Water Analysis procedures in Lab
Water Analysis procedures in Lab
[align=center]1- Determination of SO4 as BaSO4[/align]
1) Take 25 ml of sample, dil with dist. Water.
2) Acidify with (1:1) HCl using methyl orange as indicator, add 25 ml as excess.
3) Boil for five minutes , add 10 ml of 10% BaCl2 soln.. drop wise with constant stirring ,continuous stirring for 2 min
4) Digest on water or sand bath for 1 hour
5) cool , Leave to settle for at least 1 hour
6) filter in Whitman filter paper No 42
7) Wash with hot dist water until free from chlorides ,Dry,
8 ) char, ignite & weight as BaSO4
Note.
The analysis is carried out on the filtrate of iron & aluminum, interface to an appreciable extent.
Calculation
PPT of BaSO4 (gm) X 16460 = PPM SO4--
In case of 50 cc sample, the factor =8230
1) Take 25 ml of sample, dil with dist. Water.
2) Acidify with (1:1) HCl using methyl orange as indicator, add 25 ml as excess.
3) Boil for five minutes , add 10 ml of 10% BaCl2 soln.. drop wise with constant stirring ,continuous stirring for 2 min
4) Digest on water or sand bath for 1 hour
5) cool , Leave to settle for at least 1 hour
6) filter in Whitman filter paper No 42
7) Wash with hot dist water until free from chlorides ,Dry,
8 ) char, ignite & weight as BaSO4
Note.
The analysis is carried out on the filtrate of iron & aluminum, interface to an appreciable extent.
Calculation
PPT of BaSO4 (gm) X 16460 = PPM SO4--
In case of 50 cc sample, the factor =8230
[align=center]2- Determination of H2S[/align]
H2S is determined at first to minimize error due to its volatility
Procedure
1) add cold 25 mls of sample to 25 mls of 0.1 N I2 sol.
2) Cold and mix thoroughly in a glass stopper conical flask .
3) Add 2 ml of conc. HCl.
4) Titration against 0.1 N Na2S2O3 sol. Until pale yellow color , then add 1 ml starch indicator (starch give blue color) & continue titration until very faint blue end point.
Calculation
You must make standardization of 25 ml (0.1) I2 against 0.1 N Na2S2O3 .
(25-mls of 0.1 N Na2S2O3 ) X 68 = PPM H2S
@ If 10 ml of sample
(10 - mls of 0.1 N Na2S2O3 ) X 170.3 = PPM H2S
H2S is determined at first to minimize error due to its volatility
Procedure
1) add cold 25 mls of sample to 25 mls of 0.1 N I2 sol.
2) Cold and mix thoroughly in a glass stopper conical flask .
3) Add 2 ml of conc. HCl.
4) Titration against 0.1 N Na2S2O3 sol. Until pale yellow color , then add 1 ml starch indicator (starch give blue color) & continue titration until very faint blue end point.
Calculation
You must make standardization of 25 ml (0.1) I2 against 0.1 N Na2S2O3 .
(25-mls of 0.1 N Na2S2O3 ) X 68 = PPM H2S
@ If 10 ml of sample
(10 - mls of 0.1 N Na2S2O3 ) X 170.3 = PPM H2S
[align=center]5-Iron &AL[/align]
1) Take 50 cc of sample ,add 1 ml of Conc. HNO3 & boil to oxidize
Ferrous to ferric .
2) add 1 gm of solid NH4OH boil precipitate Fe(OH)3 & AL(OH)3
by addition of NH4OH Soln.. drop wise till first alkaline with
constant stirring.
3) boil to expel excess ammonia.
4) Cool, Leave settle
5) filter in Whitman filter paper No 42.
6) Wash with hot dist. Water until free from chloride
7) Dry, char* , weight as Fe2O3 &AL2O3
Calculation:
The factor converting Fe2O3 to Fe = 0.69944
The factor converting AL2O3 to AL = 0.52913
gm of Fe or AL X 2000 = PPM of Fe or AL
1) Take 50 cc of sample ,add 1 ml of Conc. HNO3 & boil to oxidize
Ferrous to ferric .
2) add 1 gm of solid NH4OH boil precipitate Fe(OH)3 & AL(OH)3
by addition of NH4OH Soln.. drop wise till first alkaline with
constant stirring.
3) boil to expel excess ammonia.
4) Cool, Leave settle
5) filter in Whitman filter paper No 42.
6) Wash with hot dist. Water until free from chloride
7) Dry, char* , weight as Fe2O3 &AL2O3
Calculation:
The factor converting Fe2O3 to Fe = 0.69944
The factor converting AL2O3 to AL = 0.52913
gm of Fe or AL X 2000 = PPM of Fe or AL