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Tsiverihasina V Rakotonimaro, Carmen Mihaela Neculita, Bruno Bussière, Thomas Genty, Gérald J Zagury
Multi-step passive systems for the treatment of iron-rich acid mine drainage (Fe-rich AMD) perform satisfactorily at the laboratory scale. However, their field-scale application has revealed dissimilarities in performance, particularly with respect to hydraulic parameters. In this study, the assessment of factors potentially responsible for the variations in performance of laboratory and field-scale multi-step systems was undertaken. Three laboratory multi-step treatment scenarios, involving a combination of dispersed alkaline substrate (DAS) units, anoxic dolomitic drains, and passive biochemical reactors (PBRs), were set up in 10...
April 17, 2018: Environmental Science and Pollution Research International
Lea Steinle, Katrin Knittel, Nicole Felber, Claudia Casalino, Gert de Lange, Chiara Tessarolo, Alina Stadnitskaia, Jaap S Sinninghe Damsté, Jakob Zopfi, Moritz F Lehmann, Tina Treude, Helge Niemann
The Kryos Basin is a deep-sea hypersaline anoxic basin (DHAB) located in the Eastern Mediterranean Sea (34.98°N 22.04°E). It is filled with brine of re-dissolved Messinian evaporites and is nearly saturated with MgCl2 -equivalents, which makes this habitat extremely challenging for life. The strong density difference between the anoxic brine and the overlying oxic Mediterranean seawater impedes mixing, giving rise to a narrow chemocline. Here, we investigate the microbial community structure and activities across the seawater-brine interface using a combined biogeochemical, next-generation sequencing, and lipid biomarker approach...
April 17, 2018: ISME Journal
Hong Thi Bich Truong, Phuoc Van Nguyen, Phuong Thi Thanh Nguyen, Ha Manh Bui
The formation of aerobic granular sludge was carried out in a sequencing batch reactor (SBR) for tapioca processing wastewater treatment. The effect of organic loading rates (OLRs) in the range of 2.5-10.0 kg COD m-3 day-1 on the granulation was investigated. The size and settleability of the aerobic granular sludge increased with increasing OLR from 2.5 to 7.5 kg COD m-3 day-1 . The mature granules had an average size of 2.5 mm and good settleability with the sludge volume index (SVI) lower than 50 mL g-1 ...
April 14, 2018: Journal of Environmental Management
Janette A Hamilton, Paul B Perrin, Thomas A Campbell, Steven J Danish, Alissa L Goldstein
This study explored the utility of the Coma Recovery Scale-Revised (CRS-R) in predicting emergence from a disorder of consciousness, using a sample of veterans who were treated at one of the five Veterans Affairs (VA) polytrauma rehabilitation centre sites in an Emerging Consciousness programme. Participants (N = 70) included both combat and non-combat active duty military personnel and veterans who sustained either a severe traumatic brain injury, or anoxic brain injury and were considered to have a disorder of consciousness at the time of admission...
April 16, 2018: Neuropsychological Rehabilitation
Feifei Zhang, Stephen J Romaniello, Thomas J Algeo, Kimberly V Lau, Matthew E Clapham, Sylvain Richoz, Achim D Herrmann, Harrison Smith, Micha Horacek, Ariel D Anbar
Explaining the ~5-million-year delay in marine biotic recovery following the latest Permian mass extinction, the largest biotic crisis of the Phanerozoic, is a fundamental challenge for both geological and biological sciences. Ocean redox perturbations may have played a critical role in this delayed recovery. However, the lack of quantitative constraints on the details of Early Triassic oceanic anoxia (for example, time, duration, and extent) leaves the links between oceanic conditions and the delayed biotic recovery ambiguous...
April 2018: Science Advances
Cornelia U Welte
The methane concentration in the Earth's atmosphere is rising, and, as methane is a potent greenhouse gas, it contributes considerably to climate change. It is produced by methanogenic archaea that thrive in anoxic habitats and can be oxidized by methane-oxidizing bacteria or archaea. In this Perspective , recent innovations and discoveries in archaeal methane microbiology are discussed and a future outlook on how novel methane-metabolizing archaea might be cultivated is provided.
March 2018: MSystems
Han Chen, Ang Li, Qiao Wang, Di Cui, Chongwei Cui, Fang Ma
The low-strength domestic wastewater (LSDW) treatment with low chemical oxygen demand (COD) has drawn extensive attention for the poor total nitrogen (TN) removal performance. In the present study, an enhanced multistage anoxic/oxic (A/O) biofilm reactor was designed to improve the TN removal performance of the LSDW treatment. Efficient nitrifying and denitrifying biofilm carriers were cultivated and then filled into the enhanced biofilm reactor as the sole microbial source. Step-feed strategy and internal recycle were adopted to optimize the substrate distribution and the organics utilization...
April 7, 2018: Biodegradation
Jianfeng Ye, Junyu Liang, Liang Wang, Giorgos Markou
To understand the mechanism of enhanced nitrogen removal by photo-sequencing batch reactors (photo-SBRs), which incorporated microalgal photosynthetic oxygenation into the aerobic phases of a conventional cycle, this study performed comprehensive analysis of one-cycle dynamics. Under a low aeration intensity (about 0.02 vvm), a photo-SBR, illuminated with light at 92.27 μ·mol·m-2 ·s-1 , could remove 99.45% COD, 99.93% NH4 + -N, 90.39% TN, and 95.17% TP, while the control SBR could only remove 98.36% COD, 83...
March 31, 2018: Bioresource Technology
Kam W Tang, Sabine Flury, Dominic Vachon, César Ordóñez, Daniel F McGinnis
Chaoborus spp. (phantom midge) are prevalent in eutrophic inland waters. In Lake Soppen, Switzerland, C. flavicans larvae diurnally migrate between the methane-rich, oxygen-depleted hypolimnion and sediments, and the methane-poor, oxygen-rich epilimnion. Using a combination of experiments and system modelling, this study demonstrated that the larvae's burrowing activities in and out of the sediment perturbed the sediment and re-introduced sequestered phosphorus into the overlying water at a rate of 0.022 μg P ind-1 d-1 , thereby exacerbating internal nutrient loading in the water column...
March 27, 2018: Water Research
Cheng Cheng, Zhen Zhou, Hongjian Pang, Yue Zheng, Liuyu Chen, Lu-Man Jiang, Xiaodan Zhao
A micro-aerobic side-stream reactor (MSSR) was inserted in returned sludge line of a membrane bioreactor (MBR) for sludge reduction. Three MSSR coupled MBRs (M-MBRs) and an anoxic/oxic MBR (AO-MBR) were operated in parallel to investigate effects of micro-aerobic condition and hydraulic retention time (HRT) of MSSR (HRTM ) on process performance. M-MBRs and AO-MBR were equally effective in COD and NH4 -N removal. Rising HRTM from 3.3 to 6.7 h increased sludge reduction from 10.8% to 47.5%, and promoted dissolved organic matters release and utilization by enriching hydrolytic, fermentative and predatory bacteria...
March 28, 2018: Bioresource Technology
Blas Blázquez, Manuel Carmona, Eduardo Díaz
Alkylbenzenes, such as toluene and m -xylene, are an important class of contaminant hydrocarbons that are widespread and tend to accumulate in subsurface anoxic environments. The peripheral pathway for the anaerobic oxidation of toluene in bacteria consists of an initial activation catalyzed by a benzylsuccinate synthase (encoded by bss genes), and a subsequent modified β-oxidation of benzylsuccinate to benzoyl-CoA and succinyl-CoA (encoded by bbs genes). We have shown here that the bss and bbs genes, which are located within an integrative and conjugative element, are essential for anaerobic degradation of toluene but also for m -xylene oxidation in the denitrifying beta-proteobacterium Azoarcus sp...
2018: Frontiers in Microbiology
Xiang Hu, Dominika Sobotka, Krzysztof Czerwionka, Qi Zhou, Li Xie, Jacek Makinia
The effects of two different external carbon sources (acetate and ethanol) and electron acceptors (dissolved oxygen, nitrate, and nitrite) were investigated under aerobic and anoxic conditions with non-acclimated process biomass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/(g MLVSS·h) (MLVSS: mixed liquor volatile suspended solids), respectively, for dissolved oxygen, nitrate, and nitrite...
2018: Journal of Zhejiang University. Science. B
Kim Phung L Nguyen, Vandana Pai, Saima Rashid, Jennifer Treece, Marie Moulton, Steven J Baumrucker
Cardiac arrest is a common cause of coma with frequent poor outcomes. Palliative medicine teams are often called upon to discuss the scope of treatment and future care in cases of anoxic brain injury. Understanding prognostic tools in this setting would help medical teams communicate more effectively with patients' families and caregivers and may promote improved quality of life overall. This article reviews multiple tools that are useful in determining outcomes in the setting of postarrest anoxic brain injury...
January 1, 2018: American Journal of Hospice & Palliative Care
Xiaoyan Y Ma, Qiyuan Li, Xiaochang C Wang, Yongkun Wang, Donghong Wang, Huu Hao Ngo
As reclaimed water use is increasing, its safety attracts growing attention, particularly with respect to the health risks associated with the wide range of micropollutants found in the reclaimed water. In this study, sophisticated analysis was conducted for water samples from a water reclamation and ecological reuse system where domestic wastewater was treated using an anaerobic-anoxic-oxic unit followed by a membrane bioreactor (A2 O-MBR), and the reclaimed water was used for replenishing a landscape lake...
March 27, 2018: Water Research
Lydia Zeibich, Oliver Schmidt, Harold L Drake
Earthworms are a dominant macro-fauna in soil ecosystems and have determinative effects on soil fertility and plant growth. These invertebrates feed on ingested material, and gizzard-linked disruption of ingested fungal and bacterial cells is conceived to provide diverse biopolymers in the anoxic alimentary canal of earthworms. Fermentation in the gut is likely important to the utilization of ingested biopolymer-derived compounds by the earthworm. This study therefore examined the fermentative response of gut content-associated microbes of the model earthworm Lumbricus terrestris to (a) microbial cell-lysate (to simulate gizzard-disrupted cells) and (b) dominate biopolymers of such biomass, protein and RNA...
March 30, 2018: Applied and Environmental Microbiology
Wentao Zhao, Qian Sui, Xuebing Mei, Xueting Cheng
Membrane bioreactors (MBRs) were shown contradictory results for the removal of antibiotics, such as sulfonamides (SAs), from wastewater in different studies, which highlighted the necessity for comprehensive investigation on removal mechanisms of sulfonamides in well-controlled lab-scale MBRs. In the present study, the removal performance of nine SAs by a lab-scale anaerobic/anoxic/oxic-membrane bioreactor (A1 /A2 /O-MBR) was studied at environmental relevant concentrations. The results showed that all the SAs were efficiently eliminated (93...
March 27, 2018: Science of the Total Environment
Jill S McClary, Alexandria B Boehm
The transcriptional response of Staphylococcus aureus strain Newman to sunlight exposure was investigated under both oxic and anoxic conditions using RNA sequencing to gain insight into potential mechanisms of inactivation. S. aureus is a pathogenic bacterium detected at recreational beaches which can cause gastrointestinal illness and skin infections, and is of increasing public health concern. To investigate the S. aureus photostress response in oligotrophic seawater, S. aureus cultures were suspended in seawater and exposed to full spectrum simulated sunlight...
2018: Frontiers in Microbiology
Ri-Qing Yu, John R Reinfelder, Mark E Hines, Tamar Barkay
Exposure to dietary sources of methylmercury (MeHg) is the focus of public health concerns with environmental mercury (Hg) contamination. MeHg is formed in anoxic environments by anaerobic microorganisms. This process has been studied mostly with single-species culture incubations, although the relevance of such studies to Hg(II)-methylation in situ is limited because microbial activities in the environment are critically modulated by interactions among microbial functional groups. Here we describe experiments in which Hg(II)-methylation was examined within the context of various microbial syntrophies...
March 29, 2018: ISME Journal
Sandip S Sathe, Chandan Mahanta, Pushpanjali Mishra
In the dynamic cycling of oxic and anoxic aqueous alluvial aquifer environments, varying Arsenic (As) concentrations are controlled by both abiotic and biotic factors. Studies have shown a significant form of toxic As (III) being released through the reductive dissolution of iron-oxy/hydroxide minerals and microbial reduction mechanisms, which leads to a serious health concern. The present study was performed in order to assess the abiotic and biotic factors influencing As release into the alluvial aquifer groundwater in Brahmaputra floodplain, India...
March 5, 2018: Journal of Contaminant Hydrology
L Pelaz, A Gómez, A Letona, G Garralón, M Fdz-Polanco
This work presents the performance of a sequencing batch reactor (SBR) system used as a means of removing nitrogen from domestic wastewater containing a low chemical oxygen demand (COD) to nitrogen ratio due to pre-treatment with an anaerobic reactor. The aim of the work was to determine the feasibility of this system for the removal of nitrogen from the domestic wastewater. An SBR with a working volume of 5 L was investigated at different cycle times of 12, 8 and 6 h, at 18 °C. The efficiency of the SBR varied together with the duration of the cycle, where the optimum performance was seen in the 6 h cycle with the anoxic-aerobic-anoxic sequence...
March 2018: Water Science and Technology: a Journal of the International Association on Water Pollution Research
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