The Efficacy of Aeration and GAC Filtration at Reducing Microtoxicity of Water

74 Pages·2015·1.2 MB·English

by  Gustave J. Michaud

Florida State University Libraries
Electronic Theses, Treatises and Dissertations The Graduate School
2013
The Efficacy of Aeration and GAC
Filtration at Reducing Microtoxicity of
Water
Gustave Michaud Jr
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FLORIDA STATE UNIVERSITY

FAMU-FSU COLLEGE OF ENGINEERING

THE EFFICACY OF AERATION AND GAC FILTRATION AT REDUCING
MICROTOXICITY OF WATER

By

GUSTAVE MICHAUD, JR.

A Thesis submitted to the
Department of Civil and Environmental Engineering
in partial fulfillment of the
requirements for the degree of
Master of Science

Degree Awarded:
Fall Semester, 2013
Gustave Michaud, Jr. defended this thesis on November 5, 2013.
The members of the supervisory committee were:

Gang Chen
Professor Directing Thesis

Adrian Barbu
Committee Member

Wenrui Huang
Committee Member

The Graduate School has verified and approved the above-named committee members, and
certifies that the thesis has been approved in accordance with university requirements.
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ACKNOWLEDGMENTS
I would like to thank my Lord and savior Jesus Christ without whom I can do nothing. I would
like to thank Dr. Michael J. Watts for allowing me to work on this project this summer and fall.
I would like to thank Dr. Gang Chen for his expertise on adsorption kinetics, Dr. Adrian Barbu
for his expertise in mathematics and applied statistics, and Dr. Wenrui Huang for his expertise in
water treatment. I would like to thank my parents for being the best parents, and for being great
examples of hard work and commitment. Last but not least, I would like to also thank all
teachers and preachers who have helped me along the way.

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TABLE OF CONTENTS
List of Tables ................................................................................................................................. vi
List of Figures .............................................................................................................................. viii
Abstract .......................................................................................................................................... ix
1. INTRODUCTION ...................................................................................................................1
1.1 Pathogens and the Need for Chlorination ......................................................................1
1.2 Chlorination Methods ....................................................................................................3
1.3 Presence of Chlorination By-products in Drinking Water .............................................7
1.4 Environmental Factors of DBP Formation ....................................................................7
1.5 Impact of Chlorine Demand and Bromide on DBP Formation ...................................10
1.6 Study Specific Removal Technologies for Disinfection By-products .........................11
1.6.1 Aeration............................................................................................................11
1.6.2 Granular Activated Carbon ..............................................................................12
1.7 Cost for Different Treatment Alternatives ...................................................................12
1.8 Bacterial Bioluminescence Test ...................................................................................13
2. METHODS AND MATERIALS ..........................................................................................15
2.1 Synthetic Surface Water ..............................................................................................15
2.2 Water Characterization ................................................................................................16
2.2.1 Alkalinity .........................................................................................................16
2.2.2 Dissolved Organic Carbon ...............................................................................17
2.2.3 Ultraviolet Absorbance ....................................................................................18
2.2.4 Chlorine Demand .............................................................................................18
2.3 GAC Column Experiment............................................................................................20
2.4 Water Aeration Experiment .........................................................................................21
2.5 Bacterial Bioluminescence Test ...................................................................................22
3. RESULTS ..............................................................................................................................25
3.1 Water Characterization ................................................................................................25
3.2 Microtox Results for Synthetic Surface Water ............................................................30
3.3 U.V. 254 Results ..........................................................................................................33
3.4 Conclusion ...................................................................................................................36

APPENDICES ...............................................................................................................................38
A. WATER CHARACTERIZATION DATA ...........................................................................38
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B. GAC COLUMN PARAMETERS/%INHIBITION DATA ..................................................40
C. U.V.254 DATA .....................................................................................................................49
REFERENCES ..............................................................................................................................62
BIOGRAPHICAL SKETCH .........................................................................................................64

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LIST OF TABLES
Table 1-1 USEPA Regulated DBPs .................................................................................................3

Table 1-2 Typical Ct Values for Log Inactivation from EPA.gov ..................................................6

Table 3-1 Alkalinity Data pH 7.9 ..................................................................................................26

Table 3-2 Alkalinity Data pH 6.8 .................................................................................................27

Table 3-3 DOC Data Synthetic Surface Waters ............................................................................28

Table 3-4 SUVA Value for Synthetic Water pH 7.9 .....................................................................28

Table 3-5 SUVA Value for Synthetic Water pH 6.8 .....................................................................28

Table 3-6 Statistical Analysis %Inhibition ....................................................................................32

Table 3-7 Statistical Analysis U.V.254..........................................................................................34

Table A-1 DPD Standards ............................................................................................................38

Table A-2 Synthetic Surface Water pH 7.9 Chlorine Demand Data .............................................39

Table A-3 Synthetic Surface Water pH 6.8 Chlorine Demand Data .............................................39

Table B-1 GAC Column Parameters .............................................................................................40

Table B-2 GAC Column Scale up Recommendations ...................................................................40

Table B-3 GAC Microtox Data pH 7.9 ..........................................................................................40

Table B-4 GAC/Bubble Column Aeration Data ............................................................................41

Table B-5 GAC Microtox Data pH 7.9 ..........................................................................................42

Table B-6 GAC/Bubble Column Aeration Microtox Data pH 7.9 ................................................42

Table B-7 GAC Filtration Microtox Data pH 6.8 ..........................................................................43

Table B-8 GAC/Bubble Column Aeration Microtox Data pH 6.8 ................................................44

Table B-9 GAC Filtration Microtox Data pH 6.8 ..........................................................................44

Table B-10 GAC/Bubble Column Aeration Microtox Data pH 6.8 ..............................................45

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Table B-11 GAC Filtration Microtox Data ....................................................................................45

Table B-12 GAC Filtration/Bubble Column Aeration Microtox Data pH 6.8 ..............................46

Table B-13 Microtox Statistical Analysis ......................................................................................47

Table B-14 Microtox 48 Hour Microtox Results ...........................................................................47

Table B-15 %Inhibition Removal ..................................................................................................48

Table C-1 U.V. 254 GAC Filtration Data pH 7.9 ..........................................................................49

Table C-2 GAC/Bubble Column Aeration U.V. 254 .....................................................................50

Table C-3 GAC Filtration U.V. 254 Data ......................................................................................51

Table C-4 GAC Filtration U.V. 254 Data Additional Data ...........................................................52

Table C-5 GAC Filtration U.V. 254 Data Additional Data 2 ........................................................53

Table C-6 GAC/Bubble Column Aeration U.V. 254 Data ............................................................54

Table C-7 GAC/Bubble Column Aeration U.V. 254 Data Additional Data .................................55

Table C-8 GAC/Bubble Column Aeration U.V. 254 Data Additional Data 2 ..............................56

Table C-9 GAC Filtration U.V. 254 Data ......................................................................................57

Table C-10 GAC/Bubble Column Aeration U.V. 254 Data ..........................................................58

Table C-11 U.V. 254 Statistical Analysis ......................................................................................59

Table C-12 %DOC Removal Data .................................................................................................60

Table C-13 U.V. 254 Data Bubble Column Aeration ...................................................................61

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LIST OF FIGURES
Figure 1-1 Mount Empire Community College Chlorine Breakpoint Curve ..................................5

Figure 2-1 pH Meter ......................................................................................................................16

Figure 2-2 TELEDYNE TEKMAR TOC Analyzer ......................................................................17

Figure 2-3 TOC Autosampler ........................................................................................................18

Figure 2-4 U.V. Spectrophotometer...............................................................................................19

Figure 2-5 Autosampler for Microtoxicity Readings .....................................................................20

Figure 2-6 GAC Column Set-up ....................................................................................................21

Figure 2-7 Bubble Column Aeration Set-up ..................................................................................22

Figure 2-8 Bioluminescence Readings Set-up ...............................................................................24

Figure 3-1 Titration Data Synthetic Surface Water pH 7.9 ...........................................................26

Figure 3-2 Titration Data Synthetic Surface Water pH 6.8 ...........................................................27

Figure 3-3 Synthetic Surface Water pH 7.9 Chlorine Demand .....................................................29

Figure 3-4 Synthetic Surface Water pH 6.8 Chlorine Demand .....................................................29

Figure 3-5 %Inhibition Results pH range 6-8 ................................................................................32

Figure 3-6 Microtoxicity Reduction ..............................................................................................33

Figure 3-7 U.V. 254 Results for GAC Filtration/Aeration ............................................................35

Figure 3-8 DOC Removal Efficiency ............................................................................................36

Figure A-1 DPD Standard Graph ...................................................................................................38

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ABSTRACT
Chlorination of water is among the cheapest and mostly widely used drinking water disinfection
methods. It also produces many disinfection by-products (DBPs) that are considered
carcinogenic. DBPs are the result of chlorine reaction with dissolved organic carbon (DOC) in
water. This study seeks to evaluate a solution for the removal of DBPs, namely bubble column
aeration in conjunction with granulated activated carbon (GAC) filtration. Trihalomethanes
(THMs), which are one of the two major types of DBPs produced by chlorination, are volatile
and therefore can be removed by aeration. This study also seeks to evaluate the effectiveness of
aeration as a form of pre-treatment, if removal of DOC is achieved. The results show that GAC
filtration is very efficient at removing DOC, and microtoxicity in neutral pH synthetic surface
water. Bubble Column aeration alone, however, is not effective at removing DOC. The results
also show that aeration improves the efficiency of GAC filtration at reducing microtoxicity of
water. The t-test between toxicity values for the GAC filtration set-up, and the GAC/Bubble
column aeration set-up indicate that the two methods give a difference in values that is
statistically significant. It is concluded that chlorination followed by a GAC/Bubble column
aeration filtration system is a viable treatment method. Alternative treatment technologies such
as ozone and chlorine dioxide create DBPs that are carcinogens, or considered potential
carcinogens.

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