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14101. 题目: Liquid fertilizer production by ammonia recovery from treated ammonia-rich regenerated streams using liquid-liquid membrane contactors
文章编号: N18121311
期刊: Chemical Engineering Journal
作者: X. Vecino, M. Reig, B. Bhushan, O. Gibert, C. Valderrama, J.L. Cortina
更新时间: 2018-12-13
摘要: The nitrogen load on urban wastewater should be considered as a secondary resource for nitrogen-based fertilizers. From this point of view, ammonia-rich streams obtained from a regeneration step with zeolites using 70–80 g NaOH/L could contain up to 3.5–4.5 g NH3/L as well as other ionic species (Na+, K+, Ca2+, Mg2+) and dissolved organic matter (DOM). Thus, they could be treated to obtain a valuable product composed by ammonia for fertilizing applications. A sorption pre-treatment process was carried out to remove the residual amount of DOM and to reduce membrane fouling before processing with hollow fibres liquid-liquid membrane contactors (HF-LLMC). Polypropylene HF-LLMC was used to selectively extract ammonia in single or two-step configurations using different acid stripping solutions (H3PO4, HNO3 or a mixture of HNO3/H3PO4). For ammonia recovery, the ammonia mass transfer coefficient (Km(NH3)) and water transport by HF-LLMC were determined. H3PO4 was found to be the best acid stripping solution by one-step HF-LLMC; the ammonia removal was 76% with a Km(NH3) of 8.8 × 10−7 m/s. Additionally, the ammonia was concentrated 26 times, and it was recovered as multi-nutrient liquid fertilizer (NP) composed of 7.8% N and 21.6% P2O5. Furthermore, ammonia recovery was increased, reaching values up to 94%, through two-step HF-LLMC, and again H3PO4 was used as stripping solution. Finally, water transport from the feed to the stripping phase was estimated to be 0.022 L/m2·h for one-step HF-LLMC with H3PO4. Finally, the use of UV–Vis and 2D-Fluorescence was shown to be a successful approach for monitoring pore wetting events.
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14102. 题目: Investigation on the control of phosphate leaching by sorption and colloidal transport: Column studies and multi-surface complexation modelling
文章编号: N18121310
期刊: Applied Geochemistry
作者: Ruben Warrinnier, Thomas Goossens, Fien Amery, Thijs Vanden Nest, Mieke Verbeeck, Erik Smolders
更新时间: 2018-12-13
摘要: Surface complexation modelling (SCM) is a powerful tool to estimate speciation and fate of solutes in soil, provided sufficient model validation. This study aims to describe phosphate (PO4) leaching with SCM. The leachate phosphorus concentrations ([P]) of 120 unsaturated columns of contrasting agricultural soils were measured and modelled. Leachate [P] ranged 0.7–240 μM. Leachate [P] increased as the ratio of P to iron and aluminium (PAlFe) in acid oxalate soil extracts increased and as leachate Fe and Al concentrations ([Al + Fe]) increased. SCM was used to describe PO4 sorption to ferrihydrite (CD-MUSIC model). This yielded adequate description of leachate [P] (RMSElog10 = 0.39), but only when reactive PO4 was described from isotopically exchangeable PO4, when organic matter was included as the main competing adsorbate and when mobile colloidal ferrihydrite was included. The model reveals that colloidal PO4 transport enhanced leachate PO4 concentrations up to a factor 50 at small soil P content and small calcium (Ca2+) concentration in solution, as a large Ca2+ concentration enhances colloidal stability. This modelling approach explained that long-term application of organic fertilisers with higher Ca content reduced P leaching, likely due to the effect of Ca2+ on colloidal stability. A two-parameter empirical Langmuir model, based on soil Fe and Al oxyhydroxides, fitted data better than any SCM, suggesting that the empirical model might be advocated for application at large scale. This study revealed the power of SCM to better understand colloidal transport of P in soil.
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14103. 题目: The immediate effects of downslope cornstalk mulch (DCM) on sediment yield, runoff and runoff-associated dissolved carbon loss in a representative hillslope, Southwestern China
文章编号: N18121309
期刊: CATENA
作者: Tianyang Li, Siyue Li, Chuan Liang
更新时间: 2018-12-13
摘要: Dissolved carbon plays a pivotal role in carbon cycles and potentially affects ecological processes of water body. While stalk mulch can regulate soil and water losses, its effects on the export of dissolved carbon from soils are poorly understood. The main objective of this study was to determine the effects of rainfall intensity and downslope cornstalk mulch (the lengths of cornstalks along the slope, DCM) on runoff, sediment yield and dissolved carbon losses, including dissolved inorganic carbon (DIC), dissolved organic carbon (DOC) and dissolved total carbon (DTC). A series of field rainfall simulations were conducted on the steep fallow land (20 °) locating in a representative hillslope of southwestern China that experiences severe soil erosion, and data for runoff, sediment and dissolved carbon loss rates were obtained from triplet parallel plots (1.5 m long and 1 m wide for each one) using 60 min rainfall simulations at 30 and 90 mm h−1 intensities on bare soils and 90 mm h−1 intensity on soils with DCM (air-dried whole plants, 60% coverage and weight 1.65 kg), respectively. Rainfall intensity showed positive effects on runoff generation, sediment yield and loss rates of DIC, DOC and DTC. The plots with immediate DCM had no difference in runoff generation, but were 71.1% lower in sediment yield and 53.9% higher in DOC loss rate relative to the bare plots. The contribution of DIC to DTC increased from 35.9% to 59.6% with the increasing rainfall intensity. Cornstalk mulching appeared efficient in reducing sediment yield, but its adoption is likely to dramatically enhance DOC exports from soils with concerns for the quality of inland waters. Further research studies are required to discriminate between soil and cornstalk mulch contribution to DOC exports by overland flow.
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14104. 题目: Statistical analysis of lake sediment geochemical data for understanding surface geological factors and processes: An example from Amazonian upland lakes, Brazil
文章编号: N18121308
期刊: CATENA
作者: Prafulla Kumar Sahoo, José Tasso Felix Guimarães, Pedro Walfir Martins Souza-Filho, Mike A. Powell, Marcio Sousa da Silva, Aline Mamede Moraes, Ronnie Alves, Alessandro Sabá Leite, Wilson Nascimento Júnior, Tarcísio Magevski Rodrigues, Vladimir Eliodoro Costa, Roberto Dall'Agnol
更新时间: 2018-12-13
摘要: Statistical evaluation applied to geochemical data of upland lake sediments and their catchment basins rocks from Serra dos Carajás was used to identify geochemical signatures associated with underlying processes, sediment provenances, and source-sink relationship. The lakes are Violão, Amendoim and Três Irmãs - TI1, TI2 and TI3. A centred log-ratio transformation (clr) was used prior to multivariate analyses in order to eliminate closure issues in compositional data. Due to the similarity between δ15N values and organic sources (mainly from C3 plants), the three lakes were clustered together. Violão Lake receives largest organic contribution from autochthonous sources, such as siliceous sponge spicules and algae, except for it shallower portion (WNW extension), which is more similar to TI2, having low δ15N values that are similar to the isotopic signature of upland swamps. The upper continental crust (UCC) normalization pattern shows that sediments are mainly enriched in Fe, P and Se, which is closely related to the catchment lithology. The distribution of elements in TI2 is significantly different from the other lakes, because it is dominated by organic carbon, while the other lakes are a mix of detritus and organic carbon. Factor Analysis (FA) using clr-transformed data distinguishes several geochemical assemblages in the sediments, with the major detritic groups being similar to catchment basin laterites: the Ti-Zr-Hf-Nb-Y-HREEs group corresponds to resistant minerals which remained stable during lateritization; the LREEs group reflects mobilization and reprecipitation by REE bearing minerals; and the Al-V-Cr-Sc association reflects metavolcanic rock. The Fe-P-Mo-As-Zn cluster in the sediments is attributed to Fe-oxyhydroxide precipitation, while TOC-SO3-Hg-Se group is controlled by organic matter. Principal Component Analysis (PCA) further indicates that detritic lake sediments are not directly derived from the parent rocks, but from weathered crusts, mainly ferruginous laterites and soils, which is consistent with their elements ratios.

14105. 题目: Lipid biomarker patterns reflect different formation environments of mussel- and tubeworm-dominated seep carbonates from the Gulf of Mexico (Atwater Valley and Green Canyon)
文章编号: N18121307
期刊: Chemical Geology
作者: Hongxiang Guan, Dong Feng, Daniel Birgel, Jörn Peckmann, Harry H. Roberts, Nengyou Wu, Duofu Chen
更新时间: 2018-12-13
摘要: Mussels and tubeworms thriving at many methane seeps typically live in symbiosis with chemosynthetic, chiefly methanotrophic or thiotrophic bacteria. It has been shown that the activities of chemosymbiotic animals can result in large differences in the sedimentary environments of their habitats. Here, we put forward the concept that such environmental variability can be archived in the lipid biomarker inventories of authigenic carbonates forming in different, locally confined environments at seeps, mussel beds and tubeworm bushes in this case. To test this hypothesis, lipid biomarker patterns of carbonates from mussel and tubeworm environments from two seep sites (Atwater Valley 340 and Green Canyon 852) of the Gulf of Mexico were analyzed. Previous work revealed stronger carbon isotope fractionation between the methane source and biomarkers of anaerobic methane oxidizing archaea-2 (ANME-2)/sulfate-reducing Desulfosarcina/Desulfococcus (DSS) consortia than for ANME-1/DSS consortia, both performing anaerobic oxidation of methane (AOM). Similar δ13Cmethane values were found at the mussel and tubeworm sites from the same seeps and the local microbial consortia also appear to be largely similar based on the observed AOM biomarker inventories. Yet, a large average offset of 32‰ between the δ13C values of molecular fossils of sulfate-reducing bacteria (SRB) involved in AOM was observed, with lower values typifying tubeworm carbonates than mussel carbonates. This pattern is interpreted to reflect local effects on isotope fractionation caused by the chemosymbiotic metazoans at mussel- and tubeworm-dominated sites. At tubeworm-dominated sites, the excess sulfate produced by thiotrophic symbionts of tubeworms and pumped down into the sediment results in persistent production of AOM-derived bicarbonate and the enrichment of 12C in sub-surface sediments. Interestingly, tubeworm carbonates also contain high amounts of non-isoprenoidal dialkyl glycerol diethers (DAGEs) with extreme 13C depletions, representing compounds that derived from non-DSS cluster SRB. Most likely, 13C-depleted AOM-derived organic intermediates were used as carbon sources by the DAGE-producing non-DSS cluster SRB, possibly performing organoclastic sulfate reduction. Our study identifies significant variation in biomarker patterns between mussel and tubeworm carbonates at two seep sites in the Gulf of Mexico. Such variation allows to characterize different habitats at seeps, which are shaped by the interaction of chemosymbiotic seep metazoans and their symbionts with the local environment. Metazoan community composition apparently controls geobiological interaction in seep ecosystems to a large degree, which may allow tracing of the effects of chemosymbiosis into the rock record.

14106. 题目: Influence of COM-peptides/proteins on the properties of flocs formed at different shear rates
文章编号: N18121306
期刊: Journal of Environmental Sciences
作者: Monika Filipenska, Petra Vasatova, Lenka Pivokonska, Lenka Cermakova, Andrea Gonzalez-Torres, Rita K. Henderson, Jana Naceradska, Martin Pivokonsky
更新时间: 2018-12-13
摘要: Coagulation followed by floc separation is a key process for the removal of algal organic matter (AOM) in water treatment. Besides optimizing coagulation parameters, knowledge of the properties of AOM-flocs is essential to maximizing AOM removal. However, the impact of AOM on the floc properties remains unclear. This study investigated how peptides/proteins derived from the cellular organic matter (COM) of the cyanobacterium Microcystis aeruginosa influenced the size, structure, and shape of flocs formed at different shear rates (G). Flocs formed by kaolinite, COM-peptides/proteins and a mixture of the same were studied, and the effect of intermolecular interactions between floc components on floc properties was assessed. The coagulation experiments were performed in a Taylor–Couette reactor, with aluminum (Al) or ferric sulphate (Fe) utilized as coagulants. Image analysis was performed to gauge floc size and obtain data on fractal dimension. It was found that floc properties were affected by the presence of the COM-peptides/proteins and the coagulant used. COM-peptides/proteins increased floc size and porosity and widened floc size distributions. The Fe coagulant produced larger and less compact flocs than Al coagulant. Moreover, the decrease in floc size that occurred in parallel with increase in shear rate was not smooth in progress. A rapid change for the kaolinite-coagulant suspension and two rapid changes for the suspensions containing COM were observed. These were attributed to various intermolecular interactions between floc components participating in coagulation at different G. Based on the results obtained, shear rates suitable for efficient separation of flocs containing COM were suggested.
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14107. 题目: Release dynamics of As, Co, and Mo in a biochar treated soil under pre-definite redox conditions
文章编号: N18121305
期刊: Science of The Total Environment
作者: Ali El-Naggar, Sabry M. Shaheen, Zeng-Yei Hseu, Shan-Li Wang, Yong Sik Ok, Jörg Rinklebe
更新时间: 2018-12-13
摘要: This study assessed the impact of pre-definite redox potential (EH) on the release dynamics and distribution of As, Co, and Mo between the dissolved and colloidal phases as well as their potential mobility and phytoavailability in the sediment phase of a mining soil treated with rice hull biochar (BC). The experiment was conducted from controlled moderately-reducing to oxidizing conditions using an automated biogeochemical microcosm system. Arsenic and Mo were more abundant in the dissolved phase due to their predominant in potential mobile fractions, while Co was more abundant in the colloidal phase due to its association with Fe-(hydr)oxides. Biochar increased the dissolved and colloidal concentrations of As, the dissolved concentration of Co, and the colloidal concentration of Mo under oxidizing condition. On the other hand, the application of BC decreased the dissolved concentration of Mo and the colloidal concentration of Co in the first redox cycle under reducing-acidic condition, due to lower pH values, and chemistry of sulfide-sulfate and Fe/Mn oxides. The phytoavailability of As and Co were higher than their potential mobility in the sediment phase, while the same trend was not discerned for Mo. The potential mobility and phytoavailability of As and Co were high under oxic-acidic conditions. The potential mobility and phytoavailability of Mo might be increased under oxic condition due to the dissolution of Fe and Mn oxides under lower pH conditions, especially in the BC treated soil. Application of such rice hull BC to soil might stimulate the release of As, Co, and Mo under flooding conditions, which might increase the environmental and health risks in such wetland ecosystems.
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14108. 题目: Residual micro organic pollutants and their biotoxicity of the effluent from the typical textile wastewater treatment plants at Pearl River Delta
文章编号: N18121304
期刊: Science of The Total Environment
作者: Feifei Xue, Bing Tang, Liying Bin, Jianwen Ye, Shaosong Huang, Fenglian Fu, Ping Li, Jiao Cui
更新时间: 2018-12-13
摘要: This work investigated the biotoxicity and the residual dissolved organic matter (DOM) of the effluents from nine typical full-scale textile plants located at Pearl River Delta (PRD) in Guangdong province, China. The fluorescence regional integration (FRI) analysis showed that the tryptophan-like (II), soluble microbial product-like (IV) and fulvic acid-like substances (III) were the dominant compounds in the DOM. The acute toxicity test showed toxic effects still remained in most textile effluents, which might attribute to the undegraded dyes or aromatic compounds. Combining with the results from multiple methods, it indicated that the selected nine textile wastewater treatment plants (tWWTPs) all contained some residual micro organic pollutants in their effluents, and the residual benzene-derived products or aromatic amines were probably the toxicity-causing substances. Both ozonization and membrane filtration were capable of further decreasing the content of residual DOM, but by comprehensively considering the effects of removing DOM and biotoxicity, membrane filtration was better than ozonization.
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14109. 题目: Microorganisms in ballast water: Disinfection, community dynamics, and implications for management
文章编号: N18121303
期刊: Science of The Total Environment
作者: Ole-Kristian Hess-Erga, Javier Moreno-Andrés, Øivind Enger, Olav Vadstein
更新时间: 2018-12-13
摘要: Increasing concerns have accelerated the development of international regulations and methods for ballast water management to limit the introduction of non-indigenous species. The transport of microorganisms with ballast water has received scientific attention in recent years. However, few studies have focused on the importance of organisms smaller than 10 μm in diameter. In this work, we review the effects of ballast water transport, disinfection, and the release of microorganisms on ecosystem processes with a special focus on heterotrophic bacteria. It is important to evaluate both direct and indirect effects of ballast water treatment systems, such as the generation of easily degradable substrates and the subsequent regrowth of heterotrophic microorganisms in ballast tanks. Disinfection of water can alter the composition of bacterial communities through selective recolonization in the ballast water or the recipient water, and thereby affects bacterial driven functions that are important for the marine food web. Dissolved organic matter quality and quantity and the ecosystem status of the treated water can also be affected by the disinfection method used. These side effects of disinfection should be further investigated in a broader context and in different scales (laboratory studies, large-scale facilities, and on the ships).
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14110. 题目: Stimulation of anaerobic organic matter decomposition by subsurface organic N addition in tundra soils
文章编号: N18121302
期刊: Soil Biology and Biochemistry
作者: Michael Philben, Jianqiu Zheng, Markus Bill, Jeffrey Heikoop, George Perkins, Ziming Yang, Stan D. Wullschleger, David E. Graham, Baohua Gu
更新时间: 2018-12-13
摘要: Increasing nitrogen (N) availability in Arctic soils could stimulate the growth of both plants and microorganisms by relieving the constraints of nutrient limitation. It was hypothesized that organic N addition to anoxic tundra soil would increase CH4 production by stimulating the fermentation of labile substrates, which is considered the rate-limiting step in anaerobic C mineralization. We tested this hypothesis through both field and lab-based experiments. In the field experiment, we injected a solution of 13C- and 15N-labeled glutamate 35 cm belowground at a site near Nome on the Seward Peninsula, Alaska, and observed the resulting changes in porewater geochemistry and dissolved greenhouse gas concentrations. The concentration of free glutamate declined rapidly within hours of injection, and the 15N label was recovered almost exclusively as dissolved organic N within 62 h. These results indicate rapid microbial assimilation of the added N and transformation into novel organic compounds. We observed increasing concentrations of dissolved CH4 and Fe(II), indicating rapid stimulation of methanogenesis and Fe(III) reduction. Low molecular weight organic acids such as acetate and propionate accumulated despite increasing consumption through anaerobic C mineralization. A laboratory soil column flow experiment using active layer soil collected from the same site further supported these findings. Glutamate recovery was low compared to a conservative bromide tracer, but concentrations of NO3 and NH4+ remained low, consistent with microbial uptake of the added N. Similar to the field experiment, we observed both increasing Fe(II) and organic acid concentrations. Together, these results support our hypothesis of increased fermentation in response to organic N addition and suggest that increasing N availability could accelerate CH4 production in tundra soils.
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14111. 题目: A novel waste activated sludge multistage utilization strategy for preparing carbon-based Fenton-like catalysts: catalytic performance assessment and micro-interfacial mechanisms
文章编号: N18121301
期刊: Water Research
作者: Jing Ai, Weijun Zhang, Guiying Liao, Feifei Chen, Dongsheng Wang
更新时间: 2018-12-13
摘要: Waste activated sludge (WAS) contains many anionic functional groups which can interact with heavy metal ions through electrostatic action and complexation reactions. The transition metals adsorbed in WAS can catalyze sludge pyrolysis in anaerobic conditions and improve structural properties of organic matter. In this work, a multistage WAS utilization process for preparing the carbon-based Fenton-like catalysis materials is proposed. More specifically, WAS is firstly used as an adsorbent for heavy metals (Cu and Ni) removal, and then complexes are converted into heterogeneous Fenton-like carbon-based catalysts through oxygen-free pyrolysis. The mechanisms of interactions between extracellular polymeric substances (EPS) and metals are investigated, and the physicochemical properties of sludge-based carbons (SBC) are comprehensively characterized using varies techniques. It is found that WAS is an excellent adsorbent for Cu and Ni removal, which is mainly due to the coordination and electrostatic interactions between EPS and heavy metals. Cu and Ni adsorbed in WAS significantly improved the porous structure of SBC. Both adsorption and catalytic oxidization of Cu/Ni-SBC contribute the removal of E2 in real wastewater. The E2 removal mechanism is explored by electron-spin resonance spectroscopy (ESR) analysis, and it is found that both of .O2- and .OH radicals are responsible for E2 degradation in Cu(II)-SBC-H2O2, while .O2- radicals contributes to E2 degradation in Ni(II)-SBC-H2O2 system, so the former performed better than the latter in total removal of E2. Besides, Cu(II) and Cu(I) are both formed in Cu(II)-SBC during the oxidation process, while only Ni(II) is found in the Ni(II)-SBC-H2O2 process, confirming that different catalytic oxidation reactions are occurred in the Cu(II)-SBC-H2O2 and Ni(II)-SBC-H2O2 processes. This study facilitates a great strategy to the sludge multi-stage circulating utilization and a better understanding about the role of the Cu/Ni existed in SBC during the estrogens removal process.
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14112. 题目: Understanding the behaviour of UV absorbance of natural waters upon chlorination using model compounds
文章编号: N18121222
期刊: Environmental Science: Water Research & Technology
作者: Nicolas Beauchamp, Caetano Dorea, Christine Beaulieu, Christian Bouchard, Manuel Rodriguez
更新时间: 2018-12-12
摘要: Differential UV absorbance (ΔA) is a promising indicator that could allow operators and utility managers to routinely monitor and manage disinfection by-product (DBP) concentrations without the limitations of regulatory sampling and analyses. So far, empirical relationships between DBP formation and ΔA at 272 nm have been proposed, but these relationships are known to be specific to the waters being analyzed. The objective of this study is qualitative rather than quantitative; it is to identify features of the spectra of simple compounds that are distinguishable in the spectra of natural water and relevant to predict DBP formation empirically. In order to meet this objective, compounds that could model the different components of natural organic matter (NOM) were chlorinated, and their UV spectra were collected at various reaction times, along with samples for DBP analyses. The same procedure was conducted on natural waters that were pretreated using coagulation and filtration. Results show that both diketone and phenolic moieties could be responsible for the initial decrease in absorbance observed around 270 nm, while the continuous gradual decrease that follows is attributable to phenolic structures. This gradual decrease is most notable around 250 nm, which means that ΔA at this wavelength might be more closely related to DBP formation than the usual ΔA at 272 nm. Other compounds such as carboxylic acids and amino acids do not seem to contribute significantly to trihalomethanes, haloacetic acids or ΔA in natural waters, although amino acids probably make up a significant proportion of the haloacetonitrile precursors.

14113. 题目: Using regional datasets of isotope geochemistry to resolve complex groundwater flow and formation connectivity in northeastern Alberta, Canada
文章编号: N18121221
期刊: Applied Geochemistry
作者: S.J. Birks, J.W. Fennell, J.J. Gibson, Y. Yi, M.C. Moncur, M. Brewster
更新时间: 2018-12-12
摘要: In the southern Athabasca Oil Sands (SAOS) Region, located in Alberta Canada, individual in-situ oil sands operators have conducted local geochemical and isotope groundwater studies to establish baseline characteristics and to improve understanding of the connectivity of water supply and disposal formations within individual leases. Canada's Oil Sands Innovation Alliance (COSIA) initiated this study to combine the data from these individual studies along with public information into a comprehensive unified dataset to evaluate conceptual models of regional groundwater flow and the degree of interaction and separation between important water supply and disposal aquifers. The unified dataset comprised over 293 groundwater samples from the main water source and disposal hydrostratigraphic units and included geochemical and isotopic tracers that can be used to identify sources (δ18O and δ2H) and age of water (3H) and associated solutes (14C-DIC, 36Cl), as well as the sources of salinity and diagenetic processes (δ13C-DIC, δ34S-SO4, 87Sr/86Sr, δ11B, δ37Cl and δ81Br) and dissolved organics (δ13C-DOC). The TDS and stable isotope composition (δ18O and δ2H) of groundwater from several Cretaceous formations were used to identify three main mixing controls. i) Areas where locally recharged groundwater mixes with glaciogenic water were identified by lower δ18O and δ18O values, high TDS, Cl:Br and δ34S-SO4, 87Sr/86Sr, and δ37Cl values consistent with dissolution of evaporites. These areas were situated where vertical pathways through otherwise competent formations are likely to occur. ii) Mixing with paleo-waters characterized by high TDS and higher δ18O and δ2H signatures indicating groundwater recharged under warmer climate periods and/or evaporative enrichment were identified in the south, and southwestern portions of the study area. The presence of these paleo-waters indicate slow-moving groundwater zones with limited lateral and vertical connectivity. iii) Areas with potential connectivity to shallow aquifers were identified by their lower TDS values, modern meteoric δ18O and δ2H signatures, HCO3 type waters, and δ34S-SO4 and 87Sr/86Sr signatures, consistent with weathering of shallow aquifer material. Geochemical and isotopic indicators that suggest that in areas where the Colorado Group aquitard is thin or absent there is greater connectivity between the Grand Rapids Formation and the shallower aquifers. Interpretation of the new unified dataset has improved understanding of the extent that glacial recharge had on Devonian aquifers, and overlying Cretaceous formations, and identified zones with relatively stagnant groundwater flow, both of which have implications for regional groundwater resource development, monitoring and potential wastewater disposal.

14114. 题目: Effects of different types of extracellular polysaccharides isolated from cyanobacterial blooms on the colony formation of unicellular Microcystis aeruginosa
文章编号: N18121220
期刊: Environmental Science and Pollution Research
作者: Ken Omori, Tania Datta, Yoshimasa Amano, Motoi Machida
更新时间: 2018-12-12
摘要: In this study, two types of extracellular polysaccharides (EPS), namely, mixed EPS (MX-EPS) and tightly bound EPS (TB-EPS), were extracted from cyanobacterial blooms using different methods. To evaluate their compositional differences, elemental composition, FTIR, and TG/DTA profile were measured for both EPS samples. Following that, unicellular Microcystis aeruginosa was cultured in a medium containing EPS, Ca2+ ion, and Mg2+ ion, and the effect of each type of EPS on the colony formation of M. aeruginosa was examined. Results showed that TB-EPS had more carboxy groups than MX-EPS, and that the TB-EPS medium contained Ca2+ and Mg2+ ions. These cations were not detected in the MX-EPS medium. During the colony formation experiment, colonies were observed when Ca2+ and Mg2+ ions were present at 250 mg/L concentration each. In addition, colony density increased when TB-EPS was added, compared to that of MX-EPS. Colonies were also observed in the medium containing only TB-EPS (100 mg/L), indicating that M. aeruginosa can form colonies using Ca2+ ion present in TB-EPS. During the MX-EPS extraction, Ca2+ ion chelated with EDTA was removed during ethanol precipitation. Therefore, the extraction protocol followed for TB-EPS was better than that of MX-EPS for maintaining Ca2+ ions, and thereby maintaining an EPS composition that enables for colony formation.

14115. 题目: Organic Carbon Amendments Affect the Chemodiversity of Soil Dissolved Organic Matter and Its Associations with Soil Microbial Communities
文章编号: N18121219
期刊: Environmental Science & Technology
作者: Xiao-Ming Li, Qing-Lin Chen, Chen He, Quan Shi, Song-Can Chen, Brian J. Reid, Yong-Guan Zhu, Guo-Xin Sun
更新时间: 2018-12-12
摘要: The “4 per mil” initiative recognizes the pivotal role of soil in carbon resequestration. The need for evidence to substantiate the influence of agricultural practices on chemical nature of soil carbon and microbial biodiversity has become a priority. However, owing to the molecular complexity of soil dissolved organic matter (DOM), specific linkages to microbial biodiversity have eluded researchers. Here, we characterized the chemodiversity of soil DOM, assessed the variation of soil bacterial community composition (BCC), and identified specific linkages between DOM traits and BCC. Sustained organic carbon amendment significantly (P < 0.05) increased total organic matter reservoirs, resulted in higher chemodiversity of DOM and emergence of recalcitrant moieties (H/C < 1.5). In the meantime, sustained organic carbon amendment shaped the BCC to a more eutrophic state while long-term chemical fertilization directed the BCC toward an oligotrophic state. Meanwhile, higher connectivity and complexity were observed in organic carbon amendment by DOM–BCC network analysis, indicating that soil microbes tended to have more interaction with DOM molecules after organic matter inputs. These results highlight the potential for organic carbon amendments to not only build soil carbon stocks and increase their resilience but also mediate the functional state of soil bacterial communities.
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14116. 题目: Deposition Kinetics of Colloidal Manganese Dioxide onto Representative Surfaces in Aquatic Environments: The Role of Humic Acid and Biomacromolecules
文章编号: N18121218
期刊: Environmental Science & Technology
作者: Xiaoliu Huangfu, Chengxue Ma, Ruixing Huang, Qiang He, Caihong Liu, Jian Zhou, Jin Jiang, Jun Ma, Yinying Zhu, Muhua Huang
更新时间: 2018-12-12
摘要: The initial deposition kinetics of colloidal MnO2 on three representative surfaces in aquatic systems (i.e., silica, magnetite, and alumina) in NaNO3 solution were investigated in the presence of model constituents, including humic acid (HA), a polysaccharide (alginate), and a protein (bovine serum albumin (BSA), using laboratory quartz crystal microbalance with dissipation monitoring equipment (QCM-D). The results indicated that the deposition behaviors of MnO2 colloids on three surfaces were in good agreement with classical Derjaguin–Landau–Verwey–Overbeek (DLVO) theory. Critical deposition concentrations (CDC) were determined to be 15.5 mM NaNO3 and 9.0 mM NaNO3 when colloidal MnO2 was deposited onto silica and magnetite, respectively. Both HA and alginate could largely retard the deposition of MnO2 colloids onto three selected surfaces due to steric repulsion, and HA was more effective in decreasing the deposition rate relative to alginate. However, the presence of BSA can provide more attractive deposition site and thus lead to greater deposition behavior of MnO2 colloids onto surfaces. The dissipative properties of the deposited layer were also influenced by surface type, electrolyte concentration, and organic matter characteristics. Overall, these results provide insights into the deposition behavior of MnO2 colloids on environmental surfaces and have significant implications for predicting the transport potential of common MnO2 colloids in natural environments and engineered systems.
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14117. 题目: In situ chemical stabilization of trace element-contaminated soil – Field demonstrations and barriers to transition from laboratory to the field – A review
文章编号: N18121217
期刊: Applied Geochemistry
作者: Jurate Kumpiene, Juan Antelo, Evelina Brännvall, Ivan Carabante, Kristina Ek, Michael Komarek, Charlotta Söderberg, Linda Wårell
更新时间: 2018-12-12
摘要: The chemical stabilization, or immobilization, of trace elements (metals and metalloids; TE) in contaminated soil has been studied for decades. A vast number of scientific publications are available on the method performance in laboratory settings, reporting that the application of various soil amendments to contaminated soil reduces TE mobility, bioavailability and toxicity. The most commonly used soil amendments include organic matter, iron oxides, phosphates, ashes, and lately biochar, alone or in combination with each other and/or lime. Most of the implemented field studies show a certain degree of improvement in soil and/or vegetation status following amendment. Regardless the positive performance of the technique in the laboratory, field validations and demonstrations remain scarce. The establishment of a field experiment often involves permits from authorities and agreements with site owners, both of which are considerably more time-consuming than laboratory tests. Due to conservative institutional structures, public authorities have been slow to adopt alternative remediation technologies, especially when the total TE concentration in soil remains the same and all of the associated risks are not yet convincingly described. For this reason, researchers should also focus on enhancing public knowledge of alternative remediation techniques so that future projects which aim to demonstrate the effectiveness of in situ immobilization techniques under natural conditions will be supported.
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14118. 题目: Influence of sulfadiazine on anaerobic fermentation of waste activated sludge for volatile fatty acids production: Focusing on microbial responses
文章编号: N18121216
期刊: Chemosphere
作者: Jing Xie, Xu Duan, Leiyu Feng, Yuanyuan Yan, Feng Wang, Haiqing Dong, Renyong Jia, Qi Zhou
更新时间: 2018-12-12
摘要: Extensive studies on anaerobic fermentation of waste activated sludge (WAS) for volatile fatty acids (VFAs) production focused on the effects of operating parameters and pretreatment methods, and little information is available for those of organic pollutants which were absorbed on sludge. The influence of sulfadiazine (SDZ), a typical antibiotic pollutant in WAS, on VFAs production during anaerobic fermentation was investigated in this study. The accumulation of VFAs was remarkably affected in the presence of SDZ. When the content of SDZ was 50 mg per kilogram dry sludge the concentration of VFAs from sludge was 2032.8 mg COD/L, much higher than that of control (1540.2 mg COD/L). Mechanism investigation revealed that the content of extracellular polymeric substances (EPS) from sludge was increased due to the presence of SDZ, which provided more substrates, i.e., protein and carbohydrate, and created a favorable environment for anaerobes. The hydrolysis and acidification of WAS were stimulated by SDZ, and the functional microorganisms were advantageous to VFAs production. The activities of protease, α-glucosidase and acetate kinase were promoted when SDZ occurred, which were beneficial for hydrolysis and acidification. The effect of SDZ on pure strains further confirmed that the formation of VFAs during anaerobic fermentation was stimulated by SDZ.
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14119. 题目: Competitive adsorption of heavy metals in aqueous solution onto biochar derived from anaerobically digested sludge
文章编号: N18121215
期刊: Chemosphere
作者: Bing-Jie Ni, Qi-Su Huang, Chen Wang, Tian-Yi Ni, Jing Sun, Wei Wei
更新时间: 2018-12-12
摘要: Heavy metals often coexist in contaminated wastewater systems and their competitive behavior could affect the adsorption capacity of biochar. Till now, the competitive adsorption of heavy metals by biochar derived from anaerobically digested sludge has never been reported. In this work, biochar from anaerobically digested sludge was synthesized and characterized to explore the competitive behavior of widely co-existed Pb(II) and Cd(II). The mutual effects and inner mechanisms of their adsorption on studied biochar were systematically investigated via single-metal and binary-metals systems. In single-metal system, the biochar exhibited much higher adsorption capacity for Pb(II) compared to that for Cd(II). The maximum adsorption capacities of Pb(II) and Cd(II) based on single-component adsorption isotherm were 0.75 and 0.55 mmoL/g, respectively, which were much higher than those reported biochars from different materials. In binary-metals system, the Cd(II) adsorption on biochar was severely inhibited, while the uptake of Pb(II) was not affected significantly. The results of binary-components adsorption isotherm clearly demonstrated the competitive adsorption between two metals occurred as well as the preference of biochar for Pb(II) compared to Cd(II). FTIR and metal characteristics analysis results revealed that Pb(II) had exactly the same adsorption sites with Cd(II), but Pb(II) has a greater affinity than Cd(II), thereby exhibiting a competitive advantage in the coexisting system.
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14120. 题目: Effects of organic molecules from biochar-extracted liquor on the growth of rice seedlings
文章编号: N18121214
期刊: Ecotoxicology and Environmental Safety
作者: Yang E., Jun Meng, Haijun Hu, Dengmiao Cheng, Changfu Zhu, Wenfu Chen
更新时间: 2018-12-12
摘要: There are many reports indicating that biochar can promote growth; however, its mechanism of action remains unclear. The aim of this study was to show that organic molecules from biochar-extracted liquor affect the growth of rice seedlings. In this study, rice seedlings were cultured under water. Agronomic traits and growth-related genes and proteins were used as markers to describe more precisely the effects of biochar on specific growth parameters of rice seedlings. Our results demonstrated that the 3% biochar-extracted liquor amendment clearly promoted growth. The growth-related gene auxin binding protein 1 and its encoded protein were up-regulated. Molecular simulations revealed that 2-acetyl-5-methylfuran from biochar-extracted liquor could interact with auxin binding protein 1 in a similar way to indoleacetic acid binding. The growth of rice seedlings was therefore affected by biochar-extracted liquor, which acted on the ABP1 signalling pathway.
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