Experiment No: 01
Determination of Total Dissolved
Solids(TDS) and Total Suspended
Solids(TSS) in water sample
What is it ?
TSS and TDS measure the amount of
particulate matter (tiny pieces of things)
floating in water. In lakes and rivers this
can include particles from algae, other
organic matter, silt and clay, and other
inorganic substances (such as minerals,
salts and metals).
These particles, or ‘solids’, can be divided
into two types by passing the water
through a filter. The particles that are Total Solids(TS): Residue left in the
large enough to be held back by the filter vessel after evaporation of a sample and
are called total suspended solids (TSS), subsequent drying in oven at defined
while the particles that pass through the temperature.
filter are called total dissolved TS = TSS + TDS ….(1)
solids (TDS).
Why is it required ?
Total suspended solids (TSS) values are often related to the turbidity (cloudiness)
of water. If TSS is high and the water is murky then light from the sun will not
travel well through the water, making it difficult for plants and algae to grow.
This, in turn, can reduce productivity (the amount of plant and animal life that a
river or lake can support) and oxygen generation. Lots of soil and silt in the water
can also clog fish gills and, if it settles to the bottom, bury fish eggs.
Total dissolved solids (TDS) include dissolved minerals and salts in the water. As a
result, TDS is often closely related to conductivity, salinity, alkalinity, and
hardness measures. Most freshwater fish and bugs cannot tolerate high TDS
because they are not adapted to saline (salty) water, like marine fish are.
Apparatus: Procedure:
• Weight • Take filter paper of size 0.2 micron and conical flask.
balance
• Clean the conical flask thoroughly.
• Conical flask
• Dry the filter paper and flask in hot air oven at more
• Filter than 100 degree Celsius.
paper(0.2
micron) • Take the initial weight of the filter paper (Wa in gm)
and flask (Wb gm).
• Oven
• Filter the 50 ml water sample through the filter paper
• Measuring into the flask.
cylinder
• Dry the filter paper and flask in hot air oven.
• Take final weights of filter paper (Wc gm) and flask
(Wd gm).
Reading & Calculation
S.No Initial Wt (gm) Final Wt (gm) TSS (mg/L) TDS(mg/L) TS(mg/L)
Filter Flask Filter Flask
Paper (Wb) Paper (Wd)
(Wa) (Wc)
𝑾𝒄 −𝑾𝒂
TSS = 𝑿 𝟏𝟎𝟎𝟎 …(2)
𝑺𝒂𝒎𝒑𝒍𝒆 𝑽𝒐𝒍.(𝒎𝒍)
𝑾𝒅 −𝑾𝒃
TDS = 𝑿 𝟏𝟎𝟎𝟎 …(3)
𝑺𝒂𝒎𝒑𝒍𝒆 𝑽𝒐𝒍.(𝒎𝒍)
And TS = TDS + TSS (from Eq 1)
Disadvantage of high TSS
❖ Can block light from reaching submerged vegetation.
❖ Higher concentrations of bacteria, nutrients, pesticides
❖ Can cause problems for industrial use, because the solids
may clog the pipes and machinery.
Disadvantage of high TDS
❖ Increases the water hardness
❖ Affects the taste of the water
❖ Aesthetically unpleasing
As per IS:10500-2012 ( Second Revision )
S.No Parameter Acceptable Limit (mg/L) Permissible Limit in
the absence of
alternate source
(mg/L)
1 Total dissolved solids 500 2000
(TDS)
http://ismenvis.nic.in/Database/Environmental_Standards_7391.aspx
S. Parameter Inland surface Public Land for Marine/coastal areas
No. water sewers irrigation
1 Suspended solids 100 600 200 (a) For process waste
mg/l, max. water
(b) For cooling water
effluent 10 per cent
above total
suspended matter of
influent.
