scholarly journals Role of Mesh Pore Size in Dynamic Membrane Bioreactors

2021 ◽  
Vol 18 (4) ◽  
pp. 1472
Author(s):  
Pompilio Vergine ◽  
Carlo Salerno ◽  
Barbara Casale ◽  
Giovanni Berardi ◽  
Alfieri Pollice
Keyword(s):  
Pore Size ◽  
Membrane Bioreactors ◽  
Operating Conditions ◽  
Major Influence ◽  
Solid Retention Time ◽  
Dynamic Membrane ◽  
Effluent Quality ◽  
Set Up ◽  
High Suction

Two identical bench-scale Self-Forming Dynamic Membrane BioReactors (SFD MBR) were set-up and operated for the treatment of real urban wastewater. The two bioreactors were equipped with meshes of different mesh pore size. Meshes having pore size values of 20 and 50 µm were tested under solid retention time (SRT) of 15 d, whereas meshes with 50 and 100 µm pore sizes were compared under SRT of 50 d. The results of long-term experiments showed very good overall performances by all systems at the steady state. High flux (in the range 61–71 L m−2 h−1) and very good effluent quality were obtained, with average suspended solids and chemical oxygen demanding values below 10 mg L−1 and 35 mg L−1, respectively. The mesh pore size did not have a major influence on the average cleaning frequency. However, the pore size affected the effluent quality in correspondence of two particular conditions: (i) immediately after mesh cleaning; and (ii) during operation under high suction pressures (mesh clogging not promptly removed through cleaning). Moreover, the mesh cleaning frequency was observed to be dependent on the SRT. In tests with 50 d SRT, the cleaning requirements were very low (one every five days), and this limited the influence of the mesh pore size on the effluent quality. In conclusion, in SFD MBR, the role of the mesh pore size on the effluent quality may be more or less relevant depending on the operating conditions that directly influence the Dynamic Membrane formation.

Feasibility of submerged anaerobic membrane bioreactor (SAMBR) for treatment of low-strength wastewater

2008 ◽  
Vol 58 (10) ◽  
pp. 1925-1931 ◽  
Author(s):  
Z. Huang ◽  
S. L. Ong ◽  
H. Y. Ng
Keyword(s):  
Membrane Fouling ◽  
Membrane Bioreactors ◽  
Organic Loading Rate ◽  
Effluent Quality ◽  
Significant Difference ◽  
Anaerobic Membrane Bioreactors ◽  
High Purification ◽  
Low Strength ◽  
Set Up ◽  
Internal Pore

Two 6-L submerged anaerobic membrane bioreactors (SAMBR) with SRT of 30 and 60 d (denoted as R30 and R60, respectively) were set up and operated for five months, with a mixture of glucose as substrate. Feasibility of SAMBR was studied for treatment of low-strength wastewater. First two months were identified as acclimation stage. A COD removal efficiency was achieved stably at around 99% and biogas productions were maintained at 0.023 and 0.028 L CH4/gMLVSS∙d for R30 and R60, respectively. Even though R60 contained higher MLVSS concentration, no significant difference of treatment performances between both reactors was found due to the low organic loading rate and high purification function of membrane. In the investigation of membrane fouling, less irreversible fouling was observed for R30 compared to R60. High non-flocculent concentration of R60 would be responsible for membrane internal pore blocking and deteriorated effluent quality.

scholarly journals Impact of microbial activity on the performance of planted and unplanted wetland at laboratory scale

2021 ◽  
Author(s):  
Priyanka Jamwal ◽  
Shahana Shirin
Keyword(s):  
Removal Efficiency ◽  
Operating Conditions ◽  
Loading Rates ◽  
N Removal ◽  
Ammonium N ◽  
Set Up ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria ◽  
P Removal

Abstract Three horizontal subsurface flow constructed wetland prototypes were set up to identify and understand the role of microflora in nutrient removal under diverse operating conditions. Out of three setups, one setup served as a control (without plants), and rest were planted with Typha domingensis. The setups were operated at two different hydraulic loading rates (5 cm/day and 16 cm/day) for two months each. Among 27 bacteria species isolated, 80% of nitrate-reducing bacteria were observed in control, and 50–77% of nitrate-reducing bacteria were observed in the plant setups. Presence of diverse denitrifying bacteria and soil organic carbon contributed to high Nitrate-N removal in control at both HLRs. Similar Ammonium-N (29%) and Ortho-P removal (30%) efficiency was observed at both HLRs in the control setup. Processes such as chemical sorption and adsorption dominated the Ammonium-N and Ortho-P removal in control setup. High average Ammonium-N removal efficiency of 89 and 52% was observed in plant setups at 5 cm/day and 16 cm/day HLR. At low HLR Ammonium-N removal in plant setups was dominated by nutrient uptake. In the plant setups, 35 and 15% Ortho-P removal efficiency was observed at low HLR (5 cm/day) and high HLR (16 cm/day) respectively. Hydraulic Retention Time (HRT) limited the uptake of Ortho-P thereby allowing mineralised phosphorus to escape the system without being absorbed by the plants.

Characteristics and role of dynamic membrane layer in anaerobic membrane bioreactors

2015 ◽  
Vol 113 (4) ◽  
pp. 761-771 ◽  
Author(s):  
Mustafa Evren Ersahin ◽  
Yu Tao ◽  
Hale Ozgun ◽  
Henri Spanjers ◽  
Jules B. van Lier
Keyword(s):  
Membrane Bioreactors ◽  
Dynamic Membrane ◽  
Membrane Layer ◽  
Anaerobic Membrane Bioreactors

scholarly journals Biodegradation of Emerging Pharmaceuticals from Domestic Wastewater by Membrane Bioreactor: The Effect of Solid Retention Time

2021 ◽  
Vol 18 (7) ◽  
pp. 3395
Author(s):  
Raghad Asad Kadhim ALOBAIDI ◽  
Kubra ULUCAN-ALTUNTAS ◽  
Rasha Khalid Sabri MHEMID ◽  
Neslihan MANAV-DEMIR ◽  
Ozer CINAR
Keyword(s):  
Biological Treatment ◽  
Membrane Bioreactor ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Pharmaceutical Compounds ◽  
Membrane Bioreactors ◽  
Solid Retention Time ◽  
Effluent Quality ◽  
Treatment Processes ◽  
By Products

Although conventional biological treatment plants can remove basic pollutants, they are ineffective at removing recalcitrant pollutants. Membrane bioreactors contain promising technology and have the advantages of better effluent quality and lower sludge production compared to those of conventional biological treatment processes. In this study, the removal of pharmaceutical compounds by membrane bioreactors under different solid retention times (SRTs) was investigated. To study the effect of SRT on the removal of emerging pharmaceuticals, the levels of pharmaceuticals were measured over 96 days for the following retention times: 20, 30, and 40-day SRT. It was found that the 40-day SRT had the optimum performance in terms of the pharmaceuticals’ elimination. The removal efficiencies of the chemical oxygen demand (COD) for each selected SRT were higher than 96% at steady-state conditions. The highest degradation efficiency was observed for paracetamol. Paracetamol was the most removed compound followed by ranitidine, atenolol, bezafibrate, diclofenac, and carbamazepine. The microbial community at the phylum level was also analyzed to understand the biodegradability of pharmaceuticals. It was noticed that the Proteobacteria phylum increased from 46.8% to 60.0% after 96 days with the pharmaceuticals. The Actinobacteria class, which can metabolize paracetamol, carbamazepine, and atenolol, was also increased from 9.1% to 17.9% after adding pharmaceuticals. The by-products of diclofenac, bezafibrate, and carbamazepine were observed in the effluent samples.

scholarly journals Experimental Simulation of the Behaviour of Diagnostic First Mirrors Fabricated of Different Metals for ITER Conditions

2016 ◽  
Vol 3 (1) ◽  
pp. 23-54 ◽  
Author(s):  
V.S. Voitsenya ◽  
A.F. Bardamid ◽  
A.J.H. Donné
Keyword(s):  
Operating Conditions ◽  
Experimental Simulation ◽  
Science Center ◽  
Plasma Facing Component ◽  
Laser Diagnostic ◽  
Set Up ◽  
The Impact ◽  
Experimental Fusion

In the experimental fusion reactor ITER, the plasma-facing component of each optical and/or laser diagnostic needs to be based on reflective optics with at least one mirror (first mirror) facing the thermonuclear plasma. The different kinds of radiation emanating from the burning plasma (neutrons, neutral atoms, electromagnetic radiation) create hostile operating conditions for the first mirrors. Therefore, a special program has been set up under the ITER framework aimed at solving the first mirror problem. This paper will review the main results in this field that have been obtained in the Institute of Plasma Physics, National Science Center “Kharkov Institute of Physics and Technology” (in many cases in cooperation with groups of other countries, as indicated in corresponding parts of the manuscript) during long-term investigations directed to find a solution of this problem,i.e., to find a material and accompanying precautions in order to satisfy the requirements for first mirrors. The main efforts were devoted to finding solutions to overcome the impact of the most severe deteriorating factors resulting in degradation of the optical properties of mirrors: sputtering by charge exchange atoms and deposition of contaminants. The obtained results are focused on: the effects of long term sputtering on mirror specimens fabricated from different metals with different structures (polycrystals, single crystals, metal film on metal substrates, amorphous), the effects of contaminating film and the possible protection to avoid of its appearance, the role of chemical processes for some metal mirrors, and the choice of material of laser mirrors.

From Trinidad and Tobago to the World: Determining the role of Calypso in a new Era

2020 ◽  
Vol 5 ◽  
pp. 7-11
Author(s):  
Malek Abdel-Shehid
Keyword(s):  
Trinidad And Tobago ◽  
Regional Integration ◽  
West African ◽  
Major Influence ◽  
New Era ◽  
Transatlantic Slave Trade ◽  
Cultural Sovereignty ◽  
Caribbean Culture ◽  
Musical Cultures

Calypso is a popular Caribbean musical genre that originated in the island nation of Trinidad and Tobago. The genre was developed primarily by enslaved West Africans brought to the region via the transatlantic slave trade during the seventeenth and eighteenth centuries. Although West-African Kaiso music was a major influence, the genre has also been shaped by other African genres, and by Indian, British, French, and Spanish musical cultures. Emerging in the early twentieth century, Calypso became a tool of resistance by Afro-Caribbean working-class Trinbagonians. Calypso flourished in Trinidad due to a combination of factors—namely, the migration of Afro-Caribbean people from across the region in search of upward social mobility. These people sought to expose the injustices perpetrated by a foreign European and a domestic elite against labourers in industries such as petroleum extraction. The genre is heavily anti-colonial, anti-imperial, and anti-elitist, and it advocated for regional integration. Although this did not occur immediately, Calypsonians sought to establish unity across the region regardless of race, nationality, and class through their songwriting and performing. Today, Calypso remains a unifying force and an important part of Caribbean culture. Considering Calypso's history and purpose, as well as its ever-changing creators and audiences, this essay will demonstrate that the goal of regional integration is not possible without cultural sovereignty.

A reconnaissance of tropical resources during Revolutionary years: the role of the Paris Museum d'Histoire Naturelle

1991 ◽  
Vol 18 (3) ◽  
pp. 333-362 ◽  
Author(s):  
MADELEINE LY-TIO-FANE
Keyword(s):  
South Africa ◽  
Natural History ◽  
Scientific Research ◽  
Extensive Literature ◽  
War Of Independence ◽  
Leading Role ◽  
Scientific Principles ◽  
Set Up ◽  
Joseph Ii

SUMMARY The recent extensive literature on exploration and the resulting scientific advances has failed to highlight the contribution of Austrian enterprise to the study of natural history. The leading role of Joseph II among the neutral powers which assumed the carrying trade of the belligerents during the American War of Independence, furthered the development of collections for the Schönbrunn Park and Gardens which had been set up on scientific principles by his parents. On the conclusion of peace, Joseph entrusted to Professor Maerter a world-encompassing mission in the course of which the Chief Gardener Franz Boos and his assistant Georg Scholl travelled to South Africa to collect plants and animals. Boos pursued the mission to Isle de France and Bourbon (Mauritius and Reunion), conveyed by the then unknown Nicolas Baudin. He worked at the Jardin du Roi, Pamplemousses, with Nicolas Cere, or at Palma with Joseph Francois Charpentier de Cossigny. The linkage of Austrian and French horticultural expertise created a situation fraught with opportunities which were to lead Baudin to the forefront of exploration and scientific research as the century closed in the upheaval of the Revolutionary Wars.

‘A disoriented vision of … fact’: Brian Friel, Francis Bacon, and Faith Healer

2020 ◽  
Vol 50 (2) ◽  
pp. 319-336
Author(s):  
Zosia Kuczyńska
Keyword(s):  
Creative Process ◽  
Francis Bacon ◽  
Major Influence ◽  
Artistic Practice ◽  
Archival Research ◽  
Faith Healer ◽  
Brian Friel ◽  
History Of ◽  
Composition Process

The Brian Friel Papers at the NLI reveal a long and relatively unexplored history of major and minor influences on Friel's plays. As the archive attests, these influences manifest themselves in ways that range from the superficial to the deeply structural. In this article, I draw on original archival research into the composition process of Friel's genre-defining play Faith Healer (1979) to bring to light a model of influence that operates at the level of artistic practice. Specifically, I examine the extent to which Friel's officially unacknowledged encounter with a book of interviews with painter Francis Bacon influenced the play in terms of character, language, and form. I suggest that Bacon's creative process – incorporating his ideas on the role of the artist, the workings of chance, and the extent to which art does violence to fact – may have had a major influence on both the play's development and on Friel's development as an artist.

A Critical Look into the Deviation of Full Scale Performance from Design Expectations

1989 ◽  
Vol 21 (10-11) ◽  
pp. 1389-1402 ◽  
Author(s):  
R. Zaloum
Keyword(s):  
Expert Systems ◽  
Waste Treatment ◽  
Full Scale ◽  
Operating Conditions ◽  
Organic Load ◽  
Computer Assisted ◽  
Uniform Load ◽  
Effluent Quality ◽  
Simulation Techniques ◽  
Steady Level

Deviations from design expectations appear to stem from views which assume that a unique response should result from a given set of operating conditions. The results of this study showed that two systems operating at equal organic loads or F/M ratios and at the same SRT do not necessarily give equal responses. This deviation was linked to the manner in which the HRT and influent COD are manipulated to obtain a constant or uniform load, and to subtle interactions between influent COD, HRT and SRT on the biomass and effluent responses. Increases of up to 200% in influent COD from one steady level to the next did not significantly influence the effluent VSS concentration while an effect on filtered COD was observed for increases as low as 20%. Effluent TKN and filtered COD correlated strongly with the operating MLVSS while phosphorus residual depended on the operating SRT and the organic load removed. These results point to the inadequacy of traditional models to predict effluent quality and point to the need to consider these effects when developing simulation techniques or computer assisted expert systems for the control of waste treatment plants.

Sign in / Sign up

Export Citation Format

Share Document