Organic Compounds in Water and Wastewater Isolation of NOM Lecture - - PDF document

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CEE 697z

Organic Compounds in Water and Wastewater

Isolation of NOM

Print version

Dave Reckhow - Organics In W & WW

Lecture #3

A USGS Preparative-based method

Water Sample Hydrophobic Bases Weak Hydrophobic Acids Hydrophobic Neutrals

Hydrophobic Resin

Amberlite XAD-8

Hydrophilic Bases Humic Acid Fulvic Acid Hydrophilic Acids Hydrophilic Neutrals

Cation Exchange Resin

MSC-1

Anion Exchange Resin

Duolite A-7

Filter

Amberlite XAD-8

Leenheer, J.A. and Noyes, T.I. (1984) A Filtration and Column- Adsorption System for Onsite Concentration and Fractionation of Organic Substances from Large Volumes of Water, U.S. Geological Survey Water Supply Paper 2230, U.S. Government Printing Office, Washington, D.C.

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Elemental Composition: Humics

Fraction C H O N P S Ash

Fulvic 51.9 5.0 40.3 1.1 0.2 0.6 1.5 Humic 50.0 4.7 39.6 2.0 5.0

Elemental Composition of Aquatic Humic Substances (average of 15 riverine samples, after Thurman, 1985) High oxygen content FA and HA Similar, except:

• humics tend to have more N

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Molecular Size: Ultrafiltration

Acid Fulvic

% of Raw Water DOC

5 10 15 20 25 < 500 AMU 500-1000 AMU 1000-5000 AMU > 5000 AMU 1000-3000 AMU > 3000 AMU

Humic Acid

% of Isolate DOC

10 20 30 40 50 60 70 < 500 AMU 500-1000 AMU  Polydisperse  Moderate to large



Polydisperse



Small to Moderate

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Aromaticity: 13C-NMR

Fraction Percent Aromatic Percent Aliphatic Average Range Average Range

Fulvic 17 14-19 59 54-64 Humic 32 30-35 45 38-49

Aromatic and Aliphatic Content of Aquatic Humic Substances (from Reckhow et al., 1990)

Aromatic Aliphatic

More reactive with disinfectants Absorbs UV light

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Functional Groups: Titration

Fraction Carboxyl Phenolic

Fulvic 11 3 Humic 8 4

Functional Group Content of Aquatic Humic Substances (meq/g-C, After Thurman, 1985)

C OH O OH C OH O Phenolic Group Carboxyl Groups

Source of electrical charge; responsible for coagulant demand

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An Aquatic Humic “Structure”

 Features

 Aromatic rings

 Reactive with

• xidants

 Aliphatic carbon

chains

 Many oxygenated

groups that can bind with coagulants

 Phenolic -OH  Aliphatic -OH  Carboxylic (COOH) COOH O COOH COOH COOH HOOC HOOC HO OH COOH H3CO OH Hydroxy Acid Aromatic Dicarboxylic Acid Aromatic Acid Aliphatic Acid Aliphatic Dicarboxylic Acid Phenolic-OH HO

From Thurman, 1985

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The Humics and Non-humics: Comprehensive NOM Fractionation

 USGS method

adapted by water industry

 Idea: separate NOM

into groups of compound of similar properties

Water Sample Hydrophobic Bases Weak Hydrophobic Acids Hydrophobic Neutrals

Hydrophobic Resin

Amberlite XAD-8

Hydrophilic Bases Humic Acid Fulvic Acid Hydrophilic Acids Hydrophilic Neutrals

Cation Exchange Resin

MSC-1

Anion Exchange Resin

Duolite A-7

Filter

Amberlite XAD-8

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UMass Lab setup

 Pre-filters  Hydrophobic resin  XAD-8  Cation Exchanger  MSC-1  Anion Exchanger  A-7

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NOM Fractions: Mass Balance

HA 8% HPL-N 25% HPO-B 2% W-HPO-A 4% HPO-N 7% FA 42% HPL-A 9% HPL-B 3% HA 0% FA 29% W-HPO- 16% HPO-B 0% uHPL-A 22% HPL-B 5% HPL-N 11% HPL-A 15% HPO-N 2%

Forge Pond Granby, MA Northeast MA Tap Water HPL=Hydrophilic HPO=Hydrophobic A=Acids B=Bases N=Neutrals

W=Weak u=ultra

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Wavelength (nm)

200 250 300 350 400 450 500 550 600 650

• Sp. Abs. (L/m/mg-C)

0.1 1 10 Weak Hydrophobic Acids Hydrophilic Acids Humic Acid Fulvic Acid

Same DOC

254 nm

Absorbance

• f Acid

Fractions

Dave Reckhow - Organics In W & WW

Different Water Types

 South Platte River

(Leenheer)

 Thoreau’s Bog

(Leenheer)

 Forge Pond (Bose &

Reckhow)

Total Strong Acids

7.5 mg/L

• S. Platte R.

31 mg/L Thoreau's Bog

Weak Acids

Hydrophilic Hydrophobic

Percent Carbon

20 40 60 80 100 120

Percent Carbon

10 20 30 40 50 60

Percent Carbon

20 40 60 80 100

Percent Carbon

10 20 30 40 50

Percent Carbon

20 40 60 80 100

Percent Carbon

10 20 30 40 50 Recovery Total

Weak Acids Humic Acid Fulvic Acid

6.6 mg/L Forge Pond Acids Strong Neutrals Acids Bases Neutrals Bases Acids

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NOM Fractions: Seasonal Effects

HA 4% FA 37% W-HPO-A 15% uHPL-A 9% HPL-B 7% HPL-N 17% HPL-A 7% HPO-B 1% HPO-N 3%

New England Reservoir

Spring

New England Reservoir

Fall

HA 4% FA 32% W-HPO-A 17% HPO-N 1% HPL-N 23% HPL-A 9% uHPL-A 9% HPL-B 4% HPO-B 1%

Dave Reckhow - Organics In W & WW Dave Reckhow - Organics In W & WW

Abundance

From: Perdue & Ritchie, 2004

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Chemical Interpretation s

 May be related to

known Octanol:water partition coefficients

k

• w

0.1 1 10 100 1000 10000 100000

k

• w

0.1 1 10 100 1000 10000 100000

9 9 9 9 8 8 8 8 8 8 8 7 7 7 7 7 6 6 6 6 6 6 6 6 5 5 5 5 5 5 5 4 4 4 4 4 3 3 3 3 3 2 2 2 1 1

Fulvic Acid Hydrophilic Acids Strong Hydrophobic Acids Weak Hydrophobic Acids Hydrophobic Bases Hydrophilic Bases Hydrophilic Neutrals Hydrophobic Neutrals

Nitriles Methyl Ketones Alcohols Alkanes Alkyl Pyridines Amines Acids @ pH2 Acids @ pH7

Dave Reckhow - Organics In W & WW Dave Reckhow - Organics In W & WW

Other Qualitative Interpretations

Fraction Composition

Hydrophobic Acids Weak Tannins; phenols; intermediate MW alkyl :monocarboxylic acids (C5-C8), dicarboxylic acids (C8- C11) Strong Fulvic acids; humic acids; high MW alkyl monocarboxylic acids (C9), and dicarboxylic acids (C12); aromatic acids Bases Amphoteric proteinaceous materials; high MW (C12) alkyl amines; alkyl pyridines; aromatic amines Neutrals Hydrocarbons; high MW (C6) methyl ketones; furans; most ethers; high MW (C5) alkyl alcohols, and aldehydes; lactones; pyrrole Hydrophilic Acids hydroxy acids; sugar acids; sulfonic acids; low MW alkyl monocarboxylic acids (C1-C4), and ,dicarboxylic acids (C2-C7) Bases low MW (C1-C11) alkyl amines; amino acids; purines; pyrimidines; pyridine; hydroxy pyridines Neutrals polysaccharides; Low MW (C1-C4) alkyl alcohols, aldehydes, and ketones; poly-ketones; amides

Based on: Leenheer and Noyes, 1984; Leenheer et al., 1982; and others

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Proposed Assignments for Organic Fractions

Fraction Composition

Colloidal

Bacterial peptidoglycan cell wall components (hydrophilic neutral)1

Hydrophobic

Acids Weak tannins; phenols; intermediate MW alkyl monocarboxylic acids (C5-C8), dicarboxylic acids (C8-C11) Strong fulvic acids; humic acids; high MW alkyl monocarboxylic acids (C9), and dicarboxylic acids (C12); aromatic acids Bases amphoteric proteinaceous materials; high MW (JC12) alkyl amines; alkyl pyridines; aromatic amines Neutrals hydrocarbons; high MW (C6) methyl ketones; furans; most ethers; high MW (C5) alkyl alcohols, and aldehydes; lactones; pyrrole, alkyl aromatic sulfonates1

Hydrophilic

Acids hydroxy acids; sugar acids; sulfonic acids; low MW alkyl monocarboxylic acids (C1- C4), and dicarboxylic acids (C2-C7) Bases low MW (C1-C11) alkyl amines; amino acids; purines; pyrimidines; pyridine; hydroxy pyridines Neutrals polysaccharides; Low MW (C1-C4) alkyl alcohols, aldehydes, and ketones; poly- ketones; amides, N-acetyl amino sugars1, non-carbohydrate alcohols1

+Based on: Leenheer and Noyes, 1984; Leenheer et al., 1982; and Reckhow et al., 1992

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