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https://www.readbyqxmd.com/read/28811146/n2o-emissions-from-an-intermittently-aerated-semi-aerobic-aged-refuse-bioreactor-combined-effect-of-cod-and-nh4-n-in-influent-leachate
#1
Weihua Li, Yingjie Sun, Rongxing Bian, Huawei Wang, Dalei Zhang
The carbon-nitrogen ratio (COD/NH4(+)-N) is an important factor affecting nitrification and denitrification in wastewater treatment; this factor also influences nitrous oxide (N2O) emissions. This study investigated two simulated intermittently aerated semi-aerobic aged refuse bioreactors (SAARB) filled with 8-year old aged refuse (AR). The research analyzed how differences in and the combination of influent COD and NH4(+)-N impact N2O emissions in leachate treatment. Experimental results showed that N2O emissions increased as the influent COD/NH4(+)-N decreased...
August 12, 2017: Waste Management
https://www.readbyqxmd.com/read/28807555/improving-biogas-production-from-anaerobic-co-digestion-of-sewage-sludge-with-a-thermal-dried-mixture-of-food-waste-cheese-whey-and-olive-mill-wastewater
#2
A E Maragkaki, I Vasileiadis, M Fountoulakis, A Kyriakou, K Lasaridi, T Manios
Anaerobic co-digestion of sewage sludge and other organic wastes at a wastewater treatment plant (WWTP) is a promising method for both energy and material recovery. However, transportation and storage of wastes to WWTP may be the bottleneck for the successful implementation of this technology. In case of wet wastes and wastewater it is possible to reduce their volume and as a result the transportation and storage cost by using a drying process. During this study, the optimization of biogas production from sewage sludge (SS) was attempted by co-digesting with a dried mixture of food waste, cheese whey and olive mill wastewater (FCO)...
August 11, 2017: Waste Management
https://www.readbyqxmd.com/read/28793836/simultaneous-wastewater-treatment-and-biogas-production-using-integrated-anaerobic-baffled-reactor-granular-activated-carbon-iabrgac-from-baker-yeast-wastewater
#3
Meghdad Pirsaheb, Samira Mohamadi, Sama Rahmatabadi, Hooshyar Hossini, Fabrício Motteran
In this study simultaneous degradation of organic matter and color removal from food processing industries wastewater using an integrated anaerobic baffled reactor-granular activated carbon (IABRGAC) was investigated. To evaluate the efficiency of IABRGAC, the effective parameters were studied such as hydraulic retention time (HRT) and GAC filling ratio. The bioreactor was operated at 3, 4, 5 d of HRT and GAC filling ratio of 20%, 35% and 50%. The parameters were evaluated in steady state condition. To analyses and optimizing the independent operating variables, response surface methodology was applied...
August 9, 2017: Environmental Technology
https://www.readbyqxmd.com/read/28782075/extracellular-enzymatic-activity-of-two-hydrolases-in-wastewater-treatment-for-biological-nutrient-removal
#4
Jorge Mario Berrio-Restrepo, Julio César Saldarriaga, Mauricio Andrés Correa, Néstor Jaime Aguirre
Due to the complex nature of the wastewater (both domestic and non-domestic) composition, biological processes are widely used to remove nutrients, such as carbon (C), nitrogen (N), and phosphorous (P), which cause instability and hence contribute to the damage of water bodies. Systems with different configurations have been developed (including anaerobic, anoxic, and aerobic conditions) for the joint removal of carbon, nitrogen, and phosphorus. The goal of this research is to evaluate the extracellular activity of β-glucosidase and phosphatase enzymes in a University of Cape Town (UCT) system fed with two synthetic wastewaters of different molecular complexity...
August 7, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28780453/a-novel-horizontal-subsurface-flow-constructed-wetland-reducing-area-requirements-and-clogging-risk
#5
Triantafyllos Tatoulis, Christos S Akratos, Athanasia G Tekerlekopoulou, Dimitrios V Vayenas, Alexandros I Stefanakis
The use of Constructed Wetlands (CWs) has been nowadays expanded from municipal to industrial and agro-industrial wastewaters. The main limitations of CWs remain the relatively high area requirements compared to mechanical treatment technologies and the potential occurrence of the clogging phenomenon. This study presents the findings of an innovative CW design where novel materials were used. Four pilot-scale CW units were designed, built and operated for two years. Each unit consisted of two compartments, the first of which (two thirds of the total unit length) contained either fine gravel (in two units) or random type high density polyethylene (HDPE) (in the other two units)...
August 1, 2017: Chemosphere
https://www.readbyqxmd.com/read/28780259/effect-of-hydraulic-retention-time-on-deterioration-restarting-of-sludge-anaerobic-digestion-extracellular-polymeric-substances-and-microbial-response
#6
Liangliang Wei, Xiaoyan An, Sheng Wang, Chonghua Xue, Junqiu Jiang, Qingliang Zhao, Felix Tetteh Kabutey, Kun Wang
In this study, the transformation of the sludge-related extracellular polymeric substances (EPS) during mesophilic anaerobic digestion was characterized to assess the effect of hydraulic retention time (HRT) on reactor deterioration/restarting. Experimental HRT variations from 20 to 15 and 10d was implemented for deterioration, and from 10 to 20d for restarting. Long-term digestion at the lowest HRT (10d) resulted in significant accumulation of hydrolyzed hydrophobic materials and volatile fatty acids in the supernatants...
July 22, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28765919/age-at-menopause-and-hormone-replacement-therapy-as-risk-factors-for-head-and-neck-and-oesophageal-cancer%C3%A2-review
#7
Caroline E McCarthy, John K Field, Michael W Marcus
There were ~986,000 cases of head and neck cancer (HNC) and oesophageal cancer diagnosed worldwide in 2012. The incidence of these types of cancer is much higher in males than females, although this disparity decreases in the elderly population, suggesting a role for hormones as a risk factor. This systematic review investigates the potential role of female hormones [age at menopause and use of hormone replacement therapy (HRT)] as risk factors for HNC/oesophageal squamous cell carcinoma (SCC). The electronic databases MEDLINE, Web of Science, EMBASE and Cochrane were searched...
August 1, 2017: Oncology Reports
https://www.readbyqxmd.com/read/28759450/performance-of-air-cathode-stacked-microbial-fuel-cells-systems-for-wastewater-treatment-and-electricity-production
#8
Edson Baltazar Estrada-Arriaga, Yvonne Guillen-Alonso, Cornelio Morales-Morales, Liliana García-Sánchez, Erick Obed Bahena-Bahena, Oscar Guadarrama-Pérez, Félix Loyola-Morales
Two different air-cathode stacked microbial fuel cell (MFC) configurations were evaluated under continuous flow during the treatment of municipal wastewater and electricity production at a hydraulic retention time (HRT) of 3, 1, and 0.5 d. Stacked MFC 1 was formed by 20 individual air-cathode MFC units. The second stacked MFC (stacked MFC 2) consisted of 40 air-cathode MFC units placed in a shared reactor. The maximum voltages produced at closed circuit (1,000 Ω) were 170 mV for stacked MFC 1 and 94 mV for stacked MFC 2...
July 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
https://www.readbyqxmd.com/read/28757697/corneal-ring-infiltration-in-contact-lens-wearers
#9
Seyed Ali Tabatabaei, Mohammad Soleimani, Mohammadkarim Johari
To report a case of atypical sterile ring infiltrates during wearing soft silicone hydrogel contact lens due to poor lens care. A 29-year-old woman presented with complaints of pain, redness, and morning discharge. She was wearing soft silicone hydrogel contact lens previously; her current symptoms began 1 week before presentation. On examination, best-corrected visual acuity was 20/40 in that eye. Slit-lamp examination revealed dense, ring-shaped infiltrate involving both the superficial and deep stromal layers with lucid interval to the limbus, edema of the epithelium, epithelial defect, and vascularization of the superior limbus...
May 2017: Oman Journal of Ophthalmology
https://www.readbyqxmd.com/read/28752096/breast-density-and-breast-cancer-incidence-in-the-lebanese-population-results-from-a-retrospective-multicenter-study
#10
Christine Salem, David Atallah, Joelle Safi, Georges Chahine, Antoine Haddad, Nadine El Kassis, Laura-Maria Maalouly, Malak Moubarak, Mary Dib, Michel Ghossain
PURPOSE: To study the distribution of breast mammogram density in Lebanese women and correlate it with breast cancer (BC) incidence. METHODS: Data from 1,049 women who had screening or diagnostic mammography were retrospectively reviewed. Age, menopausal status, contraceptives or hormonal replacement therapy (HRT), parity, breastfeeding, history of BC, breast mammogram density, and final BI-RADS assessment were collected. Breast density was analyzed in each age category and compared according to factors that could influence breast density and BC incidence...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28743579/seeking-to-enhance-the-bioenergy-of-municipal-sludge-effect-of-alkali-pre-treatment-and-soluble-organic-matter-supplementation
#11
S Zahedi, M Rivero, R Solera, M Perez
The aim of this research is to enhance the mesophilic anaerobic digestion of municipal sludge from Cadiz-San Fernando (Spain) wastewater treatment plant at 20days hydraulic retention time (HRT). Two different strategies were tested to improve the process: co-digestion with the addition of soluble organic matter (1% v/v); and alkali sludge pre-treatment (NaOH) prior to co-digestion with glycerine (1% v/v). Methane production (MP) was substantially enhanced (from 0.36±0.09 L CH4 l/d to 0.85±0.16 L CH4 l/d), as was specific methane production (SMP) (from 0...
July 22, 2017: Waste Management
https://www.readbyqxmd.com/read/28738552/nutrients-removal-and-bacterial-community-structure-for-low-c-n-municipal-wastewater-using-a-modified-anaerobic-anoxic-oxic-ma2-o-process-in-north-china
#12
Shihua Zhang, Zhijia Huang, Shujian Lu, Jun Zheng, Xinxi Zhang
A modified anaerobic/anoxic/oxic (mA2/O) process based on utilizing the internal carbon source and adding polypropylene carriers was operated for 90d to investigate the nutrients removal performance and bacterial community. This system exhibited a stable and efficient performance, particularly, in removing the NH4(+)-N and total phosphorus. The results of high-throughput sequencing showed that the 13 dominant genera containing Pseudomonas, Comamonas, Arcobacter, Nitrobacteria, Nitrosospira, Nitrosomonas, Bacteroides, Flavobacterium, Rhizobium, Acinetobacter, Zoogloea, Rhodocyclus and Moraxella were shared by five zones, inferring that they were the essential players in treating low C/N (below 5...
July 12, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28735204/developing-an-ecosystem-model-of-a-floating-wetland-for-water-quality-improvement-on-a-stormwater-pond
#13
Brendan McAndrew, Changwoo Ahn
An ecosystem model was developed to assist with designing and implementing a floating wetland (FW) for water quality management of urban stormwater ponds, focusing on nitrogen (N) removal. The model is comprised of three linked submodels: hydrology, plant growth, and nitrogen. The model was calibrated with the data that resulted from a FW constructed and implemented as part of an interdisciplinary pedagogical project on a university campus, titled "The Rain Project", which raised awareness of stormwater issues while investigating the potential application of green infrastructure for sustainable stormwater management...
July 20, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28728975/continuous-nitrogen-removal-by-a-single-stage-reactor-packed-with-ring-laced-string-medium
#14
Masahiro Tatara, Shu Ishikawa, Yoshiyuki Ueno
The efficiency of nitrogen removal by a partial-nitritation/anammox (PNA) reaction was investigated using a packed-bed reactor in which ring-laced strings were used as the supporting medium. A stable population of PNA microorganisms was established from typical activated sludge, after less than two months of acclimation in the packed-bed reactor, by applying a high nitrogen-loading rate (NLR: 0.53 kg/m(3)/d) and short hydraulic retention time (HRT: 1.8 h). The stability of reactor performance was confirmed in industrial wastewater (IW), demonstrating a nitrogen removal efficiency (NRE) of greater than 77% during 260 days of continuous operation, between 0...
July 17, 2017: Journal of Bioscience and Bioengineering
https://www.readbyqxmd.com/read/28727836/the-disc-damage-likelihood-scale-diagnostic-accuracy-and-correlations-with-cup-to-disc-ratio-structural-tests-and-standard-automated-perimetry
#15
Andrea C Kara-José, Luiz Alberto S Melo, Bruno L B Esporcatte, Angelica T N H Endo, Mauro Toledo Leite, Ivan Maynart Tavares
Our objective was to compare the diagnostic accuracies of and to determine the correlations between the disc damage likelihood scale (DDLS) and anatomical and functional tests used for glaucoma detection. A total of 54 healthy subjects (54 eyes) and 47 primary open-angle glaucoma patients (47 eyes) were included in this cross-sectional observational study. DDLS scores and cup-to-disc (C/D) ratios were evaluated. Subjects underwent standard automated perimetry (SAP), optic disc and retinal nerve fiber layer (RNFL) imaging with time and spectral-domain optical coherence tomography (TD and SD-OCT), Heidelberg Retina Tomograph (HRT II), and scanning laser polarimetry (GDx-VCC)...
2017: PloS One
https://www.readbyqxmd.com/read/28724252/effect-of-operating-conditions-on-speciation-and-bioavailability-of-trace-metals-in-submerged-anaerobic-membrane-bioreactors
#16
Pham Minh Thanh, Balachandran Ketheesan, Yan Zhou, David C Stuckey
This study investigated the effect of changes in pH (7, 6.5 and 6), hydraulic retention time (HRT) (6h, 4h, and 2h), solids retention time (SRT) (100d and 25d) on the speciation of trace metals (TMs) in submerged anaerobic membrane bioreactors (SAMBRs). The results showed that the metal retention capacity of SAMBRs reduced when the pH, HRT and SRT were reduced i.e. up to 21.9%, 39.1%, and 17.1%, respectively, but it was also found that the speciation of these TMs generally shifted towards highly bioavailable fractions i...
July 8, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28712782/cu-removal-and-response-mechanisms-of-periphytic-biofilms-in-a-tubular-bioreactor
#17
Lan Ma, Fengwu Wang, Yuanchun Yu, Junzhuo Liu, Yonghong Wu
This work studied Cu removal and response mechanisms of periphytic biofilms in a tubular bioreactor. Periphytic biofilms immobilized in a tubular bioreactor were used to remove Cu from wastewater with different Cu concentrations. Results showed that periphytic biofilms had a high removal efficiency (max. 99%) at a hydraulic retention time (HRT) of 12h under initial Cu concentrations of 2.0 and 10.0mgL(-1). Periphyton quickly adapted to Cu stress by regulating the community composition. Species richness, evenness and carbon metabolic diversity of the periphytic community increased when exposed to Cu...
July 6, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28712332/comparison-of-commercial-baker-s-yeast-versus-bacteria-based-membrane-bioreactors-for-landfill-leachate-treatment
#18
M C S Amaral, G C B Brito, B G Reis, L C Lange, W G Moravia
This paper compares the performance of the membrane bioreactor (MBR) inoculated with commercial baker's yeast (Saccharomyces cerevisiae) (MBRy) versus one inoculated with bacterial sludge (MBRb) for treatment of landfill leachate (LFL). The MBRb and MBRy were operated with a hydraulic retention time (HRT) of 48 h, solids retention time (SRT) of 60 d, and specific air demand based on membrane area (SADm) of 0.6 m(3) h(-1) m(-2). The MBRy was more efficient in removing COD (68 ± 12%), color (79 ± 8%), ammoniacal nitrogen (58 ± 18%), and phosphorus (62 ± 19%) compared to MBRb, which showed removal efficiencies of 44 ± 18%, 46 ± 20%, 45 ± 17%, and 29 ± 15% for COD, color, ammoniacal nitrogen, and phosphorus...
July 17, 2017: Environmental Technology
https://www.readbyqxmd.com/read/28711803/investigation-on-the-response-of-anaerobic-membrane-bioreactor-to-temperature-decrease-from-25%C3%A2-c-to-10%C3%A2-c-in-sewage-treatment
#19
Ryoya Watanabe, Yulun Nie, Shinichiro Wakahara, Daisuke Komori, Yu-You Li
Anaerobic membrane bioreactor (AnMBR) for sewage treatment was operated for 650days with the decrease of temperature from 25°C to 10°C. At higher temperature >15°C, COD removal was above 94% while sewage treatment efficiency and relevant CH4 production decreased below 15°C. The effluent COD at 10°C was 134mg/L at HRT of 16h. Moreover, low temperature can result in a higher membrane fouling rate due to the microbial self-protection behavior in coping with the temperature decrease by releasing soluble microbial products (SMP) and extracellular polymeric substances (EPS)...
July 4, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28709740/effects-of-size-and-thermophilic-pre-hydrolysis-of-banana-peel-during-anaerobic-digestion-and-biomethanation-potential-of-key-tropical-fruit-wastes
#20
Mary Jesuyemi Odedina, Boonya Charnnok, Kanyarat Saritpongteeraka, Sumate Chaiprapat
Methane production potential of tropical fruit wastes, namely lady-finger banana peel, rambutan waste and longan waste were compared using BMP assay and stoichiometric modified Buswell and Mueller equation. Methane yields based on volatile solid (VS) were in the order of ground banana peel, chopped banana peel, chopped longan waste, and chopped rambutan waste (330.6, 268.3, 234.6 and 193.2 mLCH4/gVS) that corresponded to their calculated biodegradability. In continuous operations of banana peel digestion at feed concentrations based on total solid (TS) 1-2%, mesophilic single stage digester run at 20-day hydraulic retention time (20-day HRT) failed at 2%TS, but successfully recovered at 1...
July 11, 2017: Waste Management
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