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https://www.readbyqxmd.com/read/29241136/submillimeter-scale-heterogeneity-of-labile-phosphorus-in-sediments-characterized-by-diffusive-gradients-in-thin-films-and-spatial-analysis
#1
Yuting Meng, Shiming Ding, Mengdan Gong, Musong Chen, Yan Wang, Xianfang Fan, Lei Shi, Chaosheng Zhang
Sediments have a heterogeneous distribution of labile redox-sensitive elements due to a drastic downward transition from oxic to anoxic condition as a result of organic matter degradation. Characterization of the heterogeneous nature of sediments is vital for understanding of small-scale biogeochemical processes. However, there are limited reports on the related specialized methodology. In this study, the monthly distributions of labile phosphorus (P), a redox-sensitive limiting nutrient, were measured in the eutrophic Lake Taihu by Zr-oxide diffusive gradients in thin films (Zr-oxide DGT) on a two-dimensional (2D) submillimeter level...
December 5, 2017: Chemosphere
https://www.readbyqxmd.com/read/29241127/high-strength-n-methyl-2-pyrrolidone-containing-process-wastewater-treatment-using-sequencing-batch-reactor-and-membrane-bioreactor-a-feasibility-study
#2
Chun Heng Loh, Bing Wu, Liya Ge, Chaozhi Pan, Rong Wang
N-methyl-2-pyrrolidone (NMP) is widely used as a solvent in polymeric membrane fabrication process, its elimination from the process wastewater (normally at a high concentration > 1000 mg/L) prior to discharge is essential because of environmental concern. This study investigated the feasibility of treating high-strength NMP-containing process wastewater in a sequencing batch reactor (SBR; i.e., batch feeding and intermittent aerobic/anoxic condition) and a membrane bioreactor (MBR; i.e., continuous feeding and aeration), respectively...
December 6, 2017: Chemosphere
https://www.readbyqxmd.com/read/29241125/the-enhancement-and-inhibition-of-mercury-reduction-by-natural-organic-matter-in-the-presence-of-shewanella-oneidensis-mr-1
#3
Seyong Lee, Dong-Hun Kim, Kyoung-Woong Kim
Reduction-oxidation (Redox) processes of mercury (Hg) are of significant importance in influencing Hg speciation, bioavailability, and fate in anoxic environments where natural organic matter (NOM) and dissimilatory metal reducing bacteria (DMRB) are widely observed. However, the redox reaction between Hg and NOM, has not yet been studied in the presence of S. oneidensis MR-1 in anoxic environments. We have found that the reduction rate of mercuric mercury [Hg(II)] in the presence of Elliott soil humic acid (ESHA) was 0...
December 5, 2017: Chemosphere
https://www.readbyqxmd.com/read/29238131/manganese-redox-buffering-limits-arsenic-release-from-contaminated-sediments-union-lake-new-jersey
#4
Alison R Keimowitz, Brian J Mailloux, Karen Wovkulich, Jennifer Harkness, James M Ross, Steven N Chillrud
The sediments of Union Lake in Southern New Jersey are contaminated with arsenic released from the Vineland Chemical Company Superfund site 11 km upstream. Seasonal anoxia has been shown to release arsenic from sediments to similar lakes; this process was hypothesized as a major arsenic source to Union Lake. Data indicate, however, that releases of arsenic to bottom waters from the sediments or from pore waters within the sediments are relatively minor: bottom water arsenic concentrations reached ~30 ppb (~12 μM) at most, representing <13% of the dissolved arsenic content of the lake...
February 2017: Applied Geochemistry: Journal of the International Association of Geochemistry and Cosmochemistry
https://www.readbyqxmd.com/read/29236023/effect-of-cod-n-ratio-on-n2o-production-during-nitrogen-removal-by-aerobic-granular-sludge
#5
V F Velho, B S Magnus, G C Daudt, J A Xavier, L B Guimarães, R H R Costa
N2O-production was investigated during nitrogen removal using aerobic granular sludge (AGS) technology. A pilot sequencing batch reactor (SBR) with AGS achieved an effluent in accordance with national discharge limits, although presented a nitrite accumulation rate of 95.79% with no simultaneous nitrification-denitrification. N2O production was 2.06 mg L-1 during the anoxic phase, with N2O emission during air pulses and the aeration phase of 1.6% of the nitrogen loading rate. Batch tests with AGS from the pilot reactor verified that at the greatest COD/N ratio (1...
December 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/29235527/assessment-of-low-concentration-wastewater-treatment-operations-with-dewatered-alum-sludge-based-sequencing-batch-constructed-wetland-system
#6
Wei Kang, Hongxiang Chai, Yu Xiang, Wei Chen, Zhiyu Shao, Qiang He
Competition of volatile fatty acids between anoxic denitrification and anaerobic phosphorus release is prominent. Therefore, low concentration wastewater has restricted effects on nitrogen and phosphorus removal. The purpose of this study is to treat dormitory sewage with a biochemical oxygen demand (BOD) ranging from 50 to 150 mg/L using dewatered alum sludge-based sequencing batch constructed wetland system. Vegetation in the wetland system was chosen to be Phragmites australis. Three parallel cases were carried out to assess impacts due to different hydraulic retention time (HRT) and artificial aeration...
December 13, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29232639/tracking-variations-of-fluorescent-dissolved-organic-matter-during-wastewater-treatment-by-accumulative-fluorescence-emission-spectroscopy-combined-with-principal-component-second-derivative-and-canonical-correlation-analyses
#7
Xujing Guo, Huibin Yu, Zongcheng Yan, Hongjie Gao, Yizhang Zhang
Accumulative fluorescence emission (AFE) spectroscopy combined with principal component analysis (PCA), second derivative and canonical correlation analysis (CCA) was firstly developed into an available tool to track variations in dissolved organic matter (DOM) fractions and contents during wastewater treatment. Samples were collected from a wastewater treatment plant with a traditional anaerobic/anoxic/oxic (A2O) process. The AFE spectroscopy deduced from the sum of intensities along the excitation wavelengths of fluorescence excitation emission matrix (EEM), could distinctly track tyrosine-like, tryptophan-like, fulvic-like substances...
December 6, 2017: Chemosphere
https://www.readbyqxmd.com/read/29228161/reductive-tetrachloroethene-dehalogenation-in-the-presence-of-oxygen-by-sulfurospirillum-multivorans-physiological-studies-and-proteome-analysis
#8
Jennifer Gadkari, Tobias Goris, Christian L Schiffmann, Raffael Rubick, Lorenz Adrian, Torsten Schubert, Gabriele Diekert
Reductive dehalogenation of organohalides is carried out by organohalide-respiring bacteria (OHRB) in anoxic environments. The tetrachloroethene (PCE)-respiring Epsilonproteobacterium Sulfurospirillum multivorans is one of few OHRB able to respire oxygen. Therefore, we investigated the organism's capacity to dehalogenate PCE in the presence of oxygen, which would broaden the applicability to use S. multivorans, unlike other commonly oxygen-sensitive OHRB, for bioremediation, e.g. at oxic/anoxic interphases...
December 5, 2017: FEMS Microbiology Ecology
https://www.readbyqxmd.com/read/29226319/lncrna-xist-regulates-myocardial-infarction-by-targeting-mir-130a-3p
#9
Tao Zhou, Guowei Qin, Liehong Yang, Daokang Xiang, Suining Li
The study was employed to probe long non-coding RNA X-inactive specific transcript RNA (lncRNA XIST) expression profile and its influence on cell cycle, proliferation and apoptosis in myocardial cells. We also aimed to explore the possible meditating relationship between XIST, PDE4D and miR-130a-3p. Gene differential analysis was carried out using Human LncRNA Microarray V3.0. Quantitative real-time PCR (qRT-PCR) was used to test mRNA expressions of XIST, miR-130a-3p and PDE4D in normal cells and post-myocardial infarction (MI) cells...
December 11, 2017: Journal of Cellular Physiology
https://www.readbyqxmd.com/read/29223868/recirculation-of-gas-emissions-to-achieve-advanced-denitrification-of-the-effluent-from-the-anaerobic-treatment-of-domestic-wastewater
#10
L Pelaz, A Gómez, G Garralón, A Letona, M Fdz-Polanco
A denitrifying pilot plant was designed, constructed and operated for more than five months. The plant treated domestic wastewater with high ammonium nitrogen concentration, which had previously undergone an anaerobic process at 18 °C. The process consisted of one biofilter with 2 h of hydraulic retention time for denitritation. Different synthetic nitrite concentrations were supplied to the anoxic reactor to simulate the effluent of a nitritation process. This work investigates the advanced denitritation of wastewater using the organic matter and other alternative electron donors present in an anaerobic treatment process effluent: methane and sulfide...
December 7, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/29222101/divergence-in-gene-regulation-contributes-to-sympatric-speciation-of-shewanella-baltica-strains
#11
Jie Deng, Jennifer Auchtung, Konstantinos T Konstantinidis, Alejandro Caro-Quintero, Ingrid Brettar, Manfred Höfle, James M Tiedje
Niche partitioning and sequence evolution drive genomic and phenotypic divergence, which ultimately leads to bacterial diversification. This study investigated genomic composition of two Shewanella baltica clades previously identified through multi-locus sequencing typing and recovered from the redox transition zone in the central Baltic Sea. Comparative genomic analysis revealed significantly higher inter- than intra-clade genomic dissimilarity, and that a subset of genes present in Clade A were associated with potential adaptation to respiration of sulfur compounds present in the redox-transition zone...
December 8, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/29220815/influence-of-fermentation-liquid-from-waste-activated-sludge-on-anoxic-oxic-membrane-bioreactor-performance-nitrogen-removal-membrane-fouling-and-microbial-community
#12
Xiaomeng Han, Zhen Zhou, Xiaojie Mei, Yan Ma, Zhenfang Xie
In order to investigate effects of waste activated sludge (WAS) fermentation liquid on anoxic/oxic- membrane bioreactor (A/O-MBR), two A/O-MBRs with and without WAS fermentation liquid addition were operated in parallel. Results show that addition of WAS fermentation liquid clearly improved denitrification efficiency without deterioration of nitrification, while severe membrane fouling occurred. WAS fermentation liquid resulted in an elevated production of proteins and humic acids in bound extracellular polymeric substance (EPS) and release of organic matter with high MW fractions in soluble microbial product (SMP) and loosely bound EPS (LB-EPS)...
December 2, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/29220717/microbial-electricity-driven-anoxic-ammonium-removal
#13
Anna Vilajeliu-Pons, Christin Koch, Maria D Balaguer, Jesús Colprim, Falk Harnisch, Sebastià Puig
Removal of nitrogen, mainly in form of ammonium (NH4+), in wastewater treatment plants (WWTPs) is a highly energy demanding process, mainly due to aeration. It causes costs of about half a million Euros per year in an average European WWTP. Alternative, more economical technologies for the removal of nitrogen compounds from wastewater are required. This study proves the complete anoxic conversion of ammonium (NH4+) to dinitrogen gas (N2) in continuously operated bioelectrochemical systems at the litre-scale...
December 1, 2017: Water Research
https://www.readbyqxmd.com/read/29217657/the-unique-histidine-in-oscp-subunit-of-f-atp-synthase-mediates-inhibition-of-the-permeability-transition-pore-by-acidic-ph
#14
Manuela Antoniel, Kristen Jones, Salvatore Antonucci, Barbara Spolaore, Federico Fogolari, Valeria Petronilli, Valentina Giorgio, Michela Carraro, Fabio Di Lisa, Michael Forte, Ildikó Szabó, Giovanna Lippe, Paolo Bernardi
The permeability transition pore (PTP) is a Ca2+-dependent mitochondrial channel whose opening causes a permeability increase in the inner membrane to ions and solutes. The most potent inhibitors are matrix protons, with channel block at pH 6.5. Inhibition is reversible, mediated by histidyl residue(s), and prevented by their carbethoxylation by diethylpyrocarbonate (DPC), but their assignment is unsolved. We show that PTP inhibition by H+ is mediated by the highly conserved histidyl residue (H112 in the human mature protein) of oligomycin sensitivity conferral protein (OSCP) subunit of mitochondrial F1FO (F)-ATP synthase, which we also show to undergo carbethoxylation after reaction of mitochondria with DPC...
December 7, 2017: EMBO Reports
https://www.readbyqxmd.com/read/29216481/robust-performance-of-a-membrane-bioreactor-for-removing-antibiotic-resistance-genes-exposed-to-antibiotics-role-of-membrane-foulants
#15
Yijing Zhu, Yayi Wang, Shuai Zhou, Xuxin Jiang, Xiao Ma, Chao Liu
Antibiotic resistance genes (ARGs) are an emerging concern in wastewater treatment plants (WWTPs), as dissemination of ARGs can pose a serious risk to human health. Few studies, however, have quantified ARGs in membrane bioreactors (MBRs), although MBRs have been widely used for both municipal and industrial wastewater treatment. To reveal the capacity of MBRs for removal of ARGs and the response of membrane fouling after antibiotic exposure, five typical ARG subtypes (sulI, sulII, tetC, tetX and ereA) and int1 were quantified affiliated by systematic membrane foulants analysis in a laboratory-scale anoxic/aerobic membrane bioreactor (A/O-MBR)...
November 30, 2017: Water Research
https://www.readbyqxmd.com/read/29209092/opposite-effects-of-dissolved-oxygen-on-the-removal-of-as-iii-and-as-v-by-carbonate-structural-fe-ii
#16
Zeyuan Tian, Yong Feng, Yiyi Guan, Binbin Shao, Yalei Zhang, Deli Wu
Freshly prepared carbonate structural Fe(II) (CSF) was used to immobilize As(III) and As(V) in wastewater under oxic and anoxic conditions. Dissolved oxygen was found to exert opposite effects on these two arsenic species. The sorption density of As(III) was higher under oxic conditions, whereas that of As(V) was higher under anoxic conditions. X-ray diffraction and infrared spectroscopic analyses indicated that crystalline parasymplesite (Fe(II)3(AsO4)2·8H2O) was formed when As(V) was removed under anoxic conditions, while an amorphous Fe-As-containing precipitate was formed when As(III) was removed under oxic conditions...
December 5, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29208961/investigation-of-different-nitrogen-reduction-routes-and-their-key-microbial-players-in-wood-chip-driven-denitrification-beds
#17
Victoria Grießmeier, Andreas Bremges, Alice C McHardy, Johannes Gescher
Field denitrification beds containing polymeric plant material are increasingly used to eliminate nitrate from agricultural drainage water. They mirror a number of anoxic ecosystems. However, knowledge of the microbial composition, the interaction of microbial species, and the carbon degradation processes within these denitrification systems is sparse. This study revealed several new aspects of the carbon and nitrogen cycle, and these findings can be correlated with the dynamics of the microbial community composition and the activity of key species...
December 5, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29206918/differences-in-planktonic-microbial-communities-associated-with-three-types-of-macrophyte-stands-in-a-shallow-lake
#18
Anikó Mentes, Attila Szabó, Boglárka Somogyi, Balázs Vajna, Nóra Tugyi, Bianka Csitári, Lajos Vörös, Tamás Felföldi
Little is known about how various substances from living and decomposing aquatic macrophytes affect the horizontal patterns of planktonic bacterial communities. Study sites were located within Lake Kolon, which is a freshwater marsh and can be characterized by open water sites and small ponds with different macrovegetation (Phragmites australis, Nymphea alba and Utricularia vulgaris). Our aim was to reveal the impact of these macrophytes on the composition of the planktonic microbial communities using comparative analysis of environmental parameters, microscopy and pyrosequencing data...
November 29, 2017: FEMS Microbiology Ecology
https://www.readbyqxmd.com/read/29202345/effective-removal-of-bromate-in-nitrate-reducing-anoxic-zones-during-managed-aquifer-recharge-for-drinking-water-treatment-laboratory-scale-simulations
#19
Feifei Wang, Doris van Halem, Lei Ding, Ying Bai, Karin Lekkerkerker-Teunissen, Jan Peter van der Hoek
The removal of bromate (BrO3-) as a by-product of ozonation in subsequent managed aquifer recharge (MAR) systems, specifically in anoxic nitrate (NO3-)-reducing zones, has so far gained little attention. In this study, batch reactors and columns were used to explore the influence of NO3- and increased assimilable organic carbon (AOC) due to ozonation pre-treatment on BrO3- removal in MAR systems. 8 m column experiments were carried out for 10 months to investigate BrO3- behavior in anoxic NO3--reducing zones of MAR systems...
November 27, 2017: Water Research
https://www.readbyqxmd.com/read/29201569/denitrifying-metabolism-of-the-methylotrophic-marine-bacterium-methylophaga-nitratireducenticrescens-strain-jam1
#20
Florian Mauffrey, Alexandra Cucaita, Philippe Constant, Richard Villemur
Background: Methylophaga nitratireducenticrescens strain JAM1 is a methylotrophic, marine bacterium that was isolated from a denitrification reactor treating a closed-circuit seawater aquarium. It can sustain growth under anoxic conditions by reducing nitrate ([Formula: see text]) to nitrite ([Formula: see text]). These physiological traits are attributed to gene clusters that encode two dissimilatory nitrate reductases (Nar). Strain JAM1 also contains gene clusters encoding two nitric oxide (NO) reductases and one nitrous oxide (N2O) reductase, suggesting that NO and N2O can be reduced by strain JAM1...
2017: PeerJ
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