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41.
This study investigated geochemical characteristics of the acid mine drainage (AMD) discharged from the abandoned mine adits in the vicinity of the Dogye coal mine in Korea. Acid mine drainage discharged from Jeoncha pit adit of the Dogye coal mine, which is the main source of the AMD in the study area, had a pH value of 3.0 and concentrations of 2148mg SO4
2– L–1, 229mg Fe L–1, 71mg A1 L–1 and 11mg Mn L–1. The reduction of some metal concentrations downstream from the discharge point could be explained on the basis of dilution and precipitation. The order of removal of metal ions downstream from the discharge point was Fe>A1, Cu>Zn, Mn. Acidity could be used as a good determining factor offering comprehensive and quantitative values for the polluting extent of acid mine drainage. The acidities existing in all acidic water samples in the Gunahan district originated primarily from mineral acidity, especially in the upper Nahan Creek from dissolved Fe and Al and in the middle and down Nahan Creek from dissolved Al. From the application of the WATEQ4F program, it was determined that predominant species of dissolved Fe in all water samples was Fe2+, and those of dissolved Al were AlSO4
+ and Al3+ except for IW2 sample which was associated with white precipitates. The species of dissolved Al in IW2 sample include also AlOH2+ and Al(OH)2
+. The saturation indices of goethite and haematite were positive in the water samples associated with ochrous precipitates (usually called Yellow Boy), therefore these solids might be precipitated. For the IW2 sample, the saturation indices of amorphous Al(OH)3 and gibbsite were positive, so theoretically these solids might also be precipitated. By XRD analysis, it was found that goethite occurs in ochrous precipitates, and gibbsite in white precipitates. 相似文献
42.
分析了传统空管裂解生产四氟乙烯工艺存在的污染问题 ,介绍了水蒸汽稀释裂解生产四氟乙烯工艺的污染控制情况。 相似文献
43.
By using a dynamic dilution system, the atmospheric measurement of 11 selected toxics VOCs (ethylene, acetylene, propene, 1-butene, 1,3-butadiene, 1-pentene, 1-hexene, benzene, toluene, ethylbenzene, m+p-xylene) from the list WHO of 1996 and TO-14 method of US EPA by preconcentration by thermal desorption (TD), analysis by gas chromatography (GC), identification and quantification with a flame ionisation detector (FID) was developed and validated in term of metrology, especially the techniques of sampling of these VOCs with adsorbents cartridges "Air Toxics" when used with an "UMEG sampler" equipped in the inlet with a nafion membrane. In particular the influence of climatic conditions (temperature and relative humidity) and the influence of chemical factors like ozone, on the representativity of sampling were studied. Experiments made with various humidities showed that the addition of a nafion membrane in the inlet of the sampling system was required. Without this membrane, losses of compounds were observed for RH >50%. With this membrane, storage for 2 weeks in a refrigerator, as for canisters, did not induce a loss of compounds. No significative decrease of concentrations of the studied VOCs after 14 days storage, which are known to react with ozone, were observed with an ozone concentrations of 55 ppb. One explanation is that nafion membrane, placed in the inlet of the sampler, will neutralize ozone before entering the sampling tubes. This observation is in accordance with literature which states that the sampling of VOCs on Carbotrap cartridges without ozone scrubber induce a loss of compounds. 相似文献
44.
45.
Binbin Shao 《Behavioral ecology and sociobiology》1997,41(6):399-406
The reproductive success of male parental pumpkinseeds, Lepomisgibbosus, was studied in relation to the use of their nests by spawning golden shiners, Notemigonuscrysoleucas. The brood size of pumpkinseeds with and without golden shiner's young was compared in a field population. Mean egg and larval
numbers of pumpkinseeds did not differ between broods with and without shiners, suggesting that shiners had no net effect
on the fitness of host pumpkinseeds. In the laboratory, however, hatching success of pumpkinseed embryos was significantly
lower with shiners than without. This difference was attributable to fungal infection. Against this fitness loss, the presence
of shiner larvae reduced predation on pumpkinseed larvae in laboratory experiments. Thus, two counteracting mechanisms are
proposed to account for no observed net effect on the host: (1) increased fungal infection on pumpkinseed embryos and (2)
decreased predation on pumpkinseed young.
Received: 10 January 1997 / Accepted after revision: 9 August 1997 相似文献
46.
用两种土壤研究土壤与酸的反应时间对土壤酸度及土壤溶液中铝离子形态分布的影响。结果表明,土壤溶液pH随反应时间增加而增加,安徽红壤pH的增幅大于江西红壤。在pH3.0的HNO3溶液中,土壤溶液中的总铝及Al3 均随反应时间增加而减少,而在pH3.5的HNO3溶液中,土壤溶液中总铝及Al-F络合物先随反应时间的增加而减小.然后又有所增加。 相似文献
47.
哈尔滨市降水形势对大气污染物浓度稀释的影响 总被引:6,自引:0,他引:6
大量的观测事实和分析表明,随着季节的变化,降水对大气污染物浓度稀释的影响是比较复杂的。冬季,降雪越多,严重污染出现的概率越大;降雪时的天气往往风速小,湿度大,空气层结较稳定,扩散能力较弱。春季,降水对污染物浓度的影响就大一些,降水对PM10有较大的稀释作用,尤其对NO2稀释的影响更大一些,高湿的低温东风雨水对污染物浓度有降低的作用。夏季,降水大于等于10.0mm时高温高湿降水对污染物的稀释作用较大。秋季,高湿气压降低,降水10mm以下,对污染物浓度有降低的作用。 相似文献
48.
49.
Totsche O Fyson A Kalin M Steinberg CE 《Environmental science and pollution research international》2006,13(4):215-224
Background, Aims and Scope The acidification of mine waters is generally caused by metal sulfide oxidation, related to mining activities. These waters
are characterized by low pH and high acidity due to strong buffering systems. The standard acidity parameter, the Base Neutralization
Capacity (BNC) is determined by endpoint titration, and reflects a cumulative parameter of both hydrogen ions and all buffering
systems, but does not give information on the individual buffer systems. We demonstrate that a detailed interpretation of
titration curves can provide information about the strength of the buffering systems. The buffering systems are of importance
for environmental studies and treatment of acidic mining waters.
Methods Titrations were carried out by means of an automatic titrator using acidic mining waters from Germany and Canada. The curves
were interpreted, compared with each other, to endpoint titration results and to elemental concentrations contained therein.
Results and Discussion The titration curves were highly reproducible, and contained information about the strength of the buffer systems present.
Interpretations are given, and the classification and comparison of acidic mining waters, by the nature and strength of their
buffering systems derived from titration curves are discussed. The BNC-values calculated from the curves were more precise
than the ones determined by the standard endpoint titration method. Due to the complex buffer mechanisms in acidic mining
waters, the calculation of major metal concentrations from the shape of the titration curve resulted in estimates, which should
not be confused with precise elemental analysis results.
Conclusion Titration curves provide an inexpensive, valuable and versatile tool, by which to obtain sophisticated information of the
acidity in acidic water. The information about the strength of the present buffer systems can help to understand and document
the complex nature of acidic mining water buffer systems. Finally, the interpretation of titration curves could help to improve
treatment measurements and the ecological understanding of these acidic waters. 相似文献
50.
大气二次污染物是新疆独山子区大气污染物的重要组成部分,研究大气中二次组分的转化过程对区域大气污染治理有着重要意义.对新疆独山子区2015年9月至2016年7月采集到的样品进行水溶性组分分析.结果表明,水溶性无机离子(TWSIs)表现出与PM2.5一致的季节变化,为冬季(67.86μg·m-3)>秋季(13.77μg·m-3)>春季(10.09μg·m-3)>夏季(4.85μg·m-3);冬季二次无机离子(NH+4、SO2-4和NO-3)占TWSIs的98%;结合气溶胶热力学模型(E-AIM)探讨独山子区大气颗粒污染物中颗粒相含水量以及颗粒酸碱性;表明独山子区颗粒物呈酸性,年均原位pH为0.81,其中冬季样品的pH(2.93)值最高;颗粒含水季节变化为冬季(331.32μg·m-3)>秋季(5.91μg·... 相似文献