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28641. 题目: Seasonal variations of biogeochemical matter export along the Langtang-Narayani river system in central Himalaya
文章编号: N18070712
期刊: Geochimica et Cosmochimica Acta
作者: Maya P Bhatt, Jens Hartmann, Miguel F Acevedo
更新时间: 2018-07-07
摘要: Weathering and suspended matter fluxes of the Langtang Narayani river system in central Nepal Himalaya have been investigated at 16 stations for one year, based on monthly water sampling in the lower reaches and bi-monthly in higher elevation areas, to determine temporal variations of weathering fluxes along an elevation profile between 169 and 3,989 m asl. Results indicate that the lower reaches are the dominant places of weathering in the system. The sum of major base cation fluxes is 2.9 to 9.2 higher during the monsoon season compared to the pre-monsoon season. Alkalinity and sea-salt corrected sulfate were the dominant anions (97%). The lowest downstream location exports 1,611 tons km-2 yr-1 suspended sediment, 78.56 tons km-2 yr-1 of major cations (Na+K+Mg+Ca), 12.72 tons km-2 yr-1 of silica (4-fold higher than at the middle reaches of the basin), and 1.9×106 mol km-2 yr-1 of dissolved inorganic carbon (8.9-fold higher than at the middle reaches). Nitrogen and phosphorus concentrations are low in general and dissolved organic carbon export is within expected ranges. River water pCO2 values are low in general, with exception of those main stem reaches where tributaries with relevant pyrite oxidation processes, and lower pH, alter the pattern locally. Element ratios suggest seasonal shifts in the weathering flux generation, modulated by the monsoon system. During the monsoon season the most relevant weathering products alkalinity, SO4, Ca and Mg were not diluted, and increased concentrations observed at the lower reaches suggests an enhanced mobilization during this period of the year. Carbonate weathering exceeds silicate weathering along the drainage network and the carbonate- to silicate-cation mol ratio is 3.5 at the outlet. Sulfide oxidation probably enhances weathering rates besides the control of the soil-rock partial pressure of CO2. The ratio of the total alkalinity flux to sea-salt corrected sulfate equivalent flux at the base of the Himalaya at Narayanghat was 5.7. Sea-salt corrected sulfate equivalent export is about the same as the silicate cation-equivalent flux that leaves the system (98%). Therefore, further research on sulfur isotopes might be helpful to support the hypothesis that pyrite oxidation compensates for the idealized CO2-consumption by silicate weathering in the studied area.

28642. 题目: The plant-enhanced bio-cathode: Root exudates and microbial community for nitrogen removal
文章编号: N18070711
期刊: Journal of Environmental Sciences
作者: Henan Li, Youpeng Qu, Yan Tian, Yujie Feng
更新时间: 2018-07-07
摘要: A plant bio-electrochemical system (PBES) was constructed for organic pollutant removal and power generation. The bio-cathode, composed of granular activated carbon (GAC), stainless wire mesh and a plant species (Triticum aestivum L.), was able to catalyze cathodic reactions without any requirement for aeration or power input. During the 60-day-long operation, an average voltage of 516 mV (1000 Ω) and maximum power density (Pmax) of 0.83 W/m3 were obtained in the PBES. The total nitrogen removal and total organic carbon removal in the PBES were 85% and 97%, respectively. Microbial community analyses indicated that bacteria associated with power generation and organic removal were the predominant species in the bio-cathode, and plant-growth-promoting rhizobacteria were also found in the PBES. The results suggested that the coupling of plants with the GAC cathode may enhance the organic-matter degradation and energy generation from wastewater and therefore provide a new method for bio-cathode design and promote energy efficiency.

28643. 题目: Enhanced sulfate and metal removal by reduced graphene oxide self-assembled Enterococcus avium sulfate-reducing bacteria particles
文章编号: N18070710
期刊: Bioresource Technology
作者: Jia Yan, Weizhuo Ye, Zhuoyi Jian, Jiehui Xie, Kengqiang Zhong, Siji Wang, Haoshen Hu, Zixuan Chen, Huijun Wen, Hongguo Zhang
更新时间: 2018-07-07
摘要: Graphene oxide (GO) was introduced to Enterococcus avium strain BY7 sulfate-reducing bacteria culture as a carrier, GO was partially reduced by SRB to reduced graphene oxide (rGO). The rGO could further self-assemble Enterococcus avium strain BY7 sulfate-reducing bacteria to form BY-rGO particles. Growth and sulfate reduction activity of strain BY7 was promoted by rGO, which probably due to the protective effect of rGO, and enhanced electron transfer by rGO as electron shuttle. Effects of pH and temperature variance on strain BY-rGO were remarkably weakened, growth and sulfate reduction were observed from pH 2.0 to 12.0, and from 10 to 45 °C, respectively. Metal toxicity to BY7 strain SRB was sharply decreased in BY-rGO particles and heavy metal removal was remarkably accelerated (up to 50%). The immobilization methods established in this study might open a new way for the application of SRBs, especially under extreme environmental conditions.

28644. 题目: Influence of carrier media physical properties on start-up of moving attached growth systems
文章编号: N18070709
期刊: Bioresource Technology
作者: Joana Dias, Mel Bellingham, Junaid Hassan, Mark Barrett, Tom Stephenson, Ana Soares
更新时间: 2018-07-07
摘要: Five carrier media with different shapes (spherical and cylindrical), sizes, voidage and protected surface areas (112–610 m2/m3) were studied in a pilot scale moving bed biofilm reactor (MBBR). This study aimed at assessing start-up duration using biofilm formation rates. Results indicated that the spherical media required shorter periods to achieve stable biofilm formation rates associated with chemical oxygen demand (COD) (15–17 days), compared to cylindrical high surface area media (23–24 days). Protected surface area presented weaker correlations with the biofilm formation rate for COD (R2 = 0.83) and ammonia removal (R2 = 0.76). However, good correlations were observed with a combination of the media physical factors: dimensionality (Di), voidage (Voi), and hydraulic efficiency (HE) strongly correlated with biofilm formation rates for heterotrophic (R2 = 0.95) and nitrifying bacteria (R2 = 0.92). This study proposes that the media physical properties can contribute to shortening start-up, contributing to improved removal rates and fast commissioning of MBBRs.

28645. 题目: High-silica zeolites for adsorption of organic micro-pollutants in water treatment: A review
文章编号: N18070708
期刊: Water Research
作者: Nan Jiang, Ran Shang, Sebastiaan G.J. Heijman, Luuk C. Rietveld
更新时间: 2018-07-07
摘要: High-silica zeolites have been found to be effective adsorbents for the removal of organic micro-pollutants (OMPs) from impaired water, including various pharmaceuticals, personal care products, industrial chemicals, etc. In this review, the properties and fundamentals of high-silica zeolites are summarised. Recent research on mechanisms and efficiencies of OMP adsorption by high-silica zeolites are reviewed to assess the potential opportunities and challenges for the application of high-silica zeolites for OMP adsorption in water treatment. It is concluded that the adsorption capacities are well-related to surface hydrophobicity/hydrophilicity and structural features, e.g. micropore volume and pore size of high-silica zeolites, as well as the properties of OMPs. By using high-silica zeolites, the undesired competitive adsorption of background organic matter (BOM) in natural water could potentially be prevented. In addition, oxidative regeneration could be applied on-site to restore the adsorption capacity of zeolites for OMPs and prevent the toxic residues from re-entering the environment.

28646. 题目: Intercropping wheat and maize increases the uptake of phthalic acid esters by plant roots from soils
文章编号: N18070707
期刊: Journal of Hazardous Materials
作者: Wenbing Tan, Hanxia Yu, Caihong Huang, Dan Li, Hui Zhang, Xinyu Zhao, Renfei Li, Guoan Wang, Yuan Zhang, Xiaosong He, Beidou Xi
更新时间: 2018-07-07
摘要: Whether crop intercropping can affect the uptake of phthalic acid esters (PAEs) by plant roots from soils is unclear. In this study, we compare the PAE uptake by plant roots between the wheat/maize intercropping and the wheat and maize monocropping in a field work. We show that the PAE bioconcentration factors of wheat and maize roots are remarkably higher under wheat/maize intercropping than under monocropping, indicating that intercropping may significantly increase the biouptake of PAEs as compared to monocropping. The wheat/maize intercropping can increase the electron transfer capacity (ETC) of water-extractable organic matter (WEOM) in soils by increasing the abundance of redox-active functional groups in WEOM. The ETC-enhanced WEOM may be an important reason for facilitating the reduction of ferric iron [Fe(III)] minerals to soluble ferrous iron [Fe(II)] by acting as electron shuttle, thus leading to the release of the PAEs originally occluded in Fe(III) minerals into soil pore water. The increased bioavailable PAEs distributed in the soil pore water under wheat/maize intercropping eventually result in the increase in the uptake of PAEs by plant roots from soils. The results can provide insights into the link between the uptake of PAEs by crops and the cropping practices in agricultural ecosystems.

28647. 题目: Fouling resistant 2D boron nitride nanosheet – PES nanofiltration membranes
文章编号: N18070706
期刊: Journal of Membrane Science
作者: Ze-Xian Low, Jing Ji, David Blumenstock, Yong-Min Chew, Daniel Wolverson, Davide Mattia
更新时间: 2018-07-07
摘要: A novel fouling-resistant nanofiltration mixed-matrix membrane was obtained by the incorporation of 2D boron nitride nanosheets (BNNS) in polyethersulfone (PES). The addition of just 0.05 wt% of BNNS into the PES matrix led to a 4-fold increase in pure water permeance with a 10% decrease in the rejection of the dye Rose Bengal; up to 95% rejection of humic acid and nearly 100% flux recovery over two cycles in cross-flow fouling tests without the need for chemical cleansing. This performance is attributed to the uniform distribution of the BNNS in the PES matrix, observed via Raman mapping, and the surface chemistry and structure of the BNNS, which hydrophilised the polymer matrix and reduced its surface roughness. The low amount of BNNS filler needed to render the mixed-matrix membrane fouling-resistant opens the way to its use in waste-water treatment applications where organic fouling remains a major challenge.

28648. 题目: Biomarker signatures of Upper Cretaceous Latrobe Group hydrocarbon source rocks, Gippsland Basin, Australia: Distribution and palaeoenvironment significance of aliphatic hydrocarbons
文章编号: N18070705
期刊: International Journal of Coal Geology
作者: Lian Jiang, Simon C. George
更新时间: 2018-07-07
摘要: Upper Cretaceous (Maastrichtian and Campanian) hydrocarbon source rocks from the Latrobe Group, Gippsland Basin (Australia) have been analysed using gas chromatography–mass spectrometry (GC–MS) in order to understand their geochemical characteristics and to reconstruct palaeovegetation and palaeoclimate changes. n-Alkanes ranging from C10 to C37 dominate the aliphatic hydrocarbons in the rock extracts. Both the carbon preference index and the odd-to-even predominance values of n-alkanes are higher than 1.0, suggesting an input from terrigenous higher plants. Low wax indices (mostly < 1.0) and a predominance of C29 over C27 steranes corroborate a major contribution from higher plants. High pristane/phytane (Pr/Ph) ratios (>3.0), a low gammacerane index (<0.3) and the Pr/n-C17 versus Ph/n-C18 cross-plot indicate that the Upper Cretaceous hydrocarbon source rocks were probably deposited in an oxidising environment with fresh water. Thermal maturity parameters such as sterane isomerisation ratios, C31 22S/(22S + 22R) homohopane, C30 αβ/(αβ + βα) hopane and 16(H) β/(α + β) phyllocladane, together with Tmax data and the presence of C27 17β(H)-22,29,30-trisnorhopane (βTm), suggest that most of samples have a relatively low maturity in the early to mid-oil generation window. Angiosperm- and gymnosperm-derived biomarkers, including labdane, pimarane, isopimarane, phyllocladane, abietane, rimuane, ent-beyerane, ent-kaurane, oleanane, 10β(H)-des-A-oleanane, 10β(H)-des-A-lupane, 10β(H)-des-A-ursane, suggest that palaeovegetation during the Upper Cretaceous was characterised by both gymnosperms (e.g. Araucariaceae and Podocarpaceae) and angiosperms (e.g. Nothofagus), but was dominated by gymnosperms. Compared with samples from the Campanian, there was a relatively lesser contribution from angiosperms during the Maastrichtian. This shows that the palaeoclimate was becoming cooler from the Campanian to the Maastrichtian, which is consistent with previous palynology evidence and sea-surface temperature estimates.

28649. 题目: Laser diffraction analysis of aggregate stability and disintegration in forest and grassland soils of northern Minnesota, USA
文章编号: N18070704
期刊: Geoderma
作者: Chase S. Kasmerchak, Joseph A. Mason, Mengyu Liang
更新时间: 2018-07-07
摘要: A method for characterizing aggregate stability with repeated laser diffraction measurements was tested on soils spanning the prairie-forest ecotone in northern Minnesota, USA. These soils formed in similar parent material but display a wide range of upper horizon morphology, organic carbon content, and chemistry, allowing assessment of the method's performance over a wide range of aggregate stability and its utility in identifying factors influencing aggregate behavior. Equations representing fine material release through breakdown of two aggregate populations as first-order processes were fit to experimental data. The best-fit parameters for these equations, and an additional index of persistent water-stable aggregate content, indicated distinct differences in aggregate behavior among the major horizons of Mollisols and Alfisols. Linear models were developed to explore the relationships between these parameters and soil physicochemical characteristics for the dataset as a whole and for subsets corresponding to four zones with different vegetation history, soil orders, and major soil horizons. The relationships identified were relatively weak (R2 = 0.30 to 0.70). The best predictors for the parameters representing early disintegration of less stable aggregates were cation exchange capacity (CEC) and effective CEC (ECEC) for the whole dataset, although organic carbon and nitrogen contents also emerged as predictors for forest and Alfisol subsets. The best predictors for the index of persistent water-stable aggregate content were organic carbon content, base saturation, or exchangeable Ca/Mg ratio, depending on the particular subset and fine material size fraction used in the analysis. The relatively weak explanatory power of organic carbon content as a predictor of aggregate behavior in these experiments was somewhat surprising, given prior work on aggregate stability. Both CEC and ECEC may serve as proxies for the various combinations of organic matter and clay content that influence aggregate stability in these samples, explaining their importance as predictors. It is likely that other factors not examined in this research contributed to aggregate stability, including carbonate content, clay mineralogy, and differing frequency and types of pedoturbation under grassland and forest. The results of this study are relevant to reconstructing the development of texture-contrast profiles as forest invaded grassland over the past 4000 in the study area, as documented by paleoecological research. In particular, loss of organic matter below a thin A horizon may have facilitated initial development of an E horizon in which weak aggregation favored clay eluviation; loss of clay would then have weakened aggregate stability still further. We suggest this new method for assessing aggregate stability can also be applied to research on soil erosion and runoff potential as affected by land use and management.

28650. 题目: Oxidation of benzo[a]pyrene by laccase in soil enhances bound residue formation and reduces disturbance to soil bacterial community composition
文章编号: N18070703
期刊: Environmental Pollution
作者: Jun Zeng, Qinghe Zhu, Yucheng Wu, Jun Shan, Rong Ji, Xiangui Lin
更新时间: 2018-07-07
摘要: Laccases are capable of rapidly oxidizing benzo[a]pyrene. It is thought that the metabolites with an increase in water solubility caused by the oxidation of benzo[a]pyrene may stimulate the subsequent mineralization. However, to date, there has been no experimental evidence to support this. In this study, the fate of benzo[a]pyrene in soil affected by laccase amendment and the resulting soil bacterial responses were investigated. Laccase amendment promoted benzo[a]pyrene dissipation (15.6%) from soil, accompanied by trace mineralization (<0.58 ± 0.02%) and substantial bound residue formation ( 80%). An increase of 15% in the bound residue fraction was observed by laccase amendment, which mainly resulted from covalent binding of the residues to humin fraction. During the incubation, the abundance of bacterial 16S rRNA and polycyclic aromatic hydrocarbon ring-hydroxylating dioxygenase genes did not change markedly. In contrast, benzo[a]pyrene treated with laccase resulted in a smaller shift in the bacterial community composition, indicating a reduced disturbance to the soil microbial communities. These results here suggest that benzo[a]pyrene contaminated soil can be detoxified by laccase amendment mainly due to the enhanced bound residue formation to soil organic matter via covalent binding.

28651. 题目: Enhanced degradation of isoproturon in soil through persulfate activation by Fe-based layered double hydroxide: different reactive species comparing with activation by homogenous Fe(II)
文章编号: N18070702
期刊: Environmental Science and Pollution Research
作者: Yong Liu, Jie Lang, Ting Wang, Ali Jawad, Haibin Wang, Aimal Khan, Zhulei Chen, Zhuqi Chen
更新时间: 2018-07-07
摘要: Phenylurea herbicide residuals in soil may continuously contaminate surface water and groundwater due to unregulated and improper use. Herein, we reported a stable and active oxidation system including heterogeneous Fe-based layered double hydroxide materials as persulfate (PS) activators. Under mild conditions, 1% LDH in weight and 70 mM PS can completely degrade 500 mg/kg isoproturon in soil within 10 h, during which less than 0.1 ppm heavy metal leaching was detected. This remarkable performance was consistent in a broad pH range (3~11) and was resistant to various inorganic anions (Cl , Br , NO3 , HCO3 ) and humic acid. Mechanism studies from scavenging tests, EPR, and fluorescence spectra collectively proved that besides OH and SO4 , singlet oxygen (1O2) and superoxide ( O2 ) were also generated and were accounted for the oxidative degradation. This unique mechanism of generating diverse radicals was clearly distinguished from classic Fe(II)/PS system, significantly reduced the influence of varying parameters in water and soil matrix, and was suggestive to chemical oxidation system in soil remediation to avoid scavenging effects by background electrolytes or other components in water/soil matrix.

28652. 题目: Assessing the cellulase enzyme heterogeneity of bacterial strains and their feedback to cattle manure degradation in a greenhouse model of in vivo pond ecosystem
文章编号: N18070701
期刊: Environmental Monitoring and Assessment
作者: Debarati GhoshBana, Bihari Jana, Susmita Lahiri, Jatridranath Bhakta, Ankita Bhattacharjee
更新时间: 2018-07-07
摘要: The responses of cellulase enzymes of three bacterial isolates and their impacts on cattle manure decomposition were assessed in a greenhouse model in vivo pond ecosystem. Fifty grams of fresh cattle manure was placed in a fastened nylon bag (mesh size ~ 50 μm dia.) and placed in triplicate in a plastic bucket with 10 l of pond water which was hung inside the enclosed polyhouse, semi-closed and open systems for 4 weeks. Samples of manure residue directly from nylon bag and water from manure leached bucket water, water, and soil from the enclosed polyhouse were collected for enzymatic assays, enumeration of aerobic cellulose decomposing and heterotrophic bacteria, and determination of water and soil quality parameters. Responses of cellulases to different temperatures in situ were also elucidated. The values of test bacteria, endoglucanase, exoglucanase and β-glucosidase, and organic carbon were significantly (P 0.05) higher in the closed system compared to semi-closed or open system. Priming of all the enzymes coupled with the peak of aerobic cellulose decomposing bacteria and heterotrophic bacterial populations occurred on the day 14 or 21 in vivo. Since the peaks of three cellulases of bacterial isolates (KUPH1, KUPH6, and KUPH8) were demonstrated between 35 and 40 °C, and that temperature coincided with temperature of the greenhouse model, this temperature range appeared to favor the growth of cellulose decomposing bacterial populations and involved cellulase enzymes.

28653. 题目: Effects of different secondary biological treatment processes followed by flocculation and sand-filtration on subsequent DBPs control from sewage treatment plants
文章编号: N18070612
期刊: Separation and Purification Technology
作者: Weixiao Qi, Hua Zhang, Ruiping Liu, Huijuan Liu, Jiuhui Qu
更新时间: 2018-07-06
摘要: The nature and chlorine reactivity of dissolved organic matter (DOM) in reclaimed water from sewage treatment plants (STPs) are quite important for assessing the risk of wastewater reuse. Elucidating relation between DOM and its fractions characterization with different treatment processes is quite important for selection of treatment processes focusing on disinfection by-products (DBPs) control. In this study, four classical STPs in Beijing (A D) with different secondary biological treatment processes but all with flocculation and sand-filtration as advanced treatment process were selected to investigate DBPs formation potentials and DOM characterization variation during these processes and their relation. Chloroform, trichloroacetic acid (TCAA) and dichloroacetic acid (DCAA) dominated among four trihalomethanes (THMs) and nine haloacetic acids (HAAs) formation potentials respectively during chlorination of both secondary and sand-filtration effluents with the order of TCAA>chloroform>DCAA. Both THMs and HAAs formation potentials were positively related with DOC percentage for the hydrophobic fractions in the DOM. The bromine incorporation in THMs was obviously higher than that in HAAs. The especially higher bromine incorporation in D STP was probably due to the higher SUVA value in this STP with SBR as secondary biological treatment process comparing to those in the other three STPs. DOC and bromide removal, SUVA decrease were important elements for selecting secondary treatment process considering DBPs control. Flocculation and sand-filtration performed not well in removing DBPs precursors especially for chloroform and DCAA except for C STP, which had higher hydrophobic fraction percentage removal and molecular weight decreasing during the advanced treatment process. FTIR analysis revealed that flocculation and sand-filtration probably removed more aliphatic structures than aromatic or COO- structures. The absorption ratio of aromatic C=C, COO-/aliphatic CH3 peaks in D STP was the highest among the four STPs, which was consistent with the highest bromine incorporation in this STP.

28654. 题目: Oxidative removal of brilliant green by UV/S2O82?, UV/HSO5? and UV/H2O2 processes in aqueous media: A comparative study
文章编号: N18070611
期刊: Journal of Hazardous Materials
作者: Faiza Rehman, Murtaza Sayed, Javed Ali Khan, Noor S. Shah, Hasan M. Khan, Dionysios D. Dionysiou
更新时间: 2018-07-06
摘要: The removal of brilliant green (BG), a toxic organic and cationic dye, has been examined by UV/S2O82 (PS), UV/HSO5 (PMS) and UV/H2O2 processes. BG showed insignificant direct photolysis at 254 nm (i.e., 8.6% after 30 min). However, enhanced BG degradation was observed in UV/PS, UV/PMS and UV/H2O2 systems as revealed from 63.1, 47.0 and 34.8% BG degradation, respectively, at 30 min of reaction time, using 0.05 mM BG and 1.0 mM oxidant initial concentration. The bimolecular rate constants of OH and SO4 with BG were determined to be 2.35 × 109 and 2.21 × 109 M 1 s 1, respectively. Electrical energy per order (EE/O) values for UV/PS, UV/PMS and UV/H2O2 processes were calculated to be 5.4, 6.8, and 7.8 KWh/m3/order, respectively. The addition of humic acid (HA) and inorganic anions inhibited the degradation of BG by UV/PS in the order of NO2 > HA > HCO3 > Cl > NO3 ≈ SO42 . The results of frontier electron densities (FEDs) showed that C-atom holding the three rings (C7), and C-atoms at para positions to N-alkyl groups of the two rings (C4 and C14) are the predominant sites for radical addition. Furthermore, nine degradation products (DPs) of BG were detected experimentally using LC/MS/MS.

28655. 题目: Degradation behavior of palm oil mill effluent in Fenton oxidation
文章编号: N18070610
期刊: Journal of Hazardous Materials
作者: Disni Gamaralalage, Osamu Sawai, Teppei Nunoura
更新时间: 2018-07-06
摘要: An in-depth study on degradation behavior of palm oil mill effluent (POME) in Fenton oxidation was accomplished with complete carbon and nitrogen balances. Experiments were conducted for real POME with a pH range of 2-5. POME contained high COD (50000 mg/L), nitrogen (520 mg/L) and phosphorous (510 mg/L). Carboxylic acids and phenol covered 88% of organic carbons while ammonia, NO2- and NO3- contributed for 73% of nitrogen. Most of carboxylic acids and phenol were decomposed forming easily-biodegradable formic, phthalic and acetic acids, and further decomposed to carbonate and gaseous carbon dioxide. Part of carbon in liquid phase in POME transferred to solid phase by oligomerization of aromatic compounds. Ammonia was oxidized to NO2-, NO3- and gaseous N2 while, acetamide degradation led to ammonia formation. 99.9% of phosphorus was removed. Increasing H2O2 concentration elevated organic reduction and the highest TOC reduction of 91% was obtained at TOC:H2O2:Fe2+ molar ratio of 1:3.7:0.6 within 90-180 min which is extremely faster over the available biological treatments. Under the reaction conditions used in this study, Fenton oxidation at pH 3 showed the best result in terms of TOC reduction. Outcomes of this study will provide a platform for advanced oxidation processes and POME treatment.

28656. 题目: Evaluation of gas resource potentiality, geochemical and mineralogical characteristics of Permian shale beds of Latehar-Auranga Coalfield, India
文章编号: N18070609
期刊: International Journal of Coal Geology
作者: Vinod Atmaram Mendhe, Vivekanand Kumar, Vinod Kumar Saxena, Mollika Bannerjee, Alka Damodhar Kamble, Bhagwan D. Singh, Subhashree Mishra, Sadanand Sharma, Jaywardhan Kumar, Atul Kumar Varma, Divya Kumari Mishra, Suresh Kumar Samad
更新时间: 2018-07-06
摘要: The shale beds associated with Permian coal-bearing Barakar Formation of the Latehar-Auranga coalfield (north Koel Valley), India have been investigated for the hydrocarbon prospects and their critical reservoir properties. The shale core samples were collected from boreholes drilled in three different blocks like Gowa, Jagaldaga and Banhardih. The shale core samples are examined for in-situ gas content, desorbed gas composition, geochemical, Rock-Eval, scanning electron microscopy (SEM), X-ray diffraction (XRD), high pressure CH4 adsorption isotherm, porosity and permeability aspects. The shales are rich in carbonaceous and silty materials with alternate bands of intercalations; suggesting deposition of the sediments and organic matters by slow or wavering river currents under the reducing environment. The van Krevelen diagram of H/C and O/C atomic ratio of the shales has demonstrated type III/IV kerogens; specifying that organic matters transformed from the fluvio-terrestrial depositional conditions to the diagenesis and catagenesis stages and placed in wet to dry gas window (H/C ratio < 0.5). The values of in-situ gas, lost gas, desorbed gas and residual gas contents are ranging from 1.06–7.02, 0.21–0.98, 0.35–4.16 and 0.42–2.45 cc/g, respectively. The Langmuir volume (VL) is varying between 5.6 and 0.9 cc/g, when values of VL compared to the in-situ gas revealed low to moderate gas saturation (26.86–73.75%) of the shale beds. The negative trend of Langmuir pressure (PL) with depth suggests affinity of CH4 to the shale pore surfaces. The plot of lower hydrocarbons ratios like (C2/C1) × 1000 and (C3/C1) × 1000 shows the dry thermal origin of desorbed gas. The Rock-Eval pyrolysis constituents like S1, S2, S3, PI, Tmax, TOC, HI, OI and Calc. VRo% varies from 0.11–0.47, 3.45–28.34 mg HC/g, 0.11–0.89 mg CO2/g, 0.00–0.07, 414–456 °C, 1.28–16.26 wt%, 39.54–821.45 mg HC/g TOC, 1.52–20.00 mg CO2/g TOC and 0.29–1.05% respectively.The plots of hydrogen index (39.54–821.45 mg HC/g TOC) with calculated VRo (0.29–1.05%) and Tmax (414–456 °C) are signifying types I, II, III and IV kerogen in the shales prone to generate oil, wet and dry gas placed in immature to mature regions. The positive linear correlation of the VL with kaolinite and illite contents suggests that mainly clays contribute to the formation of shale matrix. The SEM images show six types of pore: i) lenticular open pores along the fissility, ii) altered pores due to weathering, iii) intergranular pores, iv) intermingled pores between crystal lattices, v) partially filled pores associated with clays and minerals, and vi) evolved pores by cracking of the organic compounds. The values of porosity and permeability have been measured under reservoir simulated confining pressure, and are ranging from 0.87–8.18% and 0.08–1.45 mD, respectively. This shows poor connectivity between the pores and fracture mechanisms controlled by the clay and minerals. It is summarized that the studied shales of Latehar-Auranga Coalfield have a low to moderate gas potential, based on their in-situ gas, TOC content (1.28–16.26 wt%), sorption capacity, Tmax values and thermal maturity. Moreover, the significant residual volume, low porosity and low permeability are the most critical properties for shale gas resource development at the Latehar-Auranga coalfield.

28657. 题目: A synthetic analysis of livestock manure substitution effects on organic carbon changes in China's arable topsoil
文章编号: N18070608
期刊: CATENA
作者: Fengling Ren, Xubo Zhang, Jian Liu, Nan Sun, Zhigang Sun, Lianhai Wu, Minggang Xu
更新时间: 2018-07-06
摘要: Application of livestock manure has been recognized as an important strategy for enhancing soil organic carbon (SOC) stocks. However, the magnitude of manure application impacts on SOC changes as compared with conventional mineral fertilizers still needs to be better assessed. In this study, we conducted a meta-analysis to address the effects of various fertilization practices on SOC changes in China's arable topsoil. The analysis was based on 148 peer reviewed articles reporting 69 sites and 729 observations with an average experimental duration of 18 years across China. We compared the response of SOC content to application of manure alone (M) or manure plus mineral fertilizers (NPKM) with the SOC response to NPK or no fertilizers (Control). We systematically analyzed how SOC responses were influenced by different environmental and management factors (land use, climate and soil properties, etc.). First, the retention coefficient of manure was used to present the percentage of C input from manure “converted” to SOC. Compared to Control, on average, manure had C-retention coefficients of 31% ± 12% (95% Confidence Interval, CI) and 18% ± 2% for the experimental duration of ≤10 years and >10 years, respectively. When compared to NPK, manure had C-retention coefficients of 29% ± 13% and 9% ± 3% for the experimental duration of ≤10 years and >10 years, respectively. In addition, compared to Control and NPK, application of manure increased SOC content by 0.23–0.26 and 0.18–0.19 g kg 1 yr 1, respectively. The results also indicated that the mean differences of SOC change between the treatments with or without manure application were mainly controlled by soil properties (28–43%) and anthropogenic farming practices (21–27%). Our results highlight the significance of improving or maintaining SOC stocks by manure applications, and provide insights for making manure application recommendations or guidelines to improve SOC stocks of China's cropland based on soil properties, climatic conditions and management practices.

28658. 题目: Soil organic carbon stocks controlled by lithology and soil depth in a Peruvian alpine grassland of the Andes
文章编号: N18070607
期刊: CATENA
作者: Songyu Yang, Erik Cammeraat, Boris Jansen, Michael den Haan, Emiel van Loon, Jorge Recharte
更新时间: 2018-07-06
摘要: The soil is the largest carbon (C) pool in the terrestrial ecosystem, and soil organic carbon (SOC) stocks play an important role in global C dynamics. Alpine grasslands of the Andes are characterized by high SOC stocks. Quantifying SOC stocks and unraveling key factors controlling SOC stocks, is necessary to obtain a better understanding of the dynamics of the large C stocks in this environment. However, most studies on C dynamics of the Andes focus on volcanic-ash soils, whereas information about non-volcanic ash soils in this region is scarce. Our objectives were: (i) to estimate SOC stocks in an alpine grassland of the Peruvian Andes (7° 11′S, 78° 35′W) with parent materials other than volcanic ash, and (ii) to identify the underlying soil formation and environmental (SFE) factors and soil properties explaining observed patterns of SOC stocks. We sampled 69 plots up to the parent material to measure soil properties and to calculate SOC stocks, in relation to lithology, land use, grazing intensity, slope angle, slope position and altitude. We applied linear models to identify key factors controlling SOC stocks. Our results showed that total SOC stocks had a mean value of 215 ± 21 T ha 1, whereas SOC stocks of the upper 10 cm and 40 cm comprised 29.3% and 80.0% of total SOC stocks respectively. The variation of the total SOC stocks was mainly explained by soil depth and soil moisture. When soil depth and soil moisture were controlled as conditional variables, lithology became the key factor controlling the total SOC stocks. For the SOC stocks of the upper 10 cm, soil moisture explained a large part of the variation, whereas lithology, grazing intensity and altitude were also significant predictors. Our results also show that when soils are sampled with limited depths instead of the entire soil profile, SOC stocks can be underestimated, and the effects of the SFE factors on SOC stocks can be overestimated.

28659. 题目: Characterization and evaluation of a tropical peat for the removal of Cr(VI) from solution
文章编号: N18070606
期刊: Environmental Earth Sciences
作者: Marilia Mayumi Augusto dos Santos, Mirian Chieko Shinzato, Juliana Gardenalli de Freitas
更新时间: 2018-07-06
摘要: Tropical peat soils present higher ash content than those generated at temperate climate areas. Therefore, this study evaluated the characteristics of a Brazilian organic soil (OS), commercialized as peat, as well as its capacity in removing Cr(VI) from contaminated waters. The OS is composed of 35.5 wt% of organic matter and 56 wt% of inorganic fraction (ash), which is formed by minerals and phytoliths rich in silica (29.2 wt%) and alumina (23.6 wt%). The Cr(VI) removal tests were carried out in batch and column systems using OS and solutions of Cr(VI) prepared with distilled water and groundwater. Batch tests revealed that the organic substances in the OS caused the reduction of Cr(VI) to Cr(III), with an efficiency depending on solution pH. At pH 5.0 the Cr(VI) removal was 0.45 mg g 1 in 24 h; whereas at pH 2.0, this removal increased to 1.10 mg g 1. Since this redox reaction is very slow, the removal of Cr(VI) at pH 5.0 increased to around 2 mg g 1 after 5 days. The removal of Cr(VI) was more effective in the column tests than in the batch test due to the greater solid/solution ratio, and their half-lives were 4.4 and 26.2 h, respectively. Chemical analysis indicated that Cr(VI) was reduced by the humic substances of OS, followed by the precipitation and/or adsorption of Cr(III) into the organic and inorganic components, as anatase. The presence of Cr(III) increased the stability of anatase structure, avoiding its transformation into rutile, even after being heated at 800 °C/2 h.

28660. 题目: Impact of drilling mud on chemistry and microbiology of an Upper Triassic groundwater after drilling and testing an exploration well for aquifer thermal energy storage in Berlin (Germany)
文章编号: N18070605
期刊: Environmental Earth Sciences
作者: Simona Regenspurg, Mashal Alawi, Guido Bl?cher, Maria B?rger, Stefan Kranz, Ben Norden, Ali Saadat, Traugott Scheytt, Lioba Virchow, Andrea Vieth-Hillebrand
更新时间: 2018-07-06
摘要: After completion of an exploration well, sandstones of the Exter Formation were hydraulically tested to determine the hydraulic properties and to evaluate chemical and microbial processes caused by drilling and water production. The aim was to determine the suitability of the formation as a reservoir for aquifer thermal energy storage. The tests revealed a hydraulic conductivity of 1–2 E-5 m/s of the reservoir, resulting in a productivity index of 0.6–1 m3/h/bar. A hydraulic connection of the Exter Formation to the overlaying, artesian “Rupelbasissand” cannot be excluded. Water samples were collected for chemical and microbiological analyses. The water was similarly composed as sea water with a maximum salinity of 24.9 g/L, dominated by NaCl (15.6 g/L Cl and 7.8 g/L Na). Until the end of the tests, the water was affected by drilling mud as indicated by the high pH (8.9) and high bicarbonate concentration (359 mg/L) that both resulted from the impact of sodium carbonate (Na2CO3) additives. The high amount of dissolved organic matter (> 58 mg/L) and its molecular-weight distribution pattern indicated that residues of cellulose, an ingredient of the drilling mud, were still present at the end of the tests. Clear evidence of this contamination gave the measured uranine that was added as a tracer into the drilling mud. During fluid production, the microbial community structure and abundance changed and correlated with the content of drilling mud. Eight taxa of sulfate-reducing bacteria, key organisms in processes like bio-corrosion and bio-clogging, were identified. It can be assumed that their activity will be affected during usage of the reservoir.