Skip to main content

civil engineering-->>To Determine the Turbidy of Water sample Using Nephelometric Method

To Determine the Turbidy of Water sample Using Nephelometric Method


Theory:

Water is said to turbid when it is seen containing materials of suspension inside it. While turbidity may be defined as the measure of visible material in suspension in water,turbidity may be caused by algae or other organisms. it is generally caused by silt or clay.
The amount and character of turbidity depends upon two things:
  1. Type of soil over which flows
  2. The velocity of flowing water
When water becomes stationary, the heavier and larger suspended particles settle down quickly and the lighter and finely divided particles settles very slowly and even takes months.
Ground waer is less turbid because of low velocity of water. turbidity may be helpful for controlling growth of paganisms by not allowing proper sunlight to water which is necessary for thier growth on the other hand it is harmful as the organisms are handling to the suspended particles.
When water becomes stationary, the heavier and larger suspended particles settle down quickly and the lighter and finely divided particles settles very slowly and even takes months. Ground waer is less turbid because of low velocity of water. turbidity may be helpful for controlling growth of paganisms by not allowing proper sunlight to water which is necessary for thier growth on the other hand it is harmful as the organisms are handling to the suspended particles.
There are Various units for the measurement of turbidity which are:
  1. Standard turbidity unit[mg/lit or ppm]
  2. Jackson turbidity unit [J.T.U]
  3. Nephelometric turbidity unit [N.T.U]
A device called nephelometric turbidity measures the turbidity of water in N.T.U the intensity of light after passing through the water gives a measure of turbidity of water.

 WHO guideline value:
WHO suggested a guideline value for turbidity as [N.T.U]for disinfection the turbidity of water should be less than 1 N.T.U.

Apparatus:

W.H.O Nephelometric turbidity meter for mazine solution of the sample by multiplying the scale reading by 0.9 N.T.U, 9 N.T.U, 99 N.T.U, test tubes and water samlples.

Procedure:

  1. Switch on the power supply and cheak the battery of the turbidimeter,
  2. Press the 1 N.T.U button and concide the scale with zero by using focusing template.
  3. Again press 1 N.T.U button and concide the scale with zero using the focusing template.
  4. A Standard formazine solution of N.T.U is placed on tubidimeter in the path of rays and scale is brought 9 n.t.u
  5. The Water sample is taken in a test and is placed in turbidimeter.
  6. Use A Cell rise if the turbidity is more than 100 N.T.U and get the turbidity dilution factor.

Comments

Post a Comment

Popular posts from this blog

civil engineering-->> overview of arches

Arches An arch is an opening spanned by a collection of wedge shaped pieces ( voussoirs ) which stay in position by pressing in on one another. The joints between the pieces appear to radiate from some central point lying within the opening, and sometimes from points which lie outside, so every type of arch has a characteristic curvature. The simplest and visually most natural shape for an arch is the semicircle but many other designs have been used. How an Arch "Works" The central voussoir ( keystone ) is traditionally the last to be set into position to "lock" the whole thing into a strong and stable structure. A keystone is not always necessary, however; there may be a joint at the apex instead, as is common in Gothic arches.  Gravity tries to pull the keystone downwards, but the thrust is carried on either side by the voussoirs immediately flanking it. These in turn have their total thrust carried through the whole semicircle of pieces in a sideways direc...
Post a Comment
Read more

civil engineering-->>Determinacy, Indeterminacy and Stability of Frames

Determinacy, Indeterminacy and Stability of Frames : Structural engineers must be able to apply judgment rather than stated rules. The most important aspect of structural design is not the ability to apply formulas or manipulate mathematics. The most important skill for the structural engineer is to be able to stand back, look at a drawing or sketch and determine whether a structure is stable, and if it is stable, to be able to determine how it will carry the applied loads. For a very complicated structure this might be more difficult and a computer can provide some help, but ultimately it is the skill and concern of a good structural engineer which produces good structural designs which have integrity. Another important closely related skill is the ability to determine whether, and to what degree, a structure is statically indeterminate. There really aren’t  many rules and rules may be difficult to apply in any case. For this reason, we need experience. A skilled structural...
1 comment
Read more

civil engineering-->> truss types

                                                                                                                           Modified-Queen-Scissors                                                          Baby Barn and Shed Trusses                                                                        floor truss       ...
1 comment
Read more