Experimental evaluation of intermittent aeration of a hollow fibre membrane bioreactor

2011 ◽  
Vol 63 (6) ◽  
pp. 1217-1223 ◽  
Author(s):  
Bart Verrecht ◽  
Christopher James ◽  
Eve Germain ◽  
Wenjing Ma ◽  
Simon Judd
Keyword(s):  
Large Scale ◽  
Membrane Bioreactor ◽  
Weather Conditions ◽  
Hollow Fibre ◽  
Membrane Bioreactors ◽  
High Flux ◽  
Intermittent Aeration ◽  
Small Plant ◽  
Membrane Aeration ◽  
Net Flux

Intermittent membrane aeration provides a substantially improved energy efficiency in hollow fibre-based immersed membrane bioreactors (HF iMBRs). The benefits of intermittent aeration have been assessed with respect to sustaining a target flux and/or limiting the fouling rate to a sustainable level based on a small plant using full-scale HF modules. Results show that for the same specific aeration demand per unit of permeate produced (SADp), fouling rates were significantly lower for 10 s filtration, 30 s relaxation (“10:30” intermittent aeration) compared to 10:10 and continuous aeration. At a net flux (Jnet) of 23.3 litres m−2 h−1 (LMH), a SADp of 4.6 was found sufficient to sustain operation, this value being up to 75% and 50% lower compared to continuous and 10:10 aeration respectively. This empirical data was compared with heuristic data from 5 large scale HF iMBR plants, which revealed that 10:30 aeration can sustain a relatively high flux (up to 25.3 LMH) under dry weather conditions in warm climates, with the recorded SADp ranging from 5.3–10.9.

Strategies for chemical cleaning in large scale membrane bioreactors

2008 ◽  
Vol 57 (3) ◽  
pp. 457-463 ◽  
Author(s):  
C. Brepols ◽  
K. Drensla ◽  
A. Janot ◽  
M. Trimborn ◽  
N. Engelhardt
Keyword(s):  
Large Scale ◽  
Membrane Bioreactor ◽  
Effective Means ◽  
Membrane Bioreactors ◽  
Ex Situ ◽  
Chemical Cleaning ◽  
Membrane Cleaning ◽  
Cleaning Agents ◽  
Cleaning Procedures ◽  
Alkaline Cleaning

Systematically testing alternative cleaning agents and cleaning procedures on a large scale municipal membrane bioreactor, the Erftverband optimized the cleaning strategies and refined the original cleaning procedures for the hollow fiber membranes in use. A time-consuming, intensive ex-situ membrane cleaning twice a year was initially the regular routine. By introducing the effective means of cleaning in place in use today, which employs several acidic and oxidative/alkaline cleaning steps, intensive membrane cleaning could be delayed for years. An overview and an assessment of various cleaning strategies for large scale plants are given.

Exploring the potential of membrane bioreactors to enhance metals removal from wastewater: pilot experiences

2008 ◽  
Vol 57 (4) ◽  
pp. 505-511 ◽  
Author(s):  
F. Fatone ◽  
A. L. Eusebi ◽  
P. Battistoni ◽  
P. Pavan
Keyword(s):  
Membrane Bioreactor ◽  
Membrane System ◽  
Hollow Fibre ◽  
Membrane Bioreactors ◽  
Permeate Flux ◽  
Nickel Ions ◽  
Filtration Cycle ◽  
Metals Removal ◽  
Membrane Effect ◽  
Membrane Effects

The potential of membrane bioreactors to enhance the removal of selected metals from low loaded sewages has been explored. A 1400 litre pilot plant, equipped with an industrial submerged module of hollow fibre membranes, has been used in three different configurations: membrane bioreactor, operating in sequencing batch modality, for the treatment of real mixed municipal/industrial wastewater; membrane-assisted biosorption reactor, for the treatment of real leachate from municipal landfills; continuously fed membrane bioreactor, for the treatment of water charged with cadmium and nickel ions. The results show that: (a) in treating wastewaters with low levels of heavy metals (< one milligram per litre concentration), operating high sludge ages is not an effective strategy to significantly enhance the metals removal; (b) Hg and Cd are effectively removed already in conventional systems with gravitational final clarifiers, while Cu, Cr, Ni can rely on a additional performance in membrane bioreactors; (c) the further membrane effect is remarkable for Cu and Cr, while it is less significant for Ni. Basically, similar membrane effects recur in three different experimental applications that let us estimate the potential of membrane system to retain selected metal complexes. The future development of the research will investigate the relations between the membrane effect and the manipulable filtration parameters (i.e., permeate flux, solids content, filtration cycle).

scholarly journals Upgrade of the Taskila WWTP with an MBR line: the first treatment results, performance assessment and lessons learnt

2020 ◽  
Vol 15 (4) ◽  
pp. 1111-1125
Author(s):  
H. Haimi ◽  
S. Risteelä ◽  
M. Di Pofi ◽  
J. Lahtinen
Keyword(s):  
Energy Consumption ◽  
Membrane Filtration ◽  
Large Scale ◽  
Membrane Bioreactor ◽  
Treatment Plant ◽  
Operating Mode ◽  
Hybrid Plant ◽  
Fine Tuning ◽  
Plant Performance ◽  
Membrane Aeration

Abstract In this paper, we present the first results of a large-scale membrane bioreactor application implemented for increasing the wastewater treatment plant capacity. The Taskila plant in Finland was upgraded in 2018 and is now operated as a hybrid system with parallel membrane bioreactor and conventional biological lines. The results showed that membrane filtration improved the plant performance significantly in terms of the solids and pathogens removal. Nitrogen removal has been stable with the current operating set-points and notably better than before the plant expansion. The analysis using key performance indicators showed that there were no significant differences in operational expenditures between the membrane and conventional lines. The membrane filtration results highlight the importance of maintaining the good sludge filterability properties that enable higher operational fluxes and reduced energy consumption. The low membrane aeration flow-rate mode, the standard operating mode with good sludge filterability, enabled reduction of total aeration energy consumption by 34% for the membrane bioreactor, including both activated sludge and membrane aeration. Fine-tuning of the hybrid plant is still going on and, therefore, improved overall results are expected in the forthcoming years.

Applied Research in Membrane Fouling in the Membrane Bioreactor Systems with Large-scale Equipment

2019 ◽  
Vol 1 (1) ◽  
pp. 1-10
Author(s):  
Kong Linghan ◽  
Zhao Weidian ◽  
Ran Deqin ◽  
Hui Bing ◽  
Lu Linguo ◽  
...  
Keyword(s):  
Membrane Fouling ◽  
Large Scale ◽  
Membrane Bioreactor ◽  
Applied Research

scholarly journals Performance of Strawberry Varieties Developed for Perennial Matted-Row Production in Annual Plasticulture in a Cold Climate Region

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1407
Author(s):  
Courtney A. Weber
Keyword(s):  
Large Scale ◽  
Fruit Size ◽  
Weather Conditions ◽  
Cold Climate ◽  
Annual Production ◽  
High Yield ◽  
Production Cycle ◽  
Late Season ◽  
Berry Weight ◽  
High Yields

Annual plasticulture production of strawberries promises superior weed control, fruit quality and yields. However, strawberry varieties adapted for perennial, matted-row production and local markets in cold climate regions have not been widely tested for adaptation to an annual production cycle. Productivity of seven short-day varieties developed for matted-row and/or annual production was examined in an annual plasticulture system in two consecutive trials in central NY (lat. 42.87° N, long. 76.99° W) harvested in 2013 and 2014. ‘Flavorfest’ demonstrated good performance in Trial 1 with high yield (390 g/plant) and large fruit size (13.9 g mean berry weight). ‘Jewel’ was shown to be well adapted to the annual plasticulture system with consistently high yields (330 and 390 g/plant) that equaled or surpassed other varieties and had moderate fruit size. ‘Chandler’ performed similarly to previous trials conducted in warmer regions with yield (340 g/plant) and fruit size (9.8 g mean berry weight) similar to ‘Jewel’. ‘Clancy’ yielded less but was consistent from year to year. The late season varieties Seneca and Ovation showed marked variability between years, possibly due to drastically different temperatures during flowering and fruit development in Trial 1 compared to Trial 2. High temperatures in Trial 1 likely caused higher early fruit yield, a compressed season and a precipitous decline in fruit size in the later season, thus reducing yield in the late season. Survival after a second dormant period was poor resulting in a small second harvest and reduced fruit size. Overall, the system demonstrated many of the expected benefits but may be more sensitive to weather conditions in the region. While many varieties developed for matted-row production may work well in an annual plasticulture system, not all varieties are equally adapted. Performance of each variety should be determined independently before large scale adoption by growers.

Comparison of the efficiency of large-scale ceramic and membrane aeration systems with the dynamic off-gas method

2002 ◽  
Vol 46 (4-5) ◽  
pp. 317-324 ◽  
Author(s):  
J.A. Libra ◽  
A. Schuchardt ◽  
C. Sahlmann ◽  
J. Handschag ◽  
U. Wiesmann ◽  
...  
Keyword(s):  
Large Scale ◽  
Operating Conditions ◽  
Air Distribution ◽  
Energy Costs ◽  
Dissolved Oxygen Concentration ◽  
Membrane Aeration ◽  
Aeration System ◽  
Oxygen Transfer Efficiency ◽  
Aeration Efficiency ◽  
Period Measurement

The aeration systems of two full-scale activated sludge basins were compared over 2.5 years under the same operating conditions using dynamic off-gas testing. Only the material of the diffuser was different, membrane vs. ceramic tube diffusers. The experimental design took the complexity and dynamics of the system into consideration. The investigation has shown that, although the membrane diffusers have higher initial standard oxygen transfer efficiency (SOTE) and standard aeration efficiency (SAE), these decreased over time, while the SAE of the ceramic diffusers started lower, but increased slightly over the whole period. Measurement of air distribution in the basins along with dissolved oxygen concentration profiles have provided important information on improving process control and reducing energy costs. The results show that dynamic off-gas testing can effectively be used for monitoring the aeration system and to check design assumptions under operating conditions. The information can be used to improve the design of new aeration systems or in retro-fitting existing basins.

scholarly journals A High-Speed, Light-Weight Scalar Magnetometer Bird for km Scale UAV Magnetic Surveying: On Sensor Choice, Bird Design, and Quality of Output Data

2021 ◽  
Vol 13 (4) ◽  
pp. 649
Author(s):  
Arne Døssing ◽  
Eduardo Lima Simoes da Silva ◽  
Guillaume Martelet ◽  
Thorkild Maack Rasmussen ◽  
Eric Gloaguen ◽  
...  
Keyword(s):  
High Speed ◽  
Large Scale ◽  
Signal To Noise Ratio ◽  
Regional Scale ◽  
Weather Conditions ◽  
Light Weight ◽  
Output Data ◽  
Efficient Manner ◽  
Flexible System ◽  
Scalar Data

Magnetic surveying is a widely used and cost-efficient remote sensing method for the detection of subsurface structures at all scales. Traditionally, magnetic surveying has been conducted as ground or airborne surveys, which are cheap and provide large-scale consistent data coverage, respectively. However, ground surveys are often incomplete and slow, whereas airborne surveys suffer from being inflexible, expensive and characterized by a reduced signal-to-noise ratio, due to increased sensor-to-source distance. With the rise of reliable and affordable survey-grade Unmanned Aerial Vehicles (UAVs), and the developments of light-weight magnetometers, the shortcomings of traditional magnetic surveying systems may be bypassed by a carefully designed UAV-borne magnetometer system. Here, we present a study on the development and testing of a light-weight scalar field UAV-integrated magnetometer bird system (the CMAGTRES-S100). The idea behind the CMAGTRES-S100 is the need for a high-speed and flexible system that is easily transported in the field without a car, deployable in most terrain and weather conditions, and provides high-quality scalar data in an operationally efficient manner and at ranges comparable to sub-regional scale helicopter-borne magnetic surveys. We discuss various steps in the development, including (i) choice of sensor based on sensor specifications and sensor stability tests, (ii) design considerations of the bird, (iii) operational efficiency and flexibility and (iv) output data quality. The current CMAGTRES-S100 system weighs ∼5.9 kg (including the UAV) and has an optimal surveying speed of 50 km/h. The system was tested along a complex coastal setting in Brittany, France, targeting mafic dykes and fault contacts with magnetite infill and magnetite nuggets (skarns). A 2.0 × 0.3 km area was mapped with a 10 m line-spacing by four sub-surveys (due to regulatory restrictions). The sub-surveys were completed in 3.5 h, including >2 h for remobilisation and the safety clearance of the area. A noise-level of ±0.02 nT was obtained and several of the key geological structures were mapped by the system.

scholarly journals Continuous transformation of chiral pharmaceuticals in enzymatic membrane bioreactors for advanced wastewater treatment

2017 ◽  
Vol 76 (7) ◽  
pp. 1816-1826 ◽  
Author(s):  
Luong N. Nguyen ◽  
Faisal I. Hai ◽  
James A. McDonald ◽  
Stuart J. Khan ◽  
William E. Price ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Membrane Bioreactor ◽  
Redox Mediator ◽  
Membrane Bioreactors ◽  
Continuous Transformation ◽  
Chiral Inversion ◽  
Enantiomeric Analysis ◽  
Chiral Pharmaceuticals ◽  
Advanced Wastewater Treatment ◽  
Enzymatic Membrane

This study demonstrates continuous enantiomeric inversion and further biotransformation of chiral profens including ibuprofen, naproxen and ketoprofen by an enzymatic membrane bioreactor (EMBR) dosed with laccase. The EMBR showed non-enantioselective transformations, with high and consistent transformation of both (R)- and (S)-ibuprofen (93 ± 6%, n= 10), but lower removals of both enantiomers of naproxen (46 ± 16%, n= 10) and ketoprofen (48 ± 17%, n= 10). Enantiomeric analysis revealed a bidirectional but uneven inversion of the profens, for example 14% inversion of (R)- to (S)- compared to 4% from (S)- to (R)-naproxen. With redox-mediator addition, the enzymatic chiral inversion of both (R)- and (S)-profens remained unchanged, although the overall conversion became enantioselective; except for (S)-naproxen, the addition of redox mediator promoted the degradation of (R)-profens only.

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