Evaluation of different configurations of hybrid membrane bioreactors for treatment of domestic wastewater

Four membrane bioreactors (MBRs) with the same dimensions were studied for 180 days: three hybrid growth membrane bioreactors with biofilm attached in different packing media and a conventional MBR (C-MBR). The four MBRs had an identical membrane module of hollow fiber with a nominal porous diameter of 0.4 μm. The MBRs were: (1) a C-MBR; (2) a moving bed membrane bioreactor (MB-MBR), which was packed with 2 L of carrier Kaldnes-K1, presenting an exposed surface area of 678.90 m2/m3; (3) a non-submerged organic fixed bed (OFB-MBR) packed with 6.5 L of organic packing media composed of a mixture of cylindrical pieces of wood, providing an exposed surface area of 178.05 m2/m3; and (4) an inorganic fixed bed non-submerged membrane bioreactor (IFB-MBR) packed with 6 L of spherical volcanic pumice stone with an exposed surface area of 526.80 m2/m3. The four MBRs were fed at low organic loading (0.51 ± 0.19 kgCOD/m3 d). The results were recorded according to the behavior of the total resistance, transmembrane pressure (TMP), permeability, and removal percentages of the nutrients during the experimental time. The results showed that the MB-MBR presented the better performance on membrane filtration, while the higher nutrient removals were detected in the OFB-MBR and IFB-MBR.

Download Full-text

Correction: Rajasekharan, S., et al. Effect of Exposed Surface Area, Volume and Environmental pH on the Calcium Ion Release of Three Commercially Available Tricalcium Silicate Based Dental Cements. Materials 2018, 11, 123

Materials ◽

10.3390/ma14020340 ◽

2021 ◽

Vol 14 (2) ◽

pp. 340

Author(s):

Sivaprakash Rajasekharan ◽

Chris Vercruysse ◽

Luc Martens ◽

Ronald Verbeeck

Keyword(s):

Surface Area ◽

Calcium Ion ◽

Tricalcium Silicate ◽

Exposed Surface ◽

Ion Release ◽

Exposed Surface Area

The authors wish to make the following correction to the paper [...]

Download Full-text

Effect of reduced exposed surface area and enhanced infiltration on ammonia emission from untreated and separated cattle slurry

Biosystems Engineering ◽

10.1016/j.biosystemseng.2021.09.003 ◽

2021 ◽

Vol 211 ◽

pp. 141-151

Author(s):

Johanna Pedersen ◽

Tavs Nyord ◽

Anders Feilberg ◽

Rodrigo Labouriau ◽

Derek Hunt ◽

...

Keyword(s):

Surface Area ◽

Ammonia Emission ◽

Exposed Surface ◽

Cattle Slurry ◽

Exposed Surface Area

Download Full-text

Immersed Membrane BioReactor (IMBR) for treatment of combined domestic and dairy wastewater in an isolated farm

Water Science & Technology ◽

10.2166/wst.2005.0382 ◽

2005 ◽

Vol 51 (10) ◽

pp. 327-334 ◽

Cited By ~ 5

Author(s):

A. Bick ◽

J.G.P. Tuttle ◽

S. Shandalov ◽

G. Oron

Keyword(s):

Membrane Bioreactor ◽

Dairy Farm ◽

Domestic Wastewater ◽

High Strength ◽

Dairy Farms ◽

Pilot Scale ◽

Dairy Wastewater ◽

Transmembrane Pressure ◽

Research Approach ◽

Permeate Flux

In many regions dairy farms and milk processing industries discharge large quantities of their wastes to the surroundings posing serious environmental risks. This problem is mostly faced in small dairy farms and isolated communities lacking both central collection and conventional wastewater treatment systems. Dairy wastewater is characterized by high concentrations of organic matter, solids, nutrients, as well as fractions of dissolved inorganic pollutants, exceeding those levels considered typical for high strength domestic wastewaters. With the purpose of treating the combined dairy and domestic wastewater from a small dairy farm in the Negev Desert of Israel, the use of a recent emerging technology of Immersed Membrane BioReactor (IMBR) was evaluated over the course of 500 test hours, under a variety of wastewater feed quality conditions (during the test periods, the feed BOD5 ranged from 315 ppm up to 4,170 ppm). The overall performance of a pilot-scale Ultrafiltration (UF) IMBR process for a combined domestic and dairy wastewater was analyzed based on the Data Envelopment Analysis (DEA) method. The IMBR performance in terms of membrane performance (permeate flux, transmembrane pressure, and organic removal) and DEA model (Technical Efficiency) was acceptable. DEA is an empirically based methodology and the research approach has been found to be effective in the depiction and analysis for complex systems, where a large number of mutual interacting variables are involved.

Download Full-text

Comparison of Calcaneal Exposure Through the Extensile Lateral and Sinus Tarsi Approaches

Foot & Ankle Specialist ◽

10.1177/1938640017713616 ◽

2017 ◽

Vol 11 (2) ◽

pp. 142-147 ◽

Cited By ~ 6

Author(s):

Katherine M. Bedigrew ◽

James A. Blair ◽

Daniel R. Possley ◽

Kevin L. Kirk ◽

Joseph R. Hsu

Keyword(s):

Surface Area ◽

Lateral Wall ◽

Exposed Surface ◽

Therapeutic Level ◽

Digital Photographs ◽

Levels Of Evidence ◽

Sinus Tarsi ◽

Significant Difference ◽

Exposed Surface Area

The purpose of this study was to compare the exposure of the posterior facet with the extensile lateral (EL) approach compared with the sinus tarsi (ST) approach. We hypothesized that the ST approach will provide a similar exposure of the posterior calcaneal facet. A total of 8 sequential ST then EL approaches were performed on cadavers. Calcaneal landmarks were identified by visualization or palpation. Calibrated digital photographs of the posterior facet and lateral calcaneal body were obtained from standardized positions and used to calculate the exposed surface area. No significant difference was found in the average square area of the posterior facet exposed with the 2 approaches. Significantly more of the lateral calcaneal body was seen with the EL approach. Excluding the posterior facet superomedial quadrant, all the landmarks were visualized in 100% of approaches. The superomedial corner was visualized in significantly more of the cadavers with the EL approach and was palpable in 12.5% of the remaining cadavers in both approaches. Whereas the ST approach exposes less of the lateral wall of the calcaneus, it exposes similar amounts of the posterior facet when compared with the EL approach. Levels of Evidence: Therapeutic, Level V

Download Full-text

Factors Governing the Activity of α‐MnO 2 Catalysts in the Oxygen Evolution Reaction: Conductivity versus Exposed Surface Area of Cryptomelane

Chemistry - A European Journal ◽

10.1002/chem.201905090 ◽

2020 ◽

Vol 26 (53) ◽

pp. 12256-12267 ◽

Cited By ~ 1

Author(s):

Justus Heese‐Gärtlein ◽

Dulce M. Morales ◽

Anna Rabe ◽

Thomas Bredow ◽

Wolfgang Schuhmann ◽

...

Keyword(s):

Surface Area ◽

Oxygen Evolution ◽

Oxygen Evolution Reaction ◽

Exposed Surface ◽

Exposed Surface Area

Download Full-text

The Contributions of Local Heating and Reducing Exposed Surface Area to the Energetic Benefits of Huddling by Short-Tailed Field Voles (Microtus agrestis)

Physiological Zoology ◽

10.1086/physzool.65.4.30158537 ◽

1992 ◽

Vol 65 (4) ◽

pp. 742-762 ◽

Cited By ~ 60

Author(s):

Jack P. Hayes ◽

John R. Speakman ◽

Paul A. Racey

Keyword(s):

Surface Area ◽

Local Heating ◽

Microtus Agrestis ◽

Exposed Surface ◽

Exposed Surface Area

Download Full-text

Brief review of operation of anaerobic wastewater treatment with membrane bioreactors

E3S Web of Conferences ◽

10.1051/e3sconf/20198600020 ◽

2019 ◽

Vol 86 ◽

pp. 00020

Author(s):

Zbigniew Mucha ◽

Włodzimierz Wójcik ◽

Michał Polus

Keyword(s):

Wastewater Treatment ◽

Energy Demand ◽

Membrane Filtration ◽

Membrane Bioreactor ◽

Municipal Wastewater ◽

Anaerobic Treatment ◽

Membrane Bioreactors ◽

Current Status ◽

Municipal Wastewater Treatment ◽

Anaerobic Membrane Bioreactor

In recent years, anaerobic membrane bioreactor (AnMBR) technology has been considered as a very appealing alternative for wastewater treatment due to its significant advantages over conventional anaerobic treatment and aerobic membrane bioreactor (MBR) technology. The paper provides an overview of the current status of the anaerobic membrane bioreactor technology with a special emphasis on its performance and drawbacks when applied for domestic and municipal wastewater treatment. According to the reported data, the renewable energy produced at the plants (i.e. from methane) covered the energy demand for membrane filtration while the excess energy can be further utilized. Anaerobic membrane bioreactors are an attractive technology that needs further research efforts and applications at an industrial scale.

Download Full-text

Highly exposed surface area of {001} facets dominated BiOBr nanosheets with enhanced visible light photocatalytic activity

Physical Chemistry Chemical Physics ◽

10.1039/c5cp06711a ◽

2016 ◽

Vol 18 (8) ◽

pp. 6113-6121 ◽

Cited By ~ 30

Author(s):

Fang Duan ◽

Xiaofeng Wang ◽

Tingting Tan ◽

Mingqing Chen

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Surface Area ◽

Exposed Surface ◽

Visible Light Photocatalytic Activity ◽

Surface Areas ◽

Exposed Surface Area ◽

Visible Light Photocatalytic

The enhanced photocatalytic activity of BiOBr nanosheets depends on the large exposed surface areas of {001} facets (S{001}).

Download Full-text

Effects of solid retention time on the performance of submerged anoxic/oxic membrane bioreactor

Water Science & Technology ◽

10.2166/wst.2006.162 ◽

2006 ◽

Vol 53 (6) ◽

pp. 7-13 ◽

Cited By ~ 8

Author(s):

H.Y. Ng ◽

T.W. Tan ◽

S.L. Ong ◽

C.A. Toh ◽

Z.P. Loo

Keyword(s):

Retention Time ◽

Membrane Fouling ◽

Membrane Bioreactor ◽

Domestic Wastewater ◽

Membrane Bioreactors ◽

Complete Conversion ◽

Solid Retention Time ◽

Solids Retention ◽

Nitrogen Concentrations ◽

Removal Efficiencies

In this study, four similar bench-scale submerged Anoxic/Oxic Membrane Bioreactors (MBR) were used simultaneously to investigate the effects of solids retention time (SRT) on organic and nitrogen removal in MBR for treating domestic wastewater. COD removal efficiencies in all reactors were consistently above 94% under steady state conditions. Complete conversion of NH4+-N to NO3--N was readily achieved over a feed NH4+-N concentration range of 30 to 50 mg/L. It was also observed that SRT did not significantly affect the nitrification in the MBR systems investigated. The average denitrification efficiencies for the 3, 5, 10 and 20 days SRT operations were 43.9, 32.6, 47.5 and 66.5%, respectively. In general, the average effluent nitrogen concentrations, which were mainly nitrate, were about 22.2, 27.6, 21.7 and 13.9 mg/L for the 3, 5, 10 and 20 days SRT systems, respectively. The rate of membrane fouling at 3 days SRT operation was more rapid than that observed at 5 days SRT. No fouling was noted in the 10 days and 20 days SRT systems during the entire period of study.

Download Full-text