CEE 697z Organic Compounds in Water and Wastewater

Transcription

1 Print version CEE 697z Organic Compounds in Water and Wastewater Origins of NOM II Lecture #5 Dave Reckhow - Organics In W & WW

2 Carbohydrates empirical formula: C x (H 2 O) y CH 2 OH H H O H OH H OH OH H OH Glucose (monosaccharide) CH 2 OH CH 2 OH H OH O O H OH H O H OH H OH OH H OH H OH Cellulose (polysaccharide) CH 2 OH Glucosamine (amino sugar) H H OH O H OH OH H 2 H NH 2

3 Carbohydrates, cont. Nomenclature Monosaccharide: 1 simple sugar 1% of DOC Oligosaccharide: 10 simple sugars Polysaccharide: > 10 simple sugars 5% of DOC Special interest in distribution systems Food for microbial regrowth Major constituents of: soluble metabolic byproducts biofilms

4 Carbohydrates, cont. Function in plants Structural cell walls Cellulose (~10,000 ᴅ-glucose units) Most abundant natural organic compound Mostly in higher plants; some algae have none Hemicelluloses ( monosaccharides of many types) Forms a matrix around cellulose fibers in cell walls Chitin (N-acetyl-ᴅ-glucosamine units) Second most abundant natural organic (~tied with lignin) Role of cellulose in most fungi, some algae & arthropods Murein or peptidoglycan, a major group of Acylheteropolysaccharides N-acetyl-ᴅ-glucosamine & N-acetylmuiramic acid cross linked by AA chains Dominant in Eubacteria: up to 75% of bacterial dry mass Energy polysaccharides Starch in plants (80% amylopectin, 20% amylose) Anti-dessicants 4

5 Carbohydrates, cont. Algae etc., Heteropolysaccharides Nitrogen-containing 5

6 Carbohydrates, cont. 6

7 Acylheteropolysaccharides (APS) 10-35% of river and lake water DOC Produced by algae in fresh and salt waters Similar to structural polysaccharides? Comprised of a nearly fixed ratio of simple sugars, acetate and lipids Refractory like humic substances 7

8 Sugars in Natural Waters From: Perdue & Ritchie,

9 Fatty Acids At neutral ph s most lose H + CH 3 -COO - maybe 4% of DOC other mixed acids may account for 2% H-COOH CH 3 -COOH CH 3 -CH 2 -COOH Formic Acid Acetic Acid Propionic Acid CH 3 -CH 2 -CH 2 -COOH H 3 -CH 2 -CH 2 -CH 2 -COOH Butyric Acid Valeric Acid 9 Common Volatile Fatty Acids in Natural Waters

10 Amino Acids and Proteins Simple Amino Acids some may form THMs and HANs Proteins much larger, comprised of many AAs HO H 2 C NH 2 C H C H 2 COOH NH 2 C H Alanine COOH Tyrosine 10 Special interests in DWT nutrients for bacterial regrowth role in chlorine decay and DBP formation

11 Amino Acids From: Perdue & Ritchie,

12 Terpenes and Terpenoids The terpenoids, sometimes called isoprenoids, are a large and diverse class of naturally occurring organics similar to terpenes, derived from fivecarbon isoprene units assembled and modified in thousands of ways. Terpenoids can be thought of as modified terpenes, wherein methyl groups have been moved or removed, or oxygen atoms added. Plant terpenoids are used extensively for their aromatic qualities. They play a role in traditional herbal remedies and are under investigation for antibacterial, antineoplastic, and other pharmaceutical functions. Terpenoids contribute to the scent of eucalyptus, the flavors of cinnamon, cloves, and ginger, the yellow color in sunflowers, and the red color in tomatoes. 12 Terpenoids can be classified according to the number of isoprene units used: Hemiterpenoids, 1 isoprene unit (5 carbons) Monoterpenoids, 2 isoprene units (10C) Sesquiterpenoids, 3 isoprene units (15C) Diterpenoids, 4 isoprene units (20C) (e.g. ginkgolides) Sesterterpenoids, 5 isoprene units (25C) Triterpenoids, 6 isoprene units (30C) (e.g. sterols) Tetraterpenoids, 8 isoprene units (40C) (e.g. carotenoids) Polyterpenoid with a larger number of isoprene units From Wikipedia

13 Terpenoids 13

14 Terpenoids, cont. 14

15 Iron Complexation 15

16 Van Krevlin Plot 16

17 Putting it all together? From Thurman, 1985 Hydroxy Acid OH COOH HO COOH COOH HOOC HOOC Phenolic-OH OH O Aliphatic Dicarboxylic Acid Aromatic Dicarboxylic Acid HO H 3 CO Aliphatic Acid COOH Many identifiable precursor structures 17 Not practical or even possible COOH Aromatic Acid

18 Concentrations: Pedogenic Land Sources From Woody & non-woody plants, lignin, etc. Depends on vegetation, soil, hydrology Attenuated by adsorption to clay soils Parallel watersheds in Australia (Cotsaris et al., 1994 [Chamonix proceedings]) Clearwater Creek, high clay content: 2.5 mg/l TOC Redwater Creek, sandy soil: 31.7 mg/l TOC 18

19 Concentrations: Aquagenic Algal & aquatic plant Sources Depend on nutrient levels / trophic state Concentrations in Lakes (mg/l) (Thurman, 1985) Trophic State Mean DOC Range Oligotrophic Mesotrophic Groundwater Eutrophic average: 0.7 mg/l Dystrophic No algae, much soil attenuation 19

20 MW vs type Algogenic organic matter (AOM) Proteins & carbohydrates Large polymers with monomers Henderson et al.,

21 Algae as THM Precursors From: Plummer & Edzwald, 2001 [ES&T:35:3661] ~25% from EOM Scenedesmus quadricauda Cyclotella sp. Algae 21 ph 7, 20-24ºC, chlorine excess

22 Algae as TCAA Precursors Not much impact? Algae 22 ph 7, 20-24ºC, chlorine excess

23 Algae as DCAA Precursors Are Algae important sources of dihalo-aa precursors? Algae 23 ph 7, 20-24ºC, chlorine excess

24 Annual TOC Cycles 18 Edisto River 16 Hanahan WTP Charleston, SC TOC: Kornegay SUVA: ICR Former source for Charleston s (SC) Hanahan WTP Flushing of TOC during high rainfall months (cold period) TOC (mg/l) or SUVA (m -1 ) Period of High Runoff TOC: ICR Influent Water ICR Month 24 6/1/1997 7/1/1997 8/1/1997 9/1/ /1/ /1/ /1/1997 1/1/1998 2/1/1998 3/1/1998 4/1/1998 5/1/1998 6/1/1998 7/1/1998 Approximate Date 8/1/1998 9/1/ /1/ /1/ /1/1998 1/1/1999 2/1/1999

25 Approximate Date Annual TOC Cycles Lake Lanier Source for Gwinnett Co. s (GA) Lanier WTP High clay content in watershed TOC (mg/l) or SUVA (m -1 ) TOC: Kornegay data SUVA: ICR TOC: ICR Lake Lanier WTP Gwinnet Co., GA ICR Month High photosynthetic activity Influent Water 25 6/1/1997 7/1/1997 8/1/1997 9/1/ /1/ /1/ /1/1997 1/1/1998 2/1/1998 3/1/1998 4/1/1998 5/1/1998 6/1/1998 7/1/1998 8/1/1998 9/1/ /1/ /1/ /1/1998 1/1/1999 2/1/1999

26 Spatial and Temporal Distribution of DOC and UV absorbing Substances in Lake Bret (from Zumstein & Buffle, 1989; and Krasner et al., 1996) 26 UV 285 (cm -1 ) Depth (m) UV 285 (cm -1 ) UV DOC (mg/l) DOC UV DOC Day of Year Depth (m) UV 285 (cm -1 ) UV DOC DOC (mg/l) DOC (mg/l)

27 THM Precursor Study Cannonsville Reservoir Catskill- Delaware water supply for NYC Stepczuk et al., 1998 J. Lake Res. Mgmt. 14(2-3)356 Epilimnion Both Epilimnion Hypolimnion 27

28 Plant biochemicals Sugars, starches Proteins Cellulose Hemicellulose Fats & waxes Lignins & phenolics Low Moderate Low Low Low high Decreasing biodegradability Terpenoids -?? Simplification: Doesn t explicitly consider bacterial metabolites 28

29 29

30 Dihalo and Trihalo DBPs NOM Fractions Evidence for greater importance of dihalo species in non-lignin based NOM CX 2 /CX 3 Formation Potential (µm/µμ) Humic Acid Fulvic Acid Weak Hydrophobic Acids Hydrophobic Bases Hydrophobic Neutrals Hydrophilic Acids Ultra Hydrophilic Acids Hydrophilic Bases Hydrophilic Neutrals regression Raw Waters b[0]= b[1]= r ²= Specific UV 254 nm (L/m/mg-C)

31 DHAN/THM Ratio vs SUVA DHAN/THM Formation Potential (µg/µg) 2.1 Humic Acid All Samples Fulvic Acid 1.8 Weak Hydrophobic Acids Hydrophobic Bases 1.5 Hydrophobic Neutrals 0.4 Hydrophilic Acids Ultra Hydrophilic Acids Hydrophilic Bases Hydrophilic Neutrals regression b[0]=0.20 b[1]= r ²=9.2e Specific UV 254 nm (L/m/mg-C)

32 DOC and runoff Ogeechee River (GA) From Aiken & Cotsaris, 1995 [JAWWA 87(1)36] 32

33 What is EfOM? Drinking water source NOM Water treatment plant NOM, DBPs Municipal use NOM, DBPs Wastewater treatment plant Wastewater reclamation and reuse Ambient water (river) EfOM NOM + SMPs EfOM: NOM, DBPs SMPs from: 33 Krasner & Amy

34 To next lecture Dave Reckhow - Organics In W & WW