reduction of broad spectrum nom contamination to ... mesa california july 26-29, 2011 presentation...

Reduction of Broad Spectrum NOM Contamination to Minimize Fouling of Membranes Using Electroadsorptive Depth Filter Media

Rod Komlenic Product Manager, Disruptor Filtration TechnologyAhlstrom Filtration [email protected]

IWA NOM ConferenceCosta Mesa CaliforniaJuly 26-29, 2011

Presentation outline

• Introduction to electroadsorptive filtration technology

• Reduce or remove a variety of NOM

• Significance of Transparent Exopolymer Particulate (TEP)

• Impact of reduction of NOM to membrane biofouling

© 2011 Ahlstrom Corporation

Electroadsorptive water filtration technology

• Nanofibers of pseudoboehmite AlO(OH)

• 2 nm X 250 nm in size

• Grafted to microglass


R.Ristau, IMS, UCONN

• Grafted to microglass carrier

• Positive electrokinetic potential

Media structure

• Average pore size of 2 microns • ~400 such pore layers in 0.8 mm depth• Torturous path, depth filter


Photo courtesy of R. Ristau, IMS, Univ. of Conn

Charge field coverage


• Charge potential is generated by the alumina fibers• Charge field radiates to a maximum distance of 1 um

Image: Dr. J Brant Univ of WY

Other removal mechanisms

• Ion Exchange - At low pH (below about 5 pH) the protons of the OH group are tightly bound. As the pH increases to > 6 the proton bonding is weakened, allowing proton exchange from some positively charged colloids.


• pH change near nanofiber up to +2 possibly causing coagulation and flocculation

Removal Capabilities

MS2 retention comparison

Media Thickness mm

Basis Wt g/m 2

Challenge Water MS2 Removal, %

pH TDS g/L

MS2, PFU/ml

0-10 ml

60-70 ml

130-140 ml

Disruptor®

0.8 200 7.2 0 3·105 99 98 94 9.2 0 6·105 90 90 7.2 30 5·105 97 97


7.2 30 5·10 97 97 9.2 30 4·105 96 88

3m Virasorb®

0.8 210 7.2 0 6·105 99 92 62 9.2 0 3·105 60 13 7.2 30 5·105 4 6 9.2 30 4·105 0 0

Data courtesy Argonide Corp

• Typical MS2 reduction for 1 layer is now > 4 LRV

Bacteria testing: PAC with silver


Trace hydrocarbon reduction


Capability to remove trace and emulsified hydrocarbons with a capacity of up to 50 g/m2 such as BTEX, etc.

Data courtesy Argonide Corp

TOC reduction using Tempe Town Lake water


Data: Arizona State University

TOC reduction of water with Suwannee River fulvic acid


Data: Arizona State University

Humic acid reduction

Average Turbidity & Flow Rate to Filter Set Volumes of 20 FTU Humic Acid at a Constant Pressure Through a 38mm (1133mm 2) Circle of 799-81

6

8

10

12

Filt

rate

Tur

bidi

ty (

FT

U)

250

300

350

400

450

Flo

w (

mL/

min

)

FTU

mL/min


0

2

4

6

100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

Set Volumes of 20FTU humic acid solution (mL)

Filt

rate

Tur

bidi

ty (

FT

U)

0

50

100

150

200

Flo

w (

mL/

min

)

mL/min

Challenge concentration = 20 FTUData: Heather Mowers, Ahlstrom Filtration LLC

TEP and chlorophyll reduction

50

75

100

% R

educ

tion

% Reduction of TEP and Chlorophyll

% TEP


Testing by Dr. Thomas Berman, Kinneret Limnological Laboratory

0

25

50

RJ WW LKW

% R

educ

tion

% TEP

% CHl

SEM of Disruptor ® - New and fouledLeft: Surface of a new sample of Disruptor®

Right: Surface after being fouled with polysaccharides. Testing done using unfiltered North Sea water.


Images courtesy of Ibrahim El-Azizi, and Robert J. G. Edyvean, University of Sheffield, UK.

Disruptor ® PAC

Features of PAC media

• Uses Powdered Activated Carbon (PAC) particles where 90% pass through a 625 mesh screen.

• PAC is retained by the electroadsorptive charge field during the wet laid paper making process.

• Retains smaller particles of carbon, than is possible by mechanical entrapment


mechanical entrapment

• Carbon has high surface area to mass ratio producing extremely rapid reaction kinetics

• Increased capacity for removing certain types of NOM

Preventing Membrane Fouling

Membrane biofoulants

NOM biofilm Constituents:• Virus• Bacteria

© 2011 Ahlstrom Corporation January 2011

Ultrapure Water April 2010 Jane Kucera, Nalco.

• Cell debris• Organic acids• Extracellular materials

TEP and membrane fouling


Images courtesy Tom Berman and Uta Passow

TEP shown as blue, bacteria shown as brown. TEP may provide the primary conditions for biofouling . Bacteria growth contribute to biofilm. Other colloids (light blue).

Nanoparticle free backwash

Removed negatively charged

nanoparticles (dp = 57 nm) from MF

filtrate

Deposition throughout membrane


Deposition throughout membrane

using MF filtrate (top)

“Polished” filtrate showed

qualitatively better removal of

nanoparticles (bottom)

Data: Dr. Jonathan Brant, University of Wyoming

Impact on membrane performance

• Disruptor® used to pretreat MF

feed containing nanoparticles

• Negatively charged (ζ = -30 mV)

TiO2 nanoparticles

• Pretreatment improved 150

200

250

300

Flu

x R

ate

(m3 /

m2

day)


• Pretreatment improved

membrane performance

• Rapid flux decline for untreated

feedwater (50% flux decline)

• No observable flux decline for

pretreated water

0

50

100

150

0 50 100 150 200 250 300

Flu

x R

ate

(m

Time (sec)

[TiO2]feed = 0.5 mg/L; pH = 8.0; n = 3I = 10 mM NaCl


Preliminary results

• Pilot trials have been ongoing for approximately one month,

• Membranes operated using same conditions, with regards to

filtration rate, backwash frequency and duration

• Laser turbidimeters installed to assess/compare MF filtrate

quality


quality

• Backwashing with “polished” MF filtrate has improved overall

membrane performance

• Polished filtrate results in less flux decline over time (Δ ~ 15%)

• Terminal TMP (ΔP = 22 psig) not yet reached for either MF

membrane


Improved TDS rejection RO prefiltration trial

% R

ejec

tion


Sample Intervals

% R

ejec

tion

• Higher TDS rejection levels with the Disruptor® prefilters

• TDS rejection more consistent with the Disruptor®

• TDS rejection from the other trains were lower and erratic

RO performance - % recovery


• The percent recovery = percentage of total influent

produced as permeate

• 0.2u and the 1u prefilters had lower initial permeate

recovery and declined significantly over the study period.

Days 1-23

Ca, Mg, Na, SiO₂₂₂₂ rejection by RO systems

% R

ejec

tion


% R

ejec

tion

• RO membranes with Disruptor® prefilters had higher rejection

rates for Magnesium, Sodium, and Silica

• Calcium rejection levels similar-slightly higher with Disruptor®

Trace Contaminant Removal

Micro contaminant removal

• Microcontaminants now being detected in many waste water and in some potable water sources.

• The dangers these contaminants present to humans and the environment are not well understood

• Reduction of removal of these compounds is of interest to


• Reduction of removal of these compounds is of interest to many health authorities and agencies

• Testing by the University of California Irvine has shown Disruptor® to be effective in removing traces of Penicillin G, Bisphenol A (BPA) an endocrine inhibitor and the antibiotic Flumequinean

Penicillin G removal


Penicillin G studied at 2 mg.l with total removal from 13 liters. At typical concentration of 2 micrograms per liter, a square foot of Disruptor® PAC could process > 900,000 l of water, free of other contaminants.

Bisphenol A (BPA) removal


BPA is an estrogenic chemical used in the manufacture of polycarbonate resins. Complete removed from 3 l of water at 10 mg/L. At 2 micrograms per l, 1 ft 2 of media could process > 1 million liters, free of other contaminants.

Flumequine removal


Flumequine, a chemotheraputic antibiotic was completely removed from 3 l having a concentration of 10 mg/L. At more typical concentration of 2 micrograms/l, a square foot of media could process > 1 million l.

PCB removal


Polychlorinated biphenyls (PCBs) are man made organic chemicals but are included for general information

Summary and conclusions

Value proposition

1

5

1

00

Pre

ssur

e in

Bar

Virus BacteriaAqueous Salts

Endotoxin

Nanofiltration

Reverse Osmosis

Disruptor®

Disruptor®

1

5

1

00

Retention Efficiency in Microns

0.0001 0.001 0.01 0.1 1.0

Pre

ssur

e in

Bar

Ultrafiltration

Disruptor®

MicrofiltrationDisruptor®

Conclusions

Ahlstrom Disruptor® is a new category of filter media removing contaminants through electroadhesion and ion exchange, not mechanical filtration.

Efficiently retains a wide range of NOM - cell debris, endotoxins, pathogens and organic acids.

High flow rate, low pressure drop and high capacity give


High flow rate, low pressure drop and high capacity give good value through filtration efficiency and energy savings.

Technology offers new opportunities for potable and waste water treatment.

Commercially available since 2006.

Thank you

Ahlstrom Filtration LLC122 West Butler Street, Mt Holly SpringsPA, 17065USA

[email protected]

reduction of broad spectrum nom contamination to ... mesa california july 26-29, 2011 presentation...

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