optimizing the solar disinfection method to produce potable water from ecologicallytreated...
TRANSCRIPT
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
1/45
THE PENNSYLVANIA STATE UNIVERSITY
SCHREYER HONORS COLLEGE
DEPARTMENT OF CIVIL AND ENVIRONMENTAL ENGINEERING
Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologically-
treated Wastewater Using Recycled Polyethylene Terephthalate Bottles
M. WILLIAM SHEEHAN
Spring 2012
A thesissubmitted in partial fulfillment
of the requirements
for a baccalaureate degreein Civil Engineering
with honors in Civil Engineering
Reviewed and approved* by the following:
Dr. Rachel A. Brennan
Associate Professor of Environmental Engineering
Thesis Supervisor
Dr. Patrick M. Reed
Associate Professor of Civil Engineering
Honors Adviser
*Signatures are on file in the Schreyer Honors College.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
2/45
i
Abstract
According to the World Health Organization, more than two million people die of
waterborne diseases every year, and 1.1 billion people lack a source of safe drinking water.
Every day, 4,500 children die from diarrhea due to a water-borne contaminant (World Health
Organization, 2000). The Solar Water Disinfection (SODIS) method is proven to remove
pathogenic contamination from water. In an epidemiological study of a cholera outbreak in
Kenya, an 88% reduction in diarrhea cases was observed among SODIS users (Conroy et al.,
2001). In this method, reused, unscratched, two liter polyethylene terephthalate (PET) bottles are
filled with water and then placed on their sides atop corrugated metal roofs in full sun for a
minimum of six hours to deactivate pathogens using the ultraviolet-A (UVA) waves from the
sun. The materials used in this method are accessible and economical, making SODIS a water
treatment process capable of helping many people who live in developing nations. To date, an
estimated 2.1 million people in 24 countries have benefited from SODIS (SODIS, 2012).
However, the SODIS method is not effective when the influent turbidity is greater than 30 NTU.
In the United States, the average turbidity value of domestic wastewater is approximately 60
NTU (Natural Resource Management and Environment Department, 1992), and drinking water
turbidity must be less than or equal to 0.3 NTU in at least 95 percent of the samples in any
month, never exceeding 1 NTU (US EPA, 2012).
The objective of this project was to investigate the potential of sustainably transforming
domestic wastewater into potable water, by combining an ecological wastewater treatment
system (i.e., Eco-Machine) to reduce turbidity, with modifications of the SODIS method to
optimize disinfection efficiency. A series of 20 oz. PET bottles were filled with Eco-Machine
effluent and placed on four different backgrounds to determine the effects of UVA intensity and
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
3/45
ii
temperature on the SODIS method. The four backgrounds included corrugated metal (a common
rooftop material in developing countries), blackened corrugated metal (to increase temperature),
a mirror (to enhance UVA transmission), and gravel (control). The level of disinfection was
quantified by sacrificing the bottles after a six hour period, and counting the number ofE. coli
and general coliforms. The broad outlook of this thesis is to refine the SODIS method and apply
it for producing potable water from wastewater in developing nations at minimal cost.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
4/45
iii
Table of Contents, List of Figures, and Tables
1. Introduction............................................................................................................................... 1
1.1 Background ........................................................................................................................... 1
1.2 History of SODIS .................................................................................................................. 1
1.3 The SODIS Procedure ........................................................................................................... 2
1.4 Turbidity Limitation .............................................................................................................. 2
Figure 1: Series of Formazin turbidity standards in NTU/FTU .............................................. 3
1.5 The Pennsylvania State University Eco-Machine ................................................................. 3
Figure 2: Cross-section of the Eco-Machine at Penn State. .................................................... 4
Figure 3: Closed anoxic tanks, CA1 and CA2......................................................................... 5
Figure 4: Picture of Open Aerobic 1 ....................................................................................... 6
Figure 5: Close-up of Floating Island. ..................................................................................... 7
Figure 6: Picture of Open Aerobic 2 ....................................................................................... 8
Figure 7: Picture of Water Hyacinths in OA2. ........................................................................ 8
Figure 8: Flow meter for the aeration system. ......................................................................... 9
Figure 9: Picture of Open Aerobic 3 ..................................................................................... 10
Figure 10: Picture of the clarifier. ......................................................................................... 11
Figure 11: Wetland and Display Pond. .................................................................................. 12
2. Materials and Methods........................................................................................................... 13
2.1 Water Collection Method for Turbidity Measurement ....................................................... 13
2.2 Water Collection Method for Bottle Samples ..................................................................... 13
2.3 Background Material Setup ................................................................................................. 13
Figure 12: Outside SODIS setup............................................................................................14
Figure 13: Outside SODIS setup............................................................................................14
2.4 UVA/B Measurement Method ............................................................................................ 15
Figure 14: Inactivation of cellular functions forE. coli based on fluence ............................ 16
2.5 Temperature Measurement Method .................................................................................... 16
2.3 Water Testing Method ......................................................................................................... 17
3. Experimental Results and Discussion ................................................................................... 19
3.1 Temperature ........................................................................................................................ 19
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
5/45
iv
Figure 15: Indoor and outdoor Air temperatures over the course of the experiment. ........... 19
Figure 16: Average final water temperatures for SODIS bottles on each background
material. ................................................................................................................................. 20
3.2 UVA/B Measurements ........................................................................................................ 21
Figure 17: Primary and bounce-back UVA/B measurements over time. .............................. 21
Table 1: Percentage of theoretical inactivation for indoor samples. ..................................... 22
Table 2: Percentage of theoretical inactivation for outdoor samples. ................................... 22
3.3 CFU/mL per Background Material ..................................................................................... 22
Figure 18: Colony-forming units per mL ofE.coli and total coliforms as a function of the
background material. ............................................................................................................. 23
Table 3: Summary of CFU/mL for total coliforms andE. coli on each outdoor background
material .................................................................................................................................. 24
3.4 Most Effective Progression ................................................................................................. 24
Figure 19: Disinfection levels throughout the combined treatment system. ......................... 25
4. Engineering Significance and Future Work ......................................................................... 27
Appendix 1- Plants of the Eco-Machine Wetland.................................................................... 29
Appendix 2- Temperature Data................................................................................................. 31
Appendix 3- UVA/B Data ........................................................................................................... 32
Appendix 4- CFU/mL Data ........................................................................................................ 33
Appendix 5- Colony Counts ....................................................................................................... 34
Appendix 6- Calculations ........................................................................................................... 35
Works Cited................................................................................................................................. 36
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
6/45
v
Acknowledgements
I am thankful for the superior guidance that Dr. Rachel Brennan has shown me during my
thesis. Her expertise and fascinating ideas regarding water remediation guided me throughout
this entire project. I greatly valued the time she dedicated to advising my project.
I am appreciative of the direction that my honor advisor, Dr. Patrick Reed, has provided
to me throughout my undergraduate career. His suggestions and opinions have been instrumental
in my completion of the Civil and Environmental curriculum at The Pennsylvania State
University.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
7/45
1
1. Introduction
1.1 Background
The World Health Organization states that 1.1 billion people lack a source of safe
drinking water (World Health Organization, 2000). As a result, many people are forced to drink
contaminated water which can cause diarrhea and various other water-borne sicknesses.
Diarrheal diseases are the cause of death for over 1.2 million children each year, most being less
than five years old (Black et al., 2010). Solar disinfection of water (SODIS) is a simple,
economical method for sanitizing water and is recommended by the World Health Organization
for those who do not have access to safe drinking water. The SODIS method is proven to remove
pathogenic contamination from water and decrease the occurrence of diarrhea by 88% (Conroy
et al., 2001).
1.2 History of SODIS
In 1980, Lebanese scientists first discovered that sunlight could disinfect water (Acra et
al., 1980). This discovery was not further explored until the 1990s when Eawag, the Swiss
Federal Institute of Aquatic Sciences and Technology, envisioned this principle benefiting those
living in developing nations. The institute launched an interdisciplinary research team consisting
of microbiologists, virologists, engineers, and drinking water specialists to develop a disinfection
process involving polyethylene terephthalate bottles and sunlight. This was the birth of the
SODIS method. The research team focused on the effectiveness and applicability of the method
and ran bench-scale tests in the laboratory and field tests in developing nations. In the tests, the
SODIS method proved to be user-friendly, economical, and effective. Other research
establishments, including the Royal College of Surgeons, Ireland, and the University of Uppsala,
Sweden, confirmed the validity of the findings and the positive effect the SODIS method has on
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
8/45
2
peoples health (McGuigan et al., 1998; Wegelin et al., 1994). The SODIS method has since
benefited 2.1 million people in 24 countries. Currently, Eawag is researching the health aspects,
educational strategies, and PET bottle deficiencies regarding the SODIS method (SODIS, 2012).
1.3 The SODIS Procedure
The SODIS method uses a clear, transparent PET bottle that is filled with biologically
contaminated water that has turbidity less than 30 NTU. The bottle must be cleaned beforehand
and be less than two liters in size to allow adequate light penetration. The bottle is filled full
and shaken for about 20 seconds to oxygenate the water. Afterwards, the remainder of the bottle
is filled to capacity and is placed in full sunlight for six hours. During the six hours, the UVA
rays interfere with the reproductive, respiratory, and metabolic capabilities of bacteria, viruses,
and helminthes (Wegelin et al., 1994). UVA light with a wavelength 320-400 nm is mainly
responsible for the inactivation of microorganisms. The rays also react with the dissolved oxygen
in the water resulting in highly reactive forms of oxygen (ex., oxygen free radicals) that damage
pathogens, and the solar energy heats the water which quickens the disinfection process. The
ambient temperature threshold for SODIS to remove fecal coliforms is above 20 C (Wegelin et
al., 1994), and if the temperature of the water reaches above 50 C, the disinfection process is
three times faster and leads to the complete disinfection of water.
1.4 Turbidity Limitation
One limiting factor of the SODIS method is that the turbidity of the influent must be less
than 30 NTU. Figure 1 is a visualization of the Formazin turbidity standards and corresponding
values. Turbidity is the visible muddiness within the water created by suspended particles. In the
United States, the average turbidity value of domestic wastewater is approximately 60 NTU
(Natural Resources Management and Environment Department, 1992). In arid climates and in
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
9/45
3
developing nations, the wastewater turbidity is significantly greater than 60 NTU because water
usage is low so the fraction of sewage in the wastewater is average to high. Due to the turbidity
restraint, SODIS is mainly used on water from tube wells, freshwater lakes, and streams. This
thesis focuses on the possibility of using SODIS on wastewater that is first treated ecologically to
reduce turbidity by means of the Eco-Machine at the Advanced Ecological Engineering Systems
Laboratory at The Pennsylvania State University. Combining ecological and SODIS treatment
methods could develop another source of potable water for people living in developing nations.
Figure 1: Series of Formazin turbidity standards in NTU/FTU (Optek, 2012).
1.5 The Pennsylvania State University Eco-Machine
The Pennsylvania State University Eco-Machine has the capacity to treat 1,000 gallons of
wastewater per day. The remediation system is head driven, and a cross-section of it can be seen
in Figure 2. The system was built in May 2003 (Cooke, J., 2003), fell dormant, and was revived
in August 2010. At the time of this research, the Eco-Machine was in a start-up period and was
processing 500 gallons per day. The incoming influent rate is gradually increased over time so
that the living organisms in the system have the opportunity to develop in order to adequately
process the nutrients in the wastewater. Due to the dependence of the system on scheduled
wastewater deliveries from the Penn State Wastewater Treatment Plant (PSU WWTP), it is
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
10/45
4
foreseen that the system will treat a maximum of 700 to 800 gallons per day with a 58% recycle
rate.
Figure 2: Cross-section of the Eco-Machine at Penn State.
At the Eco-Machine, a 3,000 gallon underground anaerobic holding tank is filled weekly
with wastewater that has passed through the PSU WWTP primary clarifier. Primary effluent,
rather than raw wastewater, is delivered to the Eco-Machine to avoid the introduction of rags,
grits, oils, and grease into the system. In the PSU WWTP primary clarifier, some organic
material is settled out of the water and fats and oils are skimmed from the surface, resulting in a
removal of approximately 30% of the biochemical oxygen demand (BOD) from the raw
wastewater. From the outer holding tank, this wastewater is pumped into a closed anoxic tank,
Closed Anoxic Tank 1 (CA1), seen below on the left in Figure 3.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
11/45
5
Figure 3: Closed anoxic tanks, CA1 (left) and CA2 (right).
Each of the closed anoxic tanks are 48-inches in diameter and have a 300-gallon volume. Within
CA1 and CA2, there is a heavy degradation of BOD due to anaerobic fermentation reactions that
breakdown complex carbon species in the wastewater into fatty acids, alcohols, methane, and
carbon dioxide. Heterotrophic fermentative bacteria and chemoautotrophic archaea perform the
majority of the microbial degradation reactions in these tanks. Heterotrophic denitrifying bacteria
also convert nitrate (NO3-) to nitrogen gas (N2), particularly in CA2, which receives recycled
flow from aerated steps later in the system. The produced gases in CA1 and CA2 passively
escape via a pipe to outside of the greenhouse, as seen in Figure 3.
Leaving CA2, the wastwater enters Open Aerobic Tank 1 (OA1), the first open aerboic
tank within a series of three. All three open aerobic tanks have a 67.5-inch diameter and a 1,000-
gallon volume. Figure 4 is a picture of OA1. In the aerobic environment, the ammonium (NH 4+)
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
12/45
6
in the wastewater begins to be converted to nitrate by chemolithotrophic nitrifying bacteria
(nitrification) and BOD is oxidized by heterotrophic aerobic bacteria. OA1 contains the most
durable plants within the system because OA1 encounters the harshest conditions and an over-
abundance of nutrients from the wastewater since it is the first aerobic remediation step within
the Eco-Machine. In addition to the microoganisms floating in the water, the tank has a floating
island. A close-up image of a floating island section from OA1 is shown in Figure 5. Floating
islands are comprised of a styrofoam ring that is covered by coconut coir fibers. Soil is located in
the inner area of the floating island and the roots of the plants pass through the soil and coir,
extending into the wastewater. The roots of the plants remove phosphorus and nitrogen and
provide a location for bacterial and fungal colonization. This growth assists in the further
degradation of the contaminated water. Snails are present in OA1, as well as in all the other
aerobic tanks, to provide water cleansing and algae removal.
Figure 4: Picture of Open Aerobic 1 (OA1).
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
13/45
7
Figure 5: Close-up of Floating Island.
From OA1, the water flows into Open Aerobic Tank 2 (OA2). OA2 is similar to OA1 in
that it has a floating island with plants that assist in the removal of nitrogen, phosphorus, and
BOD. Figure 6 is a picture of OA2. The plant species in OA2 are different than OA1, and water
hyacinths (Eichhornia) float on the water outside of the floating island. The water hyacinths are
instrumental in absorbing nitrogen and phosphorus, and there are plans to introduce the elephant
ear plant (Colocasia) to OA2 since it is also capable of absorbing the overabundance of nutrients
in the water. A close-up of the water hyacinths in OA2 can be seen in Figure 7.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
14/45
8
Figure 6: Picture of Open Aerobic 2 (OA2).
Figure 7: Picture of Water Hyacinths in OA2.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
15/45
9
From OA2, water flows into Open Aerobic Tank 3 (OA3). OA3 does not have a floating
island like the previous aerobic tanks, but instead its surface is completely covered by common
duckweed (Lemna minor). Duckweed replicates rapidly and half of its surface area in OA3 is
removed weekly and is used for other beneficial purposes (such as soil and feedstock
amendments; research in progress). In the system, the duckweed is one of the best plants at
absorbing nitrogen and phosphorus. By OA3, all of the ammonia has been converted to nitrate
with assistance from air sparging due to timed air compressors. Air compressors are timed to
aerate the tanks periodically throughout the day and night. All of the open aerobic tanks have
aeration pipes located at the bottom through which air is released through diffusing stones,
creating small bubbles. These bubbles pass upward through the tanks and increase the dissolved
oxygen concentration of the water in the system. The level of aeration is monitored by
regulators, located on the outside of the tank, which are displayed in Figure 8. Figure 9 is a
picture of OA3.
Figure 8: Flow meter for the aeration system.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
16/45
10
Figure 9: Picture of Open Aerobic 3 (OA3).
Some of the water from OA3 is internally recycled via underground piping to CA2, which can be
seen on the right side of Figure 3. From CA2, the recycled water flows through the series of open
aerobic tanks again. The internal recycle of water from OA3 to CA2 occurs at scheduled times
and is necessary in order for denitrification to occur. Denitrification is the conversion of nitrate
to nitrogen gas and only happens under anoxic conditions. Denitrification is instrumental in
wastewater treatment to avoid rising sludge in the clarifier.
After OA3, water tranquilly enters the clarifier where the sludge settles. The clarifier has
a 52-inch diameter and a 300-gallon volume. The Goulds Submersible Pump Model LEP07
currently removes the settled sludge five times, evenly spaced, throughout each day. The settled
sludge is pumped to the holding tank to give a 60% recycle rate. Within the clarifier, there is a
baffle which prevents the duckweed, located on the right side of the clarifier, from intruding into
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
17/45
11
the the left side, where the exit of the clarifier is located. This baffle prevents the duckweed from
clogging the trough exit of the clarifier. When the head of the system is greater than the rim of
the exit trough, the water will spillover and flow into the subsurface wetland or the sewer,
depending on the positioning of the exit valve. Typically, the water flows into the wetland. The
pipeway to the sewer is solely precautionary.
Figure 10: Picture of the clarifier.
From the clarifier, the water flows into a horizontal slotted header that is six inches under
the gravel subsurface and is parallel to the interior wall of the greenhouse that is the focal point
of Figure 11 (opposite the entrance door to the greenhouse). The wetland is 24 by 20 and has a
liquid volume of approximately 3,000 gallons. The subsurface flow is directed from the back
wall towards the front entry of the greenhouse (the location of the viewer in Figure 11). The
plants, sprouting through the gravel, polish the water and remove any remaining nutrients. The
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
18/45
12
list of plants in the wetland include: Red Stemmed Thalia, Water Calla, Blue Rush, Black Magic
Taro, and Canna Lilies. Appendix 1 shows images of the plants within the Eco-Machine wetland.
Once through the wetland, the water is piped to the display pond which is on the lower left side
of Figure 11. Currently, microorganisms and duckweed inhabit the display pond, but there are
plans to incorporate koi or goldfish into the pond in the near future.
Figure 11: Wetland and Display Pond.
Maintenance for the Eco-Machine plants is similar to that of a regular garden, consisting
of weekly pruning as needed. To regulate aphids, ladybugs are periodically introduced into the
greenhouse instead of using pesticides.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
19/45
13
2. Materials and Methods
2.1 Water Collection Method for Turbidity Measurement
To measure the turbidity of the system, effluent samples were taken from the left side of
the clarifier. A sample tube was submerged under the surface of the water and rinsed multiple
times. After the water was dumped the final time, the tube was submerged and capped
underwater. This was completed to ensure that there was no entrapped air that would permit
aerobic reactions prior to testing the turbidity. The turbidity of the sample was measured using
the Hach 2100P Turbidimeter. The turbidity of the clarifier was measured to confirm that the
turbidity of the pretreated water was below the 30 NTU maximum for the SODIS method to be
effective.
2.2 Water Collection Method for Bottle Samples
The PET bottles used within this experiment originally contained commercial drinking
water so contamination from prior contents would not be expected. Each of the 24 bottles were
emptied, recapped, and refilled within 30 minutes prior to the start of the experiment. To fill the
20 oz. PET bottles, each bottle was submerged underwater on the left side of the clarifier. The
labels were removed prior to submerging the bottle. After the bottle was filled to of capacity
with water from the clarifier, the bottle was removed from the water, capped, and shaken for 20
seconds. A second container was used to fill the remaining portion of the bottle with water from
the clarifier, and then capped. As soon as the required 24 PET bottles were filled, each was
placed on one of the four backgrounds either inside or outside of the greenhouse.
2.3 Background Material Setup
A mirror, sheets of corrugated metal and black corrugated metal, and a plot of gravel
were placed on the ground both inside and outside of the greenhouse. The sheets of black
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
20/45
14
corrugated metal were painted using Krylon Black Gloss Spray Paint, and the mirrors were
cleaned prior to the start of the experiment. Below are pictures of the experimental setup both
inside and outside of the greenhouse. The bottles remained in this setup without agitation until
the conclusion of the experiment.
The purpose of placing each of the samples on different background materials both inside
and outside of the greenhouse was to determine whether a heat absorptive or a reflective surface
is more effective in optimizing the SODIS method. The experiment was set up inside and outside
of the greenhouse to observe the effects of UVA/B intensity on disinfection, and to determine
whether the SODIS method could be applied within the Eco-Machine greenhouse in the future.
Figure 12: Outside SODIS setup. Figure 13: Inside SODIS setup.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
21/45
15
2.4 UVA/B Measurement Method
At each hour, the UVA/B rays were measured using the UVA/B Light Meter 850009
(SPER Scientific). The face of the detector was held perpendicular to the rays of the sun for the
most representative measurement. This same procedure was followed for both inside and outside
of the greenhouse. To measure the bounce-back UVA/B rays, the face of the detector was angled
perpendicular to the greatest concentration of reflected rays from the background material. This
procedure was followed for both inside and outside of the greenhouse.
The purpose of measuring the primary UVA/B and bounce-back intensity every hour was
to track the total attained level of UVA/B intensity that the bottles experienced during the six
hours while outside and inside the greenhouse. UVA irradiation is responsible for inactivating
bacteria during SODIS because it damages the membrane enzymes which results in the loss of
membrane potential and increased membrane permeability. Membrane potential is required for
ATP synthesis. The membrane potential is a component of the proton-motive force which drives
the counter-rotation of ATP synthase (Dimroth, et al., 1999). The ability for a cell to maintain its
ATP level is essential for dealing with environmental stressors which is when the cell requires
readily available energy for defense and to repair damage. A decrease in the ATP-generation
potential is a fatal indicator of a cell under stress (Bosshard, et al., 2010). Figure 14 shows the
decrease in cellular functions forE. coli based on UVA fluence. Fluence describes the amount of
energy delivered to a sample per unit area.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
22/45
16
Figure 14: Inactivation of cellular functions forE. coli based on fluence (Bosshard, et al., 2010).
2.5 Temperature Measurement Method
At each hour, the air temperature was measured inside and outside of the greenhouse
using the Traceable ISO 17025 Calibrated Thermometer (VWR). The thermometer was first
allowed to stabilize before the inside and outside temperatures were recorded. At the conclusion
of the experiment, the caps of the bottles were opened and the thermometer was inserted into the
water. After the reading on the thermometer stabilized, the temperature was recorded and the
bottle was recapped. Before the thermometer was inserted into the next sample, the instrument
was cleaned using a KimWipe and a 70% isopropanol and 30% water solution in order to avoid
cross-contamination. The thermometer probe was allowed to dry before it was used to measure
the temperature of the successive sample. This procedure was followed for each of the 24 bottles
of water.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
23/45
17
The purpose of measuring the hourly air temperature and the final water temperature was
to determine whether pasteurization or UVA/B disinfection was the driving factor of
disinfection.
2.3 Water Testing Method
The purpose of this experiment was to determine the attainable reduction in total
coliforms andE. coli by combining the Eco-Machine and SODIS treatment methods, and to
determine which background material produces the most effective disinfection level. The number
of total coliforms andE.coli were enumerated in the influent to the Eco-Machine system, the
water exiting the clarifier, and the water in the PET bottles after the necessary six hours of sun
exposure on each of the four backgrounds. Enumeration was conducted using Easygel
test kits
(Micrology Labs). Easygel is a commercially available pectin-gel testing method which is
provided in a sterile, two-part test unit consisting of a 10 mL bottle of liquid medium and a
pretreated Petri dish.
To prepare the water samples for testing of total coliforms and E. coli, sterilized pipette
tips were used to extract a 3.0 mL water sample from each of the PET bottles, a 1.0 mL sample
from the clarifier effluent, and 0.1 mL from the Eco-Machine influent. Each extracted water
sample was injected into a 10 mL plastic bottle containing Easygel
and gently inverted 30 times
to properly mix. Prior to this, the Easygel had been stored at -20 C, as recommended by the
manufacturer, and was thawed before the water was injected. After the solution was inverted 30
times, the liquid was poured into a Petri dish and given an hour to fully solidify at room
temperature. Afterward, the Petri dishes were labeled, inverted, sealed with parafilm, and placed
in a VWR Signature Low-Temperature/B.O.D. Incubator (Model #2005, VWR International)
at 25 C for 48 hours. The Easygel medium stains colonies ofE. coli purple and general
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
24/45
18
coliforms pink for easy identification (Illian, M. et al., 2010). General coliforms will produce the
enzyme galactosidase and the colonies that grow in the medium will be a pink color. E. coli will
produce both galactosidase and glucuronidase and will therefore grow as dark blue to purple
colonies in the medium. The combined general coliform and E. coli number equals the total
coliform number (Micrology Laboratories, 2012). The number of colonies on each Petri dish was
counted using an ISO 9001 certified manual tally (Upgreen Counters, Model HT-1) to avoid
human error.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
25/45
19
3. Experimental Results and Discussion
3.1 Temperature
The temperatures both inside and outside of the greenhouse were recorded hourly
throughout the experiment. In order for the SODIS method to be effective, the surrounding
temperature must be at least 20 C. If the temperature of the water reaches above 50 C, the
disinfection process is three times faster and leads to the complete disinfection of water. If the
temperature reaches 65 C for 30 minutes, then pasteurization is the driving disinfection method
(Ciochetti et al., 1984). Figure 15 displays the hourly temperature results.
Figure 15: Indoor and outdoor air temperatures over the course of the experiment.
Figure 15 shows that the air temperatures throughout the test were consistently greater
than 20 C, which satisfies the temperature requirement for the SODIS method (Illian, M. et al.,
10AM 11AM 12PM 1PM 2PM 3PM 4PM
19
21
23
25
27
29
31
0 1 2 3 4 5 6
Time of Day
T
emperature(C)
Experimental Time (hr)
Outside Greenhouse Inside Greenhouse
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
26/45
20
2010). The indoor temperature had less variation compared to the outdoor temperature because
the greenhouse is climate controlled. The temperature did not reach 50 C, so six hours was the
appropriate timing for the experiment. Neither the outdoor nor indoor samples were disinfected
due to pasteurization since the temperature did not exceed 65 C.
At the conclusion of the experiment, the caps of the bottles were opened and the
thermometer was inserted into the water. After the reading on the thermometer stabilized, the
temperature was recorded and the bottle was recapped. Figure 16 displays the average final water
temperature measurements of the three replicate bottles for each background material; the error
bars represent one standard deviation.
Figure 16: Average final water temperatures for SODIS bottles on each background material.
25
26
27
28
29
30
31
32
33
34
Corrugated Metal Mirror Black Corrugated
Metal
Gravel
Temperature(C)
Background Material
Outside Greenhouse Inside Greenhouse
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
27/45
21
The indoor and outdoor bottles on the black corrugated metal reached the highest internal
temperature, yet all samples were greater than the minimum temperature requirement at the end
of the experiment.
3.2 UVA/B Measurements
As sunlight passes through the atmosphere, all UVC (280-100 nm) and approximately
90% of UVB (315-280 nm) radiation is absorbed by ozone, water vapor, oxygen, and carbon
dioxide. UVA (400-315 nm) radiation is less affected by the atmosphere. Therefore, the UV
radiation reaching the Earths surface is largely composed of UVA with a small UVB component
(World Health Organization, 2012). At each hour, the primary and bounce-back UVA/B rays
were measured. Figure 17 shows the time plot of the UVA/B measurement results.
Figure 17: Primary and bounce-back UVA/B measurements over time.
The data show that the outdoor samples received the largest amount of primary UVA/B rays. The
corrugated metal and mirror background materials provided the most bounce-back UVA/B rays
compared to the gravel and black corrugated metal background materials. To relate the indoor
and outdoor UVA/B conditions, the indoor samples received as much primary UVA/B rays as
the least reflective outdoor background materials (gravel and black corrugated metal) received in
bounce-back UVA/B rays. The lack of primary UVA/B rays that penetrated the samples within
the greenhouse was likely the main reason that the disinfection was not as effective for the
indoor samples (see section 3.3, below).
1
10
100
1000
10000
0 1 2 3 4 5 6
UVA/BMeasurement(W/cm)
Experimental Time (hr)
Primary UVA/B Bounce-back UVA/B- Mirror
Bounce-back UVA/B- Corrugated Metal Bounce-back UVA/B- Gravel
Bounce-back UVA/B- Black Corrugated Metal
Outdoor Samples
0 1 2 3 4 5 6
Indoor Samples
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
28/45
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
29/45
23
ofE. coli and the total coliforms for each background material. The raw data is provided in
Appendix 4.
Figure 18: Colony-forming units per mL ofE.coli and total coliforms as a function of the
background material. The colored bars on the chart represent the average CFU/mL value, andthe error bars represent one standard deviation of the nine plated samples.
The level of disinfection for the outdoor samples was significantly better than the level of
disinfection of the indoor samples (Figure 18). This is undoubtedly due to the difference in
primary UVA irradiation. The mirror background was slightly more effective than the other three
background materials, but the difference was not statistically significant. This is likely due to the
large bounce-back UVA measurement. It can be inferred from the data in Figures 16, 17, and 18
that UVA irradiation is a larger driving factor in disinfection compared to temperature for the
SODIS method. The average CFU/mL value and standard deviation for total coliforms andE.
coli are provided in Table 3 for each of the outdoor background materials.
0
5
10
15
20
25
30
Corrugated Metal Mirror Black Corrugated
Metal
Gravel
CFU/mL
Background Material
Average Total Coliform (Inside) Average E.coli (Inside)
Average Total Coliform (Outside) Average E.coli (Outside)
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
30/45
24
Table 3: Summary of CFU/mL for total coliforms andE. coli on each outdoor background
material (n = 9).
There is some hesitancy regarding the accuracy of the outdoor sample results. It should
be noted that a count less than 20 CFUs/dish for the Easygel
medium is considered to be
statistically questionable for accuracy (Micrology, 2012). Regardless, the same volume of water
was extracted from the indoor and outdoor samples and since the outdoor samples resulted in
less colony growth, it can be concluded that the outdoor method was more effective than the
indoor method, despite possibly having statistically questionable count accuracy for the outdoor
samples.
3.4 Most Effective Progression
The disinfection levels within the combined Eco-Machine and SODIS method treatment
system can be seen in Figure 19.
Total Coliforms E. coli Total Coliforms E. coli Total Coliforms E. coli Total Coliforms E. coli
0.22 0.35 0 0 0.22 0.27 0 0 0.22 0.31 0 0 0.48 0.50 0.11 0.16
Corrugated Metal Mirror Black Corrugated Metal Gravel
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
31/45
25
Figure 19: Disinfection levels throughout the combined treatment system.
This graph shows that the combined system is an effective method of remediating and
disinfecting the primary effluent from the WWTP into potential potable water. The United States
Environmental Protection Agency lists the maximum contaminant level (MCL) of total
coliforms, includingE. coli, as 5.0%. This means that no more than 5.0% of samples are
allowed to test total coliform-positive in a month. For water systems that collect fewer than 40
routine samples per month, no more than one sample can be total coliform-positive per month.
Every sample that tests total coliform- positive must be analyzed for either fecal coliforms orE.
coli. If two consecutive samples test total coliform-positive, and one is also positive forE. coli,
then system has an acute MCL violation (US EPA, 2012). According to the experimental results,
44% of samples atop the mirror background tested positive for at least one total coliform.
0.0
20.0
40.0
60.0
80.0
100.0
120.0
System Influent Clarifier Effluent Mirror (Outside)
CFU/mL
Remediation Steps
Average Total Coliform
Average E. coli
Avg Progression of
Total Coliform
Avg Progression of E.
coli
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
32/45
26
Despite this, no substantial conclusions about the level of disinfection of the outdoor samples can
be made due to the statistically questionable count accuracy.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
33/45
27
4. Engineering Significance and Future WorkThe disinfection levels attained in this experiment confirm that the outdoor samples were
better disinfected than the indoor samples. To optimize the SODIS method further, the intensity
of the UVA irradiation must be optimized. In the application of SODIS, it would be more
realistic to intensify the driving factor of UVA irradiation, rather than the temperature, when
disinfecting water. In order to increase the temperature, combustion of a fuel source is necessary
which would not be sustainable for a developing nation.
The mirror proved to be slightly more effective than the other background materials. The
Eco-Machine and outdoor mirror SODIS combination disinfected 99.5-100% of total coliforms
from the system influent, considering one standard deviation when calculating the value. This is
only 0.1% more effective than the unpainted corrugated metal (see Appendix 6.3 for the
calculations which derived the percent disinfection range). Since mirrors are not a common
material found in developing nations, it is recommended that unpainted, corrugated metal be
used as a standard background material during SODIS. Future work could include developing an
economical, partially enclosed, corrugated metal stage set at an angle perpendicular to the suns
rays to concentrate the UV light and maximize disinfection.
The combined Eco-Machine and SODIS disinfection system has to be further enhanced
in order to comply with the EPA 5.0% maximum contaminate level regulation since 44% of
samples atop the outdoor mirror background tested positive for total coliforms. Further
disinfection can be accomplished by either extending the amount of time the samples were
subjected to sunlight during the experiment, or adjusting the angle of the bottles relative to the
sun so that they receive more direct light. During March in State College, Pennsylvania, bottles
laying flat on the ground receive sunlight at an angle of 49 from the vertical. In comparison,
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
34/45
28
bottles located in a city located close to the equator (ex. Nairobi, Kenya), would receive sunlight
at an angle of 89 from the vertical during March (Solar Electricity Handbook, 2012). Further
work could include deriving an algorithm which relates the distance from equator to the amount
of time the bottles should be subjected to direct sunlight, based on the month of the year.
In addition, further market research should be completed prior to repeating this
experiment to determine the best incubation medium to use for testing total coliforms and E. coli.
In some instances, counting the general coliforms andE.coli colonies was challenging because
the pink color was difficult to differentiate from the purple color in the Easygel matrix. If
Easygel is determined to be the best medium, the maximum allowable 5.0 mL sample input into
the Easygel should be used in order to possibly comply with the 20 colony count minimum to
ensure count accuracy. In this experiment, 3.0 mL was used and it did not provide a statistically
reliable colony count for the outdoor samples.
Finally, scalability should be considered for the combined Eco-Machine and SODIS
system to adequately serve a community in a developing nation. Using bottles smaller than two
liters is not sustainable to disinfect the large quantity of water needed by a community. Further
research could focus on the feasibility of constructing a translucent pipeline exiting the Eco-
Machine which is in direct sunlight and has a set hydraulic residence time of approximately six
hours to ensure disinfection of total coliforms.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
35/45
29
Appendix 1- Plants of the Eco-Machine Wetland
Black Magic Taro (Colocasia Esculenta) Blue Rush (Juncus glauca)
Water Calla (Zantedeschia aethipica) Red Stemmed Thalia (geniculate Ruminoides)
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
36/45
30
Canna Lily (Roi Humbert)
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
37/45
31
Appendix 2- Temperature Data
Location
Inside Greenhouse Outside Greenhouse
0 76.5F (24.7C) 68.5F (20.3C) Sample ID I CM 1 I CM 2 I CM 3
1 78.2F (25.6C) 74.8F (23.8C) 87.6F (30.9C) 88.4F (31.3C) 88.3F (31.3C)
2 85.5F (29.7C) 84.2F (29.0C)
3 84.0F (28.9C) 85.1F (29.5C) Sample ID I B 1 I B 2 I B 3
4 81.7F (27.6C) 81.4F (27.4C) 90.6F (32.6C) 91.2F (32.9C) 91.0F (32.8C)5 81.5F (27.5C) 84.2F (29.0C)
6 84.1F (28.9C) 84.0F (28.9C) Sample ID I Mir 1 I Mir 2 I Mir 3
87.6F (30.9C) 86.8F (30.4C) 84.2F (29.0C)
Turbidity 2.35 NTU Sample ID I G 1 I G 2 I G 3
Temperature 64.8F (18.2C) 82.2F (27.8C) 83.0F (28.3C) 84.0F (28.9C)
Sample ID O CM 1 O CM 2 O CM 3
86.6F (30.3C) 87.0F (30.6C) 87.2F (30.7C)
Sample ID O B 1 O B 2 O B 388.3F (31.3C) 89.0F (31.7C) 89.6F (32.0C)
Sample ID O Mir 1 O Mir 2 O Mir 3
85.6F (29.8C) 85.6F (29.8C) 84.8F (29.3C)
Sample ID O G 1 O G 2 O G 3
86.1F (30.1C) 87.6F (30.9C) 86.8F (30.4C)
Temperature Measurements
Hour Number
Gravel
Temperature of Water after 6 hours
Inside of Greenhouse
Corrugated Me tal
Black Corrugated Metal
Mirror
GravelClarifier Effluent Characteristics
Temperature of Water after 6 hours
Outside of Greenhouse
Corrugated Me tal
Black Corrugated Metal
Mirror
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
38/45
32
Appendix 3- UVA/B Data
Inside Greenhouse Outside Greenhouse Hour Number Corrugated Metal Black Corrugated Metal Mirror Gravel
0 155 W/cm 3.70 mW/cm 0 0 0 0 0
1 133 W/cm 3.24 mW/cm 1 11 0 19 0
2 208 W/cm 4.32 mW/cm 2 23 0 39 0
3 164 W/cm 4.30 mW/cm 3 43 0 54 0
4 119 W/cm 2.88 mW/cm 4 28 0 25 0
5 175 W/cm 3.25 mW/cm 5 18 0 23 0
6 114 W/cm 2.82 mW/cm 6 0 0 0 0
Hour Number Corrugated Metal Black Corrugated Metal Mirror Gravel
0 1245 69 833 92
1 1451 76 840 108
2 1182 134 1378 92
3 1786 160 1883 184
4 1302 101 1358 135
5 1422 152 1550 162
6 1178 72 1354 112
Bounce-back UVA/B Measurements (in W/cm)
Outside of Greenhouse
Hour Number
UVA/B Measurements
Location
Bounce-back UVA/B Measurements (in W/cm)
Inside of Greenhouse
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
39/45
33
Appendix 4- CFU/mL Data
General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli
O CM 1 0.33 0 0.33 I CM 1 4.67 12.33 17
1 0 1.0 12.33 14 26.33
0.67 0 0.67 8.33 10.33 18.67
O CM 2 0 0 0 I CM 2 6.33 10.33 16.67
0 0 0 10 9.7 19.67
0 0 0 5.33 16.67 22
O CM 3 0 0 0 I CM 3 5.33 13 18.33
0 0 0 8 14.33 22.33
0 0 0 6 11.67 17.67
TOTAL 2 0 2 0.22 0 0.35 0 TOTAL 66.33 112.33 178.67 19.85 12.48 2.97 2.14
General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli
O Mir 1 0 0 0 I Mir 1 8.67 16.33 25
0 0 0 8 9.67 17.67
0.33 0 0.33 3 10 13
O Mir 2 0 0 0 I Mir 2 8.67 9 17.67
0 0 0 4 8.67 12.67
0.33 0 0.33 8.33 11.33 19.67O Mir 3 0.67 0 0.67 I Mir 3 12.33 16.33 28.67
0.67 0 0.67 5.33 14.67 20
0 0 0 7.67 14.67 22.33
TOTAL 2 0 2 0.22 0 0.27 0 TOTAL 66 110.67 176.67 19.63 12.30 4.92 3
General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli
O B 1 0 0 0 I B 1 11.33 18.67 30
0 0 0 8 12.33 20.33
0 0 0 4 9.67 13.67
O B 2 0.33 0 0.33 I B 2 9 20.33 29.33
0.33 0 0.33 7.33 14 21.33
0 0 0 8.33 15.33 23.67
O B 3 1 0 1 I B 3 6.67 14 20.67
0.33 0 0.33 11 13.33 24.33
0 0 0 10.67 11 21.67TOTAL 2 0 2 0.22 0 0.31 0 TOTAL 76.33 128.67 205 22.78 14.30 4.66 3.23
General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli
O G 1 0.67 0 0.67 I G 1 9 11.67 20.7
1 0.33 1.33 8.33 11 19.3
0.33 0 0.33 6.67 15.33 22
O G 2 0 0 0 I G 2 6.33 11.67 18
0 0 0 7.33 15 22.3
0 0 0 10.67 14 24.7
O G 3 1 0.33 1.33 I G 3 8.33 12.67 21
0 0.33 0.33 5 10.33 15.3
0.33 0 0.33 9 13.67 22.7
TOTAL 3.33 1 4.33 0.48 0.11 0.50 0.16 TOTAL 70.67 115.33 186 20.67 12.81 2.62 1.68
General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli
CE 1 13 21 34 Inf 1 10 120 130
8 19 27 20 40 60
13 22 35 30 50 80
TOTAL 34 62 96 32 20.67 3.56 1.25 TOTAL 60 210 270 90 70 29.44 35.59
Colony Counts
System Influent
Sample ID
Ave rage Standard De viation
90 70 29.44 35.59
Sample ID
Average Standard Deviation
32 20.67 3.56 1.25
Colony Counts
Clarifier Effluent
Outside of Greenhouse
Mirror
0
Corrugated Me tal
Outside of Greenhouse
Colony Counts after 48 hrs of Incubation
Average
0
Average
Sample ID
0 0
0 0 0 0
Standard Deviation
0.67 0 0.27 0
Sample ID
Colony Counts after 48 hrs of Incubation
Inside of Greenhouse
Corrugated Me tal
Ave rage Standard De viation
0.78 0.11 0.42 0.16
Colony Counts after 48 hrs of Incubation
Outside of Greenhouse
Gravel
Average Standard Deviation
0.22 0 0.16 0
0.44 0 0.42 0
Outside of Greenhouse
Black Corrugated Metal
20.67 12.22 4.06 1.50
19.44 12.22 2.18 3.15
0.67 0.22 0.47 0.16
0 0 0 0
Average Standard Deviation
0 0 0 0
0.44 0
19.44 13.00 2.06 1.09
Colony Counts after 48 hrs of Incubation
Inside of Greenhouse
Sample ID
16.67 9.67 2.94 1.19
16.56 3.36 2.73
0.79
Mirror
Ave rage Standard De viation
18.56 12.00 4.94 3.07
23.67 15.22 3.66
19.67 12.22 3.14 1.40
Gravel
Ave rage Standard De viation
21 12.67 1.09 1.91
Sample ID Sample ID
Sample ID Sample ID
21. 67 13. 56
22. 22 12. 78
Colony Counts after 48 hrs of Incubation
Inside of Greenhouse
Black Corrugated Metal
Ave rage Standard De viation
2.76 1.40
1.55 1.29
Colony Counts after 48 hrs of Incubation
Inside of Greenhouse
21.33 13.56 6.71 3.77
24.78
CFU/mL
CFU/mL
CFU/mL
CFU/mL
CFU/mL
CFU/mL
CFU/mL
CFU/mL
CFU/mL
CFU/mL
Sample ID
0.31 0
Colony Counts after 48 hrs of Incubation
Standard Deviation
0.11 0 0.16 0
0.11 0 0.16 0
Colony Counts after 48 hrs of Incubation
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
40/45
34
Appendix 5- Colony Counts
General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli
O CM 1 1 0 1 I CM 1 14 37 51
3 0 3 37 42 79
2 0 2 25 31 56O CM 2 0 0 0 I CM 2 19 31 50
0 0 0 30 29 59
0 0 0 16 50 66
O CM 3 0 0 0 I CM 3 16 39 55
0 0 0 24 43 67
0 0 0 18 35 53
TOTAL 6 0 6 0.67 0 1.05 0 TOTAL 199.00 337.00 536.00 59.56 37.44 8.92 6.43
General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli
O Mir 1 0 0 0 I Mir 1 26 49 75
0 0 0 24 29 53
1 0 1 9 30 39
O Mir 2 0 0 0 I Mir 2 26 27 53
0 0 0 12 26 38
1 0 1 0 34 34
O Mir 3 2 0 2 I Mir 3 37 49 86
2 0 2 16 44 60
0 0 0 23 44 67
TOTAL 6 0 6 0.67 0 0.82 0 TOTAL 173 332 505 56.14 36.89 16.67 9
General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli
O B 1 0 0 0 I B 1 34 56 90
0 0 0 24 37 61
0 0 0 12 29 41
O B 2 1 0 1 I B 2 27 61 88
1 0 1 22 42 64
0 0 0 25 46 71
O B 3 3 0 3 I B 3 20 42 62
1 0 1 33 40 73
0 0 0 32 33 65
TOTAL 6 0 6 0.67 0 0.94 0 TOTAL 229 386 615 68.33 42.89 13.97 9.69
General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli
O G 1 2 0 2 I G 1 27 35 62
3 1 4 25 33 58
1 0 1 20 46 66
O G 2 0 0 0 I G 2 19 35 54
0 0 0 22 45 67
0 0 0 32 42 74
O G 3 3 1 4 I G 3 25 38 63
0 1 1 15 31 461 0 1 27 41 68
TOTAL 10 3 13 1.44 0.33 1.50 0.47 TOTAL 212 346 558 62.00 38.44 7.87 5.04
General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli General Coliforms E. coli Total Coliforms Total Coliforms E. coli Total Coliforms E. coli
CE 1 13 21 34 Inf 1 1 12 13
8 19 27 2 4 6
13 22 35 3 5 8
TOTAL 34 62 96 32 20.67 3.56 1.25 TOTAL 6 21 27 9 7 2.94 3.56
Ave rage Standard De viation
32 20.67 3.56 1.25 9 7 2.94 3.56
Colony Counts Colony Counts
Clarifier Effluent System Influent
Sample ID
CFU/mL Average Standard Deviation
Sample ID
CFU/mL
8.29 4.19
2.00 0.67 1.41 0.47 59.00 36.67 9.42 4.19
0 0 0 0 65.00 40.67
Ave rage Standard De viation
2.33 0.33 1.25 0.47 62 38.00 3.27 5.72
Sample ID
CFU/mL Average Standard Deviation
Sample ID
CFU/mL
Colony Counts after 48 hrs of Incubation Colony Counts after 48 hrs of Incubation
Outside of Greenhouse Inside of Greenhouse
Gravel Gravel
10.08 8.18
1.33 0 0.00 0 66.67 38.33 4.64 3.86
0.67 0 0.47 0 74.33 49.67
Ave rage Standard De viation
0 0 0 0 64.00 40.67 20.12 11.32
Sample ID
CFU/mL Average Standard Deviation
Sample ID
CFU/mL
Colony Counts after 48 hrs of Incubation Colony Counts after 48 hrs of Incubation
Outside of Greenhouse Inside of Greenhouse
Black Corrugated Metal Black Corrugated Metal
8.10 3.56
1.33 0 0.94 0 71.00 45.67 10.98 2.36
0.33 0 0.47 0 41.75 29.00
Ave rage Standard De viation
0.33 0 0.47 0 55.67 36.00 14.82 9.20
Sample ID
CFU/mL Average Standard Deviation
Sample ID
CFU/mL
Colony Counts after 48 hrs of Incubation Colony Counts after 48 hrs of Incubation
Outside of Greenhouse Inside of Greenhouse
Mirror Mirror
6.55 9.46
0 0 0 0 19.33 39.00 6.18 3.27
0 0 0 0 21.67 36.67
Ave rage Standard De viation
2.00 0 0.82 0 25.33 36.67 12.19 4.50
Sample ID
CFU/mL Average Standard Deviation
Sample ID
CFU/mL
Colony Counts after 48 hrs of Incubation Colony Counts after 48 hrs of Incubation
Outside of Greenhouse Inside of Greenhouse
Corrugated Metal Corrugated Metal
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
41/45
35
Appendix 6- Calculations
6.1- Fluence
6.1.1- Indoor Fluence
(
)
6.1.2- Outdoor Fluence
(
)
6.2- Conversion of Colony Counts to CFU/mL
Extracted Volume = 3mL, 1mL, and 0.1mL for the bottle samples, clarifier effluent, and system
influent, respectively.
6.3- Percent Disinfection Range
to
, where represents the average CFU/mL value,
represents one standard deviation, and = 90 CFU/mL
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
42/45
36
Works Cited
Acra, A., Z. Raffoul, Y. Karahagopian. Solar disinfection of drinking water and oral rehydration
solutions. UNICEF Guidelines for Household Application in Developing Countries
(1984).
Black, R et al. Global, regional, and national causes of child mortality in 2008: a systematic
analysis. Lancet 2010:375. 12 May 2010. Web. 5 March 2012. .
Bosshard, F., Bucheli, M., Meur, Y., & Egli, T. The respiratory chain is the cells Achilles heel
during UVA inactivation in Escherichia coli. 2010. Microbiology, 156, 2006-2015. .
Ciochetti, D. A., and Metcalf, R. H., Pasteurization of Naturally Contaminated Water with Solar
Energy, Applied and Environmental Microbiology, 47:223-228, 1984.
Conroy, R. M., Meegan, M. E., Joyce, T., McGuigan, K., and Barnes, J. Solar disinfection of
drinking water protects against cholera in children under 6 years of age. 2001.Arch Dis
Child85, 293-295.
Cooke, Jeremy R. "Class of 2000's Gift Faces Obstacles." The Daily Collegian Online. The Daily
Collegian, 23 Apr. 2003. Web. 6 Mar. 2012.
.
Dimroth, P., Kaim, G., and Matthey, U. Crucial Role of the Membrane Potential for ATP
Synthesis by F1F0ATP Synthases. Institut fr Mikrobiologie, Eidgenssische
Technische Hochschule, ETH-Zentrum, Schmelzbergstrae 7, CH-8092. 13 December
1999. Web. 2 April 2012. .Illian, Mark, Monika Cikhart, Alex Henri The Effect of Bottle Scratches on SODIS Water
Disinfection. Nature Healing Nature. 29 Dec. 2010. Web. 12 Mar. 2012. .
McGuigan, K.G., T.M. Joyce, R.M. Conroy, J.B. Gillespie, M. Elmore-Meegan. Solar
disinfection of drinking water contained in transparent plastic bottles: characterizing the
bacterial inactivation process J. Appl. Microbiol., 84 (1998), pp. 11381148
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
43/45
37
Micrology Laboratories. Coliscan Easygel. 2012. Web. 31 March 31, 2012.
.
Natural Resource Management and Environment Department. "Wastewater Characteristics and
Effluent Quality Parameters." FAO Corporate Document Repository,1992. Web. 2 Mar.
2012. .
Optek. Typical Series of Formazin Turbidity Standards Shown in NTU/FTU.NTU FTU:
Turbidity Units of Measure. 2010. Web. 10 Mar. 2012.
.
SODIS. The SODIS Story in Vietnam. The National Centre for Rural Water Supply and
Environmental Sanitation and HELVETAS. 2012. Web. 12 Mar. 2012 .
Solar Electricity Handbook. Solar Angle Calculator. Greenstream Publishing. 2012. Web. 5
April 2012. .
US EPA. "Basic Information about E. coli 0157:H7 in Drinking Water." United StatesEnvironmental Protection Agency, 6 Mar. 2012. Web. 31 Mar. 2012. .
US EPA. "Basic Information about Pathogens and Indicators in Drinking Water." United States
Environmental Protection Agency, 6 Mar. 2012. Web. 10 Mar. 2012.
.
Wegelin, M., S. Canonica, K. Mechsner, T. Fleischmann, F. Pesara, A. Metzler. Solar water
disinfection: scope of the process and analysis of radiation experiments. J. Water SRT
Aqua., 43 (1994), pp. 154169
Wegelin, M., M. Hobbins, D. Maeusezahl, M. Z. Uddin, S. Ferdausi, A. Motaleb SODIS- an
arsenic mitigation option?. Harvard University. 1999. Web. 13 Mar. 2012. < http://phys4.harvard.edu/~wilson/arsenic/remediation/sodis/SODIS_Paper.html>.
World Health Organization. "Global Water Supply and Sanitation Assessment 2000 Report."
WHO, UNICEF, and Water Supply & Sanitation, 2000. Web. 14 Mar. 2012.
.
World Health Organization. Ultraviolet radiation and health. 2012. Web. 31 March 2012.
.
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
44/45
M. WILLIAM SHEEHAN3 Stanfield Lane Broomall, PA 19008 cell: 610-550-9143 [email protected]
EDUCATIONThe Pennsylvania State University, Schreyer Honors College University Park, PABachelor of Science in Civil Engineering Expected May 2012
Thesis:Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologically-treated Wastewater Using Recycled Polyethylene Terephthalate Bottles
ACADEMIC PROJECTSEnvironmental Engineering Laboratory University Park, PAResearch Assistant Dec 2008 - May 2010Project Title: Arsenic Removal with Iron-Tailored Activated Carbon plus Zero-Valent Iron
Collaborated on a team of five to develop an effective and economical way to filter arseniccontaminated water using iron-preloaded activated carbon
Published by The Water Research Foundation and by WERC- a Consortium for EnvironmentalEducation and Technology Development at New Mexico University
Sponsored by The U.S. Department of Energy and The Water Research FoundationWORKEXPERIENCES
Tianjin University Tianjin, ChinaResearch Intern May 2011-Aug 2011
Conducted dynamic sounding tests on site for a pipeline connecting the North and South of ChinaUtilized vacuum preloading pressure on dredged soil to create reclaimed land in the Bohai GulfImmersed in the Chinese culture for three months and fully sponsored by Schreyer Honors College
Community Energy Inc. Radnor, PASummer Intern June 2010-Aug 2010Cataloged and analyzed all Request for Proposal (RFP) databases to streamline the current procedures
at Community Energy, a leading renewable energy companyBrainstormed and presented a business plan to the company highlighting pathways to become
involved in the nations Smart Grid project
Waffle Shop Restaurant State College, PAWaiter May 2009-May 2010Worked 16 to 32 hours a week while enrolled as a full-time student
LEADERSHIP EXPERIENCESUniversity Park Undergraduate Association, Executive Board Member University Park, PAChief of Staff Apr 2011-Apr 2012
Managed the student governments 12-person executive board and chaired the weekly board meetingsAdvocated the student bodys voice concerning various student-life issues to the administrationResponsible for the allocation of a $58,800 budget
Penn State Interfraternity Council, Executive Board Member University Park, PA
Vice President for Programming Dec 2010-Apr 2011Oversaw all community service, philanthropic events, and educational programming completed by
each of the 49 fraternity chapters at Penn StateOrganized large scale outreach events and responsible for a $13,100 budgetCompiled the outreach hours for each of the fraternity chapters and was a factor in decisions affecting
the 4,000+ Greek life students, one of the largest Greek communities in the country
Penn States Habitat for Humanity Chapter, Executive Board Member University Park, PAFundraising Coordinator Sept 2009-May 2010Supervised a committee that connected student volunteers with local community members in need
-
8/2/2019 Optimizing the Solar Disinfection Method to Produce Potable Water from Ecologicallytreated Wastewater Using Recy
45/45
M. William Sheehan, page 2
Student Handbook Committee, Executive Board Member University Park, PAAssistant Editor Jan 2012- Present
Revised and edited a 100-page student-written handbook that serves as a guide for incoming studentsBeta Theta Pi Fraternity University Park, PACommunity Service and Philanthropy Chairman; Homecoming Chairman Apr 2010- Oct 2011Motivated the fraternity to participate in outreach service events and the annual Homecoming parade
CERTIFICATIONS AND SKILLSEngineer-In-Training (EIT) Certificate, Laboratory Safety Certification, Microsoft Office Suite,Basic CAD, Basic C++, 6 years of Spanish language study
AWARDS AND HONORSSchreyer Academic Excellence Scholarship 2008-2012Granted to members of the Schreyer Honors College and renewable to each student in good standing
National Society of Collegiate Scholars 2009-2012Admitted based on excellence in leadership, service, and ranking academically in the top 20% of class
Stan and Flora Kappe Research Endowment Scholarship 2010-2012Awarded to one student in the Engineering College who shows exceptional promise in environmental
engineering
Hittner and Griner Scholarship 2011Elected by my fraternity chapter to receive this scholarship for demonstrating the most leadership to
Beta Theta Pi and community
Penn State Homecoming Court 2011Selected to represent Penn States senior class as a Homecoming Court member