was investigated by applying 3 kinds of test solutions to the surfaces of soil profiles planted with five combinations of...

  18. Chemical characterization of fog and rain water collected at the eastern Andes cordillera

    NASA Astrophysics Data System (ADS)

    Beiderwieden, E.; Wrzesinsky, T.; Klemm, O.

    2005-06-01

    During a three month period in 2003 and 2004, the chemistry of fog and rainwater were studied at the "El Tiro" site in a tropical mountain forest ecosystem in Ecuador, South America. The fogwater samples were collected using a passive fog collector, and for the rain water, a standard rain sampler was employed. For all samples, electric conductivity, pH, and the concentrations of NH4+, K+, Na+, Ca2+, Mg2+, Cl-, NO3-, PO43-, and SO42-, were measured. For each fog sample, a 5 day back trajectory was calculated by the use of the HYSPLIT model. Two types of trajectories occurred. One type was characterized by advection of air masses from the East over the Amazonian basin, the other trajectory arrived one from the West after significant travel time over the Pacific Ocean. We found considerably higher ion concentrations in fogwater samples than in rain samples. Median pH values are 4.58 for fog water, and 5.26 for the rain samples, respectively. The median electric conductivity was 23 µS cm-1 for the fog and 6 µS cm-1 for the rain. The concentrations of all analysed ions were relatively low compared to other mountainous sites (Weathers et al., 1988; Elias et al., 1995; Schemenauer et al., 1995; Wrzesinsky and Klemm, 2000; Zimmermann and Zimmermann, 2002). The continent samples exhibit higher concentrations of most ions as compared to the pacific samples.

  19. Acidic pH and divalent cation sensing by PhoQ are dispensable for systemic salmonellae virulence.

    PubMed

    Hicks, Kevin G; Delbecq, Scott P; Sancho-Vaello, Enea; Blanc, Marie-Pierre; Dove, Katja K; Prost, Lynne R; Daley, Margaret E; Zeth, Kornelius; Klevit, Rachel E; Miller, Samuel I

    2015-05-23

    Salmonella PhoQ is a histidine kinase with a periplasmic sensor domain (PD) that promotes virulence by detecting the macrophage phagosome. PhoQ activity is repressed by divalent cations and induced in environments of acidic pH, limited divalent cations, and cationic antimicrobial peptides (CAMP). Previously, it was unclear which signals are sensed by salmonellae to promote PhoQ-mediated virulence. We defined conformational changes produced in the PhoQ PD on exposure to acidic pH that indicate structural flexibility is induced in α-helices 4 and 5, suggesting this region contributes to pH sensing. Therefore, we engineered a disulfide bond between W104C and A128C in the PhoQ PD that restrains conformational flexibility in α-helices 4 and 5. PhoQ(W104C-A128C) is responsive to CAMP, but is inhibited for activation by acidic pH and divalent cation limitation. phoQ(W104C-A128C) Salmonella enterica Typhimurium is virulent in mice, indicating that acidic pH and divalent cation sensing by PhoQ are dispensable for virulence.

  20. Development of Online Spectroscopic pH Monitoring for Nuclear Fuel Reprocessing Plants: Weak Acid Schemes.

    PubMed

    Casella, Amanda J; Ahlers, Laura R H; Campbell, Emily L; Levitskaia, Tatiana G; Peterson, James M; Smith, Frances N; Bryan, Samuel A

    2015-05-19

    In nuclear fuel reprocessing, separating trivalent minor actinides and lanthanide fission products is extremely challenging and often necessitates tight pH control in TALSPEAK (Trivalent Actinide-Lanthanide Separation by Phosphorus reagent Extraction from Aqueous Komplexes) separations. In TALSPEAK and similar advanced processes, aqueous pH is one of the most important factors governing the partitioning of lanthanides and actinides between an aqueous phase containing a polyaminopolycarboxylate complexing agent and a weak carboxylic acid buffer and an organic phase containing an acidic organophosphorus extractant. Real-time pH monitoring would significantly increase confidence in the separation performance. Our research is focused on developing a general method for online determination of the pH of aqueous solutions through chemometric analysis of Raman spectra. Spectroscopic process-monitoring capabilities, incorporated in a counter-current centrifugal contactor bank, provide a pathway for online, real-time measurement of solution pH. The spectroscopic techniques are process-friendly and can be easily configured for online applications, whereas classic potentiometric pH measurements require frequent calibration/maintenance and have poor long-term stability in aggressive chemical and radiation environments. Raman spectroscopy discriminates between the protonated and deprotonated forms of the carboxylic acid buffer, and the chemometric processing of the Raman spectral data with PLS (partial least-squares) regression provides a means to quantify their respective abundances and therefore determine the solution pH. Interpretive quantitative models have been developed and validated under a range of chemical composition and pH conditions using a lactic acid/lactate buffer system. The developed model was applied to new spectra obtained from online spectral measurements during a solvent extraction experiment using a counter-current centrifugal contactor bank. The model

  1. A wireless pH sensor using magnetoelasticity for measurement of body fluid acidity.

    PubMed

    Pang, Pengfei; Gao, Xianjuan; Xiao, Xilin; Yang, Wenyue; Cai, Qingyun; Yao, Shouzhuo

    2007-04-01

    The determination of body fluid acidity using a wireless magnetoelastic pH-sensitive sensor is described. The sensor was fabricated by casting a layer of pH-sensitive polymer on a magnetoelastic ribbon. In response to an externally applied time-varying magnetic field, the magnetoelastic sensor mechanically vibrates at a characteristic frequency that is inversely dependent upon the mass of the pH polymer film, which varies as the film swells and shrinks in response to pH. As the magnetoelastic sensor is magnetostrictive, the mechanical vibrations of the sensor launch magnetic flux that can be detected remotely using a pickup coil. The sensor can be used for direct measurements of body fluid acidity without a pretreatment of the sample by using a filtration membrane. A reversible and linear response was obtained between pH 5.0 and 8.0 with a measurement resolution of pH 0.1 and a slope of 0.2 kHz pH(-1). Since there are no physical connections between the sensor and the instrument, the sensor can be applied to in vivo and in situ monitoring of the physiological pH and its fluctuations.

  2. Comparing the acidities of aqueous, frozen, and freeze-dried phosphate buffers: Is there a "pH memory" effect?

    PubMed

    Vetráková, Ľubica; Vykoukal, Vít; Heger, Dominik

    2017-09-15

    The concept of "pH memory" has been established in the literature for the correlation between the pH of a pre-lyophilization solution and the ionization state of freeze-dried powder (lyophile). In this paper, the concept of "pH memory" is explored for the system of an aqueous solution, a frozen solution, and a lyophile. Sodium and potassium phosphate buffers in the pH range of 5-9 were frozen and lyophilized with sulfonephthalein indicators as acidity probes, and their Hammett acidity functions were compared to the initial pH of the aqueous solution. The results show that the acidities of the lyophiles are somewhat changed compared to the initial pHs, but the acidities in the frozen state differ more substantially. The Hammett acidity functions of the frozen buffers were found to be markedly dissimilar from the initial pH, especially in the sodium phosphate frozen at 233K, where an increase in the initial pH led to a decrease in the Hammett acidity function of the frozen state at a certain pH range. The large acidification observed after freezing the sodium phosphate buffer was not detected in the lyophiles after the sample had been dried; the phenomenon is explained considering the formed crystals analyzed by X-ray powder diffraction. The results suggest that monitoring the final acidity of a lyophile is not sufficient to predict all the acidity changes throughout the whole lyophilization process. The importance of well-controlled freezing and lyophilization conditions follows from the results of the research. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Acidic pH retards the fibrillization of human Islet Amyloid Polypeptide due to electrostatic repulsion of histidines.

    PubMed

    Li, Yang; Xu, Weixin; Mu, Yuguang; Zhang, John Z H

    2013-08-07

    The human Islet Amyloid Polypeptide (hIAPP) is the major constituent of amyloid deposits in pancreatic islets of type-II diabetes. IAPP is secreted together with insulin from the acidic secretory granules at a low pH of approximately 5.5 to the extracellular environment at a neutral pH. The increased accumulation of extracellular hIAPP in diabetes indicates that changes in pH may promote amyloid formation. To gain insights and underlying mechanisms of the pH effect on hIAPP fibrillogenesis, all-atom molecular dynamics simulations in explicit solvent model were performed to study the structural properties of five hIAPP protofibrillar oligomers, under acidic and neutral pH, respectively. In consistent with experimental findings, simulation results show that acidic pH is not conducive to the structural stability of these oligomers. This provides a direct evidence for a recent experiment [L. Khemtemourian, E. Domenech, J. P. F. Doux, M. C. Koorengevel, and J. A. Killian, J. Am. Chem. Soc. 133, 15598 (2011)], which suggests that acidic pH inhibits the fibril formation of hIAPP. In addition, a complementary coarse-grained simulation shows the repulsive electrostatic interactions among charged His18 residues slow down the dimerization process of hIAPP by twofold. Besides, our all-atom simulations reveal acidic pH mainly affects the local structure around residue His18 by destroying the surrounding hydrogen-bonding network, due to the repulsive interactions between protonated interchain His18 residues at acidic pH. It is also disclosed that the local interactions nearby His18 operating between adjacent β-strands trigger the structural transition, which gives hints to the experimental findings that the rate of hIAPP fibril formation and the morphologies of the fibrillar structures are strongly pH-dependent.

  4. Acidic pH retards the fibrillization of human islet amyloid polypeptide due to electrostatic repulsion of histidines

    NASA Astrophysics Data System (ADS)

    Li, Yang; Xu, Weixin; Mu, Yuguang; Zhang, John Z. H.

    2013-08-01

    The human Islet Amyloid Polypeptide (hIAPP) is the major constituent of amyloid deposits in pancreatic islets of type-II diabetes. IAPP is secreted together with insulin from the acidic secretory granules at a low pH of approximately 5.5 to the extracellular environment at a neutral pH. The increased accumulation of extracellular hIAPP in diabetes indicates that changes in pH may promote amyloid formation. To gain insights and underlying mechanisms of the pH effect on hIAPP fibrillogenesis, all-atom molecular dynamics simulations in explicit solvent model were performed to study the structural properties of five hIAPP protofibrillar oligomers, under acidic and neutral pH, respectively. In consistent with experimental findings, simulation results show that acidic pH is not conducive to the structural stability of these oligomers. This provides a direct evidence for a recent experiment [L. Khemtemourian, E. Domenech, J. P. F. Doux, M. C. Koorengevel, and J. A. Killian, J. Am. Chem. Soc. 133, 15598 (2011)], 10.1021/ja205007j, which suggests that acidic pH inhibits the fibril formation of hIAPP. In addition, a complementary coarse-grained simulation shows the repulsive electrostatic interactions among charged His18 residues slow down the dimerization process of hIAPP by twofold. Besides, our all-atom simulations reveal acidic pH mainly affects the local structure around residue His18 by destroying the surrounding hydrogen-bonding network, due to the repulsive interactions between protonated interchain His18 residues at acidic pH. It is also disclosed that the local interactions nearby His18 operating between adjacent β-strands trigger the structural transition, which gives hints to the experimental findings that the rate of hIAPP fibril formation and the morphologies of the fibrillar structures are strongly pH-dependent.

  5. What is the critical pH and why does a tooth dissolve in acid?

    PubMed

    Dawes, Colin

    2003-12-01

    This paper discusses the concept of critical pH for dissolution of enamel in oral fluids. The critical pH does not have a fixed value but rather is inversely proportional to the calcium and phosphate concentrations in the solution. The paper also discusses why teeth dissolve in acid, why remineralization of white-spot caries lesions is possible and why remineralization of teeth eroded by acid is not possible.

  6. Adsorption of aliphatic polyhydroxy carboxylic acids on gibbsite: pH dependency and importance of adsorbate structure.

    PubMed

    Schneckenburger, Tatjana; Riefstahl, Jens; Fischer, Klaus

    2018-01-01

    Aliphatic (poly)hydroxy carboxylic acids [(P)HCA] occur in natural, e.g. soils, and in technical (waste disposal sites, nuclear waste repositories) compartments . Their distribution, mobility and chemical reactivity, e.g. complex formation with metal ions and radionuclides, depend, among others, on their adsorption onto mineral surfaces. Aluminium hydroxides, e.g. gibbsite [α-Al(OH) 3 ], are common constituents of related solid materials and mimic the molecular surface properties of clay minerals. Thus, the study was pursued to characterize the adsorption of glycolic, threonic, tartaric, gluconic, and glucaric acids onto gibbsite over a wide pH and (P)HCA concentration range. To consider specific conditions occurring in radioactive wastes, adsorption applying an artificial cement pore water (pH 13.3) as solution phase was investigated additionally. The sorption of gluconic acid at pH 4, 7, 9, and 12 was best described by the "two-site" Langmuir isotherm, combining "high affinity" sorption sites (adsorption affinity constants [Formula: see text] > 1 L mmol -1 , adsorption capacities < 6.5 mmol kg -1 ) with "low affinity" sites ([Formula: see text] < 0.1 L mmol -1 , adsorption capacities ≥ 19 mmol kg -1 ). The total adsorption capacities at pH 9 and 12 were roughly tenfold of that at pH 4 and 7. The S-shaped pH sorption edge of gluconic acid was modelled applying a constant capacitance model, considering electrostatic interactions, hydrogen bonding, surface complex formation, and formation of solved polynuclear complexes between Al 3+ ions and gluconic acid. A Pearson and Spearman rank correlation between (P)HCA molecular properties and adsorption parameters revealed the high importance of the size and the charge of the adsorbates. The adsorption behaviour of (P)HCAs is best described by a combination of adsorption properties of carboxylic acids at acidic pH and of polyols at alkaline pH. Depending on the molecular properties of the adsorbates and

  7. [Characteristics of soil pH and exchangeable acidity in red soil profile under different vegetation types].

    PubMed

    Ji, Gang; Xu, Ming-gang; Wen, Shi-lin; Wang, Bo-ren; Zhang, Lu; Liu, Li-sheng

    2015-09-01

    The characteristics of soil pH and exchangeable acidity in soil profile under different vegetation types were studied in hilly red soil regions of southern Hunan Province, China. The soil samples from red soil profiles within 0-100 cm depth at fertilized plots and unfertilized plots were collected and analyzed to understand the profile distribution of soil pH and exchangeable acidity. The results showed that, pH in 0-60 cm soil from the fertilized plots decreased as the following sequence: citrus orchard > Arachis hypogaea field > tea garden. As for exchangeable acidity content, the sequence was A. hypogaea field ≤ citrus orchard < tea garden. After tea tree and A. hypogaea were planted for long time, acidification occurred in surface soil (0-40 cm), compared with the deep soil (60-100 cm), and soil pH decreased by 0.55 and 0.17 respectively, but such changes did not occur in citrus orchard. Soil pH in 0-40 cm soil from the natural recovery vegetation unfertilized plots decreased as the following sequence: Imperata cylindrica land > Castanea mollissima garden > Pinus elliottii forest ≥ Loropetalum chinensis forest. As for exchangeable acidity content, the sequence was L cylindrica land < C. mollissima garden < L. chinensis forest ≤ P. elliottii forest. Soil pH in surface soil (0-20 cm) from natural forest plots, secondary forest and Camellia oleifera forest were significantly lower than that from P. massoniana forest, decreased by 0.34 and 0.20 respectively. For exchangeable acidity content in 0-20 cm soil from natural forest plot, P. massoniana forest and secondary forest were significantly lower than C. oleifera forest. Compared with bare land, surface soil acidification in unfertilized plots except I. cylindrica land had been accelerated, and the natural secondary forest was the most serious among them, with surface soil pH decreasing by 0.52. However, the pH increased in deep soils from unfertilized plots except natural secondary forest, and I. cylindrica

  8. The pH ruler: a Java applet for developing interactive exercises on acids and bases.

    PubMed

    Barrette-Ng, Isabelle H

    2011-07-01

    In introductory biochemistry courses, it is often a struggle to teach the basic concepts of acid-base chemistry in a manner that is relevant to biological systems. To help students gain a more intuitive and visual understanding of abstract acid-base concepts, a simple graphical construct called the pH ruler Java applet was developed. The applet allows students to visualize the abundance of different protonation states of diprotic and triprotic amino acids at different pH values. Using the applet, the student can drag a widget on a slider bar to change the pH and observe in real time changes in the abundance of different ionization states of this amino acid. This tool provides a means for developing more complex inquiry-based, active-learning exercises to teach more advanced topics of biochemistry, such as protein purification, protein structure and enzyme mechanism.

  9. pH shift protein recovery with organic acids on texture and color of cooked gels.

    PubMed

    Paker, Ilgin; Beamer, Sarah; Jaczynski, Jacek; Matak, Kristen E

    2015-01-01

    Isoelectric solubilization and precipitation (ISP) processing uses pH shifts to separate protein from fish frames, which may increase commercial interest for silver carp. Texture and color properties of gels made from silver carp protein recovered at different pH strategies and organic acid types were compared. ISP was applied to headed gutted silver carp using 10 mol L(-1) sodium hydroxide (NaOH) and either glacial acetic acid (AA) or a (1:1) formic and lactic acid combination (F&L). Protein gels were made with recovered protein and standard functional additives. Texture profile analysis and the Kramer shear test showed that protein gels made from protein solubilized at basic pH values were firmer, harder, more cohesive, gummier and chewier (P < 0.05) than proteins solubilized under acidic conditions. Acidic solubilization led to whiter (P < 0.05) gels, and using F&L during ISP yielded whiter gels under all treatments (P < 0.05). Gels made from ISP-recovered silver carp protein using organic acids show potential for use as a functional ingredient in restructured foods. © 2014 Society of Chemical Industry.

  10. Low pH affects survival, growth, size distribution, and carapace quality of the postlarvae and early juveniles of the freshwater prawn Macrobrachium rosenbergii de Man

    NASA Astrophysics Data System (ADS)

    Kawamura, Gunzo; Bagarinao, Teodora; Yong, Annita Seok Kian; Chen, Chiau Yu; Noor, Siti Norasidah Mat; Lim, Leong Seng

    2015-06-01

    Acidification of rain water caused by air pollutants is now recognized as a serious threat to aquatic ecosystems. We examined the effects of low pH (control pH 7.5, pH 6, pH 5, pH 4) on the survival, growth, and shell quality of Macrobrachium rosenbergii postlarvae and early juveniles in the laboratory. Hatcheryproduced postlarvae (PL 5) were stocked at 250 PL per aquarium, acclimated over 7 d to experimental pH adjusted with hydrochloric acid, and reared for 30 d. Dead specimens were removed and counted twice a day. After 27 d rearing, all specimens were measured for total length and body weight. Carapace quality was assessed by spectrophotometry. Survival of juveniles was highest at pH 6 (binomial 95% confidence interval 79 - 89%) followed by control pH 7.5 (56 - 68%) and pH 5 (50 - 60%) and was lowest for unmetamorphosed postlarvae and juveniles at pH 4 (43 - 49%). The final median total length and body weight of juveniles were similar at control pH 7.5 (18.2 TL, 50.2 mg BW) and pH 6 (17.7 mm TL, 45.0 mg BW) but significantly less at pH 5 (16.7 mm TL, 38.2 mg BW); at pH 4, the postlarvae did not metamorphose and measured only 9.8 mm TL, 29.3 mg BW. Length frequency distribution showed homogeneous growth at pH 6, positive skew at control pH 7.5 and pH 5, and extreme heterogeneity at pH 4. The carapace showed different transmittance spectra and lower total transmittance (i.e. thicker carapace) in juveniles at pH 7.5, pH 6, and pH 5 than in unmetamorphosed postlarvae and juveniles with thinner carapace at pH 4. Thus, survival, growth, size distribution, and carapace quality of M. rosenbergii postlarvae and early juveniles were negatively affected by pH 5 and especially pH 4. The thinner carapace of the survivors at pH 4 was mostly due to their small size and failure to metamorphose. Natural waters affected by acid rain could decimate M. rosenbergii populations in the wild.

  11. Dissolved Divalent Metal and pH Effects on Amino Acid Polymerization: A Thermodynamic Evaluation.

    PubMed

    Kitadai, Norio

    2017-03-01

    Polymerization of amino acids is a fundamentally important step for the chemical evolution of life. Nevertheless, its response to changing environmental conditions has not yet been well understood because of the lack of reliable quantitative information. For thermodynamics, detailed prediction over diverse combinations of temperature and pH has been made only for a few amino acid-peptide systems. This study used recently reported thermodynamic dataset for the polymerization of the simplest amino acid "glycine (Gly)" to its short peptides (di-glycine and tri-glycine) to examine chemical and structural characteristics of amino acids and peptides that control the temperature and pH dependence of polymerization. Results showed that the dependency is strongly controlled by the intramolecular distance between the amino and carboxyl groups in an amino acid structure, although the side-chain group role is minor. The polymerization behavior of Gly reported earlier in the literature is therefore expected to be a typical feature for those of α-amino acids. Equilibrium calculations were conducted to examine effects of dissolved metals as a function of pH on the monomer-polymer equilibria of Gly. Results showed that metals shift the equilibria toward the monomer side, particularly at neutral and alkaline pH. Metals that form weak interaction with Gly (e.g., Mg 2+ ) have no noticeable influence on the polymerization, although strong interaction engenders significant decrease of the equilibrium concentrations of Gly peptides. Considering chemical and structural characteristics of Gly and Gly peptides that control their interactions with metals, it can be expected that similar responses to the addition of metals are applicable in the polymerization of neutral α-amino acids. Neutral and alkaline aqueous environments with dissolved metals having high affinity with neutral α-amino acids (e.g., Cu 2+ ) are therefore not beneficial places for peptide bond formation on the primitive

  12. Spectroscopic investigation on structure and pH dependent Cocrystal formation between gamma-aminobutyric acid and benzoic acid

    NASA Astrophysics Data System (ADS)

    Du, Yong; Xue, Jiadan; Cai, Qiang; Zhang, Qi

    2018-02-01

    Vibrational spectroscopic methods, including terahertz absorption and Raman scattering spectroscopy, were utilized for the characterization and analysis of gamma-aminobutyric acid (GABA), benzoic acid (BA), and the corresponding GABA-BA cocrystal formation under various pH values of aqueous solution. Vibrational spectroscopic results demonstrated that the solvent GABA-BA cocrystal, similar as grinding counterpart, possessed unique characteristic features compared with that of starting parent compounds. The change of vibrational modes for GABA-BA cocrystal comparing with starting components indicates there is strong inter-molecular interaction between GABA and BA molecules during its cocrystallization process. Formation of GABA-BA cocrystal under slow solvent evaporation is impacted by the pH value of aqueous solution. Vibrational spectra indicate that the GABA-BA cocrystal could be stably formed with the solvent condition of 2.00 ≤ pH ≤ 7.00. In contrast, such cocrystallization did not occur and the cocrystal would dissociate into its parent components when the pH value of solvent is lower than 2.00. This study provides experimental benchmark to discriminate and identify the structure of cocrystal and also pH-dependent cocrystallization effect with vibrational spectroscopic techniques in solid-state pharmaceutical fields.

  13. Kinetics of salivary pH after acidic beverage intake by patients undergoing orthodontic treatment.

    PubMed

    Turssi, Cecilia P; Silva, Carolina S; Bridi, Enrico C; Amaral, Flavia Lb; Franca, Fabiana Mg; Basting, Roberta T

    2015-01-01

    The saliva of patients undergoing orthodontic treatment with fixed appliances can potentially present a delay in the diluting, clearing, and buffering of dietary acids due to an increased number of retention areas. The aim of this clinical trial was to compare salivary pH kinetics of patients with and without orthodontic treatment, following the intake of an acidic beverage. Twenty participants undergoing orthodontic treatment and 20 control counterparts had their saliva assessed for flow rate, pH, and buffering capacity. There was no significant difference between salivary parameters in participants with or without an orthodontic appliance. Salivary pH recovery following acidic beverage intake was slower in the orthodontic subjects compared to controls. Patients with fixed orthodontic appliances, therefore, seem to be at higher risk of dental erosion, suggesting that dietary advice and preventive care need to be implemented during orthodontic treatment.

  14. Pinonaldehyde and some other organics in rain and snow in central Japan.

    PubMed

    Satsumabayashi, H; Nishizawa, H; Yokouchi, Y; Ueda, H

    2001-11-01

    Solvent-extractable organic compounds in the rain and snow collected at local cities in the mountainous region in central Japan, were analyzed by GC/MS and GC. Pinonaldehyde (2,2-dimethyl-3-acetyl-cyclobutyl-ethanal), an atmospheric reaction product of alpha-pinene, was detected in the rain and snow for the first time, and n-alkanes (C17-C33), fatty acids (C8-C23), and benzoic acid were also detected as major organic components. Concentrations of pinonaldehyde, C17-C33 n-alkanes, C8-C11 fatty acids, C12-C23 fatty acids and benzoic acid ranged between <0.02-13, 0.10-35, 0.55-5.7, 4.2-19 and <0.02-6.0 microg/l, respectively. Their composition showed some difference in summer and winter. In summer, fatty acids and benzoic acid were more abundant, while pinonaldehyde and n-alkanes were much less. Higher photochemical reactivity and higher bioactivity in summer could explain these seasonal changes except for pinonaldehyde, which would suffer from further oxidation in the atmosphere after its photochemical production from alpha-pinene. Predominance of pinonaldehyde and C12-C23 fatty acids in the rain and snow showed a remarkable contrast to n-alkanes in aerosol phase, which were the most abundant components. It indicated that oxygenated products from biogenic compounds might be important as cloud condensation nuclei in forest areas.

  15. Terrestrial acidification and ecosystem services: effects of acid rain on bunnies, baseball, and Christmas trees

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Irvine, Irina C.; Greaver, Tara; Phelan, Jennifer

    Often termed “acid rain,” combined nitrogen and sulfur deposition can directly and indirectly impact the condition and health of forest ecosystems. Researchers use critical loads (CLs) to describe response thresholds, and recent studies on acid-sensitive biological indicators show that forests continue to be at risk from terrestrial acidification. However, rarely are impacts translated into changes in “ecosystem services” that impact human well-being. Further, the relevance of this research to the general public is seldom communicated in terms that can motivate action to protect valuable resources. To understand how changes in biological indicators affect human well-being, we used the STEPS (Stressor–Ecologicalmore » Production function–final ecosystem Services) Framework to quantitatively and qualitatively link CL exceedances to ecosystem service impacts. We specified the cause-and-effect ecological processes linking changes in biological indicators to final ecosystem services. The Final Ecosystem Goods and Services Classification System (FEGS-CS) was used within the STEPS Framework to classify the ecosystem component and the beneficiary class that uses or values the component. We analyzed two acid-sensitive tree species, balsam fir (Abies balsamea) and white ash (Fraxinus americana), that are common in northeastern USA. These well-known species provide habitat for animals and popular forest products that are relatable to a broad audience. We identified 160 chains with 10 classes of human beneficiaries for balsam fir and white ash combined, concluding that there are resources at risk that the public may value. Two stories resulting from these explorations into the cascading effects of acid rain on terrestrial resources are ideal for effective science communication: the relationship between (1) balsam fir as a popular Christmas tree and habitat for the snowshoe hare, a favorite of wildlife viewers, and (2) white ash because it is used for half of all

  16. Terrestrial acidification and ecosystem services: effects of acid rain on bunnies, baseball, and Christmas trees

    DOE PAGES

    Irvine, Irina C.; Greaver, Tara; Phelan, Jennifer; ...

    2017-06-22

    Often termed “acid rain,” combined nitrogen and sulfur deposition can directly and indirectly impact the condition and health of forest ecosystems. Researchers use critical loads (CLs) to describe response thresholds, and recent studies on acid-sensitive biological indicators show that forests continue to be at risk from terrestrial acidification. However, rarely are impacts translated into changes in “ecosystem services” that impact human well-being. Further, the relevance of this research to the general public is seldom communicated in terms that can motivate action to protect valuable resources. To understand how changes in biological indicators affect human well-being, we used the STEPS (Stressor–Ecologicalmore » Production function–final ecosystem Services) Framework to quantitatively and qualitatively link CL exceedances to ecosystem service impacts. We specified the cause-and-effect ecological processes linking changes in biological indicators to final ecosystem services. The Final Ecosystem Goods and Services Classification System (FEGS-CS) was used within the STEPS Framework to classify the ecosystem component and the beneficiary class that uses or values the component. We analyzed two acid-sensitive tree species, balsam fir (Abies balsamea) and white ash (Fraxinus americana), that are common in northeastern USA. These well-known species provide habitat for animals and popular forest products that are relatable to a broad audience. We identified 160 chains with 10 classes of human beneficiaries for balsam fir and white ash combined, concluding that there are resources at risk that the public may value. Two stories resulting from these explorations into the cascading effects of acid rain on terrestrial resources are ideal for effective science communication: the relationship between (1) balsam fir as a popular Christmas tree and habitat for the snowshoe hare, a favorite of wildlife viewers, and (2) white ash because it is used for half of all

  17. Estimated net acid excretion inversely correlates with urine pH in vegans, lacto-ovo vegetarians, and omnivores.

    PubMed

    Ausman, Lynne M; Oliver, Lauren M; Goldin, Barry R; Woods, Margo N; Gorbach, Sherwood L; Dwyer, Johanna T

    2008-09-01

    Diet affects urine pH and acid-base balance. Both excess acid/alkaline ash (EAA) and estimated net acid excretion (NAE) calculations have been used to estimate the effects of diet on urine pH. This study's goal was to determine if free-living vegans, lacto-ovo vegetarians, and omnivores have increasingly acidic urine, and to assess the ability of EAA and estimated NAE calculations to predict urine pH. This study used a cross-sectional design. This study assessed urine samples of 10 vegan, 16 lacto-ovo vegetarian, and 16 healthy omnivorous women in the Boston metropolitan area. Six 3-day food records from each dietary group were analyzed for EAA content and estimated NAE, and correlations with measured urine pH were calculated. The mean (+/- SD) urine pH was 6.15 +/- 0.40 for vegans, 5.90 +/- 0.36 for lacto-ovo vegetarians, and 5.74 +/- 0.21 for omnivores (analysis of variance, P = .013). Calculated EAA values were not significantly different among the three groups, whereas mean estimated NAE values were significantly different: 17.3 +/- 14.5 mEq/day for vegans, 31.3 +/- 8.5 mEq/day for lacto-ovo vegetarians, and 42.6 +/- 13.2 mEq/day for omnivores (analysis of variance, P = .01). The average deattenuated correlation between urine pH and EAA was 0.333; this value was -0.768 for estimated NAE and urine pH, with a regression equation of pH = 6.33 - 0.014 NAE (P = .02, r = -0.54). Habitual diet and estimated NAE calculations indicate the probable ranking of urine pH by dietary groups, and may be used to determine the likely acid-base status of an individual; EAA calculations were not predictive of urine pH.

  18. Predicting Thermodynamic Behaviors of Non-Protein Amino Acids as a Function of Temperature and pH

    NASA Astrophysics Data System (ADS)

    Kitadai, Norio

    2016-03-01

    Why does life use α-amino acids exclusively as building blocks of proteins? To address that fundamental question from an energetic perspective, this study estimated the standard molal thermodynamic data for three non-α-amino acids (β-alanine, γ-aminobutyric acid, and ɛ-aminocaproic acid) and α-amino- n-butyric acid in their zwitterionic, negative, and positive ionization states based on the corresponding experimental measurements reported in the literature. Temperature dependences of their heat capacities were described based on the revised Helgeson-Kirkham-Flowers (HKF) equations of state. The obtained dataset was then used to calculate the standard molal Gibbs energies ( ΔG o) of the non-α-amino acids as a function of temperature and pH. Comparison of their ΔG o values with those of α-amino acids having the same molecular formula showed that the non-α-amino acids have similar ΔG o values to the corresponding α-amino acids in physiologically relevant conditions (neutral pH, <100 °C). In acidic and alkaline pH, the non-α-amino acids are thermodynamically more stable than the corresponding α-ones over a broad temperature range. These results suggest that the energetic cost of synthesis is not an important selection pressure to incorporate α-amino acids into biological systems.

  19. Predicting Thermodynamic Behaviors of Non-Protein Amino Acids as a Function of Temperature and pH.

    PubMed

    Kitadai, Norio

    2016-03-01

    Why does life use α-amino acids exclusively as building blocks of proteins? To address that fundamental question from an energetic perspective, this study estimated the standard molal thermodynamic data for three non-α-amino acids (β-alanine, γ-aminobutyric acid, and ε-aminocaproic acid) and α-amino-n-butyric acid in their zwitterionic, negative, and positive ionization states based on the corresponding experimental measurements reported in the literature. Temperature dependences of their heat capacities were described based on the revised Helgeson-Kirkham-Flowers (HKF) equations of state. The obtained dataset was then used to calculate the standard molal Gibbs energies (∆G (o)) of the non-α-amino acids as a function of temperature and pH. Comparison of their ∆G (o) values with those of α-amino acids having the same molecular formula showed that the non-α-amino acids have similar ∆G (o) values to the corresponding α-amino acids in physiologically relevant conditions (neutral pH, <100 °C). In acidic and alkaline pH, the non-α-amino acids are thermodynamically more stable than the corresponding α-ones over a broad temperature range. These results suggest that the energetic cost of synthesis is not an important selection pressure to incorporate α-amino acids into biological systems.

  20. Chemical characterization of rain water in a seasonally dry tropical region (Varanasi), India.

    PubMed

    Pandey, Jitendra; Singh, Ashima

    2012-05-01

    Rain water samples, covering 44 rain events of 2008 and 52 rain events of 2009, were collected at urban and suburban locations of Varanasi and analyzed for pH, conductivity and for metal and nutrient ions. The pH of rainwater varied between 6.3 and 7.9, with over 70% of samples having alkaline range. Volume weighed mean concentration of ions indicated Ca2+ (11.62- 41.60 microeq l(-1)) to be the most dominant species followed by SO4(2-) (4.7-25.2 microeq I(-1)), Na+ (1.60-10.25 microeq l(-1)), Mg2+ (0.22-7.21 microeq I(-1)), (NO3(-) (0.73-4.02 microeq l(-1)), K+(0.50-3.70 microeq l(-1)) and PO4(3-) (0.02-0.97 microeq l(-1)) respectively. Among the heavy metals, Cr (12.60 to 44.60 microg l(-1)), Zn (4.25 to 34.55 microg l(-1)) and Mn (10.62 to 28.40 microg l(-1)) were found to be the dominant component of rain water. The varimax rotation of PCA results extracted four major factors namely urban-industrial emission, crustal aerosols, wind transport and biomass burning accounting for 80% of the total variance. The study has relevance in establishing cause-effect relationships for terrestrial as well as for aquatic ecosystems.

  1. pH studies in the synthesis of amino acid coated hydrophilic MNPs

    NASA Astrophysics Data System (ADS)

    Saxena, Namita; Dube, Charu Lata

    2018-04-01

    Magnetic iron oxide nanoparticles magnetite and maghemite (MNPs) are specially useful in various fields like biomedical, waste disposal, catalysis etc. because of their biocompatibility and magnetic properties. They can be manipulated by applying magnetic field and hence their easier separation, wider applications and unending scope in the field of research. They are inherently hydrophobic, and aggregate easily mainly due to magnetic and nanosize effects. The present work reports the synthesis of hydrophilic, stably dispersed MNPs coated by different amino acids at different pH values. Lower concentration of amino acids, 1/3 (moles by moles) of Iron salts concentration was used in the study. Crystallites were found to be approximately 6-7 nm in size, as determined by XRD and also found to have good magnetization values in VSM studies. The effects of coating are mainly studied by FTIR and TG. Higher/lower pH values have been studied for better coating, and it is observed that higher pH is more helpful in getting better results, on bare MNPs synthesized under a pH of approximately 13.3. The effects of net charge on coating efficiency were also studied.

  2. Thermal resistance parameters of acid-adapted and unadapted Escherichia coli O157:H7 in apple-carrot juice blends: effect of organic acids and pH.

    PubMed

    Usaga, Jessie; Worobo, Randy W; Padilla-Zakour, Olga I

    2014-04-01

    Numerous outbreaks involving fresh juices contaminated with Escherichia coli O157:H7 have occurred in the United States and around the world, raising concern for the safety of these products. Until now, only a few studies regarding the thermal tolerance of this pathogen in acidic juices over a wide range of pH values have been published. Therefore, the effect of varying the pH with different organic acids on the thermal inactivation of non-acid-adapted and acid-adapted E. coli O157:H7 (strain C7927) was determined. The decimal reduction times (D-values) and the change in temperature required for the thermal destruction curve to traverse 1 log cycle (z-values) were calculated for non-acid-adapted E. coli in an apple-carrot juice blend (80:20) adjusted to three pH values (3.3, 3.5, and 3.7) by the addition of lactic, malic, or acetic acid and at a pH of 4.5 adjusted with NaOH. Thermal parameters were also determined for acid-adapted cells in juices acidified with malic acid. The effect of the soluble solids content on the thermal tolerance was studied in samples with a pH of 3.7 at 9.4 to 11.5 °Brix. The D-values were determined at 54, 56, and 58 °C, and trials were conducted in triplicate. Non-acid-adapted E. coli exhibited the highest thermal tolerance at pH 4.5 (D-value at 54 °C [D54 °C] of 20 ± 4 min and z-value of 6.2 °C), although on average, the D-values increased significantly (P < 0.01) due to acid adaptation. In acidified juices, the highest tolerance was observed in acid-adapted E. coli in samples adjusted to pH 3.7 with malic acid (D54 °C of 9 ± 2 min and z-value of 5.4 °C) and the lowest in unadapted E. coli at pH 3.3 acidified with acetic acid (D58 °C of 0.03 ± 0.01 min and z-value of 10.4 °C). For juices acidified to the same endpoint pH with different acids, E. coli was found to be more tolerant in samples acidified with malic acid, followed by lactic and acetic acids. Increasing the soluble solids content from 9.4 to 11.5 °Brix showed no

  3. Waste activated sludge hydrolysis and short-chain fatty acids accumulation under mesophilic and thermophilic conditions: effect of pH.

    PubMed

    Zhang, Peng; Chen, Yinguang; Zhou, Qi

    2009-08-01

    The effect of pH (4.0-11.0) on waste activated sludge (WAS) hydrolysis and short-chain fatty acids (SCFAs) accumulation under mesophilic and thermophilic conditions were investigated. The WAS hydrolysis increased markedly in thermophilic fermentation compared to mesophilic fermentation at any pH investigated. The hydrolysis at alkaline pHs (8.0-11.0) was greater than that at acidic pHs, but both of the acidic and alkaline hydrolysis was higher than that pH uncontrolled under either mesophilic or thermophilic conditions. No matter in mesophilic or thermophilic fermentation, the accumulation of SCFAs at alkaline pHs was greater than at acidic or uncontrolled pHs. The optimum SCFAs accumulation was 0.298g COD/g volatile suspended solids (VSS) with mesophilic fermentation, and 0.368 with thermophilic fermentation, which was observed respectively at pH 9.0 and fermentation time 5 d and pH 8.0 and time 9 d. The maximum SCFAs productions reported in this study were much greater than that in the literature. The analysis of the SCFAs composition showed that acetic acid was the prevalent acid in the accumulated SCFAs at any pH investigated under both temperatures, followed by propionic acid and n-valeric acid. Nevertheless, during the entire mesophilic and thermophilic fermentation the activity of methanogens was inhibited severely at acid or alkaline pHs, and the highest methane concentration was obtained at pH 7.0 in most cases. The studies of carbon mass balance showed that during WAS fermentation the reduction of VSS decreased with the increase of pH, and the thermophilic VSS reduction was greater than the mesophilic one. Further investigation indicated that most of the reduced VSS was converted to soluble protein and carbohydrate and SCFAs in two fermentations systems, while little formed methane and carbon dioxide.

  4. EFFECT OF AN ACID RAIN ENVIRONMENT ON LIMESTONE SURFACES.

    USGS Publications Warehouse

    Mossotti, Victor G.; Lindsay, James R.; Hochella, Michael F.

    1987-01-01

    Salem limestone samples were exposed to weathering for 1 y in several urban and one rural environments. Samples exposed in the rural location were chemically indistinguishable from the freshly quarried limestone, whereas all samples collected from urban exposure sites developed gypsum stains on the ground-facing surfaces where the stones were not washed by precipitation. The gas-solid reaction of SO//2 with calcite was selected for detailed consideration. It appears from the model that under arid conditions, the quantity of stain deposited on an unwashed surface is independent of atmospheric SO//2 concentration once the surface has been saturated with gypsum. Under wet conditions, surface sulfation and weight loss are probably dominated by mechanisms involving wet stone. However, if the rain events are frequent and delimited by periods of dryness, the quantity of gypsum produced by a gas-solid reaction mechanism should correlate with both the frequency of rain events and the atmospheric SO//2 level.

  5. Investigation of pH Influence on Skin Permeation Behavior of Weak Acids Using Nonsteroidal Anti-Inflammatory Drugs.

    PubMed

    Chantasart, Doungdaw; Chootanasoontorn, Siriwan; Suksiriworapong, Jiraphong; Li, S Kevin

    2015-10-01

    As a continuing effort to understand the skin permeation behavior of weak acids and bases, the objectives of the present study were to evaluate skin permeation of nonsteroidal anti-inflammatory drugs (NSAIDs) under the influence of pH, investigate the mechanism of pH effect, and examine a previous hypothesis that the effective skin pH for drug permeation is different from donor solution pH. In vitro permeability experiments were performed in side-by-side diffusion cells with diclofenac, ibuprofen, flurbiprofen, ketoprofen, and naproxen and human skin. The donor solution pH significantly affected skin permeation of NSAIDs, whereas no effect of the receiver pH was observed. Similar to previous observations, the apparent permeability coefficient versus donor solution pH relationships deviated from the predictions (fractions of unionized NSAIDs) according to the acid/base theory. The influences of the viable epidermis barrier, polar pathway transport, ion permeation across skin, and effective skin pH were investigated. The effective pH values for skin permeation determined using the NSAIDs (weak acids) in this study were different from those obtained previously with a weak base at the same donor solution pH conditions, suggesting that the observed permeability-pH relationships could not be explained solely by possible pH differences between skin and donor solution. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

  6. Deletion of the pH sensor GPR4 decreases renal acid excretion.

    PubMed

    Sun, Xuming; Yang, Li V; Tiegs, Brian C; Arend, Lois J; McGraw, Dennis W; Penn, Raymond B; Petrovic, Snezana

    2010-10-01

    Proton receptors are G protein-coupled receptors that accept protons as ligands and function as pH sensors. One of the proton receptors, GPR4, is relatively abundant in the kidney, but its potential role in acid-base homeostasis is unknown. In this study, we examined the distribution of GPR4 in the kidney, its function in kidney epithelial cells, and the effects of its deletion on acid-base homeostasis. We observed GPR4 expression in the kidney cortex, in the outer and inner medulla, in isolated kidney collecting ducts, and in cultured outer and inner medullary collecting duct cells (mOMCD1 and mIMCD3). Cultured mOMCD1 cells exhibited pH-dependent accumulation of intracellular cAMP, characteristic of GPR4 activation; GPR4 knockdown attenuated this accumulation. In vivo, deletion of GPR4 decreased net acid secretion by the kidney and resulted in a nongap metabolic acidosis, indicating that GPR4 is required to maintain acid-base homeostasis. Collectively, these findings suggest that GPR4 is a pH sensor with an important role in regulating acid secretion in the kidney collecting duct.

  7. A Three-Tier Diagnostic Test to Assess Pre-Service Teachers' Misconceptions about Global Warming, Greenhouse Effect, Ozone Layer Depletion, and Acid Rain

    ERIC Educational Resources Information Center

    Arslan, Harika Ozge; Cigdemoglu, Ceyhan; Moseley, Christine

    2012-01-01

    This study describes the development and validation of a three-tier multiple-choice diagnostic test, the atmosphere-related environmental problems diagnostic test (AREPDiT), to reveal common misconceptions of global warming (GW), greenhouse effect (GE), ozone layer depletion (OLD), and acid rain (AR). The development of a two-tier diagnostic test…

  8. Acidic pH increases airway surface liquid viscosity in cystic fibrosis

    PubMed Central

    Tang, Xiao Xiao; Ostedgaard, Lynda S.; Hoegger, Mark J.; Moninger, Thomas O.; Karp, Philip H.; McMenimen, James D.; Choudhury, Biswa; Varki, Ajit; Stoltz, David A.; Welsh, Michael J.

    2016-01-01

    Cystic fibrosis (CF) disrupts respiratory host defenses, allowing bacterial infection, inflammation, and mucus accumulation to progressively destroy the lungs. Our previous studies revealed that mucus with abnormal behavior impaired mucociliary transport in newborn CF piglets prior to the onset of secondary manifestations. To further investigate mucus abnormalities, here we studied airway surface liquid (ASL) collected from newborn piglets and ASL on cultured airway epithelia. Fluorescence recovery after photobleaching revealed that the viscosity of CF ASL was increased relative to that of non-CF ASL. CF ASL had a reduced pH, which was necessary and sufficient for genotype-dependent viscosity differences. The increased viscosity of CF ASL was not explained by pH-independent changes in HCO3– concentration, altered glycosylation, additional pH-induced disulfide bond formation, increased percentage of nonvolatile material, or increased sulfation. Treating acidic ASL with hypertonic saline or heparin largely reversed the increased viscosity, suggesting that acidic pH influences mucin electrostatic interactions. These findings link loss of cystic fibrosis transmembrane conductance regulator–dependent alkalinization to abnormal CF ASL. In addition, we found that increasing Ca2+ concentrations elevated ASL viscosity, in part, independently of pH. The results suggest that increasing pH, reducing Ca2+ concentration, and/or altering electrostatic interactions in ASL might benefit early CF. PMID:26808501

  9. Degradation kinetics of chlorogenic acid at various pH values and effects of ascorbic acid and epigallocatechin gallate on its stability under alkaline conditions.

    PubMed

    Narita, Yusaku; Inouye, Kuniyo

    2013-01-30

    5-Caffeoylquinic acid (5-CQA) is generally referred to as chlorogenic acid and exhibits various biological activities such as antioxidant activity and porcine pancreas α-amylase inhibitory activities. 5-CQA may be useful as an antioxidant for food and to prevent diabetes and obesity. The degradation of 5-CQA and caffeic acid (CA) in an aqueous solution at 37 °C and pH 5.0-9.0 was studied. The degradation of 5-CQA and CA, demonstrating time and pH dependence (i.e., the rate constant, k, was higher at higher pH), was satisfactorily described by the Weibull equation. The stability of 5-CQA at pH 7.4 and 9.0 was improved by adding (-)-epigallocatechin gallate (EGCG) and ascorbic acid (AA). Moreover, the degradation of 5-CQA in the presence of EGCG or AA could be described by the Weibull equation. The k value in the presence of EGCG or AA was dependent on their concentration.

  10. Breeding biology of the spotted salamander Ambystoma maculatum (Shaw) in acidic temporary ponds at Cape Cod, USA

    USGS Publications Warehouse

    Portnoy, J.W.

    1990-01-01

    The relationship between water chemistry and breeding success of spotted salamanders Ambystoma maculatum (Shaw) was examined in temporary woodland ponds on outer Cape Cod, Massachusetts in 1985 and 1986. Most pond waters were dilute (3median coductivity = 57 umhos cm-1 (1 umhos cm-1 = 0?1 mSm-1)), acidic (median pH = 4?82), and highly colored (median = 140 Pt-Co units). Most acidity was due to abundant organic acids. Salamander survival to hatching was over 80% at 8 of 12 ponds monitored. Complete mortality, preceded by gross abnormalities, was observed only among embryos in the most acidic spawning pond (pH 4?3-4?5) in both years. Embryo transfers between ponds and laboratory studies indicated that reduced survival was due to the interaction of low pH with high tannin-lignin concentration. The use of amphibian embryonic survival to indicate acid rain effects is complicated by multiple habitat parameters and should only be attempted in conjunction with long-term population monitoring.

  11. Extracellular Acidic pH Activates the Sterol Regulatory Element-Binding Protein 2 to Promote Tumor Progression.

    PubMed

    Kondo, Ayano; Yamamoto, Shogo; Nakaki, Ryo; Shimamura, Teppei; Hamakubo, Takao; Sakai, Juro; Kodama, Tatsuhiko; Yoshida, Tetsuo; Aburatani, Hiroyuki; Osawa, Tsuyoshi

    2017-02-28

    Conditions of the tumor microenvironment, such as hypoxia and nutrient starvation, play critical roles in cancer progression. However, the role of acidic extracellular pH in cancer progression is not studied as extensively as that of hypoxia. Here, we show that extracellular acidic pH (pH 6.8) triggered activation of sterol regulatory element-binding protein 2 (SREBP2) by stimulating nuclear translocation and promoter binding to its targets, along with intracellular acidification. Interestingly, inhibition of SREBP2, but not SREBP1, suppressed the upregulation of low pH-induced cholesterol biosynthesis-related genes. Moreover, acyl-CoA synthetase short-chain family member 2 (ACSS2), a direct SREBP2 target, provided a growth advantage to cancer cells under acidic pH. Furthermore, acidic pH-responsive SREBP2 target genes were associated with reduced overall survival of cancer patients. Thus, our findings show that SREBP2 is a key transcriptional regulator of metabolic genes and progression of cancer cells, partly in response to extracellular acidification. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

  12. pH of Aerosols in a Polluted Atmosphere: Source Contributions to Highly Acidic Aerosol.

    PubMed

    Shi, Guoliang; Xu, Jiao; Peng, Xing; Xiao, Zhimei; Chen, Kui; Tian, Yingze; Guan, Xinbei; Feng, Yinchang; Yu, Haofei; Nenes, Athanasios; Russell, Armistead G

    2017-04-18

    Acidity (pH) plays a key role in the physical and chemical behavior of PM 2.5 . However, understanding of how specific PM sources impact aerosol pH is rarely considered. Performing source apportionment of PM 2.5 allows a unique link of sources pH of aerosol from the polluted city. Hourly water-soluble (WS) ions of PM 2.5 were measured online from December 25th, 2014 to June 19th, 2015 in a northern city in China. Five sources were resolved including secondary nitrate (41%), secondary sulfate (26%), coal combustion (14%), mineral dust (11%), and vehicle exhaust (9%). The influence of source contributions to pH was estimated by ISORROPIA-II. The lowest aerosol pH levels were found at low WS-ion levels and then increased with increasing total ion levels, until high ion levels occur, at which point the aerosol becomes more acidic as both sulfate and nitrate increase. Ammonium levels increased nearly linearly with sulfate and nitrate until approximately 20 μg m -3 , supporting that the ammonium in the aerosol was more limited by thermodynamics than source limitations, and aerosol pH responded more to the contributions of sources such as dust than levels of sulfate. Commonly used pH indicator ratios were not indicative of the pH estimated using the thermodynamic model.

  13. Evaluation of TRMM Ground-Validation Radar-Rain Errors Using Rain Gauge Measurements

    NASA Technical Reports Server (NTRS)

    Wang, Jianxin; Wolff, David B.

    2009-01-01

    Ground-validation (GV) radar-rain products are often utilized for validation of the Tropical Rainfall Measuring Mission (TRMM) spaced-based rain estimates, and hence, quantitative evaluation of the GV radar-rain product error characteristics is vital. This study uses quality-controlled gauge data to compare with TRMM GV radar rain rates in an effort to provide such error characteristics. The results show that significant differences of concurrent radar-gauge rain rates exist at various time scales ranging from 5 min to 1 day, despite lower overall long-term bias. However, the differences between the radar area-averaged rain rates and gauge point rain rates cannot be explained as due to radar error only. The error variance separation method is adapted to partition the variance of radar-gauge differences into the gauge area-point error variance and radar rain estimation error variance. The results provide relatively reliable quantitative uncertainty evaluation of TRMM GV radar rain estimates at various times scales, and are helpful to better understand the differences between measured radar and gauge rain rates. It is envisaged that this study will contribute to better utilization of GV radar rain products to validate versatile spaced-based rain estimates from TRMM, as well as the proposed Global Precipitation Measurement, and other satellites.

  14. Strategies for regulation of hemolymph pH in acidic and alkaline water by the larval mosquito Aedes aegypti (L.) (Diptera; Culicidae).

    PubMed

    Clark, Thomas M; Vieira, Marcus A L; Huegel, Kara L; Flury, Dawn; Carper, Melissa

    2007-12-01

    The responses of larval Aedes aegypti to media of pH 4, 7 and 11 provide evidence for pH regulatory strategies. Drinking rates in pH 4 media were elevated 3- to 5-fold above those observed in pH 7 or 11. Total body water was elevated during acute exposure to acidic media. During chronic exposure, total body water was decreased and Malpighian tubule mitochondrial luminosity, quantified using Mitotracker Green FM, increased. Malpighian tubule secretion rates and energy demands thus appear to increase dramatically during acid exposure. In alkaline media, drinking rates were quite low. Larvae in pH 11 media excreted net acid (0.12 nequiv H(+) g(-1) h(-1)) and the pH indicators azolitmin and bromothymol blue revealed that the rectal lumen is acidic in vivo at all ambient pH values. The anal papillae (AP) were found to be highly permeant to acid-base equivalents. Ambient pH influenced the length, and the mass-specific length, of the AP in the presence of NaCl (59.9 mmol l(-1)). In contrast, the length and mass-specific length of AP were not influenced by ambient pH in low NaCl conditions. Mitochondrial luminosity was reduced in AP of larvae reared in acidic media, and was not elevated in alkaline media, relative to that of larvae reared in neutral media. These data suggest that the AP may compromise acid-base balance in acidic media, and may also be an important site of trade-offs between H(+) homeostasis and NaCl uptake in dilute, acidic media.

  15. A Combined Proteomic and Transcriptomic Analysis on Sulfur Metabolism Pathways of Arabidopsis thaliana under Simulated Acid Rain

    PubMed Central

    Wang, Wenhua; Simon, Martin; Wu, Feihua; Hu, Wenjun; Chen, Juan B.; Zheng, Hailei

    2014-01-01

    With rapid economic development, most regions in southern China have suffered acid rain (AR) pollution. In our study, we analyzed the changes in sulfur metabolism in Arabidopsis under simulated AR stress which provide one of the first case studies, in which the systematic responses in sulfur metabolism were characterized by high-throughput methods at different levels including proteomic, genomic and physiological approaches. Generally, we found that all of the processes related to sulfur metabolism responded to AR stress, including sulfur uptake, activation and also synthesis of sulfur-containing amino acid and other secondary metabolites. Finally, we provided a catalogue of the detected sulfur metabolic changes and reconstructed the coordinating network of their mutual influences. This study can help us to understand the mechanisms of plants to adapt to AR stress. PMID:24595051

  16. Intracellular pH Response to Weak Acid Stress in Individual Vegetative Bacillus subtilis Cells

    PubMed Central

    Pandey, Rachna; Vischer, Norbert O. E.; Smelt, Jan P. P. M.; van Beilen, Johan W. A.; Ter Beek, Alexander; De Vos, Winnok H.; Manders, Erik M. M.

    2016-01-01

    ABSTRACT Intracellular pH (pHi) critically affects bacterial cell physiology. Hence, a variety of food preservation strategies are aimed at perturbing pHi homeostasis. Unfortunately, accurate pHi quantification with existing methods is suboptimal, since measurements are averages across populations of cells, not taking into account interindividual heterogeneity. Yet, physiological heterogeneity in isogenic populations is well known to be responsible for differences in growth and division kinetics of cells in response to external stressors. To assess in this context the behavior of intracellular acidity, we have developed a robust method to quantify pHi at single-cell levels in Bacillus subtilis. Bacilli spoil food, cause disease, and are well known for their ability to form highly stress-resistant spores. Using an improved version of the genetically encoded ratiometric pHluorin (IpHluorin), we have quantified pHi in individual B. subtilis cells, cultured at an external pH of 6.4, in the absence or presence of weak acid stresses. In the presence of 3 mM potassium sorbate, a decrease in pHi and an increase in the generation time of growing cells were observed. Similar effects were observed when cells were stressed with 25 mM potassium acetate. Time-resolved analysis of individual bacteria in growing colonies shows that after a transient pH decrease, long-term pH evolution is highly cell dependent. The heterogeneity at the single-cell level shows the existence of subpopulations that might be more resistant and contribute to population survival. Our approach contributes to an understanding of pHi regulation in individual bacteria and may help scrutinizing effects of existing and novel food preservation strategies. IMPORTANCE This study shows how the physiological response to commonly used weak organic acid food preservatives, such as sorbic and acetic acids, can be measured at the single-cell level. These data are key to coupling often-observed single-cell heterogeneous

  17. Autoinducer-2 detection among commensal oral streptococci is dependent on pH and boric acid.

    PubMed

    Cuadra, Giancarlo A; Frantellizzi, Ashley J; Gaesser, Kimberly M; Tammariello, Steven P; Ahmed, Anika

    2016-07-01

    Autoinducer-2, considered a universal signaling molecule, is produced by many species of bacteria; including oral strains. Structurally, autoinducer-2 can exist bound to boron (borated autoinducer-2). Functionally, autoinducer-2 has been linked to important bacterial processes such as virulence and biofilm formation. In order to test production of autoinducer-2 by a given bacterial strain, a bioassay using marine bioluminescent bacteria Vibrio harveyi as a reporter for autoinducer-2 has been designed. We hypothesize that pH adjustment and addition of boron are required for optimal bioluminescence and accurate autoinducer-2 detection. Using this reporter strain we tested autoinducer-2 activity from two oral commensal species, Streptococcus gordonii DL1 and Streptococcus oralis 34. Spent broth was collected and adjusted to pH 7.5 and supplemented with boric acid prior to measuring autoinducer- 2 activity. Results show that low pH inhibits bioluminescence of the reporter strain, but pH 7.5 allows for bioluminescence induction and proper readings of autoinducer-2 activity. Addition of boric acid also has a positive effect on bioluminescence allowing for a more sensitive detection of autoinducer-2 activity. Our data suggests that although autoinducer-2 is present in spent broth, low pH and/or low levels of boric acid become an obstacle for proper autoinducer-2 detection. For proper autoinducer-2 detection, we propose a protocol using this bioassay to include pH adjustment and boric acid addition to spent broth. Studies on autoinducer-2 activity in several bacteria species represent an important area of study as this universal signaling molecule is involved in critical bacterial phenotypes such as virulence and biofilm formation.

  18. Anaerobic digestion of food waste for volatile fatty acids (VFAs) production with different types of inoculum: effect of pH.

    PubMed

    Wang, Kun; Yin, Jun; Shen, Dongsheng; Li, Na

    2014-06-01

    Food waste anaerobic fermentation was carried out under acidic conditions using inocula based on aerobic activated sludge (Inoculum AE) or anaerobic activated sludge (Inoculum AN) for volatile fatty acids (VFAs) production. The results showed that food waste hydrolysis increased obviously when Inoculum AN was used relative to Inoculum AE at any pH investigated. Hydrolysis at pH 4.0 and uncontrolled pH was higher than that at other pHs when either inoculum was used. Additionally, VFAs production at pH 6.0 was the highest, regardless of the inoculum used. The optimum VFA yields were 0.482g/gVSSremoval with Inoculum AE and 0.918g/gVSSremoval with Inoculum AN, which were observed after 4d and 20d of fermentation, respectively. VFAs composition analysis showed that butyrate acid was the prevalent acid at pH 6.0, followed by acetate acid and propionic acid. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Protein Complexation and pH Dependent Release Using Boronic Acid Containing PEG-Polypeptide Copolymers.

    PubMed

    Negri, Graciela E; Deming, Timothy J

    2017-01-01

    New poly(L-lysine)-b-poly(ethylene glycol) copolypeptides have been prepared, where the side-chain amine groups of lysine residues are modified to contain ortho-amine substituted phenylboronic acid, i.e., Wulff-type phenylboronic acid (WBA), groups to improve their pH responsive, carbohydrate binding properties. These block copolymers form nanoscale complexes with glycosylated proteins that are stable at physiological pH, yet dissociate and release the glycoproteins under acidic conditions, similar to those found in endosomal and lysosomal compartments within cells. These results suggest that WBA modified polypeptide copolymers are promising for further development as degradable carriers for intracellular protein delivery. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. The pH profile for acid-induced elongation of coleoptile and epicotyl sections is consistent with the acid-growth theory

    NASA Technical Reports Server (NTRS)

    Cleland, R. E.; Buckley, G.; Nowbar, S.; Lew, N. M.; Stinemetz, C.; Evans, M. L.; Rayle, D. L.

    1991-01-01

    The acid-growth theory predicts that a solution with a pH identical to that of the apoplast of auxin-treated tissues (4.5.-5.0) should induce elongation at a rate comparable to that of auxin. Different pH profiles for elongation have been obtained, however, depending on the type of pretreatment between harvest of the sections and the start of the pH-incubations. To determine the acid sensitivity under in vivo conditions, oat (Avena sativa L.) coleoptile, maize (Zea mays L.) coleoptile and pea (Pisum sativum L.) epicotyl sections were abraded so that exogenous buffers could penetrate the free space, and placed in buffered solutions of pH 3.5-6.5 without any preincubation. The extension, without auxin, was measured over the first 3 h. Experiments conducted in three laboratories produced similar results. For all three species, sections placed in buffer without pretreatment elongated at least threefold faster at pH 5.0 than at 6.0 or 6.5, and the rate elongation at pH 5.0 was comparable to that induced by auxin. Pretreatment of abraded sections with pH-6.5 buffer or distilled water adjusted to pH 6.5 or above gave similar results. We conclude that the pH present in the apoplast of auxin-treated coleoptile and stems is sufficiently low to account for the initial growth response to auxin.

  1. DOE Office of Scientific and Technical Information (OSTI.GOV)

    Forsline, P.L.; Musselman, R.C.; Kender, W.J.

    Mature McIntosh, Empire, and Golden Delicious apple trees (Malus domestica) were sprayed with simulated acid rain solutions in the pH range of 2.5 to 5.5 at full bloom in 1980 and 1981. In 1981, weekly sprays were applied at pH 2.75 and pH 3.25. Necrotic lesions developed on apple petals at pH 2.5 with slight injury appearing at pH 3.0 and 3.5. Apple foliage had no acid rain lesions at any of the pH levels tested. Pollen germination was reduced at pH 2.5 in Empire. Slight fruit set reduction at pH 2.5 was observed in McIntosh. Even at the lowestmore » pH levels no detrimental effects of simulated acid rain were found on apple tree productivity and fruit quality when measured as fruit set, seed number per fruit, and fruit size and appearance.« less

  2. Quantitative structure-permeability relationships at various pH values for acidic and basic drugs and drug-like compounds.

    PubMed

    Oja, M; Maran, U

    2015-01-01

    Absorption in gastrointestinal tract compartments varies and is largely influenced by pH. Therefore, considering pH in studies and analyses of membrane permeability provides an opportunity to gain a better understanding of the behaviour of compounds and to obtain good permeability estimates for prediction purposes. This study concentrates on relationships between the chemical structure and membrane permeability of acidic and basic drugs and drug-like compounds. The membrane permeability of 36 acidic and 61 basic compounds was measured using the parallel artificial membrane permeability assay (PAMPA) at pH 3, 5, 7.4 and 9. Descriptive and/or predictive single-parameter quantitative structure-permeability relationships were derived for all pH values. For acidic compounds, membrane permeability is mainly influenced by hydrogen bond donor properties, as revealed by models with r(2) > 0.8 for pH 3 and pH 5. For basic compounds, the best (r(2) > 0.7) structure-permeability relationships are obtained with the octanol-water distribution coefficient for pH 7.4 and pH 9, indicating the importance of partition properties. In addition to the validation set, the prediction quality of the developed models was tested with folic acid and astemizole, showing good matches between experimental and calculated membrane permeabilities at key pHs. Selected QSAR models are available at the QsarDB repository ( http://dx.doi.org/10.15152/QDB.166 ).

  3. Medium pH, carbon and nitrogen concentrations modulate the phosphate solubilization efficiency of Penicillium purpurogenum through organic acid production.

    PubMed

    Scervino, J M; Papinutti, V L; Godoy, M S; Rodriguez, M A; Della Monica, I; Recchi, M; Pettinari, M J; Godeas, A M

    2011-05-01

    To study phosphate solubilization in Penicillium purpurogenum as function of medium pH, and carbon and nitrogen concentrations. Tricalcium phosphate (CP) solubilization efficiency of P. purpurogenum was evaluated at acid or alkaline pH using different C and N sources. Glucose- and (NH(4) )(2) SO(4) -based media showed the highest P solubilization values followed by fructose. P. purpurogenum solubilizing ability was higher in cultures grown at pH 6·5 than cultures at pH 8·5. Organic acids were detected in both alkaline and neutral media, but the relative percentages of each organic acid differed. Highest P release coincided with the highest organic acids production peak, especially gluconic acid. When P. purpurogenum grew in alkaline media, the nature and concentration of organic acids changed at different N and C concentrations. A factorial categorical experimental design showed that the highest P-solubilizing activity, coinciding with the highest organic acid production, corresponded to the highest C concentration and lowest N concentration. The results described in the present study show that medium pH and carbon and nitrogen concentrations modulate the P solubilization efficiency of P. purpurogenum through the production of organic acids and particularly that of gluconic acid. In the P solubilization optimization studies, glucose and (NH(4) )(2) SO(4) as C and N sources allowed a higher solubilization efficiency at high pH. This organism is a potentially proficient soil inoculant, especially in P-poor alkaline soils where other P solubilizers fail to release soluble P. Further work is necessary to elucidate whether these results can be extrapolated to natural soil ecosystems, where different pH values are present. Penicillium purpurogenum could be used to develop a bioprocess for the manufacture of phosphatic fertilizer with phosphate calcium minerals. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  4. The Simultaneous Determination of Muscle Cell pH Using a Weak Acid and Weak Base

    PubMed Central

    Adler, Sheldon

    1972-01-01

    Should significant pH heterogeneity exist within cells then the simultaneous calculation of intracellular pH from the distribution of a weak acid will give a value closest to the highest pH in the system, whereas calculation from the distribution of a weak base will give a value closer to the lowest pH. These two values should then differ significantly. Intact rat diaphragms were exposed in vitro to varying bicarbonate concentrations (pure metabolic) and CO2 tensions (pure respiratory), and steady-state cell pH was measured simultaneously either by distribution of the weak acid 5,5-dimethyloxazolidine-2,4-dione-14C (pH DMO) or by distribution of the weak base nicotine-14C (pH nicotine). The latter compound was found suitable to measure cell pH since it was neither metabolized nor bound by rat diaphragms. At an external pH of 7.40, pH DMO was 7.17 while pH nicotine was 6.69—a pH difference of 0.48 pH units (P < 0.001). In either respiratory or metabolic alkalosis both DMO and pH nicotine rose so that differences between them remained essentially constant. Metabolic acidosis induced a decrease in both values though they fell more slowly than did extracellular pH. In contradistinction, in respiratory acidosis, decreasing extracellular pH from 7.40 to 6.80 resulted in 0.35 pH unit drop in pH DMO while pH nicotine remained constant. In every experiment, under all external conditions, pH DMO exceeded pH nicotine. These results indicate that there is significant pH heterogeneity within diaphragm muscle, but the degree of heterogeneity may vary under different external conditions. The metabolic implications of these findings are discussed. In addition, the data show that true overall cell pH is between 6.69 and 7.17—a full pH higher than would be expected from thermodynamic considerations alone. This implies the presence of active processes to maintain cell pH. PMID:5009113

  5. Scientists Puzzle Over Acid Rain

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1975

    1975-01-01

    Reports on a growing concern over increased acidity in atmospheric percipitation. Explores possible causes of the increased acidity, identifies chemical components of precipitation in various parts of the world, and presents environmental changes that might be attributed to the acidity. (GS)

  6. Growth response and drought susceptibility of red spruce seedlings exposed to simulated acidic rain and ozone

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lee, W.S.; Chevone, B.I.; Seiler, J.R.

    1988-01-01

    Red spruce (Picea rubens Sarg.) is a long-lived, shade-tolerant tree that is commonly present in the cool, moist climates at high elevations of the Appalachian Mountains. Recently, an accelerated decline of red spruce has been reported in the northern Appalachians in the Green Mountains on Camels Hump, Vermont and on Whiteface Mountain in New York as well as in the mid and southern Appalachians. Even though many possible causes of this decline have been suggested, none have been established conclusively at present. High acid inputs and elevated concentrations of heavy metals, in addition to ozone stress, have been strongly suspectedmore » as contributing factors for the decline. The objectives of this research is to investigate the efforts of simulated acidic rain and ozone on growth and drought susceptibility of red spruce seedlings by measuring biomass, foliar nutrient status, root hydraulic conductivity, and gas exchange rates.« less

  7. Effect of pH on skin permeation enhancement of acidic drugs by l-menthol-ethanol system.

    PubMed

    Katayama, K; Matsui, R; Hatanaka, T; Koizumi, T

    2001-09-11

    The effect of pH on the skin permeation enhancement of three acidic drugs by the l-menthol-ethanol system was investigated. The total flux of acidic drugs from the system remarkably varied over the pH range 3.0-8.0, and the permeation enhancement factor depended on the system pH and drug. A skin permeation model, which consists of two permeant (unionized and ionized) species, two system (oily and aqueous) phases, and two permeation (lipid and pore) pathways, was developed. The assumptions were made that only the unionized species can distribute to the oily phase and transport via the lipid pathway. The model explained the relationship between the concentration of drug in the aqueous phase and system pH. The skin permeability data were also described by the model and permeability coefficients corresponding to the physicochemical properties of permeant were calculated for the lipid and pore pathways. The model simulation showed that the permeation of acidic drugs occurred from the aqueous phase and the oily phase acted as a reservoir. Whether the total flux increased with increase of pH was dependent on the lipophilicity of drug. These results suggest that the pH of l-menthol-ethanol system should be given attention to elicit the maximum permeation enhancement.

  8. Modeling the effects of sodium chloride, acetic acid, and intracellular pH on survival of Escherichia coli O157:H7.

    PubMed

    Hosein, Althea M; Breidt, Frederick; Smith, Charles E

    2011-02-01

    Microbiological safety has been a critical issue for acid and acidified foods since it became clear that acid-tolerant pathogens such as Escherichia coli O157:H7 can survive (even though they are unable to grow) in a pH range of 3 to 4, which is typical for these classes of food products. The primary antimicrobial compounds in these products are acetic acid and NaCl, which can alter the intracellular physiology of E. coli O157:H7, leading to cell death. For combinations of acetic acid and NaCl at pH 3.2 (a pH value typical for non-heat-processed acidified vegetables), survival curves were described by using a Weibull model. The data revealed a protective effect of NaCl concentration on cell survival for selected acetic acid concentrations. The intracellular pH of an E. coli O157:H7 strain exposed to acetic acid concentrations of up to 40 mM and NaCl concentrations between 2 and 4% was determined. A reduction in the intracellular pH was observed for increasing acetic acid concentrations with an external pH of 3.2. Comparing intracellular pH with Weibull model predictions showed that decreases in intracellular pH were significantly correlated with the corresponding times required to achieve a 5-log reduction in the number of bacteria.

  9. Lactic acid fermentation from food waste with indigenous microbiota: Effects of pH, temperature and high OLR.

    PubMed

    Tang, Jialing; Wang, Xiaochang; Hu, Yisong; Zhang, Yongmei; Li, Yuyou

    2016-06-01

    The effects of pH, temperature and high organic loading rate (OLR) on lactic acid production from food waste without extra inoculum addition were investigated in this study. Using batch experiments, the results showed that although the hydrolysis rate increased with pH adjustment, the lactic acid concentration and productivity were highest at pH 6. High temperatures were suitable for solubilization but seriously restricted the acidification processes. The highest lactic acid yield (0.46g/g-TS) and productivity (278.1mg/Lh) were obtained at 37°C and pH 6. In addition, the lactic acid concentration gradually increased with the increase in OLR, and the semi-continuous reactor could be stably operated at an OLR of 18g-TS/Ld. However, system instability, low lactic acid yield and a decrease in VS removal were noticed at high OLRs (22g-TS/Ld). The concentrations of volatile fatty acids (VFAs) in the fermentation mixture were relatively low but slightly increased with OLR, and acetate was the predominant VFA component. Using high-throughput pyrosequencing, Lactobacillus from the raw food waste was found to selectively accumulate and become dominant in the semi-continuous reactor. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Enhanced acid rain and atmospheric deposition of nitrogen, sulfur and heavy metals in Northern China

    NASA Astrophysics Data System (ADS)

    Pan, Y.; Wang, Y.

    2013-12-01

    Atmospheric deposition is known to be important mechanism reducing air pollution. In response to the growing concern on the potential effects of the deposited material entering terrestrial and aquatic environments as well as their subsequent health effects, since 2007 we have established a 10-site monitoring network in Northern China, where particularly susceptible to severe air pollution. Wet and dry deposition was collected using an automatic wet-dry sampler. The presentation will focus on the new results of atmospheric deposition flux for a number of chemical species, such as nutrients (e.g. nitrogen and phosphorus), acidic matters (e.g. sulfur and proton), heavy metals and Polycyclic Aromatic Hydrocarbons, etc. This is to our knowledge the first detailed element budget study in the atmosphere across Northern China. We find that: (1) Over the 3 year period, 26% of precipitation events in the target area were more acid than pH 5.60 and these acidic events occurred in summer and autumn. The annual volume-weighted mean (VWM) pH value of precipitation was lower than 5.60 at most sites, which indicated the acidification of precipitation was not optimistic. The primary ions in precipitation were NH4+, Ca2+, SO42- and NO3-, with 10-sites-average concentrations of 221, 216, 216 and 80 μeq L-1, respectively. The ratio of SO42- to NO3- was 2.7; suggesting SO42- was the dominant acid component. (2) The deposited particles were neutral in general and the pH value increased from rural area to industrial and coastal sites. It is not surprising to note that the annual VWM pH value of precipitation was higher than 5.60 at three urban sites (Beijing and Tianjin mega cities) and one coastal site near the Bohai Bay, considering the fact that high buffer capacity of alkaline component, gas NH3 and mineral aerosols, at these sites compared to other places. (3) The 10-sites annual total deposition amounts for sulfur and nitrogen compounds were 60 and 65 kg N/S ha-1 yr-1

  11. Hydrothermal carbonization (HTC) of wheat straw: influence of feedwater pH prepared by acetic acid and potassium hydroxide.

    PubMed

    Reza, M Toufiq; Rottler, Erwin; Herklotz, Laureen; Wirth, Benjamin

    2015-04-01

    In this study, influence of feedwater pH (2-12) was studied for hydrothermal carbonization (HTC) of wheat straw at 200 and 260°C. Acetic acid and KOH were used as acidic and basic medium, respectively. Hydrochars were characterized by elemental and fiber analyses, SEM, surface area, pore volume and size, and ATR-FTIR, while HTC process liquids were analyzed by HPLC and GC. Both hydrochar and HTC process liquid qualities vary with feedwater pH. At acidic pH, cellulose and elemental carbon increase in hydrochar, while hemicellulose and pseudo-lignin decrease. Hydrochars produced at pH 2 feedwater has 2.7 times larger surface area than that produced at pH 12. It also has the largest pore volume (1.1 × 10(-1) ml g(-1)) and pore size (20.2 nm). Organic acids were increasing, while sugars were decreasing in case of basic feedwater, however, phenolic compounds were present only at 260°C and their concentrations were increasing in basic feedwater. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Bilayers and wormlike micelles at high pH in fatty acid soap systems.

    PubMed

    Xu, Wenlong; Liu, Huizhong; Song, Aixin; Hao, Jingcheng

    2016-03-01

    Bilayers at high pH in the fatty acid systems of palmitic acid/KOH/H2O, palmitic acid/CsOH/H2O, stearic acid/KOH/H2O and stearic acid/CsOH/H2O can form spontaneously (Xu et al., 2014, 2015). In this work, the bilayers can still be observed at 25°C with an increase of the concentration of fatty acids. We found that wormlike micelles can also be prepared in the fatty acid soap systems at high pH, even though the temperature was increased to be 50°C. The viscoelasticity, apparent viscosity, yield stress of the bilayers were determined by the rheological measurements. Wormlike micelles were identified by cryogenic transmission electron microscopy (cryo-TEM) and emphasized by the rheological characterizations, which are in accordance with the Maxwell fluids with good fit of Cole-Cole plots. The phase transition temperature was determined by differential scanning calorimetry (DSC) and the transition process was recorded. The regulating role of counterions of fatty acids were discussed by (CH3)4N(+), (C2H5)4N(+), (C3H7)4N(+), and (C4H9)4N(+) as comparison, concluding that counterions with appropriate hydrated radius were the vital factor in the formation wormlike micelles. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Improved volatile fatty acids anaerobic production from waste activated sludge by pH regulation: Alkaline or neutral pH?

    PubMed

    Ma, Huijun; Chen, Xingchun; Liu, He; Liu, Hongbo; Fu, Bo

    2016-02-01

    In this study, the anaerobic fermentation was carried out for volatile fatty acids (VFAs) production at different pH (between 7.0 and 10.0) conditions with untreated sludge and heat-alkaline pretreated waste activated sludge. In the fermentation with untreated sludge, the extent of hydrolysis of organic matters and extent of acidification at alkaline pH are 54.37% and 30.37%, respectively, resulting in the highest VFAs yield at 235.46mg COD/gVS of three pH conditions. In the fermentation with heat-alkaline pretreated sludge, the acidification rate and VFAs yield at neutral pH are 30.98% and 240.14mg COD/gVS, respectively, which are higher than that at other pH conditions. With the glucose or bovine serum albumin as substrate for VFAs production, the neutral pH showed a higher VFAs concentration than the alkaline pH condition. The results of terminal restriction fragment length polymorphism (T-RFLP) analysis indicated that the alkaline pH caused low microbial richness. Based on the results in this study, we demonstrated that the alkaline pH is favor of hydrolysis of organic matter in sludge while neutral pH improved the acidogenesis for the VFAs production from sludge. Our finding is obvious different to the previous research and helpful for the understanding of how heat-alkaline pretreatment and alkaline fermentation influence the VFAs production, and beneficial to the development of VFAs production process. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Life at acidic pH imposes an increased energetic cost for a eukaryotic acidophile.

    PubMed

    Messerli, Mark A; Amaral-Zettler, Linda A; Zettler, Erik; Jung, Sung-Kwon; Smith, Peter J S; Sogin, Mitchell L

    2005-07-01

    Organisms growing in acidic environments, pH<3, would be expected to possess fundamentally different molecular structures and physiological controls in comparison with similar species restricted to neutral pH. We begin to investigate this premise by determining the magnitude of the transmembrane electrochemical H+ gradient in an acidophilic Chlamydomonas sp. (ATCC PRA-125) isolated from the Rio Tinto, a heavy metal laden, acidic river (pH 1.7-2.5). This acidophile grows most rapidly at pH 2 but is capable of growth over a wide pH range (1.5-7.0), while Chlamydomonas reinhardtii is restricted to growth at pH>or=3 with optimal growth between pH 5.5 and 8.5. With the fluorescent H+ indicator, 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF), we show that the acidophilic Chlamydomonas maintains an average cytosolic pH of 6.6 in culture medium at both pH 2 and pH 7 while Chlamydomonas reinhardtii maintains an average cytosolic pH of 7.1 in pH 7 culture medium. The transmembrane electric potential difference of Chlamydomonas sp., measured using intracellular electrodes at both pH 2 and 7, is close to 0 mV, a rare value for plants, animals and protists. The 40,000-fold difference in [H+] could be the result of either active or passive mechanisms. Evidence for active maintenance was detected by monitoring the rate of ATP consumption. At the peak, cells consume about 7% more ATP per second in medium at pH 2 than at pH 7. This increased rate of consumption is sufficient to account for removal of H+ entering the cytosol across a membrane with relatively high permeability to H+ (7x10(-8) cm s-1). Our results indicate that the small increase in the rate of ATP consumption can account for maintenance of the transmembrane H+ gradient without the imposition of cell surface H+ barriers.

  15. Use of D(acid)-, D(bile)-, z(acid)-, and z(bile)-values in evaluating Bifidobacteria with regard to stomach pH and bile salt sensitivity.

    PubMed

    Jia, Li; Shigwedha, Nditange; Mwandemele, Osmund D

    2010-01-01

    The survival of bifidobacteria in simulated conditions of the gastrointestinal (GI) tract was studied based on the D- and z-value concept. Some Bifidobacterium spp. are probiotics that improve microbial balance in the human GI tract. Because they are sensitive to low pH and bile salt concentrations, their viability in the GI tract is limited. The D- and z-value approach was therefore adopted as a result of observing constant log-cell reduction (90%) when Bifidobacterium spp. were exposed to these 2 different stressing factors. Survivals of one strain each or 4 species of Bifidobacterium was studied at pH between 3.0 and 4.5 and in ox-bile between 0.15% and 0.60% for times up to 41 h. From the D(acid)- and D(bile)-values, the order of resistance to acid and bile was B. bifidum > B. infantis > B. longum > B. adolescentis. While the former 3 strains retained high cell viability at pH 3.5 (>5.5 log CFU/mL after 5 h) and at elevated bile salt concentration of 0.6% (>4.5 log CFU/mL after 3 h), B. adolescentis was less resistant (<3.4 log CFU/mL). The z(acid)- and z(bile)-values calculated from the D(acid)- and D(bile)-values ranged from 1.11 to 1.55 pH units and 0.40% to 0.49%, respectively. The results suggest that the D(acid)-, D(bile)-, z(acid)-, and z(bile)-value approach could be more appropriate than the screening and selection method in evaluating survival of probiotic bacteria, and in measuring their tolerance or resistance to gastric acidity and the associated bile salt concentration in the small intestine. The evaluation of the tolerance of bifidobacteria to bile salts and low pH has been made possible by use of D- and z-value concept. The calculated z(acid)- and z(bile)-values were all fairly similar for the strains used and suggest the effect of increasing the bile salt concentration or decreasing the pH on the D(acid)- and D(bile)-values. This approach would be useful for predicting the suitability of bifidobacteria and other lactic acid bacteria (LAB) as

  16. New Amino-Acid-Based β-Phosphorylated Nitroxides for Probing Acidic pH in Biological Systems by EPR Spectroscopy.

    PubMed

    Thétiot-Laurent, Sophie; Gosset, Gaëlle; Clément, Jean-Louis; Cassien, Mathieu; Mercier, Anne; Siri, Didier; Gaudel-Siri, Anouk; Rockenbauer, Antal; Culcasi, Marcel; Pietri, Sylvia

    2017-02-01

    There is increasing interest in measuring pH in biological samples by using nitroxides with pH-dependent electron paramagnetic resonance (EPR) spectra. Aiming to improve the spectral sensitivity (Δa X ) of these probes (i.e., the difference between the EPR hyperfine splitting (hfs) in their protonated and unprotonated forms), we characterized a series of novel linear α-carboxy, α'-diethoxyphosphoryl nitroxides constructed on an amino acid core and featuring an (α or α')-C-H bond. In buffer, the three main hfs (a N , a H , and a P ) of their EPR spectra vary reversibly with pH and, from a P or a H titration curves, a two- to fourfold increase in sensitivity was achieved compared to reference imidazoline or imidazolidine nitroxides. The crystallized carboxylate 10 b (pK a ≈3.6), which demonstrated low cytotoxicity and good resistance to bioreduction, was applied to probe stomach acidity in rats. The results pave the way to a novel generation of highly sensitive EPR pH markers. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Change of physical and chemical parameters of fulvic acids at different pH of the system

    NASA Astrophysics Data System (ADS)

    Dinu, Marina; Kremleva, Tatyana

    2017-04-01

    Organic substances of humic nature significantly change physicochemical properties at different pH of natural waters. As a consequence, a large number of consecutive and parallel reactions in the structure of organic polymers, and reacting with inorganic anions. The main indicators of changes in the properties of organic acids in natural systems are changes in their IR spectra, changes in the colloid stability (the zeta potential) as well as in the molecular weight and emission spectra (fluorescence emission spectra). The aim of our study was to evaluate of changing in physical and chemical properties of the fulvic acid from soil/water samples in the natural areas of European Russia and Western Siberia (the steppe and the northern taiga zones) at different pH (from 8 to 1.5). Changes in absorption bands of fulvic acid caused by both COOH groups and amino groups with varying degrees of protonation were found. Consequently, we can assume that in an electric field fulvic acid change the sign of their charge at depending on pH. During the lowering of the pH intensity of C-O bands generally decreases, while in the region 1590 cm-1 disappears. In turn, the band at 1700 cm-1 is the most intense; it could mean a complete protonation of the carboxyl groups. According to our data, the values of zeta potential changes depending on pH of the system. The zeta potential becomes more negative with increasing pH and it may be due to ionization of oxygen groups of fulvic acid. For the colloidal polymer systems the value of the zeta potential is strongly negative (less than -20 mV) and strongly positive (over 20 mV) characterize the system as the most stable. Our experimental data for the study of the zeta potential of fulvic acids extracted from the soils and waters of different climatic zones show zonal influence of the qualitative characteristics of organic substances on the surface charge of the high-molecular micelle of fulvic acids. It was found that fulvic acids extracted

  18. Developmental and anatomical changes in leaves of yellow birch and red kidney bean exposed to simulated acid precipitation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Paparozzi, E.T.; Tukey, H.B. Jr.

    Leaves of Betula alleghaniensis Britt. (yellow birch) and Phaseolus vulgaris L cv. Red Kidney (bean) were examined microscopically during development and after exposure to simulated rain of pH 5.5, 4.3, 3.2, and 2.8. Yellow birch leaves attained maximal leaf area, midvein length, and cuticle thickness at 21 days. Trichomes were either long, unicellular, or multicellular with caplike head and stalk. Epicuticular wax was a bumpy and amorphous layer. The 2nd trifoliolate leaf of red kidney bean attained maximal leaf area, midvein length, and cuticle thickness when the 3rd trifoliolate leaf was expanding. Trichomes present were long, with a unicellular headmore » and a multicellular base; long, unicellular, and terminally hooked; and small and multicellular. Epicuticular wax was present as small irregular flakes. After 2 days of pH 2.8 and 4 days of pH 3.2 simulated acid rain, round yellow and small tan lesions appeared on birch and bean leaves, respectively. Most injury occurred on or between small veins. Most trichome types were uninjured. Lesions formed as a result of collapsed epidermal and highly plasmolyzed palisade cells. The cuticle was still present over injured epidermal cells and epicuticular waxes were unchanged. There was not statistical difference in mean cuticle thickness due to pH of simulated rain. 25 references, 10 figures, 4 tables.« less

  19. Development of melamine modified urea formaldehyde resins based o nstrong acidic pH catalyzed urea formaldehyde polymer

    Treesearch

    Chung-Yun Hse

    2009-01-01

    To upgrade the performance of urea-formaldehyde (UF) resin bonded particleboards, melamine modified urea-formaldehyde (MUF) resins based on strong acidic pH catalyzed UF polymers were investigated. The study was conducted in a series of two experiments: 1) formulation of MUF resins based on a UF polymer catalyzed with strong acidic pH and 2) determination of the...

  20. Determination of the titratable acidity and the pH of wine based on potentiometric flow injection analysis.

    PubMed

    Vahl, Katja; Kahlert, Heike; von Mühlen, Lisandro; Albrecht, Anja; Meyer, Gabriele; Behnert, Jürgen

    2013-07-15

    A FIA system using a pH-sensitive detector based on a graphite/quinhydrone/silicone composite electrode was applied to determine sequentially the titratable acidity and the pH of wine, as well as the sum of calcium and magnesium ions. For all measurements the same FIA configuration was used employing different carrier solutions. The results for the determination of acidity and pH are in good agreement with those obtained by classical potentiometric titrations and by pH measurements using a conventional glass electrode. The standard deviation was less than 1.5% for both kinds of measurements and the sample volume was 150 μL. The method allows about 40 determinations of titratable acidity per hour and 30 pH measurements per hour. The titration method can be adjusted to the legal requirements in USA and Europe. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. pH gradients across phospholipid membranes caused by fast flip-flop of un-ionized fatty acids.

    PubMed Central

    Kamp, F; Hamilton, J A

    1992-01-01

    A central, unresolved question in cell physiology is how fatty acids move across cell membranes and whether protein(s) are required to facilitate transbilayer movement. We have developed a method for monitoring movement of fatty acids across protein-free model membranes (phospholipid bilayers). Pyranin, a water-soluble, pH-sensitive fluorescent molecule, was trapped inside well-sealed phosphatidylcholine vesicles (with or without cholesterol) in Hepes buffer (pH 7.4). Upon addition of a long-chain fatty acid (e.g., oleic acid) to the external buffer (also Hepes, pH 7.4), a decrease in fluorescence of pyranin was observed immediately (within 10 sec). This acidification of the internal volume was the result of the "flip" of un-ionized fatty acids to the inner leaflet, followed by a release of protons from approximately 50% of these fatty acid molecules (apparent pKa in the bilayer = 7.6). The proton gradient thus generated dissipated slowly because of slow cyclic proton transfer by fatty acids. Addition of bovine serum albumin to vesicles with fatty acids instantly removed the pH gradient, indicating complete removal of fatty acids, which requires rapid "flop" of fatty acids from the inner to the outer monolayer layer. Using a four-state kinetic diagram of fatty acids in membranes, we conclude that un-ionized fatty acid flip-flops rapidly (t1/2 < or = 2 sec) whereas ionized fatty acid flip-flops slowly (t1/2 of minutes). Since fatty acids move across phosphatidylcholine bilayers spontaneously and rapidly, complex mechanisms (e.g., transport proteins) may not be required for translocation of fatty acids in biological membranes. The proton movement accompanying fatty acid flip-flop is an important consideration for fatty acid metabolism in normal physiology and in disease states such as cardiac ischemia. Images PMID:1454821

  2. Cation effects on phosphatidic acid monolayers at various pH conditions.

    PubMed

    Zhang, Ting; Cathcart, Matthew G; Vidalis, Andrew S; Allen, Heather C

    2016-10-01

    The impact of pH and cations on phase behavior, stability, and surface morphology for dipalmitoylphosphatidic acid (DPPA) monolayers was investigated. At pH<10, DPPA monolayers on water are predominantly populated by neutral species and display the highest packing density. Cations are found to expand and stabilize the monolayer in the following order of increasing magnitude at pH 5.6: Na + >K + ∼Mg 2+ >Ca 2+ . Additionally, cation complexation is tied to the pH and protonation state of DPPA, which are the primary factors controlling the monolayer surface behavior. The binding affinity of cations to the headgroup and thus deprotonation capability of the cation, ranked in the order of Ca 2+ >Mg 2+ >Na + >K + , is found to be well explained by the law of matching water affinities. Nucleation of surface 3D lipid structures is observed from Ca 2+ , Mg 2+ , and Na + , but not from K + , consistent with the lowest binding affinity of K + . Unraveling cation and pH effects on DPPA monolayers is useful in further understanding the surface properties of complex systems such as organic-coated marine aerosols where organic films are directly influenced by the pH and ionic composition of the underlying aqueous phase. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. Rise in the pH of an unfrozen solution in ice due to the presence of NaCl and promotion of decomposition of gallic acids owing to a change in the pH.

    PubMed

    Takenaka, Norimichi; Tanaka, Masayuki; Okitsu, Kenji; Bandow, Hiroshi

    2006-09-14

    Oxidative decomposition of gallic acid occurs in alkaline solutions but hardly arises in acidic solutions. We have found that the addition of sodium chloride promotes the decomposition of gallic acid caused by freezing even under neutral and acidic conditions. Even at pH 4.5, gallic acid was decomposed by freezing in the presence of NaCl; however, in the absence of NaCl, it was hardly decomposed by freezing at pH lower than 7. Chloride ions are more easily incorporated in ice than sodium ions when the NaCl solution is frozen. The unfrozen solution in ice becomes positively charged, and as a result, protons transfer from the unfrozen solution to the ice. We measured the pH in the unfrozen solution which coexists with single-crystal ice formed from a 5 mmol dm(-3) NaCl solution and determined the pH to be 8.6 at equilibrium with CO(2) of 380 ppm or 11.3 in the absence of CO(2) compared to pH 5.6 in the original solution. From the model calculation performed for gallic acid solution in the presence of 5 mmol dm(-3) NaCl, it can be estimated that the amount of OH(-) transferred from the ice to the solution corresponds to 1.26 x 10(-5) mol dm(-3). The amount of OH(-) transferred is concentrated into the unfrozen solution and affects the pH of the unfrozen solution. Therefore, the pH in an unfrozen gallic acid solution in ice becomes alkaline, and the decomposition of gallic acid proceeds. It is expected that other base-catalyzed reactions in weakly acidic solutions also proceed by freezing in the presence of NaCl without the need for any alkaline reagents.

  4. Adaptive responses of Bacillus cereus ATCC14579 cells upon exposure to acid conditions involve ATPase activity to maintain their internal pH

    PubMed Central

    Senouci-Rezkallah, Khadidja; Jobin, Michel P; Schmitt, Philippe

    2015-01-01

    This study examined the involvement of ATPase activity in the acid tolerance response (ATR) of Bacillus cereus ATCC14579 strain. In the current work, B. cereus cells were grown in anaerobic chemostat culture at external pH (pHe) 7.0 or 5.5 and at a growth rate of 0.2 h−1. Population reduction and internal pH (pHi) after acid shock at pH 4.0 was examined either with or without ATPase inhibitor N,N’-dicyclohexylcarbodiimide (DCCD) and ionophores valinomycin and nigericin. Population reduction after acid shock at pH 4.0 was strongly limited in cells grown at pH 5.5 (acid-adapted cells) compared with cells grown at pH 7.0 (unadapted cells), indicating that B. cereus cells grown at low pHe were able to induce a significant ATR and Exercise-induced increase in ATPase activity. However, DCCD and ionophores had a negative effect on the ability of B. cereus cells to survive and maintain their pHi during acid shock. When acid shock was achieved after DCCD treatment, pHi was markedly dropped in unadapted and acid-adapted cells. The ATPase activity was also significantly inhibited by DCCD and ionophores in acid-adapted cells. Furthermore, transcriptional analysis revealed that atpB (ATP beta chain) transcripts was increased in acid-adapted cells compared to unadapted cells before and after acid shock. Our data demonstrate that B. cereus is able to induce an ATR during growth at low pH. These adaptations depend on the ATPase activity induction and pHi homeostasis. Our data demonstrate that the ATPase enzyme can be implicated in the cytoplasmic pH regulation and in acid tolerance of B. cereus acid-adapted cells. PMID:25740257

  5. Demonstration of in situ product recovery of butyric acid via CO2 -facilitated pH swings and medium development in two-phase partitioning bioreactors.

    PubMed

    Peterson, Eric C; Daugulis, Andrew J

    2014-03-01

    Production of organic acids in solid-liquid two-phase partitioning bioreactors (TPPBs) is challenging, and highly pH-dependent, as cell growth occurs near neutral pH, while acid sorption occurs only at low pH conditions. CO2 sparging was used to achieve acidic pH swings, facilitating undissociated organic acid uptake without generating osmotic stress inherent in traditional acid/base pH control. A modified cultivation medium was formulated to permit greater pH reduction by CO2 sparging (pH 4.8) compared to typical media (pH 5.3), while still possessing adequate nutrients for extensive cell growth. In situ product recovery (ISPR) of butyric acid (pKa = 4.8) produced by Clostridium tyrobutyricum was achieved through intermittent CO2 sparging while recycling reactor contents through a column packed with absorptive polymer Hytrel® 3078. This polymer was selected on the basis of its composition as a polyether copolymer, and the use of solubility parameters for predicting solute polymer affinity, and was found to have a partition coefficient for butyric acid of 3. Total polymeric extraction of 3.2 g butyric acid with no CO2 mediated pH swings was increased to 4.5 g via CO2 -facilitated pH shifting, despite the buffering capacity of butyric acid, which resists pH shifting. This work shows that CO2 -mediated pH swings have an observable positive effect on organic acid extraction, with improvements well over 150% under optimal conditions in early stage fermentation compared to CO2 -free controls, and this technique can be applied other organic acid fermentations to achieve or improve ISPR. © 2013 Wiley Periodicals, Inc.

  6. Rain-Shelter Cultivation Modifies Carbon Allocation in the Polyphenolic and Volatile Metabolism of Vitis vinifera L. Chardonnay Grapes.

    PubMed

    Gao, Yuan; Li, Xiao-Xi; Han, Mei-Mei; Yang, Xiao-Fan; Li, Zheng; Wang, Jun; Pan, Qiu-Hong

    2016-01-01

    This study investigated the effect of rain-shelter cultivation on the biosynthesis of flavonoids and volatiles in grapes, with an aim of determining whether rain-shelter application could help to improve the sensory attributes and quality of grapes. Vitis vinifera L. Chardonnay grapes, grown in the Huaizhuo basin region of northern China, were selected within two consecutive years. A rain-shelter roof was constructed using a colorless polyethylene (PE) film with a light transmittance of 80%. Results showed that rain-shelter treatment did not affect the accumulation of soluble solids during grape maturation. However, the allocation of assimilated carbon in phenolic and volatile biosynthetic pathways varied significantly, leading to alterations in polyphenolic and volatile profiles. The rain-shelter cultivation enhanced the concentration of flavan-3-ols via the flavonoid-3'5'-hydroxylase (F3'5'H) pathway, but reduced the level of flavonols and flavan-3-ols via the flavonoid-3'-hydroxylase (F3'H) pathway. In addition, the rain-shelter cultivation significantly enhanced the synthesis of fatty acid-derived volatiles, isoprene-derived terpenoids and amino acid-derived branched-chain aliphatics, but led to a decrease in the accumulation of isoprene-derived norisoprenoids and amino acid-derived benzenoids. Principal component analysis revealed some key compounds that differentiated the grapes cultivated under open-field and rain-shelter conditions. Moreover, the effect of the rain-shelter application on the accumulation of these compounds appeared to be vintage dependent. The alteration of their profiles caused by the rain-shelter treatment was significant in the vintage that received higher rainfall, which usually took place in the first rapid growth and veraison phases.

  7. Rain-Shelter Cultivation Modifies Carbon Allocation in the Polyphenolic and Volatile Metabolism of Vitis vinifera L. Chardonnay Grapes

    PubMed Central

    Han, Mei-Mei; Yang, Xiao-Fan; Li, Zheng; Wang, Jun; Pan, Qiu-Hong

    2016-01-01

    This study investigated the effect of rain-shelter cultivation on the biosynthesis of flavonoids and volatiles in grapes, with an aim of determining whether rain-shelter application could help to improve the sensory attributes and quality of grapes. Vitis vinifera L. Chardonnay grapes, grown in the Huaizhuo basin region of northern China, were selected within two consecutive years. A rain-shelter roof was constructed using a colorless polyethylene (PE) film with a light transmittance of 80%. Results showed that rain-shelter treatment did not affect the accumulation of soluble solids during grape maturation. However, the allocation of assimilated carbon in phenolic and volatile biosynthetic pathways varied significantly, leading to alterations in polyphenolic and volatile profiles. The rain-shelter cultivation enhanced the concentration of flavan-3-ols via the flavonoid-3’5’-hydroxylase (F3’5’H) pathway, but reduced the level of flavonols and flavan-3-ols via the flavonoid-3’-hydroxylase (F3’H) pathway. In addition, the rain-shelter cultivation significantly enhanced the synthesis of fatty acid-derived volatiles, isoprene-derived terpenoids and amino acid-derived branched-chain aliphatics, but led to a decrease in the accumulation of isoprene-derived norisoprenoids and amino acid-derived benzenoids. Principal component analysis revealed some key compounds that differentiated the grapes cultivated under open-field and rain-shelter conditions. Moreover, the effect of the rain-shelter application on the accumulation of these compounds appeared to be vintage dependent. The alteration of their profiles caused by the rain-shelter treatment was significant in the vintage that received higher rainfall, which usually took place in the first rapid growth and veraison phases. PMID:27218245

  8. Rain-rate data base development and rain-rate climate analysis

    NASA Technical Reports Server (NTRS)

    Crane, Robert K.

    1993-01-01

    The single-year rain-rate distribution data available within the archives of Consultative Committee for International Radio (CCIR) Study Group 5 were compiled into a data base for use in rain-rate climate modeling and for the preparation of predictions of attenuation statistics. The four year set of tip-time sequences provided by J. Goldhirsh for locations near Wallops Island were processed to compile monthly and annual distributions of rain rate and of event durations for intervals above and below preset thresholds. A four-year data set of tropical rain-rate tip-time sequences were acquired from the NASA TRMM program for 30 gauges near Darwin, Australia. They were also processed for inclusion in the CCIR data base and the expanded data base for monthly observations at the University of Oklahoma. The empirical rain-rate distributions (edfs) accepted for inclusion in the CCIR data base were used to estimate parameters for several rain-rate distribution models: the lognormal model, the Crane two-component model, and the three parameter model proposed by Moupfuma. The intent of this segment of the study is to obtain a limited set of parameters that can be mapped globally for use in rain attenuation predictions. If the form of the distribution can be established, then perhaps available climatological data can be used to estimate the parameters rather than requiring years of rain-rate observations to set the parameters. The two-component model provided the best fit to the Wallops Island data but the Moupfuma model provided the best fit to the Darwin data.

  9. The acid tolerance response and pH adaptation of Enterococcus faecalis in extract of lime Citrus aurantiifolia from Aceh Indonesia.

    PubMed

    Mubarak, Zaki; Soraya, Cut

    2018-01-01

    Background:  The objective of the present study was to evaluate the acid tolerance response and pH adaptation when Enterococcus faecalis interacted with extract of lime ( Citrus aurant iifolia ). Methods : We used E. faecalis ATCC 29212 and lime extract from Aceh, Indonesia. The microbe was analyzed for its pH adaptation, acid tolerance response, and adhesion assay using a light microscope with a magnification of x1000. Further, statistical tests were performed to analyze both correlation and significance of the acid tolerance and pH adaptation as well as the interaction activity. Results : E. faecalis was able to adapt to a very acidic environment (pH 2.9), which was characterized by an increase in its pH (reaching 4.2) at all concentrations of the lime extract (p < 0.05). E. faecalis was also able to provide acid tolerance response to lime extract based on spectrophotometric data (595 nm) (p < 0.05). Also, the interaction activity of E. faecalis in different concentrations of lime extract was relatively stable within 6 up to 12 hours (p < 0.05), but it became unstable within 24-72 hours (p > 0.05) based on the mass profiles of its interaction activity. Conclusions : E. faecalis can adapt to acidic environments (pH 2.9-4.2); it is also able to tolerate acid generated by Citrus auranti ifolia extract, revealing a stable interaction in the first 6-12 hours.

  10. A pH dependent Raman and surface enhanced Raman spectroscopic studies of citrazinic acid aided by theoretical calculations

    NASA Astrophysics Data System (ADS)

    Sarkar, Sougata; Chowdhury, Joydeep; Dutta, Soumen; Pal, Tarasankar

    2016-12-01

    A pH dependent normal Raman scattering (NRS) and surface enhanced Raman scattering (SERS) spectral patterns of citrazinic acid (CZA), a biologically important molecule, have been investigated. The acid, with different pKa values ( 4 and 11) for the two different functional groups (-COOH and -OH groups), shows interesting range of color changes (yellow at pH 14 and brown at pH 2) with the variation in solution pH. Thus, depending upon the pH of the medium, CZA molecule can exist in various protonated and/or deprotonated forms. Here we have prescribed the existence different possible forms of CZA at different pH (Forms ;C;, ;H; and ;Dprot; at pH 14 and Forms ;A;, ;D;, and ;P; at pH 2 respectively). The NRS spectra of these solutions and their respective SERS spectra over gold nanoparticles were recorded. The spectra clearly differ in their spectral profiles. For example the SERS spectra recorded with the CZA solution at pH 2 shows blue shift for different bands compared to its NRS window e.g. 406 to 450 cm- 1, 616 to 632 cm- 1, 1332 to 1343 cm- 1 etc. Again, the most enhanced peak at 1548 cm- 1 in NRS while in the SERS window this appears at 1580 cm- 1. Similar observation was also made for CZA at pH 14. For example, the 423 cm- 1 band in the NRS profile experience a blue shift and appears at 447 cm- 1 in the SERS spectrum as well as other bands at 850, 1067 and 1214 cm- 1 in the SERS window are markedly enhanced. It is also worth noting that the SERS spectra at the different pH also differ from each other. These spectral differences indicate the existence of various adsorptive forms of the CZA molecule depending upon the pH of the solution. Therefore based on the experimental findings we propose different possible molecular forms of CZA at different pH (acidic and alkaline) conditions. For example forms 'A', 'D' and 'P' existing in acidic pH (pH 2) and three other deprotonated forms 'C', 'H' and 'Dprot' in alkaline pH (pH 14). The DFT calculations for these

  11. Release of 5-Aminosalicylic Acid (5-ASA) from Mesalamine Formulations at Various pH Levels.

    PubMed

    Abinusawa, Adeyinka; Tenjarla, Srini

    2015-05-01

    Oral formulations of 5-aminosalicylic acid (5-ASA) for treatment of ulcerative colitis have been developed to minimize absorption prior to the drug reaching the colon. In this study, we investigate the release of 5-ASA from available oral mesalamine formulations in physiologically relevant pH conditions. Release of 5-ASA from 6 mesalamine formulations (APRISO®, Salix Pharmaceuticals, Inc., USA; ASACOL® MR, Procter & Gamble Pharmaceuticals UK Ltd.; ASACOL® HD, Procter & Gamble Pharmaceuticals, USA; MEZAVANT XL®, Shire US Inc.; PENTASA®, Ferring Pharmaceuticals, Ltd., UK; SALOFALK®, Dr. Falk Pharma UK Ltd.) was evaluated using United States Pharmacopeia apparatus I and II at pH values of 1.0 (2 h), 6.0 (1 h), and 6.8 (8 h). Dissolution profiles were determined for each formulation, respectively. Of the tested formulations, only the PENTASA formulation demonstrated release of 5-ASA at pH 1.0 (48%), with 56% cumulative release after exposure to pH 6.0 and 92% 5-ASA release after 6-8 h at pH 6.8. No other mesalamine formulation showed >1% drug release at pH 1.0. The APRISO formulation revealed 36% 5-ASA release at pH 6.0, with 100% release after 3 h at pH 6.8. The SALOFALK formulation revealed 11% 5-ASA release at pH 6.0, with 100% release after 1 h at pH 6.8. No 5-ASA was released by the ASACOL MR, ASACOL HD, and MEZAVANT XL formulations at pH 6.0. At pH 6.8, the ASACOL MR and ASACOL HD formulations exhibited complete release of 5-ASA after 4 and 2 h, respectively, and the MEZAVANT XL formulation demonstrated complete 5-ASA release over 6-7 h. 5-Aminosalicylic acid release profiles were variable among various commercially available formulations. Shire Development LLC.

  12. Spectroscopic investigation on structure and pH dependent Cocrystal formation between gamma-aminobutyric acid and benzoic acid.

    PubMed

    Du, Yong; Xue, Jiadan; Cai, Qiang; Zhang, Qi

    2018-02-15

    Vibrational spectroscopic methods, including terahertz absorption and Raman scattering spectroscopy, were utilized for the characterization and analysis of gamma-aminobutyric acid (GABA), benzoic acid (BA), and the corresponding GABA-BA cocrystal formation under various pH values of aqueous solution. Vibrational spectroscopic results demonstrated that the solvent GABA-BA cocrystal, similar as grinding counterpart, possessed unique characteristic features compared with that of starting parent compounds. The change of vibrational modes for GABA-BA cocrystal comparing with starting components indicates there is strong inter-molecular interaction between GABA and BA molecules during its cocrystallization process. Formation of GABA-BA cocrystal under slow solvent evaporation is impacted by the pH value of aqueous solution. Vibrational spectra indicate that the GABA-BA cocrystal could be stably formed with the solvent condition of 2.00≤pH≤7.00. In contrast, such cocrystallization did not occur and the cocrystal would dissociate into its parent components when the pH value of solvent is lower than 2.00. This study provides experimental benchmark to discriminate and identify the structure of cocrystal and also pH-dependent cocrystallization effect with vibrational spectroscopic techniques in solid-state pharmaceutical fields. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Large-scale modeling of rain fields from a rain cell deterministic model

    NASA Astrophysics Data System (ADS)

    FéRal, Laurent; Sauvageot, Henri; Castanet, Laurent; Lemorton, JoëL.; Cornet, FréDéRic; Leconte, Katia

    2006-04-01

    A methodology to simulate two-dimensional rain rate fields at large scale (1000 × 1000 km2, the scale of a satellite telecommunication beam or a terrestrial fixed broadband wireless access network) is proposed. It relies on a rain rate field cellular decomposition. At small scale (˜20 × 20 km2), the rain field is split up into its macroscopic components, the rain cells, described by the Hybrid Cell (HYCELL) cellular model. At midscale (˜150 × 150 km2), the rain field results from the conglomeration of rain cells modeled by HYCELL. To account for the rain cell spatial distribution at midscale, the latter is modeled by a doubly aggregative isotropic random walk, the optimal parameterization of which is derived from radar observations at midscale. The extension of the simulation area from the midscale to the large scale (1000 × 1000 km2) requires the modeling of the weather frontal area. The latter is first modeled by a Gaussian field with anisotropic covariance function. The Gaussian field is then turned into a binary field, giving the large-scale locations over which it is raining. This transformation requires the definition of the rain occupation rate over large-scale areas. Its probability distribution is determined from observations by the French operational radar network ARAMIS. The coupling with the rain field modeling at midscale is immediate whenever the large-scale field is split up into midscale subareas. The rain field thus generated accounts for the local CDF at each point, defining a structure spatially correlated at small scale, midscale, and large scale. It is then suggested that this approach be used by system designers to evaluate diversity gain, terrestrial path attenuation, or slant path attenuation for different azimuth and elevation angle directions.

  14. Humic Acid Effects on the Transport of Colloidal Particles in Unsaturated Porous Media: Humic Acid Dosage, pH, and Ionic Strength Dependence

    NASA Astrophysics Data System (ADS)

    Morales, V. L.; Gao, B.; Steenhuis, T. S.

    2008-12-01

    Soil colloids and biocolloids can facilitate contaminant transport within the soil profile through the complexation of pollutants previously thought to have limited mobility. Dissolved organic substances are qualitatively known to alter the behavior of colloids and surface chemistry of soil particles in aquatic environments when adsorbed to their surfaces. Specifically, it has been observed that even small amounts of adsorbed humic acids result in a pronounced increase in colloid mobility in saturated porous systems, presumably by a combination of electrostatic and steric stabilization. However, the degree to which adsorbed humic acids stabilize colloidal suspension is highly sensitive to the system's solution chemistry; mainly in terms of pH, ionic strength, and metal ions present. The objective of this study is to expound quantitatively on the role that combined stabilizing and destabilizing solution chemistry components have on humic acid-colloid transport in unsaturated media by isolating experimentally some underlying mechanisms that regulate colloid transport in realistic aquatic systems. We hypothesize that in chemically heterogeneous porous media, with ionic strength values above 0 and pH ranges from 4 to 9, the effect of humic acid on colloid suspensions cannot be simply characterized by increased stability and mobility. That a critical salt concentration must exists for a given humic acid concentration and pH, above which the network of humic acid collapses by forming coordination complexes with other suspended or adsorbed humic acids, thus increasing greatly the retention of colloids in the porous medium by sweep flocculation. In addition, capillary forces in unsaturated media may contribute further to overcome repulsive forces that prevent flocculation of humic acid-colloid complexes. The experimental work in this study will include: jar tests to determine critical solution concentration combinations for desired coagulation/flocculation rates, column

  15. The effect of pH on citric acid cough challenge: A randomised control trial in chronic cough and healthy volunteers.

    PubMed

    Rai, Z L; Fowles, H E; Wright, C; Howard, Joseph; Morice, A H

    2018-03-06

    Citric acid has been used for over six decades to induce cough; however the mechanism of its pro-tussive effect is still not fully understood. We assessed the response to inhalation of citric acid at varying levels of acidity to determine if the pH of the solution plays a role in the induction of cough. Data was collected from both healthy volunteers and patients with chronic cough. 20 chronic cough patients and 20 healthy volunteers were recruited and underwent three cough challenges on separate days. Each visit involved 5 repeated one second inhalations of 300 mM citric acid solution. The concentration of the citrate cation remained constant, but the pH of the solution altered by the addition of sodium bicarbonate to 3, 5 and 6, representing the pK a values of the individual acid moieties. The total number of coughs elicited was recorded for each inhalation. Two subjects withdrew and were not included in the analysis. Participants were gender matched, each group consisting of 12 females. 74% of chronic coughers coughed at pH 3 (mean coughs 16), 89% coughed at pH 5 (18) and 63% coughed at pH 6 (7). In healthy volunteers, 60% of subjects coughed at pH 3 (9), 30% of subjects coughed at pH 5 (3), and 10% of subjects coughed at pH 6 (0). Thus chronic cough patients coughed more than healthy volunteers and did not exhibit a clear pH concentration response. There was also a greater variability in their response to individual challenges. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Dendritic Zinc Growth in Acid Electrolyte: Effect of the pH

    NASA Astrophysics Data System (ADS)

    Bengoa, Leandro N.; Pary, Paola; Seré, Pablo R.; Conconi, M. Susana; Egli, Walter A.

    2018-03-01

    In this paper, dendritic growth at the edges of electrogalvanized steel strip has been studied using a specially designed rotating washer electrode which simulates the fluid dynamic conditions and the current density distribution at the steel strip edge found in a production line. The effect of electrolyte pH and current density on dendritic growth in an acidic zinc plating bath (ZnSO4 and H2SO4) was addressed. The temperature was kept constant at 60 °C. Solution pH was adjusted to 1, 2 or 3 using different amounts of H2SO4. In addition, the influence of temperature on the pH of the solution was determined. The current density was set at 40 or 60 A/dm2, similar to that used in the industry. Deposits were characterized using SEM and XRD. The results showed that pH strongly affects dendrites shape, length and texture. Furthermore, the morphology of dendrites at the washer edge and of deposits on the flat portion of the washer changed considerably as solution pH was increased from 1 to 3. It was found that the morphology of dendrites at the washer edge stems from the morphology of the deposit on its flat portion, which in turn determines their shape.

  17. The Potential Role of Systemic Buffers in Reducing Intratumoral Extracellular pH and Acid-Mediated Invasion

    PubMed Central

    Silva, Ariosto S.; Yunes, Jose A.; Gillies, Robert J.; Gatenby, Robert A.

    2013-01-01

    A number of studies have shown that the extracellular pH (pHe) in cancers is typically lower than that in normal tissue and that an acidic pHe promotes invasive tumor growth in primary and metastatic cancers. Here, we investigate the hypothesis that increased systemic concentrations of pH buffers reduce intratumoral and peritumoral acidosis and, as a result, inhibit malignant growth. Computer simulations are used to quantify the ability of systemic pH buffers to increase the acidic pHe of tumors in vivo and investigate the chemical specifications of an optimal buffer for such purpose. We show that increased serum concentrations of the sodium bicarbonate (NaHCO3) can be achieved by ingesting amounts that have been used in published clinical trials. Furthermore, we find that consequent reduction of tumor acid concentrations significantly reduces tumor growth and invasion without altering the pH of blood or normal tissues. The simulations also show that the critical parameter governing buffer effectiveness is its pKa. This indicates that NaHCO3, with a pKa of 6.1, is not an ideal intratumoral buffer and that greater intratumoral pHe changes could be obtained using a buffer with a pKa of ~7. The simulations support the hypothesis that systemic pH buffers can be used to increase the tumor pHe and inhibit tumor invasion. PMID:19276380

  18. A new boronic acid fluorescent sensor based on fluorene for monosaccharides at physiological pH

    NASA Astrophysics Data System (ADS)

    Hosseinzadeh, Rahman; Mohadjerani, Maryam; Pooryousef, Mona; Eslami, Abbas; Emami, Saeed

    2015-06-01

    Fluorescent boronic acids are very useful fluorescent sensor for detection of biologically important saccharides. Herein we synthesized a new fluorene-based fluorescent boronic acid that shows significant fluorescence changes upon addition of saccharides at physiological pH. Upon addition of fructose, sorbitol, glucose, galactose, ribose, and maltose at different concentration to the solution of 7-(dimethylamino)-9,9-dimethyl-9H-fluoren-2-yl-2-boronic acid (7-DMAFBA, 1), significant decreases in fluorescent intensity were observed. It was found that this boronic acid has high affinity (Ka = 3582.88 M-1) and selectivity for fructose over glucose at pH = 7.4. The sensor 1 showed a linear response toward D-fructose in the concentrations ranging from 2.5 × 10-5 to 4 × 10-4 mol L-1 with the detection limit of 1.3 × 10-5 mol L-1.

  19. Characterization of squamous esophageal cells resistant to bile acids at acidic pH: implication for Barrett's esophagus pathogenesis

    PubMed Central

    Goldman, Aaron; Chen, Hwu Dau Rw; Roesly, Heather B.; Hill, Kimberly A.; Tome, Margaret E.; Dvorak, Bohuslav; Bernstein, Harris

    2011-01-01

    Barrett's esophagus (BE) is a premalignant condition, where normal squamous epithelium is replaced by intestinal epithelium. BE is associated with an increased risk of developing esophageal adenocarcinoma (EAC). However, the BE cell of origin is not clear. We hypothesize that BE tissue originates from esophageal squamous cells, which can differentiate to columnar cells as a result of repeated exposure to gastric acid and bile acids, two components of refluxate implicated in BE pathology. To test this hypothesis, we repeatedly exposed squamous esophageal HET1A cells to 0.2 mM bile acid (BA) cocktail at pH 5.5 and developed an HET1AR-resistant cell line. These cells are able to survive and proliferate after repeated 2-h treatments with BA at pH 5.5. HET1AR cells are resistant to acidification and express markers of columnar differentiation, villin, CDX2, and cytokeratin 8/18. HET1AR cells have increased amounts of reactive oxygen species, concomitant with a decreased level and activity of manganese superoxide dismutase compared with parental cells. Furthermore, HET1AR cells express proteins and activate signaling pathways associated with inflammation, cell survival, and tumorigenesis that are thought to contribute to BE and EAC development. These include STAT3, NF-κB, epidermal growth factor receptor (EGFR), cyclooxygenase-2, interleukin-6, phosphorylated mammalian target of rapamycin (p-mTOR), and Mcl-1. The expression of prosurvival and inflammatory proteins and resistance to cell death could be partially modified by inhibition of STAT3 signaling. In summary, our study shows that long-term exposure of squamous cells to BA at acidic pH causes the cells to display the same characteristics and markers as BE. PMID:21127259

  20. Photosynthetic and antioxidant responses of Liquidambar formosana and Schima superba seedlings to sulfuric-rich and nitric-rich simulated acid rain.

    PubMed

    Chen, Juan; Wang, Wen-Hua; Liu, Ting-Wu; Wu, Fei-Hua; Zheng, Hai-Lei

    2013-03-01

    To study whether differential responses occur in photosynthesis and antioxidant system for seedlings of Liquidambar formosana, an acid rain (AR)-sensitive tree species and Schima superba, an AR-tolerant tree species treated with three types of pH 3.0 simulated AR (SiAR) including sulfuric-rich (S-SiAR), nitric-rich (N-SiAR), sulfate and nitrate mixed (SN-SiAR), we investigated the changes of leaf necrosis, chlorophyll content, soluble protein and proline content, photosynthesis and chlorophyll fluorescence characteristics, reactive oxygen species production, membrane lipid peroxidation, small molecular antioxidant content, antioxidant enzyme activities and related protein expressions. Our results showed that SiAR significantly caused leaf necrosis, inhibited photosynthesis, induced superoxide radical and hydrogen peroxide generation, aggravated membrane lipid peroxidation, changed antioxidant enzyme activities, modified related protein expressions such as Cu/Zn superoxide dismutase (SOD), l-ascorbate peroxidase (APX, EC 1. 11. 1. 11), glutathione S transferase (GST, EC 2. 5. 1. 18) and Rubisco large subunit (RuBISCO LSU), altered non-protein thiols (NPT) and glutathione (GSH) content in leaves of L. formosana and S. superba. Taken together, we concluded that the damages caused by SiAR in L. formosana were more severe and suffered from more negative impacts than in S. superba. S-SiAR induced more serious damages for the plants than did SN-SiAR and N-SiAR. Crown Copyright © 2013. Published by Elsevier Masson SAS. All rights reserved.

  1. Aerosol pH buffering in the southeastern US: Fine particles remain highly acidic despite large reductions in sulfate

    NASA Astrophysics Data System (ADS)

    Weber, R. J.; Guo, H.; Russell, A. G.; Nenes, A.

    2015-12-01

    pH is a critical aerosol property that impacts many atmospheric processes, including biogenic secondary organic aerosol formation, gas-particle phase partitioning, and mineral dust or redox metal mobilization. Particle pH has also been linked to adverse health effects. Using a comprehensive data set from the Southern Oxidant and Aerosol Study (SOAS) as the basis for thermodynamic modeling, we have shown that particles are currently highly acidic in the southeastern US, with pH between 0 and 2. Sulfate and ammonium are the main acid-base components that determine particle pH in this region, however they have different sources and their concentrations are changing. Over 15 years of network data show that sulfur dioxide emission reductions have resulted in a roughly 70 percent decrease in sulfate, whereas ammonia emissions, mainly link to agricultural activities, have been largely steady, as have gas phase ammonia concentrations. This has led to the view that particles are becoming more neutralized. However, sensitivity analysis, based on thermodynamic modeling, to changing sulfate concentrations indicates that particles have remained highly acidic over the past decade, despite the large reductions in sulfate. Furthermore, anticipated continued reductions of sulfate and relatively constant ammonia emissions into the future will not significantly change particle pH until sulfate drops to clean continental background levels. The result reshapes our expectation of future particle pH and implies that atmospheric processes and adverse health effects linked to particle acidity will remain unchanged for some time into the future.

  2. Growth and Metabolism of Lactic Acid Bacteria during and after Malolactic Fermentation of Wines at Different pH

    PubMed Central

    Davis, C. R.; Wibowo, D. J.; Lee, T. H.; Fleet, G. H.

    1986-01-01

    Commercially produced red wines were adjusted to pH 3.0, 3.2, 3.5, 3.7, or 4.0 and examined during and after malolactic fermentation for growth of lactic acid bacteria and changes in the concentrations of carbohydrates, organic acids, amino acids, and acetaldehyde. With one exception, Leuconostoc oenos conducted the malolactic fermentation in all wines and was the only species to occur in wines at pH below 3.5. Malolactic fermentation by L. oenos was accompanied by degradation of malic, citric, and fumaric acids and production of lactic and acetic acids. The concentrations of arginine, histidine, and acetaldehyde also decreased at this stage, but the behavior of hexose and pentose sugars was complicated by other factors. Pediococcus parvulus conducted the malolactic fermentation in one wine containing 72 mg of total sulfur dioxide per liter. Fumaric and citric acids were not degraded during this malolactic fermentation, but hexose sugars were metabolized. P. parvulus and species of Lactobacillus grew after malolactic fermentation in wines with pH adjusted above 3.5. This growth was accompanied by the utilization of wine sugars and production of lactic and acetic acids. PMID:16347015

  3. Stabilization of T4 bacteriophage at acidic and basic pH by adsorption on paper.

    PubMed

    Meyer, Abigail; Greene, Melissa; Kimmelshue, Chad; Cademartiri, Rebecca

    2017-12-01

    Bacteriophages find applications in agriculture, medicine, and food safety. Many of these applications can expose bacteriophages to stresses that inactivate them including acidic and basic pH. Bacteriophages can be stabilized against these stresses by materials including paper, a common material in packaging and consumer products. Combining paper and bacteriophages creates antibacterial materials, which can reduce the use of antibiotics. Here we show that adsorption on paper protects T4, T5, and T7 bacteriophage from acidic and basic pH. We added bacteriophages to filter paper functionalized with carboxylic acid (carboxyl methyl cellulose) or amine (chitosan) groups, and exposed them to pH from 5.6 to 14. We determined the number of infective bacteriophages after exposure directly on the paper. All papers extended the lifetime of infective bacteriophage by at least a factor of four with some papers stabilizing bacteriophages for up to one week. The degree of stabilization depended on five main factors (i) the family of the bacteriophage, (ii) the charge of the paper and bacteriophages, (iii) the location of the bacteriophages within the paper, (iv) the ability of the paper to prevent bacteriophage-bacteriophage aggregation, and (v) the sensitivity of the bacteriophage proteins to the tested pH. Even when adsorbed on paper the bacteriophages were able to remove E. coli in milk. Choosing the right paper modification or material will protect bacteriophages adsorbed on that material against detrimental pH and other environmental challenges increasing the range of applications of bacteriophages on materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Cytoplasmic pH Response to Acid Stress in Individual Cells of Escherichia coli and Bacillus subtilis Observed by Fluorescence Ratio Imaging Microscopy

    PubMed Central

    Martinez, Keith A.; Kitko, Ryan D.; Mershon, J. Patrick; Adcox, Haley E.; Malek, Kotiba A.; Berkmen, Melanie B.

    2012-01-01

    The ability of Escherichia coli and Bacillus subtilis to regulate their cytoplasmic pH is well studied in cell suspensions but is poorly understood in individual adherent cells and biofilms. We observed the cytoplasmic pH of individual cells using ratiometric pHluorin. A standard curve equating the fluorescence ratio with pH was obtained by perfusion at a range of external pH 5.0 to 9.0, with uncouplers that collapse the transmembrane pH difference. Adherent cells were acid stressed by switching the perfusion medium from pH 7.5 to pH 5.5. The E. coli cytoplasmic pH fell to a value that varied among individual cells (range of pH 6.2 to 6.8), but a majority of cells recovered (to pH 7.0 to 7.5) within 2 min. In an E. coli biofilm, cells shifted from pH 7.5 to pH 5.5 failed to recover cytoplasmic pH. Following a smaller shift (from pH 7.5 to pH 6.0), most biofilm cells recovered fully, although the pH decreased further than that of isolated adherent cells, and recovery took longer (7 min or longer). Some biofilm cells began to recover pH and then failed, a response not seen in isolated cells. B. subtilis cells were acid shifted from pH 7.5 to pH 6.0. In B. subtilis, unlike the case with E. coli, cytoplasmic pH showed no “overshoot” but fell to a level that was maintained. This level of cytoplasmic pH post-acid shift varied among individual B. subtilis cells (range of pH, 7.0 to 7.7). Overall, the cytoplasmic pHs of individual bacteria show important variation in the acid stress response, including novel responses in biofilms. PMID:22427503

  5. Cytoplasmic pH response to acid stress in individual cells of Escherichia coli and Bacillus subtilis observed by fluorescence ratio imaging microscopy.

    PubMed

    Martinez, Keith A; Kitko, Ryan D; Mershon, J Patrick; Adcox, Haley E; Malek, Kotiba A; Berkmen, Melanie B; Slonczewski, Joan L

    2012-05-01

    The ability of Escherichia coli and Bacillus subtilis to regulate their cytoplasmic pH is well studied in cell suspensions but is poorly understood in individual adherent cells and biofilms. We observed the cytoplasmic pH of individual cells using ratiometric pHluorin. A standard curve equating the fluorescence ratio with pH was obtained by perfusion at a range of external pH 5.0 to 9.0, with uncouplers that collapse the transmembrane pH difference. Adherent cells were acid stressed by switching the perfusion medium from pH 7.5 to pH 5.5. The E. coli cytoplasmic pH fell to a value that varied among individual cells (range of pH 6.2 to 6.8), but a majority of cells recovered (to pH 7.0 to 7.5) within 2 min. In an E. coli biofilm, cells shifted from pH 7.5 to pH 5.5 failed to recover cytoplasmic pH. Following a smaller shift (from pH 7.5 to pH 6.0), most biofilm cells recovered fully, although the pH decreased further than that of isolated adherent cells, and recovery took longer (7 min or longer). Some biofilm cells began to recover pH and then failed, a response not seen in isolated cells. B. subtilis cells were acid shifted from pH 7.5 to pH 6.0. In B. subtilis, unlike the case with E. coli, cytoplasmic pH showed no "overshoot" but fell to a level that was maintained. This level of cytoplasmic pH post-acid shift varied among individual B. subtilis cells (range of pH, 7.0 to 7.7). Overall, the cytoplasmic pHs of individual bacteria show important variation in the acid stress response, including novel responses in biofilms.

  6. A Triple-Fluorophore-Labeled Nucleic Acid pH Nanosensor to Investigate Non-viral Gene Delivery.

    PubMed

    Wilson, David R; Routkevitch, Denis; Rui, Yuan; Mosenia, Arman; Wahlin, Karl J; Quinones-Hinojosa, Alfredo; Zack, Donald J; Green, Jordan J

    2017-07-05

    There is a need for new tools to better quantify intracellular delivery barriers in high-throughput and high-content ways. Here, we synthesized a triple-fluorophore-labeled nucleic acid pH nanosensor for measuring intracellular pH of exogenous DNA at specific time points in a high-throughput manner by flow cytometry following non-viral transfection. By including two pH-sensitive fluorophores and one pH-insensitive fluorophore in the nanosensor, detection of pH was possible over the full physiological range. We further assessed possible correlation between intracellular pH of delivered DNA, cellular uptake of DNA, and DNA reporter gene expression at 24 hr post-transfection for poly-L-lysine and branched polyethylenimine polyplex nanoparticles. While successful transfection was shown to clearly depend on median cellular pH of delivered DNA at the cell population level, surprisingly, on an individual cell basis, there was no significant correlation between intracellular pH and transfection efficacy. To our knowledge, this is the first reported instance of high-throughput single-cell analysis between cellular uptake of DNA, intracellular pH of delivered DNA, and gene expression of the delivered DNA. Using the nanosensor, we demonstrate that the ability of polymeric nanoparticles to avoid an acidic environment is necessary, but not sufficient, for successful transfection. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  7. A pH dependent Raman and surface enhanced Raman spectroscopic studies of citrazinic acid aided by theoretical calculations.

    PubMed

    Sarkar, Sougata; Chowdhury, Joydeep; Dutta, Soumen; Pal, Tarasankar

    2016-12-05

    A pH dependent normal Raman scattering (NRS) and surface enhanced Raman scattering (SERS) spectral patterns of citrazinic acid (CZA), a biologically important molecule, have been investigated. The acid, with different pKa values (~4 and ~11) for the two different functional groups (-COOH and -OH groups), shows interesting range of color changes (yellow at pH~14 and brown at pH~2) with the variation in solution pH. Thus, depending upon the pH of the medium, CZA molecule can exist in various protonated and/or deprotonated forms. Here we have prescribed the existence different possible forms of CZA at different pH (Forms "C", "H" and "Dprot" at pH~14 and Forms "A", "D", and "P" at pH~2 respectively). The NRS spectra of these solutions and their respective SERS spectra over gold nanoparticles were recorded. The spectra clearly differ in their spectral profiles. For example the SERS spectra recorded with the CZA solution at pH~2 shows blue shift for different bands compared to its NRS window e.g. 406 to 450cm(-1), 616 to 632cm(-1), 1332 to 1343cm(-1) etc. Again, the most enhanced peak at ~1548cm(-1) in NRS while in the SERS window this appears at ~1580cm(-1). Similar observation was also made for CZA at pH~14. For example, the 423cm(-1) band in the NRS profile experience a blue shift and appears at ~447cm(-1) in the SERS spectrum as well as other bands at ~850, ~1067 and ~1214cm(-1) in the SERS window are markedly enhanced. It is also worth noting that the SERS spectra at the different pH also differ from each other. These spectral differences indicate the existence of various adsorptive forms of the CZA molecule depending upon the pH of the solution. Therefore based on the experimental findings we propose different possible molecular forms of CZA at different pH (acidic and alkaline) conditions. For example forms 'A', 'D' and 'P' existing in acidic pH (pH~2) and three other deprotonated forms 'C', 'H' and 'Dprot' in alkaline pH (pH~14). The DFT calculations for these

  8. Heavy rain effects

    NASA Technical Reports Server (NTRS)

    Dunham, R. Earl, Jr.

    1994-01-01

    This paper summarizes the current state of knowledge of the effect of heavy rain on airplane performance. Although the effects of heavy rain on airplane systems and engines are generally known, only recently has the potential aerodynamic effect of heavy rain been recognized. In 1977 the United States Federal Aviation Administration (FAA) conducted a study of 25 aircraft accidents and incidents which occurred between 1964 and 1976 in which low-altitude wind shear could have been a contributing factor. Of the 25 cases (23 approach or landing and 2 take-off) in the study, ten cases had occurred in a rain environment, and in five cases these were classified as intense or heavy rain encounters. These results led to the reconsideration of high-intensity, short-duration rainfall as a potential weather-related aircraft safety hazard, particularly in the take-off and/or approach phases of flight.

  9. Contaminant removal and hydraulic conductivity of laboratory rain garden systems for stormwater treatment.

    PubMed

    Good, J F; O'Sullivan, A D; Wicke, D; Cochrane, T A

    2012-01-01

    In order to evaluate the influence of substrate composition on stormwater treatment and hydraulic effectiveness, mesocosm-scale (180 L, 0.17 m(2)) laboratory rain gardens were established. Saturated (constant head) hydraulic conductivity was determined before and after contaminant (Cu, Zn, Pb and nutrients) removal experiments on three rain garden systems with various proportions of organic topsoil. The system with only topsoil had the lowest saturated hydraulic conductivity (160-164 mm/h) and poorest metal removal efficiency (Cu ≤ 69.0% and Zn ≤ 71.4%). Systems with sand and a sand-topsoil mix demonstrated good metal removal (Cu up to 83.3%, Zn up to 94.5%, Pb up to 97.3%) with adequate hydraulic conductivity (sand: 800-805 mm/h, sand-topsoil: 290-302 mm/h). Total metal amounts in the effluent were <50% of influent amounts for all experiments, with the exception of Cu removal in the topsoil-only system, which was negligible due to high dissolved fraction. Metal removal was greater when effluent pH was elevated (up to 7.38) provided by the calcareous sand in two of the systems, whereas the topsoil-only system lacked an alkaline source. Organic topsoil, a typical component in rain garden systems, influenced pH, resulting in poorer treatment due to higher dissolved metal fractions.

  10. Naturally occurring alkaline amino acids function as efficient catalysts on Knoevenagel condensation at physiological pH: a mechanistic elucidation.

    PubMed

    Li, Weina; Fedosov, Sergey; Tan, Tianwei; Xu, Xuebing; Guo, Zheng

    2014-05-01

    To maintain biological functions, thousands of different reactions take place in human body at physiological pH (7.0) and mild conditions, which is associated with health and disease. Therefore, to examine the catalytic function of the intrinsically occurring molecules, such as amino acids at neutral pH, is of fundamental interests. Natural basic α-amino acid of L-lysine, L-arginine, and L-histidine neutralized to physiological pH as salts were investigated for their ability to catalyze Knoevenagel condensation of benzaldehyde and ethyl cyanoacetate. Compared with their free base forms, although neutralized alkaline amino acid salts reduced the catalytic activity markedly, they were still capable to perform an efficient catalysis at physiological pH as porcine pancreatic lipase (PPL), one of the best enzymes that catalyze Knoevenagel condensation. In agreement with the fact that the three basic amino acids were well neutralized, stronger basic amino acid Arg and Lys showed more obvious variation in NH bend peak from the FTIR spectroscopy study. Study of ethanol/water system and quantitative kinetic analysis suggested that the microenvironment in the vicinity of amino acid salts and protonability/deprotonability of the amine moiety may determine their catalytic activity and mechanism. The kinetic study of best approximation suggested that the random binding might be the most probable catalytic mechanism for the neutralized alkaline amino acid salt-catalyzed Knoevenagel condensation.

  11. Soak Up the Rain

    EPA Pesticide Factsheets

    Soak Up the Rain promotes green infrastructure practices such as rain barrels, rain gardens, permeable pavements and green roofs to reduce stormwater runoff and prevent water pollution while bringing about a broad range of community benefits.

  12. Rain attenuation studies from radiometric and rain DSD measurements at two tropical locations

    NASA Astrophysics Data System (ADS)

    Halder, Tuhina; Adhikari, Arpita; Maitra, Animesh

    2018-05-01

    Efficient use of satellite communication in tropical regions demands proper characterization of rain attenuation, particularly, in view of the available popular propagation models which are mostly based on temperate climatic data. Thus rain attenuations at frequencies 22.234, 23.834 and 31.4/30 GHz over two tropical locations Kolkata (22.57°N, 88.36°E, India) and Belem (1.45°S, 48.49° W, Brazil), have been estimated for the year 2010 and 2011, respectively. The estimation has been done utilizing ground-based disdrometer observations and radiometric measurements over Earth-space path. The results show that rain attenuation estimations from radiometric data are reliable only at low rain rates (<30 mm/h). However, the rain attenuation estimations from disdrometer measurements show good agreement with the ITU-R model, even at high rain rates (upto100 mm/h). Despite having significant variability in terms of drop size distribution (DSD), the attenuation values calculated from DSD data (disdrometer measurements) at Kolkata and Belem differ a little for the rain rates below 30 mm/h. However, the attenuation values, obtained from radiometric measurements at the two places, show significant deviations ranging from 0.54 dB to 3.2 dB up to a rain rate of 30 mm/h, on account of different rain heights, mean atmospheric temperatures and climatology of the two locations.

  13. External concentration of organic acid anions and pH: key independent variables for studying how organic acids inhibit growth of bacteria in mildly acidic foods.

    PubMed

    Carpenter, C E; Broadbent, J R

    2009-01-01

    Although the mechanisms by which organic acids inhibit growth of bacteria in mildly acidic foods are not fully understood, it is clear that intracellular accumulation of anions is a primary contributor to inhibition of bacterial growth. We hypothesize that intracellular accumulation of anions is driven by 2 factors, external anion concentration and external acidity. This hypothesis follows from basic chemistry principles that heretofore have not been fully applied to studies in the field, and it has led us to develop a novel approach for predicting internal anion concentration by controlling the external concentration of anions and pH. This approach overcomes critical flaws in contemporary experimental design that invariably target concentration of either protonated acid or total acid in the growth media thereby leaving anion concentration to vary depending on the pK(a) of the acids involved. Failure to control external concentration of anions has undoubtedly confounded results, and it has likely led to misleading conclusions regarding the antimicrobial action of organic acids. In summary, we advocate an approach for directing internal anion levels by controlling external concentration of anions and pH because it presents an additional opportunity to study the mechanisms by which organic acids inhibit bacterial growth. Knowledge gained from such studies would have important application in the control of important foodborne pathogens such as Listeria monocytogenes, and may also facilitate efforts to promote the survival in foods or beverages of desirable probiotic bacteria.

  14. Novel stepwise pH control strategy to improve short chain fatty acid production from sludge anaerobic fermentation.

    PubMed

    Zhao, Jianwei; Wang, Dongbo; Liu, Yiwen; Ngo, Huu Hao; Guo, Wenshan; Yang, Qi; Li, Xiaoming

    2018-02-01

    This study reports an innovative strategy known as stepwise pH fermentation, developed to enhance the production of short chain volatile fatty acids (SCFA) from waste activated sludge (WAS) anaerobic fermentation. Experimental results confirmed the optimal pH for WAS disruption and acidification was 11 and 9, respectively, and corresponding optimal time was, respectively, 5 d and 2 d. In this scenario, the optimal SCFA yield was 2356 mg chemical oxygen demand (COD)/L, which was much higher than that derived from alkaline fermentation system. Investigation of the mechanism indicated that pH 11 could accelerate the disruption of WAS and inhibit the activities of methanogens; furthermore, pH 9 was beneficial to the activity of acid-producing bacteria, resulting in more SCFA production. Stepwise pH fermentation integrated with sodium chloride (NaCl) present in WAS had synergistic impacts on WAS anaerobic fermentation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Direct Measurement of pH in Individual Particles via Raman Microspectroscopy and Variation in Acidity with Relative Humidity.

    PubMed

    Rindelaub, Joel D; Craig, Rebecca L; Nandy, Lucy; Bondy, Amy L; Dutcher, Cari S; Shepson, Paul B; Ault, Andrew P

    2016-02-18

    Atmospheric aerosol acidity is an important characteristic of aqueous particles, which has been linked to the formation of secondary organic aerosol by catalyzing reactions of oxidized organic compounds that have partitioned to the particle phase. However, aerosol acidity is difficult to measure and traditionally estimated using indirect methods or assumptions based on composition. Ongoing disagreements between experiments and thermodynamic models of particle acidity necessitate improved fundamental understanding of pH and ion behavior in high ionic strength atmospheric particles. Herein, Raman microspectroscopy was used to determine the pH of individual particles (H2SO4+MgSO4) based on sulfate and bisulfate concentrations determined from νs(SO4(2-)) and νs(HSO4(-)), the acid dissociation constant, and activity coefficients from extended Debye-Hückel calculations. Shifts in pH and peak positions of νs(SO4(2-)) and νs(HSO4(-)) were observed as a function of relative humidity. These results indicate the potential for direct spectroscopic determination of pH in individual particles and the need to improve fundamental understanding of ion behavior in atmospheric particles.

  16. Combined Effects of Lanthanum (III) and Acid Rain on Antioxidant Enzyme System in Soybean Roots.

    PubMed

    Zhang, Xuanbo; Du, Yuping; Wang, Lihong; Zhou, Qing; Huang, Xiaohua; Sun, Zhaoguo

    2015-01-01

    Rare earth element pollution (REEs) and acid rain (AR) pollution simultaneously occur in many regions, which resulted in a new environmental issue, the combined pollution of REEs and AR. The effects of the combined pollution on the antioxidant enzyme system of plant roots have not been reported. Here, the combined effects of lanthanum ion (La3+), one type of REE, and AR on the antioxidant enzyme system of soybean roots were investigated. In the combined treatment of La3+ (0.08 mM) and AR, the cell membrane permeability and the peroxidation of cell membrane lipid of soybean roots increased, and the superoxide dismutase, catalase, peroxidase and reduced ascorbic acid served as scavengers of reactive oxygen species. In other combined treatments of La3+ (0.40 mM, 1.20 mM) and AR, the membrane permeability, malonyldialdehyde content, superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content increased, while the catalase activity decreased. The increased superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content were inadequate to scavenge the excess hydrogen peroxide and superoxide, leading to the damage of the cell membrane, which was aggravated with the increase in the concentration of La3+ and the level of AR. The deleterious effects of the combined treatment of La3+ and AR were stronger than those of the single treatment of La3+ or AR. Moreover, the activity of antioxidant enzyme system in the combined treatment group was affected directly and indirectly by mineral element content in soybean plants.

  17. Combined Effects of Lanthanum (III) and Acid Rain on Antioxidant Enzyme System in Soybean Roots

    PubMed Central

    Zhang, Xuanbo; Du, Yuping; Wang, Lihong; Zhou, Qing; Huang, Xiaohua; Sun, Zhaoguo

    2015-01-01

    Rare earth element pollution (REEs) and acid rain (AR) pollution simultaneously occur in many regions, which resulted in a new environmental issue, the combined pollution of REEs and AR. The effects of the combined pollution on the antioxidant enzyme system of plant roots have not been reported. Here, the combined effects of lanthanum ion (La3+), one type of REE, and AR on the antioxidant enzyme system of soybean roots were investigated. In the combined treatment of La3+ (0.08 mM) and AR, the cell membrane permeability and the peroxidation of cell membrane lipid of soybean roots increased, and the superoxide dismutase, catalase, peroxidase and reduced ascorbic acid served as scavengers of reactive oxygen species. In other combined treatments of La3+ (0.40 mM, 1.20 mM) and AR, the membrane permeability, malonyldialdehyde content, superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content increased, while the catalase activity decreased. The increased superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content were inadequate to scavenge the excess hydrogen peroxide and superoxide, leading to the damage of the cell membrane, which was aggravated with the increase in the concentration of La3+ and the level of AR. The deleterious effects of the combined treatment of La3+ and AR were stronger than those of the single treatment of La3+ or AR. Moreover, the activity of antioxidant enzyme system in the combined treatment group was affected directly and indirectly by mineral element content in soybean plants. PMID:26230263

  18. A new boronic acid fluorescent sensor based on fluorene for monosaccharides at physiological pH.

    PubMed

    Hosseinzadeh, Rahman; Mohadjerani, Maryam; Pooryousef, Mona; Eslami, Abbas; Emami, Saeed

    2015-06-05

    Fluorescent boronic acids are very useful fluorescent sensor for detection of biologically important saccharides. Herein we synthesized a new fluorene-based fluorescent boronic acid that shows significant fluorescence changes upon addition of saccharides at physiological pH. Upon addition of fructose, sorbitol, glucose, galactose, ribose, and maltose at different concentration to the solution of 7-(dimethylamino)-9,9-dimethyl-9H-fluoren-2-yl-2-boronic acid (7-DMAFBA, 1), significant decreases in fluorescent intensity were observed. It was found that this boronic acid has high affinity (K(a)=3582.88 M(-1)) and selectivity for fructose over glucose at pH=7.4. The sensor 1 showed a linear response toward d-fructose in the concentrations ranging from 2.5×10(-5) to 4×10(-4) mol L(-1) with the detection limit of 1.3×10(-5) mol L(-1). Copyright © 2015 Elsevier B.V. All rights reserved.

  19. The interfacial pH of acidic degradable polymeric biomaterials and its effects on osteoblast behavior.

    PubMed

    Ruan, Changshun; Hu, Nan; Ma, Yufei; Li, Yuxiao; Liu, Juan; Zhang, Xinzhou; Pan, Haobo

    2017-07-28

    A weak alkaline environment is established to facilitate the growth of osteoblasts. Unfortunately, this is inconsistent with the application of biodegradable polymer in bone regeneration, as the degradation products are usually acidic. In this study, the variation of the interfacial pH of poly (D, L-lactide) and piperazine-based polyurethane ureas (P-PUUs), as the representations of acidic degradable materials, and the behavior of osteoblasts on these substrates with tunable interfacial pH were investigated in vitro. These results revealed that the release of degraded products caused a rapid decrease in the interfacial pH, and this could be relieved by the introduction of alkaline segments. On the contrary, when culturing with osteoblasts, the variation of the interfacial pH revealed an upward tendency, indicating that cell could construct the microenvironment by secreting cellular metabolites to satisfy its own survival. In addition, the behavior of osteoblasts on substrates exhibited that P-PUUs with the most PP units were better for cell growth and osteogenic differentiation of cells. This is due to the hydrophilic surface and the moderate N% in P-PUUs, key factors in the promotion of the early stages of cellular responses, and the interfacial pH contributing to the enhanced effect on osteogenic differentiation.

  20. Extracellular pH regulation in microdomains of colonic crypts: effects of short-chain fatty acids.

    PubMed Central

    Chu, S; Montrose, M H

    1995-01-01

    It has been suggested that transepithelial gradients of short-chain fatty acids (SCFAs; the major anions in the colonic lumen) generate pH gradients across the colonic epithelium. Quantitative confocal microscopy was used to study extracellular pH in mouse distal colon with intact epithelial architecture, by superfusing tissue with carboxy SNARF-1 (a pH-sensitive fluorescent dye). Results demonstrate extracellular pH regulation in two separate microdomains surrounding colonic crypts: the crypt lumen and the subepithelial tissue adjacent to crypt colonocytes. Apical superfusion with (i) a poorly metabolized SCFA (isobutyrate), (ii) an avidly metabolized SCFA (n-butyrate), or (iii) a physiologic mixture of acetate/propionate/n-butyrate produced similar results: alkalinization of the crypt lumen and acidification of subepithelial tissue. Effects were (i) dependent on the presence and orientation of a transepithelial SCFA gradient, (ii) not observed with gluconate substitution, and (iii) required activation of sustained vectorial acid/base transport by SCFAs. Results suggest that the crypt lumen functions as a pH microdomain due to slow mixing with bulk superfusates and that crypts contribute significant buffering capacity to the lumen. In conclusion, physiologic SCFA gradients cause polarized extracellular pH regulation because epithelial architecture and vectorial transport synergize to establish regulated microenvironments. Images Fig. 1 Fig. 3 PMID:7724557