地下水石油烃生物降解作用研究     

焦珣 《上海国土资源》2012,33(2):16-20,33

在对某石油污染场地地质、水文地质条件、污染源污染方式调查基础上,根据地下水样测试结果,分析了地下水石油烃污染分布特征、污染晕中指示生物降解作用的电子受体、代谢产物以及重要地球化学参数的变化规律,通过计算矿物饱和指数和采用含水层介质X射线矿物衍射方法研究了污染晕中矿物沉淀反应,计算了含水层的氧化容量。结果表明：由于SO42-背景浓度值较高,硫酸盐还原是污染场地地下水石油烃生物降解的优势反应;菱铁矿、黄铁矿和FeS的沉淀反应是HS-、Fe2＋浓度异常的原因;SO42-的氧化容量在含水层中的氧化容量（OXC）所占比例最大,可进一步推断硫酸盐还原反应是引起污染场地地下水石油烃生物降解的优势反应。  相似文献   

Crystallization Kinetics of Potassium Sulphate in Aqueous System Mg~(2+),K~+//Cl,SO_4~(2-)-H_2O     

XIANG Jun  CHENG Penggao  ZHANG Lei  TANG N  WANG Xuekui 《《地质学报》英文版》2014,88(Z1):383-383

正As an excellent chemical fertilizer,Potassium Sulphate(K2SO4)could provide both potassium and sulfur elements for crops.However,it is well known that potassium resource is very poor in China.To understand the Crystallization Kinetics(CK)of K2SO4could be conducive to utilize the limited potassium resource,promote the yield and purity of K2SO4.In this study saturated solution of potassium sulphate was prepared according to the phase diagram of Mg2+、  相似文献   

Chemical weathering processes in the Yalong River draining the eastern Tibetan Plateau,China     

《Journal of Asian Earth Sciences》2014

To better understand chemical weathering and controlling processes in the Yalong River of the eastern Tibetan Plateau, this study presents major ion concentrations and stable isotopes of the dissolved loads. The isotopic compositions (δ¹³C-DIC, δ³⁴S and δ¹⁸O-SO₄) of the dissolved loads are very useful to quantify solute sources and define the carbon budget related with chemical weathering in riverine systems. The isotopic composition of sulphate demonstrates that most of the sulphate is derived from sulphide oxidation, particularly in the upper reach of the Yalong River. The correlations between δ¹³C-DIC, water chemistry and isotopes of sulphate, suggest that the carbon dynamics are mainly affected by carbonate weathering by sulphuric acid and equilibration processes. Approximately 13% of the dissolved inorganic carbon in the Yalong River originates from carbonate weathering by strong acid. The CO₂ consumption rates are estimated to be 2.8 × 10⁵ mol/km²/yr and 0.9 × 10⁵ mol/km²/yr via carbonate and silicate weathering in the Yalong River, respectively. In this study, the influence of sulphide oxidation and metamorphic CO₂ on the carbon budget is estimated for the Yalong River draining the eastern Tibetan Plateau.  相似文献   

Significance of processes in the near‐stream zone on stream water acidity in a small acidified forested catchment     

Jens Flster 《水文研究》2001,15(2):201-217

The near‐stream zone has received increasing attention owing to its influence on stream water chemistry in general and acidity in particular. Possible processes in this zone include cation exchange, leaching of organic matter and redox reactions of sulphur compounds. In this study the influences of processes in the near‐stream zone on the acidity in runoff from a small, acidified catchment in central southern Sweden were investigated. The study included sampling of groundwater, soil water and stream water along with hydrological measurements. An input–output budget for the catchment was established based on data from the International Co‐operative Programme on Integrated Monitoring at this site. The catchment was heavily acidified by deposition of anthropogenic sulphur, with pH in stream water between 4·4 and 4·6. There was also no relationship between stream flow and pH, which is indicative of chronic acidification. Indications of microbial reduction of sulphate were found in some places near the stream, but the near‐stream zone did not have a general impact on the sulphate concentration in discharging groundwater. The near‐stream zone was a source of dissolved organic carbon (DOC) in the stream, which had a median DOC of 6·8 mg L¹. The influence on stream acidity from organic anions was overshadowed by the effect of sulphate, however, except during a spring flow episode, when additional organic matter was flushed out and the sulphate‐rich ground water was mixed with more diluted event water. Ion exchange was not an important process in the near‐stream zone of the Kindla catchment. Different functions of the near‐stream zone relating to discharge acidity are reported in the literature. In this study there was even a variation within the site. There is therefore a need for more case studies to provide a more detailed understanding of the net effects that the near‐stream zone can have on stream chemistry under different circumstances. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Formation of modern dolomite in hypersaline pans of the Western Cape,South Africa     

CARLA L. MAUGER  JOHN S. COMPTON 《Sedimentology》2011,58(7):1678-1692

Authigenic calcite and dolomite and biogenic aragonite occur in Holocene pan sediments in a Mediterranean‐type climate on the western coastal plain of South Africa. Sediment was analysed from a Late Pleistocene coastal pan at Yzerfontein and four Holocene inland pans ranging from brackish to hypersaline. The pans are between 0·08 and 0·14 km² in size. The δ¹⁸O_PDB values of carbonate minerals in the pan sediments range from ?2·41 to 5·56‰ and indicate precipitation from evaporative waters. Covariance of total organic content and percentage carbonate minerals, and the δ¹³C_PDB values of pan carbonate minerals (?8·85 to ?1·54‰) suggest that organic matter degradation is a significant source of carbonate ions. The precipitation of the carbonate minerals, especially dolomite, appears to be mediated by sulphate‐reducing bacteria in the black sulphidic mud zone found in the brine‐type hypersaline pans. The knobbly, sub‐spherical texture of the carbonate minerals suggests that the precipitation of the carbonate minerals, particularly dolomite, is related to microbial processes. The ⁸⁷Sr/⁸⁶Sr ratios of pan carbonate minerals (0·7108 to 0·7116) are slightly higher than modern sea water and indicate a predominantly sea water (marine aerosol) source for calcium (Ca²⁺) ions with relatively minor amounts of Ca²⁺ derived from the chemical weathering of bedrock.  相似文献   

Comparative assessment of water treatment using polymeric and inorganic coagulants     

《Physics and Chemistry of the Earth》2016

Portable water plays a vital role in improving human life, particularly in controlling the spread of diseases. However, problems associated with lack of potable water are still common especially in developing countries including Malawi. Until now little information exists on the effectiveness of available commercial coagulants used by national water boards in Malawi. Therefore, this study was undertaken in Southern Region Water Board (SRWB) to investigate the efficiency of polymeric coagulants (sufdfloc 3850 and algaefloc 19s) in turbidity reduction comparative with inorganic coagulant (aluminium sulphate) at Zomba, Liwonde, Mangochi, Chikwawa and Mulanje Treatment plants. The jar test method was used to determine the effectiveness of the water coagulants. The results revealed that sudfloc 3850 was most effective in reducing turbidity at Mangochi (99.4 ± 0.06%) and Liwonde (97.2 ± 0.04%) using 0.4 mg L⁻¹ flocculant dose. The Zomba, Mulanje and Chikwawa plants gave 19.56 ± 0.03%, 29.23 ± 0.02% and 9.43 ± 0.02% total reductions respectively. Algaefloc 19s afforded the highest turbidity reduction at Liwonde and Mangochi plants (98.66 ± 0.06 and 97.48 ± 0.05% at a dose of 0.4 and 0.6 mg L⁻¹ respectively), while Chikwawa provided the lowest (9.52 ± 0.01%). At the Zomba and Mulanje plants 20.5 ± 0.03% and 28.4 ± 0.04% reductions were obtained respectively. The inorganic flocculant, alum provided a 99.0 ± 0.05% and 98.6 ± 0.04% reduction at a dose of 4.0 mg L⁻¹ and 6.0 mg L⁻¹ at Zomba and Liwonde plants respectively. The lowest reductions in turbidity were achieved at Chikwawa (7.50 ± 0.01%), Mangochi (12.97 ± 0.02%) and Mulanje (25.00 ± 0.02). The best and optimum pH ranges for polymeric and inorganic coagulants were 7.20–7.80 and 7.35 to 7.57 respectively. The results further revealed that sudfloc 3850 and algaefloc 19s achieved faster formation of heavy flocs than alum. At 0.4 mg L⁻¹ flocculant dosage sudfloc 3850 and algaefloc 19s required ten times lower dosages than alum. Therefore, the polymeric coagulants could be used instead of alum, the choice dependant on the type of water.  相似文献   

硫酸钾镁肥浮选尾矿热浸-冷结晶法提取七水硫酸镁工艺研究   总被引：3，自引：3，他引：0       下载免费PDF全文

李海民  雷光远  陈育刚  何勇峰 《盐湖研究》2012,20(2):44-51

以国投新疆罗布泊钾盐有限责任公司(简称国投罗钾)提供的硫酸钾镁肥浮选尾矿和氯化镁饱和卤水为原料,探索出了一条以硫酸钾镁肥浮选尾矿为原料,以氯化镁饱和溶液为浸取介质,通过中温溶浸、冷却结晶(包括盐田冷析)等工艺方法制取七水硫酸镁的工艺路线,给出了各工序的工艺技术条件及主要技术指标。  相似文献   

重大地质转折期的碳、硫循环与环境演变   总被引：4，自引：1，他引：3       下载免费PDF全文

汪建国  陈代钊  严德天 《地学前缘》2009,16(6):33

碳、硫在表层储库和地质储库以不同的形式相互转换,在这个过程中都伴随着一定的同位素分馏。碳同位素的分馏主要受到光合作用以及海水溶解无机碳与大气CO2交换的控制,而硫同位素的分馏则主要受控于硫酸盐细菌还原作用。表层储库碳、硫同位素的组成通过地质作用被很好地保存在地质储库中,因此通过对地质储库中碳、硫同位素的分析和研究,可以很好地了解地球各圈层相互作用的规律,重塑地质历史特别是重大关键转折时期的演化过程。同时文中借助一些碳、硫同位素应用实例,进一步加深理解影响碳、硫同位素组成和变化的原因,以提高对不同时期全球环境变化的认知程度。  相似文献   

超分散剂的合成及其在微细CaSO4粉体改性中的应用表征     

王少会  李宏武  潘静懿  卢尚琨  张蓓蓓  周正发  徐卫兵 《矿物学报》2009,29(1)

以硅烷为锚固基团(A段),丙烯酸丁酯为溶剂化链(B段),合成了超分散剂YB系列,研究了它对微细CaSO4粉体在液体石蜡中的沉降体积和粘度的影响。结果表明:YB系列超分散剂对CaSO4粉体有很好的分散和降粘作用,当锚固基团与溶剂化链摩尔比为1:10时,超分散剂用量为粉体质量的1%的情况下分散和降粘效果最佳,YB-2超分散剂的改性效果要优于F-2钛酸酯偶联剂和硬脂酸。同时通过对改性前后粉体做了扫描电镜(SEM)和红外光谱(FT-IR)检测,对比显示改性后的CaSO4粉体表面连接了有机基团。  相似文献   

川东北元坝地区储层溶洞石英及白云石胶结物中包裹体特征及意义     

席斌斌  余晓露  王杰  蒋宏  张隽 《地质学报》2017,91(9):2091-2104

川东北元坝气田是中国南方大型油气田之一,通过对元坝224井上二叠统储层溶洞石英及白云石中包裹体的岩相学、激光拉曼以及显微测温分析发现,溶洞石英中包裹体类型复杂,主要由气液两相包裹体、气体包裹体以及含子矿物包裹体组成,包裹体的气相组分主要由CH4、H2S以及CO2组成,包裹体的子矿物为单质硫以及沥青,包裹体共生组合关系复杂,不同类型包裹体常叠加在一起,气液两相包裹体均一温度以及含单质硫三相包裹体的气液均一温度范围相似,分别为161.5~220.6℃以及168.2~218.6℃,二者的盐度分布范围差别较大,分别为7.45%~10.36%NaCl以及8.68%~21.11%NaCl;溶洞白云石中包裹体类型单一,由气液两相包裹体组成,个别包裹体的气相中含有CH4,包裹体的均一温度为102.4~132.1℃。包裹体的古温度古压力分析表明,溶洞石英中包裹体捕获于中—晚侏罗世,包裹体捕获时地层流体为超压,捕获于原油大量裂解生成天然气阶段。溶洞石英中不同类型包裹体的组合关系以及温压特征记录了储层中TSR反应的过程,即硫酸盐先与重烃反应生成H2S以及单质硫,然后硫酸盐以及生成的单质S再与CH4继续反应生成H2S以及CO2,随着TSR反应的进行,储层中的压力逐渐增大。TSR反应生成的H2S以及CO2流体可能与储层发生了较强烈的水-岩反应,造成了储层的硅化以及溶洞中石英、白云石的沉淀。  相似文献