• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

TDS VS turbidity (1 Viewer)

Joined
Oct 29, 2011
Messages
872
Location
Narnia
Gender
Female
HSC
2013
what is the difference between the two, don't they both measure the total amount of dissolved solids? Except for TDS you first filter to remove suspended solids.

also can someone explain the term suspended solids, and dissolved solids. I had a question which asked to calculate the turbidity. is the turbidity dissolved + suspended solids. or just the suspended solids?
 

HeroicPandas

Heroic!
Joined
Mar 8, 2012
Messages
1,547
Gender
Male
HSC
2013
TDS = total dissolved solids = mass of solids that are dissolved in the water
Turbidity = in water, it means cloudness or LACK OF transparency as a result of suspended solids

DIFFERENCE: TDS does not include SUSPENDED SOLIDS, it only measures DISSOLVED SOLIDS
TURBIDITY is just a measure of cloudness in water which is as a result of SUSPENDED SOLIDS (maybe dissolved solids - like metal ions such as Fe2+ which causes solution to turn yellow-orange to pale yellow which can account for some degree of reduced transparency - this from my intuition)


Suspended solids are insoluble materials (eg. debris, or even mud)
Dissolved solids are solids that are dissolved in water forming a homogeneous solution

Turbidity is measure in NTU (nephlometric turbimetry units) which gives a measure of the amount of suspended solids present (so u just exclude dissolved solids when calcluating it)

"I had a question which asked to calculate the turbidity. is the turbidity dissolved + suspended solids. or just the suspended solids?" - just suspended solids
 
Last edited:

someth1ng

Retired Nov '14
Joined
Sep 18, 2010
Messages
5,558
Location
Adelaide, Australia
Gender
Male
HSC
2012
Uni Grad
2021
TDS = total dissolved solids = mass of solids that are dissolved in the water
Turbidity = in water, it means cloudness or LACK OF transparency as a result of suspended solids

DIFFERENCE: TDS does not include SUSPENDED SOLIDS, it only measures DISSOLVED SOLIDS
TURBIDITY is just a measure of cloudness in water which is as a result of SUSPENDED SOLIDS (maybe dissolved solids - like metal ions such as Fe2+ which causes solution to turn yellow-orange to pale yellow which can account for some degree of reduced transparency - this from my intuition)


Suspended solids are insoluble materials (eg. debris, or even mud)
Dissolved solids are solids that are dissolved in water forming a homogeneous solution

Turbidity is measure in NTU (nephlometric turbimetry units) which gives a measure of the amount of suspended solids present (so u just exclude dissolved solids when calcluating it)

"I had a question which asked to calculate the turbidity. is the turbidity dissolved + suspended solids. or just the suspended solids?" - just suspended solids
This part contradicted what you said previously. Dissolved solids can have an effect on the turbidity of water but typically, suspended solids are most responsible for it.

Total dissolved solids are things that are in solution. Suspended solids are not in solution.
 

HeroicPandas

Heroic!
Joined
Mar 8, 2012
Messages
1,547
Gender
Male
HSC
2013
This part contradicted what you said previously. Dissolved solids can have an effect on the turbidity of water but typically, suspended solids are most responsible for it.

Total dissolved solids are things that are in solution. Suspended solids are not in solution.
1st point: i used a low modailty word "maybe" to expose my uncertainty
2nd point: why isnt suspended solids in a solution? this causes the cloudiness of some waters. Say i took a sample of highly turbid water, this solution would have to contain suspended solids
 
Last edited:

hayabusaboston

Well-Known Member
Joined
Sep 26, 2011
Messages
2,387
Location
Calabi Yau Manifold
Gender
Male
HSC
2013
TDS = total dissolved solids = mass of solids that are dissolved in the water
Turbidity = in water, it means cloudness or LACK OF transparency as a result of suspended solids

DIFFERENCE: TDS does not include SUSPENDED SOLIDS, it only measures DISSOLVED SOLIDS
TURBIDITY is just a measure of cloudness in water which is as a result of SUSPENDED SOLIDS (maybe dissolved solids - like metal ions such as Fe2+ which causes solution to turn yellow-orange to pale yellow which can account for some degree of reduced transparency - this from my intuition)


Suspended solids are insoluble materials (eg. debris, or even mud)
Dissolved solids are solids that are dissolved in water forming a homogeneous solution

Turbidity is measure in NTU (nephlometric turbimetry units) which gives a measure of the amount of suspended solids present (so u just exclude dissolved solids when calcluating it)

"I had a question which asked to calculate the turbidity. is the turbidity dissolved + suspended solids. or just the suspended solids?" - just suspended solids

Nephelometric turbidity units**
 
Joined
Oct 29, 2011
Messages
872
Location
Narnia
Gender
Female
HSC
2013
unfortunately, i can't find the actual question. but i did stumble onto something else. For determining the hardness of water quantitatively, why do they use mg of CaCO2/L as a measure of hardness. I though hardness was mass of calcium + magnesium/L??
 

someth1ng

Retired Nov '14
Joined
Sep 18, 2010
Messages
5,558
Location
Adelaide, Australia
Gender
Male
HSC
2012
Uni Grad
2021
1st point: i used a low modailty word "maybe" to expose my uncertainty
2nd point: why isnt suspended solids in a solution? this causes the cloudiness of some waters. Say i took a sample of highly turbid water, this solution would have to contain suspended solids
If you can filter it out using filter paper, it is not in solution. Simple as that.
 

someth1ng

Retired Nov '14
Joined
Sep 18, 2010
Messages
5,558
Location
Adelaide, Australia
Gender
Male
HSC
2012
Uni Grad
2021
Sunlight will stop photosynthesis but it will allow algae to continue respiring.

You want the biochemical oxygen demand which is the oxygen used by bacteria in water - you can only measure this is there's no oxygen constantly added to the water (ie stopping photosynthesis).
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top