CHLORINE CONCENTRATION AND BACTERIAL
PRESENCE BETWEEN POOL CLEANINGS.
Samuel Hernandez and Robert McLaughlin. Department of Biological
Sciences, Saddleback College, Mission Viejo, CA, 92692. All headings
(Introduction, Materials and Methods, etc...) should be in bold and centered on the
column. Including the title and your names.
Abstract Abstract is missing!!!
Background you may want to use word Introduction instead of background also the
headline needs to be Centered
Water is among one of the most valuable resources on earth. It is essential for life on
earth as we know it. For humans alone it is required to sustain life, develop agriculture,
and even provide the popular recreational activity of swimming. The prevalent use and
dependence on water in society today also has the effect of increasing our risk of
exposure to waterborne illnesses. A report by Elizabeth Hilborn found that in the 20092010 year, 33 cases of water-associated outbreaks were reported to the CDC you may
want to say what CDC is when you mansion it for the first time in the paper (United
States center for disease control). These outbreaks comprised more than 1000 cases of
illness, almost 100 hospitalizations, and even death (3) not a proper way to cite your
source. To reduce this risk, regulations are in place to ensure water supplies are
disinfected and kept sanitary up until use or consumption. One such regulation is the
chlorination of water for use in swimming pools.
Chlorine is currently the disinfectant of choice among recreational swimming pools.
A study by Rice, Clark, and Johnson in 1998 found that only a 1.1 mg/l mg/L use caps
lock for L so it is not confusing with number one of concentrated chlorine, the average
concentration in municipal water supplies, could deactivate E. coli Escherichia coli
always for the first time write the genes and species full name in a matter of minutes (4)
not the correct way to cite your source, we don’t use number for our citation in this paper.
Chlorine works by first forming hypochlorous acid (HOCl). The hypochlorous acid then
attacks lipids in the cell wall and enzymes inside the cell, denaturing them and rendering
them inoperable in the organism. According to the CDC, current standards require
chlorine concentrations to be between 1-3 mg/l and have a pH somewhere between 7 and
8 (5) no number for citation. Chlorine must also be regularly added into the system, as
organic contaminants or sunlight can extract free chlorine out of the system, rendering it
useless for disinfection.
Despite standardized regulations for recreational water disinfection, many public
waters are not maintained appropriately. According to a collection of studies reported by
the CDC in the Morbidity and Mortality Weekly Report in 2008, 15 state states and local
agencies across the US inspected 120,020 swimming pools. Of those inspected, over 12
thousand had a violation due to inadequate disinfectant, and another 13,532 pools had to
be closed due to serious violations that threatened public health (1) citation problem. A
2012 study in Atlanta, Georgia of 161 swimming pools plural backwash filter samples
found that 58% had samples of nucleic acids belonging to E. coli, which strongly
suggests fecal contamination by swimmers (1). Rewrite this part, also citation is
incorrect.
Chlorine concentrations will be examined over time between one pool cleaning cycle,
and water samples will be collected over the period of time to test for the presence of E.
coli bacteria. Based on past research you may want to reference this, it is predicted that as
chlorine concentration in pool water decreases, bacterial presence will increase.
Materials and methods centered
The was chosen to be the collection site twelve water samples over a 24 hours period
between pool cleanings on November 24, 2013 and November 25, 2013. Sets of three 50
ml samples were collected at 4 times of day: 9:00 AM, 3:00 PM, 9:00 PM, and 7:00 AM
the next day of the following day, with each sample coming from a different site in the
pool (North, South and East four sample three location? Add your fourth location). The
samples were tested for chlorine concentration using SenSafe Chlorine Test Strips.
Lactose broths were prepared in triple strength (36 tubes) and single strength (72 tubes)
and autoclaved to ensure sterility of equipment. Using aseptic technique, the following
volumes of sample were instilled into a lactose broth tube: 10 ml in each triple strength
tube, 1 ml in 36 single strength tubes, and 0.1 ml in the other 36 single strength tubes.
The lactose tubes were stored in an incubator for 4 days at 37 oC. After 4 days, the
samples were removed from the incubator and examined for color change from green to
yellow, which would indicate a change in pH secondary to fermentation, and gas
production. So the lactose tubes were used in this project. After four days the color
change from green to yellow confirm the acid production, and any formation of bubble
10% or more confirm the gas production. Acid production has to deal with PH also. So
you may want to explain this part more clearly because it is a bit confusing.
Result centered
Chlorine concentration was found to decrease over time (figure 1). Statistical analysis
by ANOVA found statistical significance. The bonferroni correction found this
significance to be when comparing between sample samples1 to samples 2 through 4,
while no significant difference was found to exist determined between samples 2, 3, and
4. Presumptive testing with the lactose broth solutions had one sample belonging to group
4 turn yellow, suggesting pH change by fermentation. Gas production however, was not
observed in that or any other tube. The absence of fermentation acid fermentation? and
gas production together strongly suggests that no E. coli was cultured in the lactose
broths, and the test was negative for E. coli. Make sure the table is in the same page and it
doesn’t cut off between two pages.
Sample
collection
Chlorine
concentration
(ppm)
Fermentation/Gas
Production
Fermentation/Gas
Production
Fermentation/Gas
Production
10 ml tubes
1.0 ml tubes
0.1 ml tubes
MPN
9:00 AM
1.40
0
0
0
< 0.5
3:00 PM
0.73
0
0
0
< 0.5
9:00 PM
0.47
0
0
0
< 0.5
7:00 AM
0.43
0
0
0
< 0.5
1.80
Chlorine Concentration (mg/l)
1.60
1.40
1.20
1.00
0.80
0.60
0.40
0.20
0.00
0
200
400
600
800
1000
Time (min)
1200
1400
1600
Figure 1. Decline in chlorine concentrations over time
Discussion centered
The initial drop in chlorine concentration was statistically significant, dropping below
the 1.0 mg/l line that is the current standard in pool disinfection by chlorination. Based on
prior research, this suggests it is possible that E. coli bacteria could colonize and grow in
the pool water. The presumptive test produced one test tube with a color change to yellow
due to pH change secondary to bacterial fermentation how about acid production?. The
bacteria in this tube did not produce any gas, making the presumptive test negative for E.
coli. Based on the results obtained, it does not support that doesn’t support what?
hypothesis? as concentration of chlorine decreases, bacterial presence increases.
References Cited centered
1) CDC. Violations Identified from Routine Swimming Pool Inspections --- Selected
States and Counties, United States, 2008. Morbidity and Mortality Weekly
Report. May 21, 2010. 2013 Dec. 59(19);582-587.
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5919a2.htm
2) CDC. Microbes in Pool Filter Backwash as Evidence of the Need for Improved
Swimmer Hygiene — Metro-Atlanta, Georgia, 2012. Morbidity and Mortality
Weekly Report, May 17, 2013. 2013 Dec. 62(19);385-388.
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6219a3.htm?s_cid=mm6219a
3_w
3) Hilborn, Elizabeth D., D.V.M. 2013, Surveillance for Waterborne Disease
Outbreaks Associated with Drinking Water and Other Non-recreational Water United States, 2009-2010. Atlanta: U.S. Center for Disease Control, 2013.
4) Rice EW, Clark RM, Johnson CH. Chlorine Inactivation of Escherichia
coliO157:H7. Emerg Infect Dis [serial on the Internet]. 1999, Jun. 2013 Dec.
http://wwwnc.cdc.gov/eid/article/5/3/99-0322.htm
5) http://www.cdc.gov/safewater/publications_pages/chlorineresidual.pdf
Incorrect setting for all your references and all the citation through the paper, you are no
suppose to use number. for more information how to do your citation refer to Bio 3B
webpage go to peer review page and item 3. Format information for citations can be
found here. Click on the link….
Review Form
Department of Biological Sciences
Saddleback College, Mission Viejo, CA 92692
Author (s):____ Samuel Hernandez and Robert McLaughlin _________
Title: CHLORINE CONCENTRATION AND BACTERIAL PRESENCE BETWEEN POOL
CLEANINGS
Summary
Summarize the paper succinctly and dispassionately. Do not criticize here, just show that you understood the
paper.
Samples of water were collected from Solana community pool in Rancho Santa Margarita,
California during 24 hour in 4 different times and location (east, west, south, and north).
Lactose broth tube (triple and single) was used to determine acid production and acid
production. After 4 day of incubation no gas production observed which determine that
there is no E. coli presence is water sample from pool. Based on the result that was
determined the hypothesis was rejected which is as flowing as concentration of
chlorination decreases, bacterial presence in water increases.
General Comments
Generally explain the paper’s strengths and weaknesses and whether they are serious, or important
to our current state of knowledge.
The topic that they choose is very interesting how ever, no abstract was included in this
paper!! and the most weakness is the reference page and the way they cited sources
through out the paper. Also the method and material section needs to be more clear in
order to understand the process of this experiment.
Technical Criticism
Review technical issues, organization and clarity. Provide a table of typographical errors,
grammatical errors, and minor textual problems. It's not the reviewer's job to copy Edit the paper,
mark the manuscript.
◻︎This paper was a final version
☒This paper was a rough draft
Recommendation
◻︎This paper should be published as is
☒This paper should be published with revision
◻︎This paper should not be published