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本文研究桂中坳陷西北部中泥盆统页岩氧化还原条件和古沉积环境。利用该区典型页岩气调查井(桂页1井)岩心,通过X射线荧光光谱分析(XRF)和电感耦合等离子体质谱分析(ICPMS),对中泥盆统岩心(320.35m~938.5m)以1.5m采样间隔进行了微量元素测试。结果显示,纳标组地层V/(V+Ni)、V/Cr和Ni/Co平均值分别大于0.67、4.65和7.71,且富集竹节石、菊石等生物组合,指示其沉积时期海平面相对上升,处于有利于有机质保存的深水陆棚环境;罗富组和塘丁组V/(V+Ni)、V/Cr和Ni/Co分别为0.38~0.65、0.73~4.10和3.70~6.72,指示沉积阶段海平面相对下降,水体变浅,沉积环境为弱氧化的浅水陆棚环境;同时,有机碳含量(TOC)的变化与Ba元素的富集程度相关性较高,表明缺氧环境有利于机质的富集和保存;此外,通过微量元素指标判别,认为桂中坳陷西北部中泥盆统沉积时期,自下而上经历了海平面的相对上升到相对下降的沉积旋回,纳标组时期相对海平面上升至最高,沉积了厚度稳定且有机质含量高的富有机质页岩,可作为本区有利的勘探目标层段。 相似文献
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矿物-微生物交互作用广泛参与地球表层系统物质循环与能量流动过程,深刻地影响着一系列重要的地表生物地球化学进程。近年来地表半导体矿物的相关研究,为矿物-微生物交互作用提供了崭新研究方向,揭示地表“日光-半导体矿物-微生物”系统电子传递过程及其环境效应,是地质微生物学交叉领域研究的核心科学问题之一。本研究从地表不同生境“矿物膜”出发,以光电化学技术证实喀斯特、红壤、岩石漆“矿物膜”在1 000 min长时间循环实验中平均光电流值约为5.4、3.4、3.2 μA/cm2,证实“矿物膜”良好日光响应特性且铁锰氧化物矿物在其中发挥核心作用。基于笔者前期研究所发现的“矿物膜”电活性菌富集且与半导体矿物分布呈正相关性这一现象,本文进一步构建模拟光电子红壤细菌群落系统,20天后细菌群落α多样性显著提升,研究证实细菌群落具有模拟光电子响应活性,且电极与溶液群落均具有演化方向性;16S rRNA测序分析表明模拟光电子作用下Shewanella、Pseudomonas、Streptococcus、Lactobacillus、Acinetobacter等电活性菌显著富集。综上,本文研究结果间接证实地表半导体矿物光电子可有效调控微生物群落结构并促进电活性菌在“矿物膜”中富集。 相似文献
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土著微生物作用下含水层沉积物砷的释放与转化 总被引：4，自引：0，他引：4
在原位采集内蒙古河套平原高砷含水层中沉积物和土著微生物的基础上,进行了室内微生物淋滤实验研究。实验过程中,使用了3种水溶液(包括去离子水和2种人工配水)和2种营养条件(包括添加2%葡萄糖和未添加葡萄糖)。结果表明,葡萄糖可强化土著微生物的活性,使得悬浮液pH值明显降低,并增加悬浮液中As质量浓度。配水成分影响悬浮物中As质量浓度。在第9 d之后,添加葡萄糖的样品中存在一定强度的硫酸根还原作用,且这种脱硫酸作用受配水成分的影响较小。研究表明,土著微生物影响下砷的释放和转化过程包括沉积物中As(V)的释放、溶液中As(V)的还原以及沉积物中As(Ⅲ)的释放等。与溶液As(V)相比,As(Ⅲ)更有利于沉积物As的释放。在As释放的过程中,溶液中Fe/Mn含量同时增加,且呈很好的线性相关关系。这意味着土著微生物作用下Fe/Mn氧化物矿物的还原性溶解是导致沉积物As释放的主要原因之一。 相似文献
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结合甘肃省民勤红沙岗矿区疏干水利用实例,基于Visal Modflow4.1软件对矿区第四系疏干水可利用量进行了数值模拟计算,并对矿区第四系松散岩类孔隙水的补给及储量进行了研究。研究结果表明:矿区第四系松散岩类孔隙水天然补给源为沟谷雨洪水入渗量和基岩裂隙水的侧向流入量之和98.41×10~4m~3/a(2 696.16 m~3/d),其储存量为2 798.45×10~4 m~3;设计矿区疏干水开采时间为30年、40年及50年时,与其对应第四系可利用疏干水量分别为281.98×10~4m~3/a(7 725.48 m~3/d)、225.32×10~4m~3/a(6 173.15 m~3/d)和183.55×10~4m~3/a(5 028.77 m~3/d),矿区疏干水不能满足计划用水量600.00×10~4 m~3/a,需寻找新的供水水源;计算结果较真实地反映了矿区疏干水储量,具有较好的实用性;所建模型为其它类似矿区疏干水可利用量的计算提供了借鉴。 相似文献
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羌塘盆地孔孔茶卡地区石炭系擦蒙组烃源岩沉积环境分析 总被引：2，自引：0，他引：2
对羌塘盆地孔孔茶卡地区石炭系擦蒙组(C2c)烃源岩形成的沉积环境进行探讨和研究。擦蒙组的岩石学、沉积相、元素地球化学的综合分析结果表明：该套烃源岩地层发育的沉积相为三角洲相;水解性元素和Fe族元素含量较高,表明其水体环境为滨岸-浅海,且古水深较浅;古气候指数C(C= ∑(Fe+Mn+Cr+Ni+V+Co)/∑(Ca+Mg+Sr+Ba+K+Na))的计算结果均大于0.8,指示出湿润的气候环境;Sr/Ba比值全部小于1,介于0.13~0.23之间,表明为盐度较低的陆相淡水沉积水体;根据V/Cr与V/Sc、V/(V＋Ni)、Th/U、Ni/Co和Fe2+/Fe3+比值的变化,综合判断为富氧水体环境。上述这些条件均有利于繁殖大量的陆地生物和水生生物,这些有机物质通过水体的搬运沉积、富集形成了研究区石炭系一套较好的烃源岩。 相似文献
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海洋沉积物中氧化还原敏感元素对水体环境缺氧状况的指示作用 总被引：2，自引：0，他引：2
近年来由于人为污染水体富营养化加剧,缺氧区面积不断增大,利用沉积物中氧化还原敏感元素反演水体缺氧情况已经发展成为海洋化学领域的热点研究方向。本文详细阐述了氧化还原敏感元素的富集机制,并总结了利用沉积物中氧化还原敏感元素在不同氧化还原条件下的富集程度反映海水缺氧程度和底质氧化还原状况的一系列指标,如Re/Mo、Cd/U、Th/U、V/Sc、V/(V+Ni)值,U—Mo共变模型,δ~(98/95)Mo,多指标微/痕量元素模型以及氧化还原敏感元素-有机质共变模型等。沉积物中Re、Mo含量、Re/Mo值、自生Mo/U值、Th/U值对上层水体缺氧和氧化条件区分良好,可定量指征上层水体的缺氧情况。沉积物中Re含量近似于1 ng/g(地壳值),Mo含量1μg/g(地壳值),Re/Mo值接近0.3×10~(-3),Mo—U富集系数比为(0.1～0.3)×现代海水,Th/U值2,可指示氧化环境;Re含量在10～30 ng/g,Mo含量近似于1μg/g,Re/Mo值10×10~(-3)～30×10~(-3),Mo—U富集系数比1×现代海水,Th/U值在0～2范围内,可指示缺氧环境;Re含量30 ng/g,Mo富集达到20～40μg/g,Re/Mo值接近0.7×10~(-3)(海水中Re/Mo值),Mo—U富集系数比为(3～10)×现代海水,可指示极度缺氧的硫化环境。Mo_(EF)—U_(EF)交会对数坐标图、氧化还原敏感元素-有机质共变模型指标可定性分析上层水体的缺氧情况;V/(V+Ni)值对于次氧化沉积物指示效果不佳;Cd/U值在次缺氧条件下的变化机制复杂,还需进一步研究。生物扰动、成岩作用、人为污染、水体局限、高有机碳通量、Fe、Mn氧化物循环等因素通过影响氧化还原敏感元素在沉积物中的富集与迁移,从而影响氧化还原敏感元素指标的应用,应剔除有机质吸附与陆源输入等非自生部分的影响,结合各种指标互相印证,综合判别水体氧化还原状态。 相似文献
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本文在对普通培养条件下异养微生物粪产碱杆菌(Alcaligenes faecalis,A.faecalis)反硝化特征研究的基础上,运用电化学方法于一定电势下(-0.15 V、-0.06 V、+0.06 V vs.NHE)模拟半导体矿物导带光电子能量,探讨不同能量的光电子对A.faecalis反硝化特性及细胞生长代谢的影响。实验显示,在普通培养条件下,A.faecalis在有氧和无氧环境中均不能还原NO-3,但还原NO-2效果明显。在模拟光电子实验体系中,A.faecalis可在不同电势(-0.15 V、-0.06 V、+0.06 V)的阴极石墨电极表面附着并形成具有反硝化活性的菌膜;其中,外加电势为-0.15V的实验组菌膜量最多,其NO-3去除率也最高,10天达到52%;-0.06 V体系略低,NO-3去除率为30.5%,+0.06 V体系菌膜量最少,其NO-3去除效果也最差,仅为10.6%。而在不添加微生物的电化学体系中,3个外加电势下的NO-3浓度均未发生明显变化。本实验研究结果证明了一定能量的半导体矿物光电子可影响土壤异养微生物A.faecalis的生长代谢及反硝化行为。 相似文献
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不同碳源对缺氧生物滤池生物脱氮的试验研究 总被引：3，自引：0，他引：3
针对生活污水的特点,采用曝气生物滤池技术对不同碳源（甲醇、乙酸钠和葡萄糖）条件下的生物脱氮效果进行了试验研究。结果表明,在C/N为3∶1～4∶1、滤速为1.0 m/h时,不同碳源对缺氧生物滤池的生物脱氮效果影响很大,其中以甲醇和乙酸钠作为外碳源时,脱氮效果较好,而以葡萄糖为碳源时的脱氮效果明显逊于二者。 相似文献
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Recent studies have indicated that in situ aerobic bioremediation is one of the most effective methods for remediating groundwater contaminated with nitrobenzene (NB). Aerobic bioremediation is largely dependent on the maintenance of adequate dissolved oxygen (DO) levels in the groundwater. Traditional in situ aeration has various disadvantages, such as high operational costs and nonuniform aeration. In this study, integrative cubes were prepared and utilized as a novel biological permeable reactive barrier (bio-PRB) medium to enhance the aerobic bioremediation of NB-contaminated groundwater. The results revealed an NB removal rate greater than 98.68% after 15–20 days of continuous oxygen release from the bio-PRB medium. DO concentrations reached 8.0 mg/L during treatment, and NB-degrading bacteria were able to tolerate a range of pH conditions. This multifaceted bio-PRB medium can simultaneously adsorb and biodegrade NB, release oxygen, and neutralize the pH with phosphate buffer. The results of this study suggest that this bio-PRB medium represents a highly effective in situ bioremediation method for NB-contaminated groundwater. 相似文献
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Isolation and application of a wild strain photosynthetic bacterium to environmental waste management 总被引：1，自引：0，他引：1
E. I. Madukasi M.Sc. Ph.D. H. Chunhua B.Sc. G. Zhang Ph.D. 《International Journal of Environmental Science and Technology》2011,8(3):513-522
A new photosynthetic bacterium isolate was morphologically identified as a non-motile rod-shape gram-negative bacterium. It produced a dark red culture under phototrophic condition, reproduced by budding and formed a lamellar intracytoplasmic membrane system parallel to cytoplasmic membrane, which contained bacteriochlorophyll a and caratenoids. It’s physiological and nutrient requirement tests gave indication that the isolate thrived and multiplied in varied environmental conditions. It was consequently named Z08 and identified as Rhodobacter sphaeroides by 16SrDNA. Adaptation of Z08 to biodegradation of two environmentally concerned wastewaters, i.e. soybean and pharmaceutical wastewaters, attested its potential in wastewater bioremediation. Z08 adaptation in a suspended batch photobioreactor treating pharmaceutical wastewater at 3500lx radiation recorded best result after wastewater dilution of 1:4 with concomitant chemical oxygen demand reduction, biomass yield and specific growth of 50 %, 780 mg/L and 0.015/h, respectively at the lowest hydraulic retention time of three days. Furthermore, gas chromatography mass spectra analyses of treated and raw pharmaceutical wastewater indicated that high molecular weight recalcitrant compounds found in the pharmaceutical wastewater were transformed to less toxic and acceptable lower molecular weight substances through biodegradation. Whilst Z08 treatment of soybean wastewater under natural light intensity radiation recorded 80 % reduction, 1540 mg/L and 0.025/h for chemical oxygen demand, biomass and specific growth rate respectively regardless of the food to microorganism ratio. This preliminary investigation showed that isolate Z08 has some toxic tolerance level which could detoxify refractory substances with great potential for cell protein recovery in high organic strength wastewater. Therefore, strain Z08 could be employed in biodegradation of contaminated wastewater streams. 相似文献
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Y.-S. Oon S.-A. Ong L.-N. Ho Y.-S. Wong Y.-L. Oon H. K. Lehl W.-E. Thung 《International Journal of Environmental Science and Technology》2017,14(11):2435-2442
A double-chambered biocathode microbial fuel cell with carbon felt employed as electrodes was developed for wastewater treatment and bioelectricity generation simultaneously. The system was operated in fed-batch mode for over eight batches. The effect of circuit connections on organic and nitrate reduction was investigated. The maximum power density recorded was 21.97 mW/m2 at current density of 88.57 mA/m2. The Coulombic efficiency and internal resistance of the system were 5% and 100 Ω. Up to 89.9 ± 5.9% of chemical oxygen demand reduction efficiency achieved with an influent of 1123 ± 28 mg/L. There was no significant difference in the chemical oxygen demand reduction when system operated in either open or closed circuit. This study clearly showed that higher nitrate reduction efficiency obtained in closed circuit (74.7 ± 7.0%) due to bio-electrochemical denitrification compared to only 41.7% in the open circuit. The result also successfully demonstrated nitrate as terminal electron acceptor for the cathodic nitrate reduction. 相似文献
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A. Al-Mamun O. Lefebvre M. S. Baawain H. Y. Ng 《International Journal of Environmental Science and Technology》2016,13(4):1055-1064
A denitrifying biocathode in a microbial fuel cell was developed to investigate the replacement of the costly Pt-coated abiotic cathodes for electricity generation. The denitrifying biocathode was sandwiched between the dual-anode systems. The study investigated the performance for simultaneous treatment of wastewater on the anode, biological denitrification on the cathode and the potential recovery of electrical energy. Autotrophic biofilms performed denitrification on the cathode using supplied electrons by the biodegradation of organics on the anode. Graphite granules were used as electrodes for biofilm attachment, and nafion membranes were used as separators between electrodes. The system achieved a volumetric power of 7 ± 0.4 W m?3 net cathodic compartment (NCC) with the simultaneous removal of 229.5 ± 18 mg L?1 COD on anode and 88.9 g m?3 NCC day?1 nitrogen on cathode, respectively. The columbic efficiency for cathodic and anodic reactions was 98.9 ± 0.57 and 23.54 ± 0.87 %, respectively. This is a combined study for domestic wastewater treatment and biological denitrification in a compact MFC reactor. Further optimization of the system is desired to improve its performance and applicability. 相似文献
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松辽盆地十屋断陷区油气分布复杂,勘探程度高,油田外排污水规模巨大,常规技术处理污水效果不理想。区内4 km以下部分地层呈负压态,若容储介质参数达到相应地质填埋标准,则可在工程实践中尝试应用。结合该区水文及地质资料,建立地下水流及污水污染物迁移数值模拟模型,模拟研究区低压系统入注污水时地下水流动特征及污染物的迁移规律,同时估算了系统空间污水容储量。在预测过程中,分析了断陷区负压形成机制及分布特点,同时结合虚拟粒子示踪及注水过程,对污水的环境影响度进行了预测。研究结果表明,十屋断陷异常低压区是一个天然污水封闭储藏区,系统地层压力梯度仅为0.005~0.008 MPa/m,容储量高达1.241×108 m3,且污染物逃逸概率极小,非常适合油田污水的处置。 相似文献
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重金属铅污染是一种主要的环境污染类型,对生态以及人类健康存在着极大的威胁。如何修复铅污染是目前亟待解决的关键性问题。在众多的铅污染修复方法中,微生物修复法具有独特的优势。本实验中所使用的钋青霉菌是已被验证的对铅具有高耐受度和高吸附率的优秀菌种。在此基础上,本实验的主要研究目的在于进一步提高该菌种对铅的吸附、固定能力。实验采用双室电解池体系,分组设置0.5 V至1.5 V的梯度槽压,以观察不同电压下电流对钋青霉菌生长环境及对铅离子吸附作用的影响。实验结果表明,电流既可能促进也可能抑制钋青霉菌对铅离子的吸附和固定作用,其作用结果与外加电压的大小有关,在1.0~1.25 V的最适电压区间下,电流能增强钋青霉菌对铅离子的吸附和固定能力。 相似文献
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Treatment of poultry slaughterhouse wastewater in upflow anaerobic filter under low upflow velocity 总被引：2，自引：2，他引：0
R. Rajakumar M.E. Ph.D. DIS. T. Meenambal M.E. Ph.D. J. Rajesh Banu M.Sc. Ph.D. I. T. Yeom 《International Journal of Environmental Science and Technology》2011,8(1):149-158
The wastewater discharged by poultry slaughterhouse industries are characterized mainly by high biochemical oxygen demand, high suspended solids and complex mixture of fats, proteins and fibers requiring systematic treatment prior to disposal. In this study, the performance of an upflow anaerobic filter reactor for treating Indian poultry slaughterhouse wastewater under low upflow velocity of 1.38 m/day at mesophilic temperature (29-35 °C) was investigated. The reactor was inoculated with anaerobic non-granular sludge from an anaerobic reactor treating the poultry slaughterhouse wastewater. The reactor took 147 days for complete start-up with removal efficiencies of total chemical oxygen demand and soluble chemical oxygen demand of 70 and 79 % respectively. The maximum total chemical oxygen demand removal efficiency of 78 % was achieved at an organic loading rate of 10.05 kg/m3/day and at an hydraulic retention time of 12 h. The average methane content varied between 46 and 56 % and methane yield at maximum removal efficiency was 0.24 m3 CH4/kg CODremoved·day. Sludge granules of 1–2 mm were observed in between the packing media. Scanning electron microscope analysis revealed that sludge granules are composed of clumps of Methanosarcina clustered with less intertwined Methanosaeta fibre of granules. The lower velocity used in this study has achieved better performance of the reactor by creating active microbial formation with stable pH upto an organic loading rate of 14.3 kg/m3/day. This has proved that the poultry slaughterhouse wastewater can be treated using anaerobic filter reactor under low upflow velocity. 相似文献
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A. Kaushik S. K. Jadhav 《International Journal of Environmental Science and Technology》2017,14(8):1771-1780
The present study deals with the capability of pulp industry wastewater to produce bioelectricity with isolation and screening of native electrogenic bacteria from wastewater. In the screening process, three bacterial isolates were obtained; they were studied on the basis of morphology and biochemical characteristics. The maximum bioelectricity producing bacteria was identified by sequencing method and was identified as Pseudomonas fluorescens, and it is a novel bacteria reported in bioelectricity production from pulp industry wastewater. Further, the work focuses on optimization of various parameters, i.e., inoculum size, pH, temperature, mediators and its concentration. It was observed that with pulp industry wastewater, inoculum size of 1.5% gave the maximum voltage and current of 1.244 ± 0.003d V and 5.946 ± 0.005d mA, respectively. A pH of 7.0 gave maximum voltage and current of 0.956 ± 0.009e V and 2.692 ± 0.016e mA. At 35 °C temperature, maximum production of voltage and current of 1.045 ± 0.003d V and 2.167 ± 0.037d mA were recorded. Among the various mediators, humic acid was found to be most effective as it produced a voltage of 1.054 ± 0.004f V and current of 1.070 ± 0.004d mA. Maximum voltage of 1.291 ± 0.021f V and current of 1.896 ± 0.006f mA were recorded with 200 μM of humic acid. Physicochemical analysis of the effluent was conducted before and after experimental run, and the values suggested that the microbial fuel cell technology is an efficient method for biological treatment of wastewater. 相似文献
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Microbial community changes in contaminated soils in response to phenanthrene amendment 总被引：4，自引：1，他引：3
S. Y. Zhang Q. F. Wang S. G. Xie Ph.D. 《International Journal of Environmental Science and Technology》2011,8(2):321-330
Leachate and reclaimed wastewater have become the important sources of polycyclic aromatic hydrocarbons in soils. However, the information on bioremediation of leachate and reclaimed wastewater-contaminated soils is still lacking. Identification of changes in microbial structure or of enriched genera related to biodegradation could aid identification of particular organisms or consortia capable of degrading polycyclic aromatic hydrocarbons in these contaminated soils. In this study, terminal restriction fragment length polymorphism, coupled with 16S Ribosomal ribonucleic acid clone library analysis, was applied to investigate the composition of bacterial community in leachate-contaminated soil or grassland soil irrigated reclaimed wastewater and the response to phenanthrene amendment. Results showed that phenanthrene amendment had significant but different impacts on microbial community structure, dependent on soil source. Several greatly enriched terminal restriction fragments with phenanthrene biodegradation were identified. Moreover, genus rhizobacteria, possibly linked to phenanthrene biodegradation, was firstly reported in this study. This work might provide some new insights into bioremediation of polycyclic aromatic hydrocarbons-contaminated soils. 相似文献