Patterns Recognition of Anions and NOM Rejections by RO and NF Membranes under Low to High

Salinity Conditions, associated with Membrane Properties

Sunjin Kim1, Sungyun Lee1, Hyunggyu Park2, Sungro Yoon2, Jaeweon Cho1

1 Gwangju Institute of Science & Technology (GIST)Department of Environmental Science and Engineering

NOM NRL ecology lab.2 Woongjin Chemical

• Size effect • Electrostatic interaction• Hydrophobicity

BackgroundsRemoval behavior factors

- -- -- Hydrophobic membrane

NOM hydrophobic

2/24

Backgrounds

--

- - -- -

-SO4

2- NO3-

--

Electrostatic interaction

membrane

membrane

--

-- -

-SO4

2- NO3-

Size effect

Weakly negative Strongly negative

-- -

SO42- NO3

-

Small MWCO

-- -

SO42- NO3

-

`

Large MWCO

L. Paugam et al. (2004)

3/24

Tested membranes

• NF- NE 40- NE 70- NE 90

Membrane Manfacturer Material MWCO(Daltons)

NE40NE70NE90

SR

Woongjin Chemical

Woongjin Chemical

Woongjin Chemical

Woongjin Chemical

Piperazine based polyamide

Piperazine based polyamide

MPD based polyamide

MPD based polyamide

100025020075

Table 1. Membrane properties

- SR• RO

MPD: Meta phenylene diamine

piperazine

Hydrophilic

m-Phenylenediamine

Hydrophobic

4/24

Damyang WWTP effluent

Temp. conductivity DOC TN NH3-N23℃ 823 μS/cm 7.2 ppm 10.3 ppm 4.6 ppm

NO2--N NO3

--N F- Cl- Br- SO42- PO4

3-

2.70 4.54 0.14 187.2 0.29 50.0 1.92

(ppm)- Anions concentration

Chemical Composition of DY WWTP water

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WWTP

Sea water (Suncheon estuarine

wetland)

River surface water

Brackish water

Suncheon Estuarine Wetland 6/24

Suncheon Estuarine Wetland

Conductivity DOC TNRiver water 75.8 μS/cm 0.98 ppm 1.04 ppm

Brackish water 17.1 mS/cm 2.38 ppm 8.43 ppmSeawater 27.9 mS/cm 2.21 ppm 3.20 ppm

NO2--N NO3

--N F- Cl- Br- SO42- PO4

3-

River water

Brackish water

Seawater

0.01 1.21 0.06 8.86 0.03 5.18 -

- 2.21 0.32 6300 17.6 730 0.87

- 1.32 0.61 12460 29.8 1400 -

(ppm)- Anions concentration

- Chemical Composition of Suncheon water7/24

- DOC/TN

Methods

TOC VCPH/TNM-1, Shimadzu Corporation, Japan

ICS-90, Dionex Corporation, USA

- IC

contact angle goniometer (model 100, Ramé-Hart, Inc. USA)

ELS-8000, Photal, OtsukaElectronics, Japan

- Contact angle

- Zeta potential

8/24

Methods

Membrane chraterization

- Contact angle

- Zeta potential

- HPLC - PSD - AFM

- SEM

Results

Contact angle

NF: NE40, Piperazine based polyamide1000Da

NE70, Piperazine based polyamide250Da

NE90, MPD based polyamide200Da

RO: SR, MPD based polyamide, 100Da

Hydrophilic

Hydrophobic

Hyd

roph

ilic

Hyd

roph

obic

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NE40

SR

NE90

NE70

Zeta potential

NE40 Zeta potential

Stronglynegative

Weakly negative

NE70NE90SR

Neutral pH

Zeta potential of all membranes are negative.

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Characterization of NF and RO NE40 NE70 NE90

Piperazinebased polyamide

MPD based polyamide

200 Da

50.6 °

Zeta potential(at pH 7)

-16.0 mV -51.5 mV -50.5 mV -60.9 mV

Roughness 11 nm 11 nm 43 nm 117 nm

250 Da

32.2 °

SR

Material Piperazinebased polyamide

MPD based polyamide

MWCO 1000 Da 75 Da

Contact angle 24.2 ° 44.5 °

NE40 NE70 NE90 SR

AFM Images

12/24

Anticipated removal efficiency – SR > NE90 > NE70 > NE40

RO size, hydrophobicity,electrostatic interaction

Anticipated removal behaviorsNOM

Cl-Br-

NO2-

NO3-

SO42-

PO43- Humic Non-

humic

RO High/size

High/size

High/size

High/size

High/size

Non-charged Low Medium Low

Medium Low

Medium Low Low

Medium Low Medium High

Medium High

Medium High Low

Highly-negative

Medium/charge

High/charge,

size

High/charge,

size

High/charge,

size

Medium/charge

NF

13/24

NH4+ -N NO2

- -N NO3- -N TN DOC

Removal efficiency of NF membranes(DY WWTP)

SR

>>

NE90

NE40

NE70

>14/24

Comparisons among NF membranes(DY WWTP)

NE40 NE70Piperazine based

polyamidePiperazine based

polyamide

250 Da

32.2°

-51.5 mV

83.5%

13.9%

28.1%

-6.7%

-10.0%

100%

99.4%

1000 Da

24.2 °

-16.0 mV

79.0%

40.4%

57.5%

29.4%Removal efficiency of NO3

- -N 25.1% 66.8%Removal efficiency of PO4

3- 83.1% 95.7%Removal efficiency of SO4

2- 87.0% 95.3%

NE90

Material MPD based polyamide

Removal efficiency of NH4+-N 82.0%

MWCO 200 Da

Contact angle 50.6 °

Zeta potential (at pH 7) -50.5 mVRemoval efficiency of DOC 86.3%Removal efficiency of TN 72.5%

Removal efficiency of NO2--N 70.0%

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Removal behaviors – anions( DY WWTP )

NE40 NE70

29.4% -6.7%

-10.0%

60.9%

11.3%

-150.5%

Removal efficiency of NO3- -N 25.1% 66.8%

Removal efficiency of F- 68.7% 82.1%Removal efficiency of Cl- 50.4% 84.4%Removal efficiency of Br- - 94.8%

NE90Removal efficiency of NO2

--N 70.0%

NE40 NE70Removal efficiency of PO4

3- 83.1% 100%

99.4%

95.7%Removal efficiency of SO4

2- 87.0% 95.3%

NE90

monovalent anions – NE90 > NE40 > NE70

divalent anions – NE70 > NE90 > NE40trivalent anions

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Removal behaviors – RO membrane(DY WWTP)

SR

Material MPD based polyamide

Removal efficiency of NH3-N 94.9%

Removal efficiency of NO3- -N 98.6%

Removal efficiency of PO43- 100%

Removal efficiency of SO42- 99.7%

MWCO 75Da

Contact angle 44.5 °

Zeta potential (at pH 7) -60.9 mV

Removal efficiency of DOC 93.0%Removal efficiency of TN 96.1%

Removal efficiency of NO2--N 98.7% Removal efficiency of F- 100%

Removal efficiency of Cl- 99.5%

Removal efficiency of Br- 100%

m-Phenylenediamine

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Removal efficiency(Suncheon Estuarine wetland)

TN Conductivity DOC NO2--N NO3

--N

TN Conductivity DOC NO3--N TN Conductivity DOC NO3

--N

River surface water> Brackish water> Sea water

Removal behaviors – anions(Suncheon Estuarine wetland)

NE40 NE70

31.4% 16.4%

17.8%

14.1%

96.3%

Removal efficiency of Br- 26.1% 65.8%Removal efficiency of Cl- 33.1% 54.7%

Removal efficiency of SO42- 73.0% 91.9%

NE90Removal efficiency of NO3

- -N 40.5%

NE40 NE70Removal efficiency of NO3

- -N 5.58% 0.70%Removal efficiency of Br- 23.1% 3.86% 36.1%Removal efficiency of Cl- 28.3% 16.3% 40.8%

Removal efficiency of SO42- 74.9% 97.7% 84.4%

19.97%NE90

Brackish water – NE90 > NE40 > NE70

Sea water – NE90 > NE40 > NE70

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38.2%

26.5%

83.3%

Removal behaviors – NF membranes

NaCl : 2000 mg/LPressure :75 psiTemp : 25 ℃

20/24

Summary

Summary 22/24

NE 70 membrane could not remove monovalentanions compared to the NE40 membrane even with lower MWCO and greater negative charge.

The RO membrane provided the highest efficiencies for all contaminants.

Under high salinity condition, removal efficiencies of TN, conductivity and anions by all membranes except RO membrane decreased.

- IC / MSPerchlorateChlorateBromate

On going research 23/24

• Microanalysis of ion rejection

- XAD WWTPAfter filtration

• Removal of hydrophilic and hydrophobic NOM

comparing

Thank you~!

This research was supported by a grant from the National Research Laboratory Program by the Korea Science and Engineering Foundation (NOM Ecology Lab: R0A-2007-000-20055-0).

Presenter: skyblueg@gist.ac.kr*Advisor: jwcho@gist.ac.kr)

Acknowledgement