2. Josie Ochsner Chemistry 2012 Miss Wang
Contents
1.0 Abstract:............................................................................................................................. 3
2.0 Introduction:....................................................................................................................... 4
3.0 Hypothesis:......................................................................................................................... 6
3.1 Temperature vs. dissolved oxygen........................................................................................ 6
3.2 Turbidity vs. pH................................................................................................................... 6
3.3 Salinity vs. pH...................................................................................................................... 6
4.0 Aim:....................................................................................................................................7
5.0 Materials:........................................................................................................................... 8
5.1 Dissolved oxygen:................................................................................................................ 8
5.2 Turbidity:............................................................................................................................ 8
5.3 pH: .....................................................................................................................................8
5.4 Temperature:...................................................................................................................... 8
5.5 Salinity:............................................................................................................................... 8
6.0 Method: ............................................................................................................................. 9
7.0 Risk Assessment:............................................................................................................... 10
8.0 Results:............................................................................................................................. 12
8.10 Saltwater lake longitudinal results:................................................................................... 12
8.11 Longitudinal pH data for saltwater lake............................................................................. 12
8.20 Fresh water pond longitudinal results:.............................................................................. 13
8.21 Longitudinal temperature data for freshwater pond.......................................................... 13
8.22 Longitudinal DO data for freshwater pond ........................................................................ 14
9.0 Discussion:........................................................................................................................ 15
10.0 Conclusion:..................................................................................................................... 17
11.0 Bibliography.................................................................................................................... 18
12.0 Appendices:.................................................................................................................... 19
12.1 Water collection sites:..................................................................................................... 19
12.20 Dissolved oxygen colorimeter instructions: ..................................................................... 19
12.21 Dissolved oxygen colorimeter instructions: ..................................................................... 20
12.31 Turbidity colorimeterinstructions:.................................................................................. 20
12.32 Turbidity colorimeterinstructions:.................................................................................. 21
12.33 Turbidity colorimeterinstructions:.................................................................................. 21
12.4 Dissolved oxygen saturation graph: .................................................................................. 22
13.0 Acknowledgements:........................................................................................................ 23
3. Josie Ochsner Chemistry 2012 Miss Wang
1.0 Abstract:
The sitesthat were experimentedonwere the saltwaterlake andthe freshwaterpond waterinthe
EmeraldLakessystem,inwhichthe resultswere comparedand contrastedtooutline anydifferences
infindings anditwas determinedthere wasnochemical corruption.The variablestestedwere
temperature,pH,turbidity,salinityanddissolvedoxygen. A Multiparametermeterwaschosento
testfor temperature,pHand salinity inwhich2Ljugs were filledwiththe watersamplesandthe
meterinserted.Althoughaturbiditytube andadissolvedoxygentestkitwere usedtofindthe
turbidityandDO content,colorimeterswere alsoused.The turbiditywastestedinacolorimeter
back at the laboratoryand a dissolvedoxygencolorimeterwasusedonsite andthe resultsfrom
bothcolorimeterswillbe used forthisinvestigation. Itwasexpectedthatthe saltwaterlake would
be healthierthanthe pondwaterbecause itisused more so itwouldhave more circulationand
therefore higherDOcontentandit alsoappearedlessturbid.Thiswasshowntobe correct as the
saltwaterDOcontentwas 9.5mg/L and the pondwaterhad only7.3mg/L and for turbidity, the salt
waterhad 0.01NTU whereasthe pondwaterhad 0.03NTU. It wasexpectedthatthe higherthe
temperature,the lowerthe DOcontentbutthis wasincorrectas the saltwaterhada higher
temperature andDOcontentthan the pondwater,being18.15°C with9.5mg/L of DO and17.45°C
with7.3mg/L of DO inthe pond. It was expectedthatthe higherthe turbiditylevel,the lessneutral
the waterwill be,whichwasincorrectas the pondwaterwas more turbidand wascloserto havinga
pH of 7 than the saltwater.The saltwater’s turbiditywas0.01 NTU witha pH of 7.38 (0.38 away
fromneutral) andthe pondwater hada higherturbidityof 0.03NTU witha pH of 7.22 (only0.22
away fromneutral).Itwasexpectedthatthe higherthe salinity,the more acidicthe waterwouldbe,
makingthe pH lessthan7 but thiswasincorrectalsoas the saltlake’ssalinitywas827ppmwitha pH
of 7.38 and the pondwater’ssalinitywas114ppmwitha pH of 7.22.
4. Josie Ochsner Chemistry 2012 Miss Wang
2.0 Introduction:
This Extended Experimental Investigation is based on the health of different water sources
in Emerald Lakes. The two sites chosen to test water from were the freshwater pond and
the saltwater lake (see appendices 11.1). Both of these sites contain fish life and are not
considered as drinking water. The different variables that can be tested for water quality are
as follows: temperature, turbidity, salinity, pH and dissolved oxygen, carbon dioxide and
nitrate content. For different types of water sources, different results are suitable, which
will be analysed in depth later on.
Temperature is an important variable to test as it influences the amount of dissolved oxygen
contained in the water (Monteath, 2008). A water sample should not be tested for health
through only the analysis of temperature, but also with a combination of other tests
(Monteath, 2008). These may include tests regarding; temperature, turbidity, salinity, pH,
dissolved oxygen and carbon dioxide and nitrate content. This is because the temperature
naturally changes depending on the season, weather or day (Monteath, 2008). Not only is
dissolved oxygen a linking factor, but if water temperature is too high or low the organisms
may begin to die (University of Wisconsin, 2007). Fish are cold-blooded but they have
different body temperatures depending on the temperature of the water they naturally
occur in (Guderley, 2007). Temperature can be tested using a thermometer or data logger
(Monteath, 2008). A data logger, also known as a Multiparameter Meter, was used for this
investigation as it was easier to read and could be used to test other variables at the same
time.
Turbidity is the measure of water transparency due to the amount of sediments withheld
(HarperCollins Publishers, 2009). Turbidity is significant to the overall health of water as it
determines the water’s purity or pollution. It is measured in nephelometric turbidity units
(NTU), which can be measured with a Colorimeter or a turbidity tube (University of
Wisconsin, 2009). Freshwater should be 5 or less NTU and a water system is considered
‘polluted’ if the NTU is >20 (Monteath, 2008). This long, thin, clear tube is filled with the
water sample until the mark on the bottom is no longer visible (University of Wisconsin,
2009). A sample of the water is inserted into the Colorimeter to determine the amount of
penetrable light. The best method is using the Colorimeter as it is more accurate because an
exact number is given for the result rather than relying on one’s eye sight for the turbidity
tube.
Dissolved oxygen is vital for the health of water as organisms rely on oxygen for survival.
Dissolved oxygen is used by both underwater plants and animals for respiration at night
(Gould, 2008). This can be tested using Dissolved Oxygen monitoring test kits or a Dissolved
Oxygen Colorimeter. Dissolved Oxygen monitoring test kits contain reagents that must be
added to determine the results (University of Wisconsin, 2009). It is measured in milligrams
per litre (mg/L) but can also be expressed using percentage saturation (Gould, 2008).
5. Josie Ochsner Chemistry 2012 Miss Wang
Freshwater should contain between 80-90% saturation but for fish life there needs to be at
least 5-6mg/L (Gould, 2008). Saturation should not reach over 110% as such a high level of
oxygen indicates a high level of algae growth. Both of these methods were undertaken but
the colorimeter results will be used as they are more likely to be accurate. This is because it
gives an exact reading rather than relying on eye sight to determine when the solution has
turned clear as is done with the Dissolved Oxygen Test Kits.
Salinity is the amount of salt that is dissolved in water. This must be monitored as high
salinity can makes it harder for plants to absorb water so they may become wilted, growth
stunted or die and is also unpalatable for animals and humans to drink. It can be measured
using a Multiparameter Meter or through titration, in which the water is reacted with silver
nitrate to determine the concentration of chloride ions (measured in mg/L) using the
formula: Clˉ(aq) + Ag⁺(aq) AgCl(s) (Gould, 2008). Alternatively, a calibration graph can be
used if the concentration of the salt solution is known to determine the amount of current
flowing through, measured in ųS/cm (Gould, 2008). Freshwater can contain 100-1000mg/L
and salt water between 1000-35 000mg/L (from slightly saline to ocean water) (Gould,
2008). The results from the Multiparameter Meter will be used in this investigation as it
seems a more accurate method than manually testing the sample, as with the titration.
Another very important factor in the health of water is pH as organisms require a specific
range to survive, usually between 6.5 and 8, where 7 is neutral (Smith, 2008). It can be
measured using a pH meter or universal indicator or paper (Smith, 2008). A pH meter will be
used for this investigation as determining the colour from a universal indicator/paper could
be inaccurate compared to a reading on the meter.
A Multiparameter Meter was used to measure pH, temperature, conductivity, salinity and
dissolved solids because it did all the calculations together, which was helpful with the
limited time frame on the excursion day. Also on the day of collection, the turbidity was
tested with a turbidity tube and the dissolved oxygen was tested with a colorimeter and a
Dissolved Oxygen Test Kit. These were all quantitative tests that were carried out on site.
The qualitative tests were carried out in the science laboratory using the 2L samples
collected from each site (tests can be found under method). These include finding the
presence of the following: chloride, iron, calcium, lead, copper, sulphate and phosphate ions.
These qualitative tests were done because, in every case, the ions are healthy for marine life,
but only in moderation. If the quantities of these ions dramatically increase or decrease, the
health of marine life will deteriorate and organisms won’t survive, therefore starting a chain
link of event, resulting in the whole ecosystem collapsing.
6. Josie Ochsner Chemistry 2012 Miss Wang
3.0 Hypothesis:
It isexpectedthatthe saltwaterlake willbe healthierthanthe freshwaterpond because itisamuch
larger,openareawhichis used forrecreational activities more,therefore there ismore circulation to
increase DO, and itappearslessturbid.
3.1 Temperature vs. dissolved oxygen- It isexpectedthatthe higherthe temperature is,
the lowerthe level of dissolvedoxygenwill be and the lowerthe temperatureis,the higherthe level
of dissolvedoxygenwill be.
3.2 Turbidity vs. pH- It was expectedthatthe higherthe turbiditylevel,the lessneutral the
waterwill be,eitherturningmore acidicormore basicdependingonthe solidscontainedwithin.
3.3 Salinity vs. pH- It was expectedthatthe higherthe salinity,the more acidicthe water
wouldbe,makingthe pHlessthan 7, because saltisan acid.
7. Josie Ochsner Chemistry 2012 Miss Wang
4.0 Aim:
To compare and contrast the qualityof watercontainedinthe freshwaterpondandthe saltwater
lake fromEmeraldLakes by testingfortemperature,pH,turbidity,salinityanddissolvedoxygenand
determine anypossiblereasonsforanysubstantial chemical corruptionif detectedanddifferences
inresults.
9. Josie Ochsner Chemistry 2012 Miss Wang
6.0 Method:
NOTE: Use instructionsfromtestkits
A long-handledwaterscoopwasusedtoscoopwaterrepeatedly fromthe freshwaterpond (fromat
leastone meterin) intoa 2L bottle foranalysisbackat the laboratory.Anotherscoopwastakenand
usedimmediatelyinthe DissolvedOxygenTestKit#HI3810 and the resultsrecorded.The scoopwas
usedto pourwater intoa turbiditytube where itwasfilleduntilthe crossat the bottomcouldno
longerbe seenfromlookingdownthroughthe tube.The markingwhere the tube wasfilledtowas
recordedin centimetres.Usingthe long-handledwaterscoop,a2L jugwas filledanda
MultiparameterMeterwasinsertedtogive the pH,temperature andsalinity readings.
A long-handledwaterscoopwasusedtoscoopwaterrepeatedlyfromthe saltwaterlake (fromat
leastone meterin) intoa 2L bottle foranalysisbackat the laboratory.Anotherscoopwastakenand
usedimmediatelyinthe DissolvedOxygenTestKit#HI3810 and the resultsrecorded.The turbidity
tube was againfilleduntil the crossat the bottomcouldno longerbe seenfromlookingdown
throughthe tube and the markingwas recordedincentimetres.Usingthe long-handledwaterscoop,
a 2L jug wasfilledandaMultiparameterMeterwasinsertedtogive the pH,temperature andsalinity
readings.
Also,a sample wastakenfromeachsite ina beaker thenadissolvedoxygencolorimeter(see
appendices12.2) wasusedconsecutively with‘AccuVac® Ampules’andthe resultsrecorded. Inthe
laboratory, a colorimeter (see appendices 12.3) was used to find the turbidity of both water samples.
The salinitywastestedwiththe SalinityTestKit#HI3835 and a titrationwasdone to testfor chloride
presence.Inthe titration,a25mL pipette wasusedtotransferthe sample intoaclean250mL conical
flask(the saltwaterwasfirstdiluted1:10 but adding250mL of distilledwaterto25mL of the salt
water).1mL of chromate indicatorwasadded andtitratedwith2.902g/L silvernitrate solutiontothe
firstpermanentred-orangecolour.1mLwas subtractedfromthe resulttoallow forthe solubility
productof the indicatorwhichwill notchange colouruntil the volume isadded.A directcomparison
was made forthisconcentrationof silvernitrate;the numberof mLs=ppm.
10. Josie Ochsner Chemistry 2012 Miss Wang
7.0 Risk Assessment:
Substance Risk Control measure
0.1M Ethanoic acid (CH3COOH) Seriouseye damage
Corrosive;cancause
burns
Alwayswearsafety
glasses
Do not make contact
withskin
0.1M SilverNitrate (AgNO3) Poisonousif swallowed
or inhaled
Stainsskin
Alwayswearsafety
glasses
Do not make contact
withskin
0.1M SodiumThiocyanate
(CNNaS)
Harmful if swallowed
Poisonousif swallowed
or inhaled
Alwayswearsafety
glasses
Ensure adequate
ventilation
0.1M Ammoniumoxalate
monohydrate
(NH4OCOCOONH4 H2O)
May be fatal if
swallowed
Corrosive;cancause
burns
Harmful if swallowedor
inhaled
Alwayswearsafety
glasses
Do not make contact
withskin
Ensure adequate
ventilation
1.0M Potassiumchromate
(K2CrO4)
Can cause cancer or
reproductive defects
May be fatal if
swallowed
Harmful if there isskin
contact or inhaled
Alwayswearsafety
glassesandgloves
Do not make contact
withskin
Ensure adequate
ventilation
0.1M Sodiumhydroxide
(NaOH)
Seriouseye damage
Corrosive;cancause
burns
Alwayswearsafety
glasses
Do not make contact
withskin
0.1M Barium chloride (BaCl2) Seriouseye damage
May be fatal if
swallowed
Harmful if there isskin
contact or inhaled
Alwayswearsafety
glasses
Do not make contact
withskin
Ensure adequate
ventilation
Nitric acid (HNO3) Seriouseye damage
Corrosive;cancause
burns
Fumesare harmful if
inhaled
Alwayswearsafety
glasses
Do not make contact
withskin- evenif
diluted
Ensure adequate
ventilation
0.1M Ammoniummolybdate
(H24Mo7N6O24)
Irritatingtoeyes,lungs
and,if there ispronged
contact, skin
Alwayswearsafety
glasses
0.1M Lead chloride (FeCl2) Harmful if swallowed,
inhaledandif there is
skincontact
Alwayswearsafety
glassesandgloves
Do not make contact
11. Josie Ochsner Chemistry 2012 Miss Wang
withskin
Ensure adequate
ventilation
0.1M Calciumchloride (CaCl2) Harmful if swallowed
Irritatingtoeyes
Alwayswearsafety
glassesandgloves
0.1M Iron (III) chloride (FeCl3) Seriouseye damage
Corrosive;cancause
burns
Alwayswearsafety
glassesandgloves
Do not make contact
withskin
Ensure adequate
ventilation
0.1M Copper(II) sulfate
(CuSO4)
Seriouseye damage
Corrosive;cancause
burns
Alwayswearsafety
glassesandgloves
Do not make contact
withskin
Ensure adequate
ventilation
0.1M Magnesiumsulfate
(MgSO4 7H2O)
Irritantto eyes
Harmful if swallowed
Alwayswearsafety
glassesandgloves
0.1M Sodiumphosphate
(Na3PO4)
Irritantto eyesandskin
Harmful if swallowed
Alwayswearsafety
glassesandgloves
Do not make contact
withskin
Phenolphthalein(C3H6O) Harmful if swallowed
Can cause cancer or
reproductive defects
Harmful if there isskin
contact or inhaled
Alwayswearsafety
glassesandgloves
Do not make contact
withskin
0.1M Sodiumhydroxide
(NaOH)
Seriouseye damage
Corrosive;cancause
burns
Harmful if swallowed
Alwayswearsafety
glassesandgloves
Do not make contact
withskin
Ensure adequate
ventilation
12. Josie Ochsner Chemistry 2012 Miss Wang
6.8
7
7.2
7.4
7.6
7.8
8
2009 2010 2011 2012
Longitudinal pH data
pH
8.0 Results:
Pond and lake test results
Variable Test Saltwaterresults Pondwaterresults
Salinity Multiparametermeter 827ppm (826.1 mg/L) 114ppm (113.8 mg/L)
Temperature Multiparametermeter Surface:18.4°C
Bottom:17.9°C
Average:18.15°C
Surface:17.7°C
Bottom:17.2°C
Average:17.45°C
pH Multiparametermeter 7.38 7.22
Dissolvedoxygen Colorimeter 9.5 mg/L 7.3 mg/L
Turbidity Colorimeter 0.01 NTU 0.03 NTU
8.10 Saltwater lake longitudinal results:
Variable 2009 2010 2011 2012
Temp– surface
(0
C)
16 21 19 18.5
Temp – bottom
(0
C)
17 20 19 18
Temp – average
(0
C)
16.5 20.5 19 18.25
Turbidity (cm) 73.5 62 >80 >100
DissolvedOxygen
(mg/L)
7.5 6.2 7.5 9.0
Salinity-probe
(mg/L)
7400 11400 10200 9700
pH 7.2 7.5 7.8 7.9
8.11 Longitudinal pH data for saltwater lake
13. Josie Ochsner Chemistry 2012 Miss Wang
0
5
10
15
20
25
2009 2010 2011 2012
Temperature(°C)
Year
Longitudinal pond temperatures
Surface
Bottom
Average
8.20 Fresh water pond longitudinal results:
8.21 Longitudinal temperature data for freshwater pond
Variable 2009 2010 2011 2012
Temp– surface
(0
C)
17 22 21 19
Temp – bottom
(0
C)
16 19 17 17.5
Temp – average
(0
C)
16.5 20.5 19 18.25
Turbidity (cm) 25 72 25 35
Dissolved Oxygen
(mg/L)
7.3 5.0 6.7 6.1
Salinity-probe
(mg/L)
600 180 200 110
pH 7.3 6.7 7.2 6.8
14. Josie Ochsner Chemistry 2012 Miss Wang
0
1
2
3
4
5
6
7
8
2009 2010 2011 2012
DO(mg/L)
Year
Longitudinal DO Content
DO
8.22 Longitudinal DO data for freshwater pond
15. Josie Ochsner Chemistry 2012 Miss Wang
9.0 Discussion:
A fewissueswere apparentinthisinvestigation.Whentestingtemperature forthe freshwaterpond,
a thermometerwasusedbutthe mercurydidn’tseemtobe movingcorrectlyandothergroups
specifiedthattheyalsohadtroubleswiththe thermometer.Instead, aMultiparameterMeterwas
used.Onfirstattempt,a sample of waterwascollectedina small containertogetthe readingsfrom
a MultiparameterMeter. The pH readingwaschangingveryslowlybutcontinuouslysoinsteadwe
useda 2L jugto holda largersample of waterandthe readingsettledsoonafter.Whenusingthe
large jug,it washeldat the rim so bodytemperature wouldn’taffectthe watertemperature. When
usingthe colorimetertofindthe dissolvedoxygencontentinthe saltwater, an‘AccuVac® Ampule’
was usedtosuck up a sample of the water.It wasaccidentallyliftedoutof the sample before itwas
filledsoitsuckedupsome air.Thisone was discardedandanotherone used because itgave a much
higherdissolvedoxygenreadingof 13.0mg/L, whichwas incorrect.
A long-handledwaterscoopwasusedtogetwatersamplesfromfurtherintothe pond/lake sothey
are a more accurate representationof the whole bodyof water.If the waterwascollectedfromthe
edge there maybe more dirt, causing higherturbidityormore warmthfromthe soil,causinga
temperature change andsoon. 2L sampleswere retrievedtobe testedonbackat the laboratory so
qualitative testscouldbe done thatwouldn’tbe effectedbythe amountof time afteritwas
removed fromthe pond/lake.Othertests,suchasdissolvedoxygenandtemperature hadtobe done
on site asthe resultswoulddifferif theywere doneawhile aftercollection. Testingtemperatureis
importantas itdirectlyaffectsthe amountof dissolvedoxygen inthe waterandaquaticlife need
dissolvedoxygenforsurvival.If the temperature isincreased,the amountof dissolvedoxygen
decreases,therefore temperature isanimportantfactorinwater health.The levelof dissolved
oxygenisalsoimportanttotestto ensure there isa sufficientamountformarine life andwiththe
amountof dissolvedoxygen(inmg/L) andthe temperature of the water,the saturationcanbe
calculated.SalinityandpHare importantfactorsto keepcontrolledasthe healthylevelmayvary
dependingonthe watersource andthe organismsthatlive there sothe delicate balance ineach
ecosystemmustbe preserved. Anerrorthatoccurred wasthat when temperature was being
measuredinthe small containeritsettledonareadingthe firsttime thenitwasre-testedandithad
raised0.7°C due to hand temperature.Thissecondresultwasthendiscardedasitwasinaccurate
and the restof the variablesthatwere measured withthe MultiparameterMeterwere testedinthe
2L jug.Thiswouldhave slightlychangedthe saturationreadingasthe temperature wouldseem
higherforthe same dissolvedoxygenlevel.
Longitudinal datahasbeenrecordedoverthe past4 years to monitorhow the watersystemsare
changing(see results8.1and 8.2). It can be seeningraph 8.11 that the pH forthe saltwaterlake is
steadilyincreasingeachyearsoif that trendcontinues,the lake willcontinuetobecome lessneutral
and therefore more unhealthy.Itcan be seenbycomparinggraphs8.21 and8.22 that DO content
has changedinverselyasa resultof the changingtemperature- sowhenthe temperature isatit’s
highest;the DOis at itslowestandso on.
The firsthypothesiswasshowntobe correct as the saltwaterlake hada higherDO contentand
lowerturbiditythanthe pondwater.The DO forthe saltwaterwas9.5mg/L where itwasonly
7.3mg/L for the pondwater andthe turbiditywas0.01NTU for the lake and 0.03NTU for the pond.
The secondhypothesiswasincorrectasitwas expectedthatthe higherthe temperatureis,the
16. Josie Ochsner Chemistry 2012 Miss Wang
lowerthe level of dissolvedoxygenwill be andvice versabutinstead,the saltwaterhada
temperature andDOcontenthigherthanthe pond water’s.The saltwaterwas,onaverage,18.15°C
with9.5mg/L of DO and the pondwaterwas 17.45°C withonly7.3mg/L of DO.This maybe because
the salt lake hasa much largersurface area than the pondso itcan absorbmore heat,thus
explainingthe highertemperatureandthe DOmay be as a resultof more watercirculationinthe
lake due to humanactivitywhere there isnone inthe pond.Therefore,the DOcontentwouldn’t
have beenrelyingonthe temperature alone sothe temperaturebeinghigherdidn’tresultinthe DO
beinglower.The thirdhypothesiswasalsowrongasit wasexpectedthatthe higherthe turbidity
level,the lessneutral the waterwillbe,eitherturningmore acidicormore basicdependingonthe
solidscontainedwithinbutthe pondwaterwasmore turbid andwas closerto havinga pH of 7 than
the saltwater. The saltwater’sturbiditywas0.01 NTU witha pH of 7.38 (0.38 awayfromneutral)
and the pondwaterhad a higherturbidityof 0.03NTU witha pH of 7.22 (only0.22 away from
neutral). Thismayhave beenthe resultof aninaccurate methodas the turbiditywastestedinthe
colorimeterinthe laboratoryona differentdaytothe testingof the pH, whichwouldallow the
sedimentsinthe watertime tosettle,causingalowerturbidity.Itisa possibilitythatif the tests
were done onthe same day, the saltwater’sturbiditymaybe higherthanthe pondwater,thus
givinga reasonforthe pH to be furtherawayfromneutral. The fourthhypothesiswasincorrectasit
was expectedthatthe higherthe salinity,the more acidic the waterwouldbe,makingthe pHless
than 7, because saltisan acid but actually the salinityandpHforthe saltlake were bothhigherthan
the pondwater’s.The salt lake’ssalinitywas827ppmwitha pH of 7.38 andthe pondwater’ssalinity
was 114ppm witha pH of 7.22. This mayhave beena resultof othersedimentsfloatinginthe water,
whichcouldhave beenmore alkaline inthe saltlake,therefore neutralizingthe highamount of salt
and causingthe pH to be evenmore basicthan the pondwater,whichhas lesssalt.
The salinityforthe freshwaterpondwas withinthe guidelinesas itcan have from100-1000mg/L of
salt and it contained 113.8 mg/L.The saltwaterlake was slightlyunderthe normal range fora salt
watersystemas the range is usually between1000-35000 mg/L but itonlycontained826.1 mg/L.
The pH forboth siteswaswithinthe guidelines;saltwaterhavingapH of 7.38 and the pondwater
being7.22, where itcouldrange from6-8. Both watersystemscontainedenoughdissolvedoxygen
to sustainfishlife (atleast5-6mg/L);the lake contained9.5mg/Land the pond 7.3mg/L. The
saturationlevelswere measured(seeappendices12.4) and the saltwaterlake’ssaturationlevelwas
too high,being136% where itshouldbe nomore than 110%. The pondwater wasat exactly110%
saturation,whichisrighton the limitforthe guidelines,butthe highamountof saturationinthe
lake mustbe due to large amountsof algae growth.The turbidityforfreshwatermustbe below
5NTU and anythingabove 20NTU is‘polluted’sobothsitesfitintothose guidelinesasthe freshwater
pondwas only0.03NTU and the saltwaterlake was0.01NTU. The bodytemperature forfishdepends
on the environmenttheynaturally occurin,buttheyare cold-blooded(bloodisbelow 30°C) sothe
watershouldbe below30°C to sustainfishlife.Highdissolvedoxygensaturationoccurswhenboth
the temperature andDO are high.The DO saturationwasquite highforbothsites butthe DO results
were innormal range so that meansthat the temperaturesmusthave causedthe highsaturation.
The salt lake temperatureswere:surface- 18.4°C,bottom- 17.9°C and average- 18.15°C and the
pond’swere:Surface- 17.7°C, bottom:17.2°C and average- 17.45°C so althoughthere are no
guidelinesstatingexactideal temperatures(asitchangesbasedon season,weatherorday) they
mustbe slightlytoohightogive sucha highsaturation.
17. Josie Ochsner Chemistry 2012 Miss Wang
10.0 Conclusion:
The qualityof watercontainedinthe freshwaterpondandthe saltwaterlake fromEmeraldLakes
were comparedandcontrastedby testingfortemperature,pH,turbidity,salinityanddissolved
oxygenandanypossible reasonsforanysubstantial chemical corruptionanddifferencesinresults
were determined.The firsthypothesiswasshowntobe correctas the saltwaterlake hada higher
DO contentand lowerturbiditythanthe pondwaterasexpected.The secondhypothesiswas
incorrectas it wasexpectedthatthe higherthe temperature is,the lowerthe level of dissolved
oxygenwill be andvice versabutinstead,the saltwaterhada temperature andDOcontenthigher
than the pondwater’s.The thirdhypothesiswasalsowrongasit wasexpectedthatthe higherthe
turbiditylevel,the lessneutral the waterwillbe,eitherturningmore acidicormore basicdepending
on the solidscontainedwithinbutthe pondwaterwasmore turbidandwas closerto havinga pH of
7 thanthe saltwater.The fourthhypothesiswasincorrectasitwas expectedthatthe higherthe
salinity,the more acidicthe waterwouldbe,makingthe pHlessthan7, because saltisan acid but
actuallythe salinityandpHfor the saltlake were bothhigherthanthe pond water’s.
18. Josie Ochsner Chemistry 2012 Miss Wang
11.0 Bibliography
Gould,M. (2008). Chemistry in Use,book1. NorthRyde:McGraw-Hill AustraliaPtyLtd.
Guderley,H.(2007, March 15). Metabolicresponsesto low temperaturein fish muscle.Retrieved
August26, 2012, from WileyOnlineLibrary:
http://onlinelibrary.wiley.com/doi/10.1017/S1464793103006328/abstract
HarperCollinsPublishers.(2009). Turbidity . RetrievedJuly24,2012, from Dictionary.com:
http://dictionary.reference.com/browse/turbidity?s=t
Monteath,S. (2008). Chemistry in Use,book1. North Ryde:McGraw-Hill AustraliaPtyLtd.
Smith,R.(2008). Chemistry in Use,book1. NorthRyde:McGraw-Hill AustraliaPtyLtd.
Universityof Wisconsin.(2009). Dissolved Oxygen.RetrievedJuly24,2012, from watermonitoring:
http://watermonitoring.uwex.edu/wav/monitoring/oxygen.html
Universityof Wisconsin.(2007). Temperature.RetrievedJuly24,2012, fromWatermonitoring:
http://watermonitoring.uwex.edu/wav/monitoring/temp.html
Universityof Wisconsin.(2009). Transparency.RetrievedJuly24 , 2012, from Watermonitoring:
http://watermonitoring.uwex.edu/wav/monitoring/transparency.html
19. Josie Ochsner Chemistry 2012 Miss Wang
12.0 Appendices:
12.1 Water collection sites:
12.20 Dissolved oxygen colorimeter instructions:
Emmanuel College
Saltwater lake
Freshwater pond
20. Josie Ochsner Chemistry 2012 Miss Wang
12.21 Dissolved oxygen colorimeter instructions:
12.31 Turbidity colorimeter instructions:
21. Josie Ochsner Chemistry 2012 Miss Wang
12.32 Turbidity colorimeter instructions:
12.33 Turbidity colorimeter instructions:
23. Josie Ochsner Chemistry 2012 Miss Wang
13.0 Acknowledgements:
My groupmembers,Kate MorrisandAlex Butlerhelpedme tocollectand analyse watersamples.
Miss Wang taughtus the basic informationneededtoknow aboutwaterqualityandhelpedus
complete andunderstandthe testsandtheirresults. JamesMcVicar,Kyle Jackson,OliviaTregoning
and Alex Philipswhere partof an online chemistrygroupinwhichtheyhelpedtoanswersome
questionsIwasunsure about.