WASHINGTON TECHNICAL INSTITUTE WRRC REPORT NO. 9 ...

WASHINGTON TECHNICAL INSTITUTE WASHINGTON, D.C. 20008

WRRC REPORT NO. 9

CHARACTERIZATION OF NONVOLATILE ORGANIC MATERIAL DURING PHYSICAL- CHEMICAL

TREATMENT OF THE DISTRICT OF COLUMBIA RAW WASTEWATER

MARY H. ALDRIDGE THOMAS A. PRESLEY

CHARLES CHAPIN ANDREW WELEBIR

WATER RESOURCES RESEARCH CENTER

CHARACTERIZATION OF THE NONVOLATILE ORGANIC MATERIAL DURING PHYSICAL-CHEMICAL TREATMENT OF THE

DISTRICT OF COLUMBIA RAW WASTEWATER

Mary H. Aldridge 1/ Thomas A. Pressley

Charles Chapin Andrew Welebir

FINAL REPORT

Project No. B-007-DC

The work upon which this publication is based was supported by the Office of Water Research and Technology, U. S. Department of the Interior, under

the provisions of Public Law 88-379, as amended.

Agreement No. 14-34-0001-6066

Water Resources Research Center Washington Technical Institute Washington, D. C. 20008

August 1976

1/ Principal Investigator

TABLE OF CONTENTS

Page

LIST OF TABLES.......................................................................................

iii LIST OF

FIGURES..................................................................................... iii

INTRODUCTION......................................................................... 1

A. Physical-Chemical Treatment Systems H, I, and J............................................................................... 1

B. Sampling and Sample Preparation................................................................................... 3

C. Separation Scheme......................................................................................... 5

D. Analysis....................................................................................... 6

DISCUSSION OF RESULTS..................................................................................... 11

A. Preliminary Tests............................................................................................ 11

B. Principal Work............................................................................................ 14

CONCLUSION............................................................................. 26

REFERENCES.............................................................................. 28

LIST OF TABLES Page

1. Removal Efficiencies……………………………………………………. 4 2. Mass Distribution of Ether-Soluble Material…………………………… 13 3. Chemical Parameters of Composite Samples Before Concentration (mg / l)…………………………………………. 15 4. Metal Analysis of Composite Samples Before Concentration………… 16 5. Organic Losses During Concentration………………………………… 18 6. Total Dissolved Solids Balance……………………………………….. 19

7. COD Distribution of the Ether-Soluble Nonvolatile Organic Material (Percent)……………………………….. 20

8. Ultraviolet Absorption at 254 nm (Absorbance Units)…………………. 23 9. Amphoteric Materials…………………………………………………… 25

LIST OF FIGURES 1. The Pilot Plant………………………………………………………….. 2 2. Protein Analysis Standard Curves……………………………………… 9

The low-lime chemical clarification system was operated during September at a constant

feed rate of 35 gallons per minute (gpm) [50,400 gallons per day (gpd)]. Following screening of the

raw waste water by the Bauer Hydrasieve, the screened effluent flowed by gravity to the flash mix

tank of the low-lime chemical clarification

The low-lime chemical clarification system, H, was operated for the entire month of

September 1974, as were Systems I and J. The low-lime clarified effluent was evenly split and fed

to parallel systems, I and J. The two parallel systems included breakpoint chlorination, carbon

adsorption and dual-media filtration (System I) and neutralization, carbon adsorption and dual-

media filtration (System J). Alum was added ahead of the filters in both systems (Figure 1). All of

these systems were shut down on October 1, 1974 (Figure 1).

A. Physicals Chemical Treatment Systems H, I and J

Wastewater samples used in these studies were taken at the Environmental Protection

Agency District of Columbia Plant located at 50000 Overlook Avenue, S.W., Washington, D.C. The

pilot plant was designed for research in the development and demonstration of more efficient

methods of municipal wastewater treatment. The physical-chemical treatment process examined in

this study represented only half of the total system being evaluated at the pilot plant (Figure 1).

CHARACTERIZATION OF THE NONVOLATILE ORGANIC

MATERIAL DURING PHYSICAL-CHEMICAL TREATMENT OF

THE DISTRICT OF COLUMBIA RAW WASTEWATER

CHLORI CHLORINE

FIGURE I BACKWASH FROM FILTERS AND COLUMNS RAW WATER LIME (CaO) FeCl3

The results of the operation of the physical-chemical treatment system are presented in

Table 1. There was a slight deterioration in the quality of the effluent from the chemical clarifier.

The effluent-suspended solids increased from 9.7 mg/l in August to 13.7 mg/1 in September. The

organic and phosphorus concentrations were nearly the same.

system. Backwash water from the carbon adsorption and filtration systems was returned to the

flash mix tank at a rate of 10 gpm. Powdered calcium oxide was added to the flash mix tank at an

average dose of 201 mg/1 as CaO, which maintained the required pH of 10.5. The alkalinity of

the raw wastewater averaged 120 mg/1 as CaCO3. Ferric chloride (15 mg/1 as Fe+++) was added

to improve clarification. Settled solids were recycled to the flash mix tank at 15% of the total

flow. The waste rate was 2.25% of the total flow. The solids. concentration in the waste and

recycle streams averaged 21,000 mg/1.

(H-0) Raw Wastewater (Influent)

(H-7) Lime Clarified (Splitter Box)

(I-6) Breakpoint Chlorination and Carbon Adsorption

(I-7) Alum Coagulation and Filtration

Hourly grab samples were taken and composited after the following stages within the

physical-chemical treatment process for 24 hours in accordance with the retention times and flow

(Figure 1):

B. Sampling and Sample Preparation

Grab sample volumes were taken so as not to exceed the total volume

TABLE 1

REMOVAL EFFICIENCIES

TOC mg/1 XR

BOD mg/l ZR

COD mg/l %R

mg/l TP04 %R

TRN mg/l XR

mg/l NH3-N%R

Suspended Solids

mg/l %R

Raw H-0 81.1 - 104.0 - 247.0 - 20.30 - 20.1 - 16.5 - 128.0 -

2.0 98.5

1.7 98.7

1.7 98.7

1.5 98.9

13.4.-89.5

1.3 99.0

13.8 89.2

3.1 97.6

14.3 88.8 Breakpoint I-2 21.5 73.5 28.5 72.6 60.8 75.4 1.53 92.5 3.9 80.3* 2.2 86.7

Filtered J-7 5.06 93.8 3.6 96.6 11.3 95.4 0.23 98.9 10.3 48.8 9.8 40.5

Filtered I-7 7.2 91.1 8.0 92.2 18.8 92.4 0.32 98.4 2.5 87.6 1.8 88.9

Adsorbed J-6 8.13 90.0 8.2 92.1 18.1 92.7 0.39 98.0 12.1 39.8 10.5 36.4

Adsorbed J-4 14.1 82.6 12.6 87.9 28.9 88.3 0.40- 98.0 12.0 40.3 11.0 33.3

Adsorbed I-6 8.5 89.5 9.3 91.0 21.7 91.2 0.43 97.9 3.0 84.9. 2.2 86.5

Neutralized J-2 21.7 73.2 24.7 76.3 53.8 78.2 1.23 93.9 13.5 32.8 11.3 31.5

Clarified H-7 22.3 72.5 29.3 71.8 56.6 77.1 1.42 93.0 12.7 36.8 11.7 29.1

Adsorbed I-4 13.6 83.2 16.2 84.4 34.7 86.0 0.51 97.5 3.4 83.3 2.1 86.9

of the composite sample containers. The hourly grab samples were filtered through glass fiber filters

(without organic binders) (A. H. Thomas Co.) to remove gross suspended matter prior to compositing.

The composited samples were kept at approximately 4°C during sampling.

The 24 composited grab samples, taken after each stage, were taken to The American University

and stored at 4°C for approximately 20 hours prior to filtration (0.3 micron glass fiber filters without

organic binders) and concentration.

After filtration, and before concentration, one-liter aliquots were removed from each of

the composited samples for analysis.

The composited samples were concentrated after filtration in continuous-feed rotary

evaporators at 40°C and at reduced pressure to approximately 100 ml, and then concentrated to dryness

by freeze-drying. The freeze-dried concentrates were stored at 4°C prior to separation and analysis.

C. Separation Scheme

The freeze-dried concentrates were removed from the cold room and allowed to come to

room temperature, weighed, and treated with 100 ml distilled water. The aqueous concentrates were

homogenized by sonification (Sonifier-Cell Disrupter, Model W-185, Ultrasonics, Inc.) at 70 watts,

setting number 9, using the micro-probe. Aliquots (5 and 10 ml) were removed and diluted to 100 ml

for analysis. The remainder of the aqueous concentrates was separated into strong

acids, weak acids, neutrals, bases, and amphoteric compounds according to the procedure of

Shriner and Fuson (1). Peroxide-free redistilled diethyl ether (bp 34 - 35°C) was chosen as the

organic solvent in this study because of its wide range as a solvent. The separated fractions were

dried over anhydrous sodium sulfate overnight then diluted to 100 ml with diethyl ether and held

at 4°C for analysis. The entire separation procedure was performed in duplicate on 100 ml distilled

water samples to serve as reagent blanks.

D. Analysis

The one-liter aliquots taken prior to concentration were analyzed for total organic carbon in

a Beckman Carbonaceous Analyzer, Model 915. Total Kjeldahl Nitrogen (TKN), ammonia

nitrogen, and heavy metals were analyzed in accordance with the procedures described in the EPA

Manual (2). Total solids, BOD, and hydroxylated aromatic compounds (tannins and lignins), were

analyzed by the procedures described in Standard Methods (3). Total carbohydrates were analyzed

by the procedures described in H. L. Golterman (4). using the Anthrone Method.

Total proteins and amino acids at the 1 to 20 mg/l range were analyzed by modifying the

Ninhydrin Procedure described by J. M. Clark in Experimental Biochemistry (5).

1. To 25 ml of aqueous sample containing 1 to 20 mg/l protein, amino acid, or other primary

amine in a 125 ml erlenmyer flask, add slowly 25 ml of concentrated HC1 and some inert

boiling chips. The solution should be approximately 6 N in HC1.

2. Boil on a hotplate for 30 minutes.

3. Cool and add 2 drops of 0.5% phenolphthalein.

4. Neutralize carefully with 15 N NaOH solution and add two extra drops. The pH of the solution

should be approximately 10.

5. Dilute back to approximately 50 ml with distilled water and boil on a hotplate for 15 minutes to

remove ammonia.

6. Cool and neutralize with 6 N HCl (disappearance of red color). Add 1 N NaOH until just

pink again and neutralize with 0.1 N HC1.

7. Filter and wash the residue. Catch filtrate and washings in a marked or graduated test tube,

with stopper, of approximately 100 ml capacity.

8. Dilute to 50 ml with distilled water and add 10.0 ml of acetate-cyanide buffer and mix by inverting.

9. Add 10.0 ml of 3% ninhydrin solution and mix well by inverting.

10. Place in a boiling water bath for 30 minutes.

11. Cool and measure optical density of samples and standards against blank at 570 mp.

Reagents

0.01 M Stock NaCN Solution: Dissolve 490 mg NaCN in distilled water and dilute to one liter.

Acetate Buffer: Dissolve 180 g sodium acetate-3 H20 in 300 ml of distilled water. Add 33.3

ml of glacial acetic acid and dilute to 500 ml with distilled water. The pH of this

solution should be 5.3 to 5.4.

Acetate-Cyanide Buffer Solution: Dilute 10.0 ml of stock cyanide solution to 500 ml with

acetate buffer solution.

3% Ninhydrin Solution: Dissolve 3.0 g ninhydrin in 80 ml of methyl cello-solve and dilute to

100 ml. Stopper and wrap the 3% ninhydrin solution in aluminum foil and store at 4°C for

extended stability.

A low pressure (500 psi) liquid chromatograph was constructed in the laboratory in an

attempt to separate and examine organic materials which are insufficiently volatile for GC. A UV

detector, pre-set at 254 nm, and a refractive index detector (Laboratory Data Control, Inc.) were

used to monitor the column effluent. A glass

Colorimetric measurements were made on a Bausch and Lomb Spectronic-20. PH

measurements were made on a Beckman Zero-matic pH Meter. A Beckman DBG-T Recording

Spectrophotometer with 10mm quartz cells and a Perkin Elmer Infracord 137 IR

Spectrophotometer were used to obtain UV and visible spectra and it spectra, respectively. Gas

chromatographic examinations were performed on a Varian 1200 Gas Chromatograph with FID,

using a 5' x 1/8" column containing 5% SE-30 on 60/80 mesh DMCS-AW Chromosorb W.

Column conditions were as prescribed by the Varian-1200 instruction manual.

The COD procedure of Ramanathan, Gaudy, and Cook (6) was used for analysis of the

ether extracts.

Ammonia and urea concentrations of 20 mg/l as N showed no interferences by this

procedure (Figure 2).

o BSA PROTEIN STANDARD CURVE

BSA PROTEIN WITH 20 mg/l NH3 - N BSA PROTEIN WITH 20 mg/l UREA-N

0 .9

0 .8

0 .7

0 .6

0 .5

0 .4

0 .3

0 .2

0 .1

0 .0 0 5 10 15 20 mg/1 BSA

FIG. 2 PROTEIN ANALYSIS STANDARD CURVES

OPTICAL DENSITY

column, 30 cm long and 1 cm id., was packed with HC-Pellosil, a silica pellicle chemically

bonded on the surface of a bead (Reeve Angel). Additional features of the lc system

included: low dead column positive displacement pump (Milton-Roy, Inc.); pulse

dampener, a coiled length of tubing from a "T" to a pressure guage; a 25 ill injector, loop

type (Chromatronics, Inc.).

The solvent systems used for elution were as follows:

1. heptane

2. 1% 2-propanol in heptane





7. 2-propanol

The solvents were changed manually by turning off the pump and switching the tubing to the

next solvent flask. All solvents were run for 30 minutes at 1.0 ml/min (100 to 400 psi)

except for the pure 2-propanol which was run for 45 minutes. Temperatures were ambient.

All reagents and solvents used in this study were of reagent quality or better and were used

as received.

DISCUSSION OF RESULTS

A. Preliminary Tests

Preliminary investigations of the amount and nature of the nonvolatile

soluble organic materials in the District of Columbia raw wastewater included 0.3 u glass

fiber filtration (without organic binders) of 18 liters of D. C. raw wastewater and evaporation

at reduced pressure to about 400 ml. The concentrate was then freeze-dried to a tan powder.

Approximately 2.5 g of the residue was homogenized by grinding and mixing. Exactly 1.000

g of the residue was treated with 100 ml of distilled water and the aqueous solution

homogenized by sonification. The aqueous homogenized solution was stirred overnight and

centrifuged to separate the insoluble material. The clear concentrate was removed and held.

The residue was twice washed with 10 ml of distilled water and centrifuged, and dried over

CaC12 for 7 days before weighing.

The water-insoluble residue was treated with 100 ml of anhydrous diethyl

ether, homogenized by sonification, and stirred overnight. The ether solution was

centrifuged, washed twice by resuspension in 10 ml of anhydrous diethyl ether, followed by

centrifugation. The residue was dried in a vacuum over CaCl2 for two days prior to

weighing.

The results of this test revealed that while 62.1% of the material was water soluble,

3.6% of the material was soluble in diethyl ether but insoluble in water at the designated

volumes (Ph 8.8).

The total amount of ether-soluble material in this test was less than half that in the

previous test, probably due to an averaging effect because the previous test sample was a grab

sample and the test under present consideration was a composite of 24 hourly grab samples.

Following the lime clarification stage, approximately 34.8 mg or 0.5% of the total residue after

evaporation was ether soluble. Of the ether-soluble material, 94% was distributed among strong

acids (42%), weak acids (27%), and neutral material (27%). Less than 10% of the ether-soluble

materials

Further extractions of the remaining residue under acidic and basic conditions revealed

that 4.4% of the material was a fibrous, inert, polymeric material.

Further preliminary studies included an attempt to better characterize the organic

material at various stages throughout the physical-chemical treatment process in terms of

solubility, as described is the Experimental Section. These studies involved careful evaporation

of the ether extracts in 100 ml pre-weighed containers and the weighing of the residues after

evaporation of the solvent. The results of these tests revealed that 1.7% of the total residue after

evaporation of the raw wastewater sample was soluble in ether, and 55% of the ether-soluble

material in the raw wastewater concentrate occurred as neutral material, 28% occurred as weak

acids, 14% occurred as strong acids, and approximately 3% occurred as organic bases (Table 2).

12

TABLE 2

MASS DISTRIBUTION OF ETHER-SOLUBLE MATERIAL

Ether-Soluble Material (mg)

Sample Sample Volume(liters)

Total Residue After Concentration

(gm) Strong Acids

Weak Acids Neutrals Bases Total

Raw Wastewater

(Influent) 11.00 3.73 8.6 18.0 35.0 2.0 63.6

Lime Clarification 18.00

Filtration 19.60 6.17 0.0 2.6 1.4 4.0 8.0

5.68 11.8 7.4 7.0 1.6 27.8

Carbon Adsorption 19.65 3.2 6.2 2.0 1.0 0.0

Note: All values corrected for control blanks.

5.74

The dramatic reduction in total ether-soluble material from 1.72% in the raw

wastewater (influent) to 0.5% following lime clarification may be caused by precipitation of

these organic materials and/or adsorption on the surface of other precipitated species.

Following chlorination, for the oxidation of ammonia, and carbon adsorption, only traces (if

any) of ether-soluble organic materials were detected by evaporation of the ether extracts and

weighing the residues (Table 2). The gravimetric analysis of the ether extracts was therefore

abandoned for a more sensitive analysis of the ether-soluble organic material in water

following carbon adsorption.

The method of Ramanathan, Gaudy, and Cook (6) for determining COD of ether

extracts was chosen for use in these studies. This provided a sensitivity of 0.5 mg when

using 0.01 N ferrous ammonium sulfate as the titrant.

B. Principal. Work

Following the preliminary tests, three independent samplings were made at various

stages throughout the physical chemical treatment process to characterize the nonvolatile,

soluble organic material in the water.

Chemical parameters of the 1 liter aliquots removed prior to concentration are

listed in Tables 3 and 4. Metal analyses were conducted to better understand the inorganic

composition of

occurred as organic bases (Table 2).

TABLE 3

CHEMICAL PARAMETERS OF COMPOSITE SAMPLES BEFORE CONCENTRATION (mg/1)

Sample TOC COD TKN NH 3-N Org-N Total P Ortho-P Org-P Dissolved

Solids

Volume (1) Date .

8/15/74 Raw Wastewater (Influent) 12.0 32.0 4.1 1.9 2.2 3.90 3.69 0.21 329 11.00

Lime Clarification 7.2 19..2 10.6 10.3 0.3 0.03 0.00 0.03 505 18.00

Carbon Adsorption 2.1 5.6 1.7 1.1 0.6 0.00 0.00 0.00 644 19.65

Filtration 4.5 12.0 1.8 0.6 1.2 0.09 0.00 0.09 624 19.60


Lime Clarification 8.5 22.5 15.1 10.4 4.7 0.03 0.00 0.03 401 18.60


Filtration 3.7 10.0 1.7 0.8 0.9 0.11 0.00 0.11 676 21.22


Lime Clarification 11.9 31.9 13.2 12.0 1.2 0.11 0.00 0.11 347 17.50


Filtration 9.0 24.0 2.8 1.4 1.4 0.00 0.00 0.00 625 19.30

Sample Date Sample Cu

mg/1 Ni

mg/l As

mg/l Zn

mg/1Mn mg/l

Se mg/l

Cd keg/1

Hg vg/1

Al Pg/1

Cr Pg/1

Pb Pg/l

Fe Pg/l

8/15/74 Raw Wastewater (Influent) <.05 <.02 <.02 .01 .07 <.0l 0.5 <1.0 19.0 3.5 <1.0 3.0

Lime Clarification .05 <.02 <.02 <.0l <.0l < .01 <0.1 <1.0 400.0 3.5 <1.0 2.0

Carbon Adsorption .05 .02 <.02 .01 <.01 <.01 2.6 <1.0 70.0 3.0 2.0 3.0

Filtration .05 <.02 <.02 .02 <.0l <.01 2.2 <1.0 30.0 3.0 2.0 <1.0

9/4/74 Raw Wastewater (Influent) <.05 .11 <.02 .02 .09 <.01 <0.1 <1.0 10.0 4.0 2.0 145.0

Lime Clarification <.05 <.02 <.02 <.01 <.01 <.0l 0.2 <1.0 130.0 7.0 1.0 <1.0

Carbon Adsorption <.05 <.02 <.02 .01 <.01 <.01 <0.1 <1.0 20.0 3.0 <1.0 <1.0

Filtration .05 <.02 <.02 .01 <.0l <.01 1.1 <1.0 25.0 6.0 2.0 <1.0

9/25/74

Raw Wastewater (Influent) <.05 <.02 <.02 .02 .09 <.01 0.2 <1.0 30.0 3.0 2.0 75.0

Lime Clarification <.05 <.02 <.02 <.01 <.01 <.01 0.2 <1.0 550.0 3.0 <1.0 <1.0

Carbon Adsorption <.05 <.02 <.02 .01 <.01 <.01 3.1 <1.0 29.0 1.0 1.0 <1.0

Filtration .05 <.02 <.02 <.0l <.01 <.01 1.3 <1.0 35.0 2.0 2.0 <1.0

TABLE 4

METAL ANALYSIS OF COMPOSITE SAMPLES BEFORE CONCENTRATION

The percent COD distribution of ether-soluble nonvolatile organic material (Table 7) revealed

an increase in the amount of strong acids between the influent raw wastewater and the lime clarification

process which followed. In contrast, the amount of weak acids decreased from 44.8 - 52.2% in the raw

wastewater samples to 14.9 - 28.2% following lime clarification. These results indicate that the reversal

in the ratio of weak acids to strong acids occurred during lime treatment (ester hydrolysis, etc.) Neutral

and basic materials exhibited no significant change during lime clarification. No dramatic changes

occurred in the

After evaporation, the TOC of the concentrates was measured for an estimate of the amount of volatile

organic materials lost during evaporation (Tables5 and 6). The volatile materials lost on evaporation

ranged from 16.9% to 49.5% in the raw wastewater samples, and from 8.3% to 22.5% following lime

clarification at pH 10.5. The volatile organic loss ranged from 22.5% to 36.1% following carbon

adsorption, and from 16.9% to 37.6% following alum coagulation and filtration. In all samples examined

in this study however, the majority of the organic material present may be classified as nonvolatile.

the samples. Iron, magnesium, and manganese were the only metals which exhibited significant removal

throughout the process. Aluminum, cadmium, and lead concentrations increased throughout the system.

This increase in concentration may be attributable to impurities in the lime and ferric chloride additives

(Table 4).

TABLE 5

ORGANIC LOSSES DURING CONCENTRATION

Percent TOC :Lost on

Concentration

CompositeOrganic N (mg)

ConcentrateOrganic N Sample Sample Composite Concentrate

Date TOC (mg) TOC (mg) (mg)

Percent Organic N

Lost on Concentration

8/15/74 Raw Wastewater (Influent) 132.0 105.6 20.0 24.2 20.6 14.9

Lime Clarification 130.0 114.0 12.3 5.4 - -


Filtration 88.2 68.0 22.9 23.5 - -


Lime Clarification 158.1 145.0 8.3 87.4 29.1 66.7

Carbon Adsorption 53.5 34.2 36.1 12.1 13.6

Filtration 78.5 63.0 19.7 19.1 14.1 26.2




Filtration 173.7 108.4 37.6 27.0 12.5 53.7

TABLE 6

TOTAL DISSOLVED SOLIDS BALANCE

Composite Dissolved Solids

(gm)

Residue After Concentration Sample Sample Date (gm)

Organic Carbon In Residue (mg)

Percent Organic Carbon

In Residue

8/15/74 Raw Wastewater (Influent) 3.619 3.730 105.6 2.81

Lime Clarification 9.090 10.200 114.0 1.12

Carbon Adsorption 12.655 11.280 29.1 0.26

Filtration 12.230 12.095 68.0 0.56




Filtration 14.345 11.470 63.0 0.55


Lime Clarification 6.073 4.368 161..4 3.70


Filtration 12.063 12.130 108.4 0.89

TABLE 7

COD DISTRIBUTION OF THE ETHER-SOLUBLE NONVOLATILE ORGANIC MATERIAL (PERCENT)

WeakAcids

Neutrals _ Bases

Total Ether-- Soluble COD (mg)

Sample Strong Total COD ofSample Date Acids Concentrate*Percent Ether

Soluble COD

8/15/74 Raw Wastewater (Influent) 9.8 44.8 37.4 7.9 . 27.6 281.6 9.8

Lime Clarification 24.9 28.2 37.7 9.3 13.5 306.5 4.4

Carbon Adsorption 12.9 50.8 34.9 1.4 33.8

Filtration

9/4/74 Raw Wastewater (Influent) 23.7 52.2 20.1 4.0 21.6 402.0 5.4


Carbon Adsorption 22.4 14.7 28.8 34.1 1.3 57.8 2.2

Filtration 44.5 14.8 40.6 0.0 0.7 170.4 0.4

9/25/74 Raw Wastewater (Influent) 22.8 51.4 23.2 2.6 18.2 230.0 7.9


Carbon Adsorption 60.6 20.5 12.7 6.2 4.2 224.2 1.9

Filtration 72.1 11.5 11.8 4.5 6.7 289.0 2.3

*Calculated from TOC values by assuming that if a certain percentage of TOC was lost on concentration,

an equal amount of COD was lost (Table 5).

distribution following carbon adsorption although carbon adsorption may have been responsible for a

slight increase in the amount of weak acids.. The 34.1% value for the organic bases observed following

carbon adsorption in the September 4, 1974 sample may be questionable.

The nonvolatile organic distribution following the alum coagulation and filtration step revealed

an increase in the strong acids from 12.9 - 60.6% after carbon adsorption to 44.5 - 72.1% after alum

coagulation and filtration. The increase in strong acids was accompanied by an apparent decrease in the

amount of weak acids following carbon adsorption from 14.7 - 50.8% to"11.8 - 14.8% following the

alum coagulation and filtration. Since near neutral pH was maintained at this, stage of the process, a

probable explanation may be bacterial action on the filter media. Again, the neutral and basic material

distribution showed no significant change.

The solubility classification of the nonvolatile organic material remaining after concentration

revealed less than 10% as ether soluble, and better than 90% as water soluble amphoteric materials in all

of the samples examined. Organic nitrogen losses during concentration ranged from 14.9% to 70.3% in

the raw wastewater samples, and 12.9% to 66.7% following lime clarification. Organic nitrogen losses

during concentration ranged from 23.7% to 50.8% following carbon adsorption and 26.2% to 53.7%

following alum coagulation and filtration (Table 5). These results indicate that as much as 50% of the

initial nitrogenous organic matter may have been volatile.

TKN analysis of the ether extracts revealed only traces of the total organic nitrogen initially

present in the concentrates as being ether soluble.

The ir spectra of the ether extracts revealed that the aliquots removed for it analysis were too

dilute for intelligible analysis and the decision was made not to use more sample (ether extract)

for it analysis at the expense of the other tests.

The UV spectra of the ether extracts exhibited maxima at 225 nm only, and with varying

intensities. Table 7 lists the absorbance values of the ether extracts at 254 mm. These data

indicate that the majority of the ether-soluble organic materials, following breakpoint

chlorination and carbon adsorption, were strong acids (Tables 7 and 8). This increase in strong

acids may well have been accompanied by a comparable increase in chloroform formation.

Gas chromatography of up to 10 microliters of the ether extracts produced no peaks within

45 minutes under the conditions previously described. This may be attributed to:

insufficient sample concentration, organic material not volatile enough for GC analysis, or

organic material did not elute from the column.

Similar results were obtained with the liquid chromatographic analysis; however, it is felt

that better results could have been obtained by using a 1 meter column of 1/8" i.d. and a more

concentrated sample because most of the samples exhibited UV adsorption at 254 nm (Table 8).

TABLE 8

ULTRAVIOLET ABSORPTION AT 254 nm (ABSORBANCE UNITS)

Sample Date Sample Strong

Acids Weak Acids Neutrals Bases




Filtration 0.20 0.0 0.10 0.00


0.15

0.00 0.00

0.00

Lime Clarification 1.85 0.4 0.35

0.00

0.0

Filtration 1.00 0.0

0.85 Carbon Adsorption

Analysis of the samples, after concentration for proteins and amino acids, carbohydrates, and

hydroxylated aromatic compounds, was made in an attempt to better define the organic composition

of the amphoteric group. Total carbohydrate material, hydroxylated compounds, and proteins

accounted for 26.7 - 49.0% of the total organic carbon present in the raw wastewater concentrate,

33.0 - 35.4% in the lime clarification concentrate, approximately 35% in the carbon adsorption

concentrate, and 23.6 - 29.6% in the alum coagulation and filtration concentrate (Table 9). These

results also indicate that approximately 60% of the amphoteric materials may have been "humic"

materials as proposed by Rebhun and Manka (7) and Bunch et al. (8) for secondary effluents.

However, no further attempt was made to substantiate this due to insufficient sample.

24

TABLE 9

AMPHOTERIC MATERIALS

Proteins and Carbohy-drates

Hydroaylated Amino Acids(mg Bovine Aromatic

Compounds (mg Tannic Acid)

Proteins and Amino Acids Percent TOC*

Carbohydrates Sample Sample Date (mg Glucose)

Percent TOC Serum Albumin)

Hydroxylated Aromatic

Compounds Percent TOC

8/15/74 Raw Wastewater (Influent) 9.0 4.6

Lime Clarification - - 5.1 - - 2.4

Carbon Adsorption 1.0 17.7 - 1.8

Filtration - - 0.0 - - 0.0



Carbon Adsorption - 21.0 trace - 24.5 trace

Filtration 12.3 21.0 0.0 10.3 13.3 0.0


Lime Clarification 32.3 56.2 25.6 10.6 13.9 8.5 Carbon Adsorption 21.5 32.6 10.2 13.6 15.5 6.5 Filtration 21.0 42.0 7.6 10.3 1S.5 3.8

*Bovine Serum Albumin 53% Carbon (59).

CONCLUSIONS

1. When wastewaters undergo physical-chemical treatment

there may be an increase in concentration of certain heavy metals

due to impurities present in the chemical additives.

2. The major portion of the organic materials in treated

and untreated wastewater exists as nonvolatile materials.

3. Of the nonvolatile organic materials, 90% were classified

as ether-insoluble, amphoteric materials.

4. Organic bases represented the least amount of ether-soluble organic material,

while 95% or more of the ether-soluble materials existed as acidic and neutral

materials.

5. Following breakpoint chlorination and carbon adsorption, an increase in

strong acids was observed which may well have been accompanied by a comparable

increase in the volatile chloroform.

6. As much as 50% or more of the nitrogenous organic material in both

untreated wastewater and that which has undergone physical-chemical treatment may

be classified as volatile.

7. The nonvolatile nitrogenous organic material in both untreated wastewaters

and that which has undergone physical-chemical treatment existed as ether-insoluble,

amphoteric materials.

8. Proteins and amino acids, carbohydrates, and hydroxylated aromatic

compounds represented approximately 30% of the organic amphoteric materials in the

treated and untreated wastewaters.

Recommendations for Further Studies 1. A vacuum distillation system better suited for handling large volumes is recommended for a more

accurate characterization of nonvolatile organic materials in wastewater.

2. Molecular weight distribution of the nonvolatile organic materials in wastewaters should provide more

valuable character information.

3. Reversed phase liquid chromatography and ion exchange chromatography followed by a suitable

detector should provide at least partial separation of the nonvolatile organic materials in

wastewaters.

28

REFERENCES

1. R. L. Shriner and R. C. Fuson, Systematic Identification of Organic Compounds, 2nd Ed., John

Wiley and Sons, New York, 1940, pp 252-3.

2. EPA, Methods for Chemical Analysis of Water and Wastes, Office of

Technology Transfer, U.S. Environmental Protection Agency, Washington, D. C.

3. Standard Methods for the Examination of Water and Wastewater,

12th Ed., American Public Health Association, New York, 1965.

4. H. L. Golterman in IBP Handbook, No. 8, 3d rev. printing, Blackwell Scientific Publications,

Oxford, England, 1971.

5. John M. Clark, ed., Experimental Biochemistry, W. H. Freeman and Co., San Francisco, California,

1964, p 95.

6. M. Ramanathan, A. F. Gaudy, Jr., and E. E. Cook, Selected Analytical Methods for Research in

Water Pollution Control, Publication M-2, Center for Water Research in Engineering, Oklahoma State

University, Stillwater, Oklahoma, 1974.

7. M. Rebhum and J. Manka, Environ. Sci. and Tech., 5, 607 (1971).

8. R. L. Bunch, E. F. Barth, and M. B. Ettinger, J. Water Poll. Control Fed., 33, 122 (1961).

http://1965.4.h.l.golterman/

http://1965.4.h.l.golterman/

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