Basic Water Properties 2 Experiment
Transcript of Basic Water Properties 2 Experiment
ABSTRACT
Bas ic wa te r p roper t ies 2 exper iment i s conduc ted to
de te rmine d isso lved chemica l tha t con ta in in wa te r such as ch lo r ine ,
su l fa te , ch romium, i ron , and phosphorus . A sample o f Tas ik Seksyen
7 , Shah A lam i s taken to be tes ted . The ob jec t i ve o f th i s exper iment
i s to de te rmine whether i t reach the range o f the d isso lved heavy
meta ls (ch lo r ine , su l fa te , ch romium, i ron , and phosphorus) in wa te r
when a cer ta in vo lume is taken to be exper imented . F rom the resu l t s
ob ta ined , the qua l i t y and sa fe ty o f the wate r can a lso be de te rmined .
Ch lo r ine , su l fa te , phosphorus , i ron and chromium wh ich ex is t i n the
sample o f wa te r a re the po l lu tan ts tha t to be de te rmined by us ing the
Por tab le Spec t ropho tometer DR 2400 . I t i s a lso be used to measure
the wave leng th and the mass o f the po l lu tan ts , accord ing to the
dens i t y shown by the appara tus . The concen t ra t ions o f the heavy
meta ls in the wate r sample a re as fo l lows ; ch lo r ine to ta l (0 .36 mg/L ) ,
ch lo r ine f ree (0 .10 mg/L ) , su l fa te (25 .0 mg/L ) , phosphorus reac t i ve
(0 .43 mg/L ) , i ron (0 .96 mg/L ) , and chromium hexava len t (0 .00 mg/L ) .
The exper iment i s comple ted and conduc ted success fu l l y .
INTRODUCTION
I n 2006 , a to ta l o f 1 ,064 wate r qua l i t y mon i to r ing s ta t ions
loca ted w i th in 146 r i ve r bas ins were mon i to red . Out o f these 1 ,064
mon i to r ing s ta t ions , 619 (58%) were found to be c lean , 359 (34%)
s l igh t l y po l lu ted and 86 (8%) po l lu ted . S ta t ions loca ted ups t ream
were genera l l y c lean , wh i le those downs t ream were e i ther s l igh t l y
po l lu ted o r po l lu ted . In te rms o f r i ve r bas in wate r qua l i t y , 80 r i ve r
bas ins (55%) were c lean , 59 (40%) s l igh t l y po l lu ted and 7 (5%) were
po l lu ted .
The ma jo r po l lu tan ts were B iochemica l Oxygen Demand (BOD) ,
Ammon iaca l N i t rogen (NH3-N) and Suspended So l ids (SS) . In 2006 ,
22 r i ve r bas ins were ca tegor ized as be ing po l lu ted by BOD, 41 r i ve r
bas ins by NH3-N and 42 r i ve r bas ins by SS. H igh BOD was
con t r ibu ted la rge ly by un t rea ted o r par t ia l l y t rea ted sewage and
d ischarges f rom agro-based and manufac tu r ing indus t r ies . The ma in
sources o f NH3-N were domest i c sewage and l i ves tock fa rming ,
wh i l s t the sources fo r SS were mos t l y ear thworks and land c lear ing
ac t i v i t i es .
Ana lys is o f heavy meta ls in 5 ,613 wate r samples revea led tha t
a lmos t a l l samp les compl ied w i th C lass I I I , Na t iona l Water Qua l i t y
S tandards fo r a rsen ic (As) , mercury (Hg) , cadmium (Cd) , ch romium
(Cr ) , l ead (Pb) and z inc (Zn) , excep t i ron (Fe) w i th 83 percen t
compl iance .
( source :h t tp : / /www.wepa-db .ne t /po l i c ies /s ta te /ma lays ia / r i ve r .h tm)
The s ta tements above shows the rea l i t y o f today ’s wa te r
qua l i t y , where mos t o f i t i s con tamina ted by heavy meta ls , such as
lead (Pb) , mercury (Hg) , Cadmium (Cd) , and ch lo r ine (C l ) . The
exposure and ex is tence o f these heavy meta ls a re apparen t l y one o f
the ma in th rea ts to human ’s hea l th . These meta ls have been s tud ied
ex tens ive ly and the i r c i r cumstances on human hea l th regu la r l y
rev iewed by in te rna t iona l par t ies such as the Wor ld Hea l th
Organ iza t ion (WHO) .
For thousands o f years have heavy meta ls been used by
humans , and a l though severa l adverse hea l th e f fec t upon exposure
o f these hazardous meta ls a re be ing in fo rmed to pub l i c awareness ,
the harmfu l s i tua t ions a re never the less s t i l l go ing on , par t i cu la r l y in
many no t -so-deve loped coun t r ies .
The perspec t i ve o f peop le regard ing the heavy meta ls po l lu t ion
i s tha t i t i s assoc ia ted on ly in a reas where g rea t dea ls o f indus t r ies
a re opera t ing . On the con t ra ry , roadways and au tomob i les a re now
cons idered as la rge poss ib le sources fo r such hazardous heavy
meta ls . Z inc , copper and lead a re the mos t common heavy meta ls
wh ich by chance a re re leased f rom road t rave ls , wh ich accoun ts fo r
a t l eas t 90 percen ts o f the to ta l meta ls in road runo f f .
On the road sur face , mos t heavy meta ls become bound to the
sur faces o f road dus t o r o ther par t i cu la tes . Dur ing p rec ip i ta t ion , the
bound meta ls w i l l e i the r become so lub le (d isso lved) o r be swept o f f
the roadway w i th the dus t . In e i ther case , the meta ls en te r the so i l o r
a re channe l led in to a s to rm dra in . Whether in the so i l o r aqua t i c
env i ronment , meta ls can be t ranspor ted by severa l p rocesses . These
p rocesses a re governed by the chemica l na tu re o f meta ls , so i l and
sed iment par t i c les , and the pH o f the sur round ing env i ronment .
(source
:h t tp : / /www. fa i r faxcoun ty .gov /nvswcd/news le t te r /heavymeta l .h tm )
As a mat te r o f fac t , heavy meta ls can be very harmfu l to one ’s
hea l th i f a d r ink ing wate r con ta in ing such dead ly meta ls i s
consumed. The adverse c i rcumstances inc lude d is tu rbance in g rowth
and deve lopment , t r i gger ing cancer , o rgan damage, nervous sys tem
damage, and in ex t reme cases , caus ing fa ta l .
Research shows tha t youngs te rs a re more suscep t ib le to be
a f fec ted to the tox ic i t y o f the heavy meta ls , as the rap id ly deve lop ing
body sys tems in foe tus , in fan ts and young ch i ld ren a re fa r more
sens i t i ve than the adu l t s . The e f fec ts inc lude learn ing d i f f i cu l t i es ,
memory impa i rment , damage to the nervous sys tem, and behav ioura l
p rob lems such as hyperac t i v i t y and aggress iveness . I r revers ib le
b ra in damage resu l t s f rom overdose o f the meta ls .
Humans a re there fo re needed to be h igh ly aware w i th the
harmfu l e f fec ts the wate r con ta in ing heavy meta ls cou ld b r ing to
one ’s hea l th . Heavy meta l po l lu t ion i s a qu ick ly g row ing p rob lem fo r
our oceans , lakes , and r i ve rs . R igh t now i t may no t be the b igges t
po l lu t ion p rob lem, bu t jus t wa i t ing fo r i t t o go away o r to le t i t so lve
i t se l f i s no t go ing to he lp . We need to be aware o f the p rob lems
heavy meta l c rea tes , so we a l l , i n our own l i t t l e ways , can con t r ibu te
to the so lu t ions . Heavy meta l po l lu t ion i s a th rea t to human hea l th ,
an ima ls , p lan ts , and the p lane t i t se l f , and i s ma in ly caused by
indus t r ia l i za t ion and i t s consequences . Wh i le some o f the meta l
po l lu tan ts come f rom fe r t i l i ze rs and sewage, the b igges t source o f
heavy meta l po l lu t ion de f in i te l y i s indus t r ia l i za t ion .
OBJECTIVE
The ma in ob jec t i ve o f th i s exper iment i s to de te rmine the
d isso lved heavy meta ls in wa te r sample co l lec ted f rom Tas ik
Seksyen 7 , Sha l A lam wh ich i s ch lo r ine to ta l , ch lo r ine f ree , su l fa te ,
phosphorus reac t i ve , i ron and chromium hexava len t . Bes ides tha t ,
the re a re a lso s ide ob jec t i ve o f th i s exper iment , wh ich i s d iscuss ing
the e f fec ts o f p resence o f heavy meta ls in wa te r sources .
THEORY
Pol lu ted d r ink ing wate r can be found anywhere . Even in c i t i es
o r coun t r ies tha t c la im to have hea l thy wate r supp l ies , the re a re s t i l l
cases regard ing po l lu ted wate r because the loca l wa te r may con ta in
un ique bac te r ia tha t human ’s body i s no t used to . Unsa fe d r ink ing
wate r sources can spread ser ious d iseases , such as po ten t ia l wa te r -
borne i l l nesses l i ke Hepat i t i s A , Typho id Fever , v i ra l gas t roen te r i t i s ,
cho le ra , cyc lospor ias is and sch is tosomias is . Mos t o f these d iseases
have d i f fe ren t t ypes o f sys tems, bu t they a l l resu l t i n abdomina l
pa in , c ramp ing and d ia r rhoea .
The Un i ted S ta tes o f Amer ica a re one o f the coun t r ies tha t
opera tes numerous heavy indus t r ia l fac to r ies and have records o f
po l lu ted env i ronment , wh ich exp la ins lo ts o f news and repor ts s ta t ing
tha t mos t tap and we l l wa te r in tha t coun t ry i s no t sa fe fo r d r ink ing
purpose recen t l y . The heavy meta ls pene t ra te and po l lu te our na tu ra l
wa te r sources a long w i th tox ic bac te r ia and o ther chemica ls , mak ing
peop le s ick as we l l as caus ing long te rm hea l th consequences such
as l i ve r damage, cancer and o ther se r ious hea l th p rob lems. I t i s
even be l ieved tha t a lmos t a l l ou r sources o f wa te r , i nc lud ing
mun ic ipa l wa te r sys tems, we l l s , l akes , r i ve rs , and even g lac ie rs ,
con ta in some leve l o f con tamina t ion . Even some brands o f bo t t led
wate r have been found to be po l lu ted and harmfu l in add i t ion to
p las t i c chemica l leach ing f rom the bo t t le .
Chlor ine , f o r examples , i s usua l l y added to wa te r to deac t i va te
and des t roy d isease-caus ing mic roorgan isms and i s the mos t w ide ly
used as d is in fec tan t in the Un i ted S ta tes . I t can reac t w i th na tu ra l l y
occur r ing o rgan ic compounds found in wa te r supp ly , wh ich in tu rns
p roduce hazardous compounds , known as d is in fec t ion by -p roduc ts
(DBPs) . T r iha lomethanes (THMs) and ha loace t i c ac ids a re common
DBPs. I t i s unden iab ly po ten t ia l l y ca rc inogen ic espec ia l l y to o rgans
such as k idney and l i ve r . Due to th is , federa l regu la t ions in the
Un i ted S ta tes o f Amer ica requ i re regu la r mon i to r ing o f the
concen t ra t ions o f these compounds in the d is t r ibu t ion sys tems o f
mun ic ipa l wa te r sys tems. Never the less , the WHO s ta tes tha t the
r i sks to hea l th f rom DBPs a re ex t reme ly sma l l i n compar ison w i th
inadequate d is in fec t ion .
The Secondary Dr ink ing Water Regu la t ions recommend a
max imum concen t ra t ion o f 250 mg/L fo r su l fa te ions (SO 42 - ) . Sul fa te
i s in fac t occurs in a lmos t a l l na tu ra l wa te rs . Su l fa te i s indeed one o f
the ma jo r d isso lved cons t i tuen ts in ra inwate r . H igh concen t ra t ions o f
su l fa te in d r ink ing wate r cause a laxa t i ve e f fec t when combined w i th
magnes ium and ca lc ium. Bac te r ia wh ich in fac t a t tacks and reduces
su l fa tes , causes the fo rmat ion o f hydrogen su l f ide gas (H 2 S) .
Phosphorus occurs na tu ra l l y in rocks and o ther m inera l
depos i t s . Techn ica l l y , the rocks re lease the phosphorus as
phosphate ions wh ich a re so lub le in wa te r and the minera l i ze
phosphate compounds b reakdown. Phosphates (PO 43 - ) a re fo rmed
f rom th is e lement . Phosphate occurs in l i v ing and decay ing p lan ts
and an ima ls as f ree ions o r weak ly chemica l l y bounded in aqueous ,
to sed iments and so i l s , o r as m inera l i zed compounds in so i l s , rocks
and sed iments . The phosphorus i s o f ten scarce in the we l l -
oxygenated wate rs and low leve ls o f phosphorus resu l t s in the
l im i ta t ion o f p roduc t ion o f f reshwater sys tems. Phosphates a re
genera l l y no t tox ic to humans o r an ima ls un less they a re p resen t in
h igh leve ls o f concen t ra t ion . Phosphorus po l lu t ion acce le ra tes a
p rocess ca l led eu t roph ica t ion , wh ich i s essen t ia l l y the p rocess o f a
lake ’s b io log ica l dea th due to dep le ted b ioava i lab le oxygen . (Source :
h t tp : / /www.sercon l ine .o rg /phosphorus /background .h tml ) The bu i ld -up
o f phosphate in the lake wate r o r any sur face wate r ecosys tem leads
to overp roduc t ion o f lake o r wa te r body wh ich resu l t s in the
imba lance in the nu t r ien t and mater ia l cyc l ing p rocess . There w i l l be
mass ive p roduc t ion o f phy top lank ton and there fo re cause var ie ty o f
p rob lems rang ing f rom anox ic wa te rs to tox ic a lga l b looms as we l l as
decrease in d ive rs i t y , food supp ly and des t roy ing the hab i ta ts .
Excess ive g rowth o f a lga l due to phosphorus po l lu t ion inc rease
wate r t rea tments cos ts , degrades f i sh ing and boa t ing ac t i v i t i es as
we l l as impac ts tour i sm and p roper ty va lues .
The max imum con taminan t leve l (MCLs) o f i ron i s 0 .3 mg/L .
I ron inges t ion i s no t genera l l y unhea l thy and abso lu te ly necessary in
sma l l amounts . However , research has found tha t exposure to h igh
leve ls o f i ron can lead to hear t d isease , cancer and d iabe tes . I ron i s
of ten inc luded in supp lements and enr i ched p roduc ts . I t a l so
con ta ins in red meat , the re fo re eas i l y to be consumed.
Chromium hexavalent re fe rs to chemica l compounds tha t
con ta in the e lement ch romium in the +6 ox ida t ion s ta te . I t i s used fo r
the p roduc t ion o f s ta in less s tee l , tex t i l e dyes , wood p reserva t ion ,
lea ther tann ing , and as an t i - co r ros ion and convers ion coa t ings as
we l l as var ie ty o f n iche used . Hexava len t ch romium compounds a re
geno tox ic ca rc inogens . Chron ic inha la t ion o f the compounds
inc reases r i sk o f lung cancer . Bes ides , ch romium hexava len t a lso
causes shor t te rm hea l th p rob lems such as sk in i r r i t a t ion o r
u lce ra t ion , whereas the long te rm e f fec ts o f exposure inc lude
damage to l i ve r , k idney c i rcu la to ry and nerve t i ssues .
EXPERIMENTAL PROCEDURE
Exper iment A: Chlor ine , Tota l (0 -2 .00 mg/L) – Using DPD Method
1. The s to red p rogram number fo r f ree and to ta l ch lo r ine (C l 2 )
powder p i l l ow i s en te red . (8 0 ENTER) and d isp lay w i l l show: D ia l
nm to 530
2 . The wave leng th d ia l i s ro ta ted un t i l t he sc reen shows the d ia l
number tha t equa ls to the one tha t recommended. When the
cor rec t d ia l wave leng th i s d ia l led , the d isp lay w i l l qu ick ly show:
Zero Sample then : mg/L C l 2 .
3 . The 10-mL ce l l r i se r i s inser ted in to the sample compar tment .
4 . A 10-mL sample ce l l i s f i l l ed w i th 10-mL o f sample .
5. One con ten ts o f DPD To ta l Ch lo r ine Powder P i l l ow i s added to the
sample ce l l known as p repared sample . The sample then i s
covered w i th s topper and shaked fo r 20 seconds . S topper i s then
removed.
6 . The SHIFT T IMER bu t ton i s p ressed and a th ree-minu te reac t ion
per iod w i l l beg in .
7 . Ano ther sample ce l l known as the b lank w i th 10-mL o f sample i s
f i l l ed and then p laced in to the ce l l ho lder . The l i gh t sh ie ld then i s
c losed . A l l these a re done jus t a f te r the t imer beeps .
8 . Zero bu t ton i s p ressed and the d isp lay w i l l show: Zero ing… then :
0 .00 mg/L C l 2
9. Wi th in th ree minu tes a f te r t imer beeps , the p repared sample i s
p lace in to the ce l l ho lder then the l i gh t sh ie ld i s c losed .
10 .Read bu t ton i s p ressed and i t w i l l show: Read ing… .The resu l t i n
mg/L C l 2 w i l l appear and then recorded .
Exper iment B: Chlor ine , Free (0 -2 .00 mg/L) – Using DPD Method
1. The s to red p rogram number fo r f ree and to ta l ch lo r ine (C l 2 )
powder p i l l ow i s en te red . (8 0 ENTER) and d isp lay w i l l show: D ia l
nm to 530
2 . The wave leng th d ia l i s ro ta ted un t i l t he sc reen shows the d ia l
number tha t equa ls to the one tha t recommended. When the
cor rec t d ia l wave leng th i s d ia led , the d isp lay w i l l qu ick ly show:
Zero Sample then : mg/L C l 2 .
3 . The 10-mL ce l l r i se r i s inser ted in to the sample compar tment .
4 . A 10-mL sample ce l l i s f i l l ed w i th 10-mL o f sample known as the
b lank and then i t i s p laced in to the ce l l ho lder and the l i gh t i s
c losed .
5. Zero bu t ton i s p ressed and the d isp lay w i l l show: Zero ing… then :
0 .00 mg/L C l 2
6. Another ce l l i s f i l l ed w i th the 10-mL o f sample .
7 . One con ten ts o f DPD Free Ch lo r ine Powder P i l l ow i s added to the
sample ce l l known as p repared sample . The sample then i s
covered w i th s topper and shake fo r 20 seconds .
8 . Immed ia te ly a m inu te a f te r reagen t add i t ion , the s topper i s
removed. The p repared sample i s p lace in to the ce l l ho lder then
the l i gh t sh ie ld i s c losed .
9 . Read bu t ton i s p ressed and i t w i l l show: Read ing… .The resu l t i n
mg/L C l 2 w i l l appear and then recorded .
Exper iment C: Sul fa te (0 to 70 mg/L) – Sul fa Ver 4 Method
1. The s to red p rogram number fo r su l fa te (SO42- ) powder p i l l ow i s
en te red . (6 8 0 ENTER or 9 ? ? ENTER) and d isp lay w i l l show:
D ia l nm to 450
2 . The wave leng th d ia l i s ro ta ted un t i l t he sc reen shows the d ia l
number tha t equa ls to the one tha t recommended. When the
cor rec t d ia l wave leng th i s d ia led , the d isp lay w i l l qu ick ly show:
Zero Sample then : mg/L SO 42 - .
3 . A 25-mL sample ce l l i s f i l l ed w i th 25-mL o f sample .
4 . One con ten ts o f Su l fa Ver 4 Su l fa te Reagent Powder P i l l ow i s
added to the sample ce l l known as p repared sample . The sample
i s sw i r led to d isso lve the mix tu re . A wh i te tu rb id i t y i s deve loped .
5 . The SHIFT T IMER bu t ton i s p ressed and a f i ve -minu te reac t ion
per iod w i l l beg in . The ce l l i s a l lowed to s tand und is tu rbed .
6 . Ano ther sample ce l l known as the b lank w i th 25-mL o f sample i s
f i l l ed and then p laced in to the ce l l ho lder . The l i gh t sh ie ld then i s
c losed . A l l these a re done jus t a f te r the t imer beeps .
7. Zero bu t ton i s p ressed and the d isp lay w i l l show: Zero ing… then :
0 . mg/L SO 42 - .
8 . Wi th in f i ve m inu tes a f te r t imer beeps , the p repared sample i s
p lace in to the ce l l ho lder then the l i gh t sh ie ld i s c losed .
9 . Read bu t ton i s p ressed and i t w i l l show: Read ing… .The resu l t i n
mg/L SO 42 - w i l l appear and then recorded .
Exper iment D: Phosphorus, React ive (0 -2 .50 mg/L PO43- ) – Us ing
Phos Ver 3 (Ascorb ic Acid) Method
1. The s to red p rogram number fo r reac t i ve phosphorus , ascorb ic ac id
method , powder p i l l ows i s en te red . (4 9 0 ENTER) and d isp lay w i l l
show: D ia l nm to 890
2 . The wave leng th d ia l i s ro ta ted un t i l t he sc reen shows the d ia l
number tha t equa ls to the one tha t recommended. When the
cor rec t d ia l wave leng th i s d ia led , the d isp lay w i l l qu ick ly show:
Zero Sample then : mg/L PO 43 - PV
3. The 10-mL ce l l r i se r i s inser ted in to the sample compar tment .
4 . A 10-mL sample ce l l i s f i l l ed w i th 10-mL o f sample .
5 . One con ten ts o f Phos Ver 3 Phosphate Powder P i l l ow i s added to
the sample ce l l known as p repared sample . And then i t i s sw i r led
immed ia te ly to m ix .
6 . The SHIFT T IMER bu t ton i s p ressed and a two-minu te reac t ion
per iod w i l l beg in .
7 . Ano ther sample ce l l known as the b lank w i th 10-mL o f sample i s
f i l l ed and then p laced in to the ce l l ho lder . The l i gh t sh ie ld then i s
c losed . A l l these a re done jus t a f te r the t imer beeps .
8 . Zero bu t ton i s p ressed and the d isp lay w i l l show: Zero ing… then :
0 .00 mg/L PO 43 - PV
9. The p repared sample i s p lace in to the ce l l ho lder then the l i gh t
sh ie ld i s c losed .
10 . Read bu t ton i s p ressed and i t w i l l show: Read ing… .The resu l t
i n mg/L PO 43 - w i l l appear and then recorded the resu l t s o f fo rms
P , PO 43 - and P 2 O 5 .
Exper iment E: I ron , Tota l (0 -3 .00 mg/L) – Using Ferro Ver Method
1. The s to red p rogram number fo r i ron (Fe) Fer ro Ver powder p i l l ow
i s en te red . (2 6 5 ENTER) and d isp lay w i l l show: D ia l nm to 510
2 . The wave leng th d ia l i s ro ta ted un t i l t he sc reen shows the d ia l
number tha t equa ls to the one tha t recommended. When the
cor rec t d ia l wave leng th i s d ia led , the d isp lay w i l l qu ick ly show:
Zero Sample then : mg/L Fe FV.
3 . The 10-mL ce l l r i se r i s inser ted in to the sample compar tment .
4 . A 10-mL sample ce l l i s f i l l ed w i th 10-mL o f sample .
5 . One con ten ts o f Fer ro Ver I ron Reagent Powder P i l l ow i s added to
the sample ce l l known as p repared sample and then sw i r led to
m ix .
6 . The SHIFT T IMER bu t ton i s p ressed and a th ree-minu te reac t ion
per iod w i l l beg in .
7 . When the t imer beeps , the d isp lay w i l l show: mg/L Fe FV and
ano ther sample ce l l known as the b lank w i th 10-mL o f sample i s
f i l l ed .
8 . Then p laced in to the ce l l ho lder . The l i gh t sh ie ld then i s c losed .
9 . Zero bu t ton i s p ressed and the d isp lay w i l l show: Zero ing… then :
0 .00 mg/L Fe FV
10. Wi th in th i r t y m inu tes a f te r t imer beeps , the p repared sample i s
p lace in to the ce l l ho lder then the l i gh t sh ie ld i s c losed .
11. Read bu t ton i s p ressed and i t w i l l show: Read ing… .The resu l t
i n mg/L i ron w i l l appear and then recorded .
Exper iment F : Chromium, Hexavalent (0 -0 .60 mg/L Cr6+) – Using
1 ,5 -Diphenylcarbohydraz ide Method
1. The s to red p rogram number fo r ch romium hexava len t ( Cr 6 + ) i s
en te red . (9 0 ENTER) and d isp lay w i l l show: D ia l nm to 540
2 . The wave leng th d ia l i s ro ta ted un t i l t he sc reen shows the d ia l
number tha t equa ls to the one tha t recommended. When the
cor rec t d ia l wave leng th i s d ia led , the d isp lay w i l l qu ick ly show:
Zero Sample then : mg/L Cr 6 +
3. The 10-mL ce l l r i se r i s inser ted in to the sample compar tment .
4 . A 10-mL sample ce l l i s f i l l ed w i th 10-mL o f sample .
5 . One con ten ts o f Chroma Ver 3 Reagent Powder P i l l ow i s added to
the sample ce l l known as p repared sample . And then i t i s sw i r led
immed ia te ly to m ix .
6 . The SHIFT T IMER bu t ton i s p ressed and a f i ve -minu te reac t ion
per iod w i l l beg in .
7 . Ano ther sample ce l l known as the b lank w i th 10-mL o f sample i s
f i l l ed . When the t imer beeps , the d isp lay w i l l show: mg/L Cr 6 + and
then p laced in to the ce l l ho lder .
8 . Zero bu t ton i s p ressed and the d isp lay w i l l show: Zero ing… then :
0 .00 mg/L Cr 6 +
9. The p repared sample i s p lace in to the ce l l ho lder then the l i gh t
sh ie ld i s c losed .
10 . Read bu t ton i s p ressed and i t w i l l show: Read ing… .The resu l t
i n mg/L Cr 6 + w i l l appear and then recorded the resu l t s o f fo rms P ,
PO 43 - and P 2 O 5 .
APPARATUS / REAGENTS
Apparatus
Pour -Thru Ce l l
Por tab le Spec t ropho tome te r DR 2400
250 ml Er lenmeyer f l ask
10-mL and 25-mL ce l l r i se r
Cl ippers
25-mL gradua ted cy l inder
Reagents
Sample wate r
DPD Tota l Ch lo r ine Powder P i l l ow
DPD Free Ch lo r ine Powder P i l l ow
Sul fa Ver 4 Su l fa te Reagent Powder P i l l ow
Phos Ver 3 Phosphate Powder P i l l ow
Fer ro Ver I ron Reagent Powder P i l l ow
Chroma Ver 3 Reagent Powder P i l l ow
RESULT
S u b s t a n c e R e a g e n t C o l o u r o f s o l u t i o n
R a n g e ( m g / L ) R e s u l t ( m g / L )
C h l o r i n e , t o t a l D P D t o t a l c h l o r i n e
p o w d e r p i l l o wC o l o u r l e s s 0 . 0 2 – 2 . 0 0 0 . 3 6
C h l o r i n e , f r e e D P D f r e e c h l o r i n e
p o w d e r p i l l o wC o l o u r l e s s 0 . 0 2 – 2 . 0 0 0 . 1 0
S u l f a t e S u l f a v e r 4 r e a g e n t
p o w d e r p i l l o w
S l i g h t l y c l o u d y s o l u t i o n i s
f o r m e d2 . 0 – 7 0 . 0 2 5 . 0
P h o s p h o r u s r e a c t i v e
P h o s v e r 3 p h o s p h a t e
p o w d e r p i l l o w
P a l e b l u e s o l u t i o n i s
f o r m e d0 . 0 2 – 2 . 5 0 0 . 4 3
I r o n F e r r o v e r I r o n r e a g e n t
p o w d e r p i l l o w
L i g h t o r a n g e s o l u t i o n i s
f o r m e d0 . 0 2 – 3 . 0 0 0 . 9 6
C h r o m i u m H e x a v a l e n t
C h r o m a v e r 3 p o w d e r p i l l o w
C o l o u r l e s s 0 . 0 1 – 0 . 7 0 0 . 0 0
SAMPLE CALCULATIONS
Sample 1 – Chlor ine , Tota l (C l 2 )
The concen t ra t ion o f Ch lo r ine (C l 2 ) = 0 .36 mg/L
The vo lume o f a sample = 10ml /1000 = 0 .01 L
The mass o f Ch lo r ine (C l 2 ) = 0 .36 mg/L x 0 .01 L
= 3 .6 x 10 - 3 mg
Sample 2 – Chlor ine Free (C l 2 )
The concen t ra t ion o f Ch lo r ine F ree (C l 2 ) = 0 .10 mg/L
The vo lume o f sample = 10 ml /1000 = 0 .01 L
The mass o f Ch lo r ine F ree (C l 2 ) = 0 .10 mg/L x 0 .01 L
= 1 .0 x 10 - 3 mg
Sample 3 – Sul fa te (SO 4 2 - )
The concen t ra t ion o f Su l fa te (SO 42 - ) = 25 .00 mg/L
The vo lume o f sample = 10 ml /1000 = 0 .01 L
The mass o f Su l fa te (SO 42 - ) = 25 .00 mg/L x 0 .01 L
= 0 .25 mg
Sample 4 – Phosphorus, React ive
The concen t ra t ion o f Phosphorus , Reac t i ve = 0 .43 mg/L
The vo lume o f sample = 10 ml /1000 = 0 .01 L
The mass o f Phosphorus , Reac t i ve = 0 .43 mg/L x 0 .01 L
= 4 .3 × 10 - 3 mg
Sample 5 – I ron Tota l (Fe)
The concen t ra t ion o f Fe = 0 .96 mg/L
The vo lume o f sample = 10 ml /1000 = 0 .01 L
The mass o f Fe = 0 .96 mg/L x 0 .01 L
= 9 .6 × 10 - 3 mg
Sample 6 – Chromium, Hexavalent (Cr 6 + )
The concen t ra t ion o f Chromium, Hexava len t = 0 .00 mg/L
The vo lume o f sample = 0 .01 L
The mass o f Chromium, Hexava len t = 0 .00 mg/L x 0 .01 L
= 0 .00 mg
DISCUSSION
Based on the resu l t s ob ta ined , there a re cer ta in e r ro rs tha t
m igh t have been done w i thou t purpose and thus lead to e r roneous
da ta .
F i rs t and fo remost , the read ing fo r each sample i s on ly done
once . Never the less , lack o f ins t ruments and long t ime consuming
fac to rs evade f rom tak ing a t leas t two read ings fo r each sample , and
t he re fo re an average va lue canno t be ob ta ined to ensure the
accuracy and p rec is ion o f the resu l t s .
Nex t , the improper hand l ing o f the round wate r sample may
a lso caused inaccura te read ings . Any fingerprints or smudge imprinted
on the outer surface of the round water sample can become an
unfavourably interference for the solutions to absorb wavelengths of l ight
in the spectrophotometer. Thus, the reading of concentrations by the
instruments may not be accurate.
Besides, some of the samples are supposedly be immediately
inserted into the spectrophotometer after being poured in their
corresponding reagents. Thus, any careless procedures or unobservant
may lead to inaccuracy of the readings taken.
CONCLUSION
The concentrations of chlorine total in the water sample is 0.36
mg/L, Chlorine free is 0.10 mg/L, Sulfate is 25.0 mg/L, Phosphorus
reactive is 0.43 mg/L, Iron is 0.96 mg/L and Chromium Hexavalent is 0.00
mg/L. Based on the following data, the water sample is mostly
concentrated with sulfate and contains no chromium hexavalent, which
explains the colourless solution formed, indicating no change or reaction
occurs to detect any presence of chromium in the water sample.
Nevertheless, the exceeding value of concentration of phosphorus
reactive and iron, which is 0.1 mg/L and 0.3 mg/L respectively, requires
extensive water treatment, as it might worriedly brings any health effects
to both humans and aquatic ecosystems.
RECOMMENDATIONS
Firstly, the outside surface of the round water sample is best wiped
first before inserted into the spectrophotometer. This is to ensure that
there are no fingerprints on it which might interfere the reading analysis.
Secondly, the sample must be analyzed immediately after collection
and cannot be kept for later analysis. This is because the heavy metals
content of the water sample might differ from the time it is collected unti l
i t is analyzed.
In addit ion, the collection of the water sample is preferential ly near
the middle of the water stream and at least at one arm’s length of depth.
This is because; most heavy metals are bounded at inner depth of any
water streams.
REFERENCES
1. h t tp : / /www.wate r - research .ne t /g lossary .h tm
2. h t tp : / /en .w ik iped ia .o rg /w ik i /Hexava len t_chromium
3. h t tp : / /www.hea l thy -wate r -bes t - f i l t e rs .com/heavy-meta ls -w i th in -
wate r .h tm l
4 . h t tp : / /www. f reedr ink ingwate r .com/wate r -educa t ion /qua l i t y -
wa te r -heavymeata l .h tm
5. h t tp : / /www. lenn tech .com/per iod ic /wa te r /ch romium/chromium-
and-wate r .h tm
6. h t tp : / /en .w ik iped ia .o rg /w ik i /Ch lo r ina t ion
APPENDICES
DPD Total Chlorine Powder Pillow
Sulfa Ver 4 Sulfate Reagent DPD Free Chlorine Powder Pillow
Phos Ver 3 Phosphate
Powder
Ferro Ver Iron Reagent Powder Pillow
Chroma Ver 3 Reagent Powder Pillow
Graduated Cylinder Portable Spectrophotometer
DR 2400.