Aug 7, 2011 ... citatio n. K. +. Residual sample 1. Component 1. Component 2. Component K. E
xc ita tio n 1. Emission 1. E xc ita tio n 2. Emission 2. E xc ita tio.
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Fourth IWA NOM Specialty Conference on Natural Organic Matter: From Source to Tap and Beyond July 27-29, 2011, Costa Mesa, California, U.S.A.
Understanding dissolved organic matter in wastewater using an EfOM-focused PARAFAC model for assessment of EfOM impacts on a watershed
Seong-Nam Nam1, Gary L. Amy2 1National
Institute of Environmental Research, South Korea 2Water Desalination and Reuse Center King Abdullah University of Science and Technology (KAUST), Saudi Arabia
Objectives 1. To apply PARAFAC modeling to Fluorescence Excitation-Emission Matrix (F-EEM) data • “Quantitative” characterization of NOM, depending on its source/origin • NOM properties vs. abundance of fluorophores • Assessment of wastewater impact in a watershed
2. To understand treatability of EfOM and contributions of each NOM fluorophore to treatment processes: • Coagulation • Biodegradation • Membrane Filtration
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Experimental Methods • Source waters for EEMs dataset •
~423 EEMs from WWTPs, DWTPs, and river samples from 6 watersheds (including upstream and downstream sites of WWTPs)
•
Some representative allochthonous and autochthonous NOM isolates
•
Laboratory-generated samples
(e.g. SRHA, SRFA, SRNOM, EfOM, SMP, etc.) (e.g. coagulation, biodegradation, membrane filtration)
• Fluorescence measurement/PARAFAC processing… •
Ex/Em =240-450/290-500nm, DOC:~1.0, pH=2.8 at Signal to Ratio mode
•
Correction: Blank subtraction/Inner-filter/Water Raman correction
•
One EEM: 201 by 43 matrix dimension, total dataset: 201x43x423
•
Removing the Rayleigh scattering, non-negative constraints
•
PARAFAC N-Way V2.1 toolbox, Split-half validation method, core consistency
Fluorescence measurement
Emitted from sample
Excites sample
Sample in cuvette
Light source
Detector
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Fluorescence Excitation-Emission Matrix (F-EEM)
F-EEM Dataset for Parallel Factor Analysis (PARAFAC)
Sample N
X
Sample 2 Sample 1
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How does PARAFAC work?
Emission 1
Sample 1
Dataset
Excitation 1 Component 1
Excitation 2
Excitation 1 Sample 1
+
Sample 2
+…+
Component 2
Emission N Excitation N
+ Residual (sample 1 to N)
Sample K
Emission 2
Emission 1
Emission 1
+…+
Emission K Excitation K
X
Emission 2 Excitation 2
Excitation 1
+
+
Residual sample 1
Component K
Development of EfOM-focused PARAFAC model
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What is Effluent Organic Matter (EfOM)?
Drinking water source
NOM Drinking water NOM, Municipal treatment plant use
NOM, BOM
Wastewater treatment plant NOM, SMPs
Ambient water (river)
Wastewater reclamation and reuse
EfOM NOM + SMPs
PARAFAC: Identification of fluorophores (i.e., components) 440
420
Component 2
420 400
380
380
380
360
360
340
300 280
270/455 320
340
360
380
400 420 Em. (nm)
440
460
480
400
320 300 280 260
320
340
360
380
400 420 Em. (nm)
440
460
480
500
240 300
325/401 320
340
360
380
400 420 Em. (nm)
440
460
480
500
440
Component 4
420
360
360
Ex. (nm)
380
340
275/326
320
340
300
280
280
260
260 340
360
380
400 420 Em. (nm)
C1, C3 & C5: Humic-like
440
460
480
comp 5 > comp 3 > comp 4 > comp 2
EEMs: Membrane feed, permeate, retentate, and backwash (UF) Feed
Permeate
DOC=13.1 mg/L
DOC=10.8 mg/L
Retentate
Backwashed
DOC=14.8 mg/L
DOC=13.1 mg/L
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Application of PARAFAC to membrane filtration: changes of components 5.0
Feed Permeate Retentate Backwash
0.3
DOC of components (mg/L)
Fraction of components
0.4
0.2
0.1
Feed Permeate Retentate Backwash
4.0 3.0 2.0 1.0 0.0
0.0 1
2
3
4
5
1
2
Components
3
4
5
Components
Significant variations of component 4 Indicating protein-like organic matter as major membrane foulant ?
Conclusions Conclusions •
5 components (statistical fluorophores) identified • Allochthonous NOM: dominant with component 1 and component 5 • Autochthonous NOM: dominant with component 2 and component 4
•
Application of Fluorescence with PARAFAC modeling to NOM/EfOM • Clear differentiation between NOM and EfOM • Provides accurate evaluation of % EfOM impact
•
Advantages/Diverse Applicability of PARAFAC • Excellent sensitivity and good linearity • Applicable to various treatment processes
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Conclusions Acknowledgements • Water Research Foundation Partial Funding • Stuart Krasner: Primidone Measurements +
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