Membrane bioreactor (MBR) technology for wastewater reuse – a sustainable solution for

future water supply

J. Hoinkis

Karlsruhe University of Applied Sciences, Karlsruhe, Germany

Motivation - Freshwater availabilty

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Definition of Membrane Process

In a membrane separation process, a feed consisting of a mixture of two or more components is partially separated by means of a semipermeable barrier through which one or more species move faster than the other species

In water and wastewater treatment applications, membrane processes are used as a solid/liquid separation process. In this case, water is more readily transported through the membrane than solids (both suspended and dissolved)

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Membrane Separation

Solvent Particle or Solute

Molecule

Membrane

Permeate Feed

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Pressure-driven membranes Processes

Microfiltration (MF)

Ultrafiltration (UF)

Nanofiltration (NF)

Reverse Osmosis (RO)

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Pressure-driven Membrane Processes

10-4 10-3 10-2 10-1 1 10 100

Particle / Molecule Size [mm]

Pressure difference

[bar]

1

10

100

Nano-

filtration

Reverse

osmosis

Microfiltration

Filtration

Ultrafiltration

Bacteria Viruses

Pigments

Emulsions

Cells

Salt ions

Sugar

Proteins

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Range of pore size of MBR membranes

Membrane Bioreactor Technology

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Membranes in Treatment of Drinking Water

The application of specific pressure-driven membrane process is highly dependent on the characteristics and quality of the source water

Surface water: MF, UF, NF

Groundwater (fresh): MF, UF

Groundwater (brackish): MF/UF pretreatment, NF, RO

Seawater: MF/UF pretreatment, NF, RO

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Membranes in Treatment of Wastewater

The application of specific pressure-driven membrane process in wastewater treatment is highly dependent on the characteristics/quality of the source water and the pretreatment process/es used

Raw wastewater: MF/UF, MBR

Effluent: MF/UF pretreatment, NF, RO

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Membrane Technologies and their Traditional Counterparts

Membrane Separation Technology

Constituents Removed Comparable traditional Water Treatment Method

MF Bacteria and large colloids; precipitates and coagulates

Ozonation-UV, chlorination, sand filtration, bioreactors, coagulation-sedimentation

UF All of the above + viruses, high MW proteins, organics

Sand filter, bioreactor, activated carbon

NF All of the above + divalent ions, large monovalent ions, color, odor

Lime-soda softening, ion exchange

RO All of the above + monovalent ions Distillation, evaporation, ion exchange

ED/EDR Dissolved ionic salts Ion exchange

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Target Solutes

MF: Microbes (protozoa and bacteria)

Turbidity (particles and colloids)

UF: Same as MF + viruses, “some” NOM

NF: Same as UF + NOM, SOCs (e.g., Atrazine),

Divalent cations (Ca2+, Mg2+, Zn2+, Cd2+, etc.),

Polyvalent anions (SO42-, PO4

3-, AsO43-, CrO4

2-, etc.)

RO: Same as NF + simple ions (TDS, NO3-, ClO4

-)

MF + Coagulant: viruses, NOM (also fouling reduction)

UF + PAC: SOCs, NOM (also fouling reduction)

Submerged MF and UF: Fe and Mn (aeration),

NOM (with coagulant), SOCs (with PAC)

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Basic structures of membranes

Dense structure with microporous support

Reverse Osmosis, Nano Filtration

Microporous Pore size 0,01 - 10 µm

Micro Filtration, Ultra Filtration

1m

Membrane Bioreactor Technology

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MBR Technology

MBR is a combination of bioreactor and membrane technology (microfiltration, ultrafiltration)

Membranes are submerged in bioreactor

Feed

Effluent

Air

Bioreactor and membranes are separate

Bioreactor

Feed

Effluent

Air

Membrane Bioreactor Technology

Comparison of MBR Technology vs. Conventional Bioreactors

Advantages

• High efficiency in degradation of organic compounds

• Low sludge loading low rates of surplus sludge

• No clarifier needed

• High MLSS small bioreactor volume

• Cleaned water free of turbidity and very low germ level ( no disinfection!) reuse!

Challenges

• Membrane cost ( capital cost)

• Aeration cost ( operating cost)

www.hitachi-pt.com/mbr/mbr_outline.html

Membrane Bioreactor Technology

www.water-technology.net

www.microdyn-nadir.de

Commercially available submerged MBR modules

www.waterandwastewater.com

www.waterworld.com

Flat Plate Hollow fiber

www.ecomagination.com

www.huber.de

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Membrane Bioreactor Technology

15 www.lenntech.com/processes/submerged-mbr.htm

Membrane Bioreactor Technology

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Large-scale MBR Plant Nordkanal Sewage Treatment Plant (Germany)

Population: 80,000 Total membrane area: 84,500 m2

reliableplant.com/Read/19514/diving-into-access-scarcity-at-world-water-week

Membrane Bioreactor Technology

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Small-scale MBR Plant (Germany) Household level

www.yumpu.com/user/busse.gt.com

Membrane Bioreactor Technology

Challenges for MBR membranes

• Membrane fouling intensive aeration, chemical cleaning

• Water quality of permeate post-treatment (NF, RO) needed

Developing functionalized self-cleaning membranes!

VicInAqua project

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Integrated aquaculture based on sustainable water

recirculating system for the Victoria Lake Bassin

Project Coordinator

Prof. Dr.- Ing. Jan Hoinkis

Duration

01.06.16 – 31.05.19

VicInAqua has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 689427”.

VicInAqua Project

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High population density (30 Mio.) and rapid urbanisation

Growth of fish processing industry

Overfishing depletion of fish stocks

High wastewater discharge into the Lake Victoria overfertilisation

High rate of poverty and poor sanitation system

[w ww.worldatlas.com] [w ww.lake-victoria.net]

VicInAqua – Challenges at Lake Victoria

VicInAqua has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 689427”.

21 VicInAqua has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 689427”.

VicInAqua – Project partners

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VicInAqua – Project objectives

VicInAqua has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 689427”.

23 VicInAqua has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 689427”.

Microemulsion

preparation

Polymerization occurs

in some seconds

PBM Nitrogen

atmosphere

PBM is cast on a

commercial membrane

Microemulsion

UV-light

VicInAqua – Novel PBM Membrane coating

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VicInAqua – Novel PBM Membrane coating

VicInAqua has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 689427”.

[Chae S, Chung J.; Water 2015]

Less fouling by Polymerisable Bicontinuous Microemulsion (PBM) coating

Reduction of surface roughness

Higher hydrophilicity

Anti-microbial property

PBM coated

Flat sheet laboratory testing unit and small scale MBR

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VicInAqua – Test facilities

VicInAqua has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 689427”.

• MBR treatment of waste water is a robust and small footprint technology • Membrane fouling is still the main challenge in MBR technology

• MBR can provide good water quality which can comply with some reuse water requirements, however, better water quality is needed (industrial reuse!)

• Nanostructered functionalized membrane materials can contribute to develping low fouling membranes with high rejection of compounds with low molecular weight

Summary and Outlook

26 VicInAqua has received funding from the European Union’s Horizon 2020 research

and innovation programme under grant agreement No 689427”.

Thank you for your attention!

www.vicinaqua.eu

27 VicInAqua has received funding from the European Union’s Horizon 2020 research

and innovation programme under grant agreement No 689427”.