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181.
With the acceleration of industrialization, coal- burning atmospheric pollution is getting more and more serious in many regions in China. However, there are only about ten odd years literature records about pollution in some large and mid-sized cities, where the atmosphere has perhaps been polluted for several decades, and therefore it is difficult to know the process and characteristic of pollution, and diffi-cult to evaluate its damage to environment. Lacustrine sediment, a natural record w… 相似文献
182.
F. S. Turalioglu H. Bayraktar 《Stochastic Environmental Research and Risk Assessment (SERRA)》2005,19(1):41-47
In the assessment of air quality, regional distribution and dispersion with distance are important, together with the variations of pollutants in time. On this occasion, the point cumulative semi-variogram (PCSV) method is used in order to find simply regional distribution of pollutants of Erzurum urban centre. This method is based simply on the summation of square differences in air pollutant concentrations between different sites. Monthly regional variation maps of Erzurum are constructed by finding radius of influence (for SO2, from 1000 m to 3500 m and, for TSP, 1000–2000 m) and PCSV scattering diagram data at different levels by using monthly average sulphur dioxide (SO2) and total suspended particulate (TSP) matter concentrations in 2001–2002 winter season. Consequently, the air pollution distribution of Erzurum is assessed. 相似文献
183.
The identification of marine source rocks in the Tarim Basin is debated vigorously. The intention of this paper is to investigate the asphahenes in heavy oils from the Lunnan and Tabe oilfields and Well TD2 with ruthenium-ions-catalyzed oxidation technique (RICO), in order to explore its role in oil-oil and oil-source correlations, The RICO products included n-alkanoic acids, α,ω-di-n-alkanoic acids, branched alkanoic acids, tricyclic terpanoic acids, hopanoic acids, gammacerane carboxylic acid , regular sterane carboxylic acids and 4-methylsterane carboxylic acids. The n-alkyl chains and biomarkers bounded on the asphaltenes were of unsusceptibility to biodegradation. The distribution and absolute concentrations of n-alkanoic acids in the RICO products of heavy oils from the Lunnan and Tabe oilfields are different from those of Well TD2. The biomarkers bounded on the asphahenes, especially steranes, have a distribution trend similar to that of the counterparts in saturates. The sterane carboxylic acids and 4-methylsterane carboxylic acids in the RICO products of heavy oils from the Lunnan and Tahe oilfields, dominated by C30 sterane and C31 4-methylsterane carboxylic acids, respectively, are significantly different from those of the heavy oils of Well TD2, whose dominating sterane and 4-methylsterane carboxylic acids are C28 sterane and C29 4-methylsterane acids, respectively. The RICO products of the asphaltenes further indicate that the Middle-Upper Ordovician may be the main source rocks for heavy oils from the Lunnan and Tabe oilfields. 相似文献
184.
Transformation of arsenic compounds in modern intertidal sediments of Iriomote Island, Japan 总被引:1,自引:0,他引:1
The arsenic accumulation process in intertidal sediments of Iriomote Island, Japan, is analyzed as a naturally balanced arsenic-fixation system. Major and minor element chemistry is analyzed by X-ray fluorescence photometry, mineralogy is investigated by X-ray diffractometry, and four arsenic compounds are characterized by hydrogen-generated atomic absorption photometry. It is found that arsenic is accumulated by iron hydroxides/oxides precipitated following the decomposition of humic acids in the shallower sediment, and is subsequently incorporated into iron sulfide minerals at depth. The arsenic is immobile during incorporation into arsenic-bearing phases, suggesting that arsenic is unlikely to be released into the porewater under natural conditions in early diagenesis. The formation and decomposition of arsenic-bearing organic compounds appear to be associated with the formation and decomposition of arsenic in oxyhydroxides/oxides, suggesting that microbial activity may play an important role in controlling the behavior of arsenic and arsenic-bearing phases in the sediment column. 相似文献
185.
Correlation between magnetic susceptibility and heavy metals in urban topsoil: a case study from the city of Xuzhou, China 总被引:7,自引:0,他引:7
Anthropogenic influence, mainly due to urban and industrial activities and traffic exhaust, may affect urban topsoil via atmospheric contamination and solid waste. Magnetic susceptibility measurements were conducted on 21 urban topsoil samples from the city of Xuzhou, China. High intensities of magnetic susceptibility were detected in the majority of the samples. SEM analysis shows that magnetic minerals are in the form of spherules and mainly due to anthropogenic inputs. The heavy metals Pb, Cu, Zn, Se, Sc, Mo, Fe, and Bi show strong correlations with magnetic susceptibility, and Ag, Ba, Cd, Ni, Cr, Sb, and Sn, on the other hand, show a weak correlation with magnetic susceptibility. Whereas, of these metals studied, only Hg has no significant correlation with the susceptibility. The Tomlinson pollution load index (PLI) also shows significant correlation with the susceptibility (χ). The present study shows that magnetic susceptibility is a fast, inexpensive, and non-destructive method for the detection and mapping of contaminated soils. 相似文献
186.
Brijraj K. Das 《Environmental Geology》2005,49(2):230-239
A study of the water and sediment chemistry of the Nainital, Bhimtal, Naukuchiyatal and Sattal Lakes of Kumaun, has shown that the water of these lakes are alkaline and that electrical conductivity, total dissolved solid and bicarbonate HCO
3
−
are much higher in Nainital than in the other three lakes. The weathering of limestone lithology and anthropogenic pollution, the latter due to the very high density of population in the Nainital valley, are the primary sources of enhanced parameters. The low pH of Nainital Lake water is due to low photosynthesis and enhanced respiration, increasing CO2 in the water and the consequent enhancement of Ca2+ and HCO
3
−
. The dissolved oxygen in Nainital Lake is less compared to other lakes, indicating anoxic conditions developing at the mud–water interface at depth. The PO
4
3−
content in Nainital is higher (124 μg/l), showing an increasing trend over time leading to eutrophic conditions. The trace metals (Cu, Co, Zn, Ni, Mn, and Sr) are present in greater amounts in the water of Nainital Lake than in the other three lakes, though Fe and Cr are high in Bhimtal and Fe in Naukuchiyatal. The higher abundance is derived from the leaching of Fe–Mg from metavolcanic and metabasic rocks. Most of the heavy metals (Cr, Ni, Cu, Mn, Fe, Sr, and Zn) significantly enrich the suspended sediments of the lakes compared to the bed sediments which due to their adsorption on finer particles and owing to multiple hydroxide coating and organic content, except for Fe, which is enriched in the bed sediments. The high rate of sedimentation, 11.5 mm/year in Nainital, compared to Bhimtal with 4.70 mm/year, Naukuchiyatal with 3.72 mm/year, and Sattal with 2.99 mm/year, has resulted in shorter residence time, poor sorting of grains, and lesser adsorption of heavy metals, leading consequently, their depletion in the bed sediments of Nainital Lake. 相似文献
187.
The preliminary study of streams and rivers from the Roşia Montană area revealed that the concntration of heavy metals— Cd,
Mn, Cu, Pb, and Zn—are above accepted limits. The gold extraction method is based on flotation. The most important pollution
sources are mine tailings. The determinations were performed for samples collected in: April 2004, July 2004, September 2004,
November 2004, February 2005 and May 2005. The highest concentrations were found for cadmium in September 2004: 0.17 mg/L;
for copper in September 2004: 1.38 mg/L; for manganese in July 2004: 239.4 mg/L; for lead in May 2005: 0.54 mg/L; and for
zinc in September 2004: 35.37 mg/L;. This study involved three small rivers (streams) that flow into the Mureş River and finally
into the Danube River, having a great impact on human health and environmental stability in the area. In May 2005, a sample
of drinking water from the mining district was also collected. 相似文献
188.
在准噶尔盆地西北缘,寻找岩性圈闭油气藏已是至关重要的问题。但人们几乎还是用常规的手段来寻找岩性油气藏,没有实质性进展。本文是以利用宽方位角采集的地震数据为基础,对数据进行高保真资料处理和参考标准层的层拉平解释。利用前人的区域地质研究成果和钻井解释成果对侏罗系的沉积环境进行了精细的描述,确定了拐19井区在下侏罗统三工河组的出油层段附近的沉积环境由湖泊相-三角洲前缘相-河流相-湖泊相的演化过程。利用地震属性解释的结果也能较好地反映目标区的沉积环境变迁,并且与区域地质、测井解释结果相吻合,为寻找油气提供了很好的依据。由此得出利用地震属性可以进行沉积环境变迁分析,为油田寻找岩性圈闭及油气藏做出贡献。 相似文献
189.
松花江上游地区汞污染的化学生态效应 总被引:5,自引:0,他引:5
采样分析了吉林省东部松花江上游金矿开采区及其附近水、土壤、动植物及河流沉积物样品中汞的含量,发现河流沉积物中汞的污染相当严重;受其影响当地的植物和两栖类动物——中国林蛙体内总汞和甲基汞含量也明显高于对照组。实验表明,林蛙内脏对汞的富集能力大于肌肉;秋季对汞的富集大于春季;河流沉积物中甲基汞的含量与林蛙体内甲基汞的含量有较好的正相关。汞污染的来源与区域内个体金矿的滥采滥排有直接关系,表明人类活动所产生的有毒重金属在地表过程中出现了化学生态效应。 相似文献
190.
Erin M. Nicholls Sean K. Carey Elyn R. Humphreys M. Graham Clark Gordon B. Drewitt 《水文研究》2016,30(16):2739-2753
Oil sands mining in Alberta transforms the boreal landscape of forests and wetlands into open pits, tailings ponds and overburden piles. Whereas reclamation efforts have primarily focused on upland forests, rebuilding wetland systems has recently become a motivation for research. Wetland creation and sustainability in this region is complicated by the sub‐humid climate and salinity of underlying mining material. In 2012, Syncrude Canada Ltd. completed the construction of the Sandhill Fen Watershed (SFW), a 52‐ha upland‐wetland system to evaluate wetland reclamation strategies on soft tailings. SFW includes an active pumping system, upland hummocks, a fen wetland and underdrains. To evaluate the influence of management practices on the hydrology of the system, this study reports the water balance from January 2013 to December 2014, the first 2 years after commissioning. A semi‐distributed approach was taken to examine the fluxes and stores of water in uplands and lowlands. Natural and artificial inputs and outputs were measured using a series of precipitation gauges and pumps, and evapotranspiration was quantified using three eddy covariance towers. A series of near surface wells recorded water table position. Both 2013 and 2014 were normal rainfall years, with 2013 having more and 2014 less snow than normal. In 2013, inflow/outflow from pumping was the predominant hydrological fluxes, resulting in considerable variability in water table position and storage changes throughout the summer. In 2014, the artificial addition of water was negligible, yet the water table remained near the surface in lowland locations, suggesting that wetland conditions could be maintained under current conditions. Evapotranspiration rates between uplands and lowlands were similar between years and sites, ranging from 2.2 ± 1.8 to 2.5 ± 1.2 mm/day and were largely controlled by climate. These rates were less than nearby older upland systems, suggesting that water balance partitioning will change as vegetation develops. Comparison between years and with natural systems provides insight on how management practices influence hydrologic dynamics and the overall water balance of the SFW. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献