What are the applications of Turbidimetry and Nephelometry?

i) Quantitative Analysis: Gelatinous or very small size particles are difficult to filter and are so difficult to estimate. Such ppt. can be converted into ideal solution (suspension) and then can be estimated by either Nephelometry or Turbidimetry.

ii) The amount of Sulphur present in the coal, Oil, rubber, plastics and several organic materials can be determined. That material which contains sulphur is heated at very high temp so that sulphur present is oxidized to the corresponding SO₄^-2 . This is then treated with BaCl₂ so that suspension of BaSO₄ is obtained. This suspension is then subjected to Nephelometer or Turbidimeter.

iii) Water which is required in power plant (Nuclear Reactor) and steam generating plant (Boiler) must be free from any of the suspended particles that testing can be done by Nephelometer and Turbidimeter. If no response from the instrument it, means water is free from of the suspended impurities.

iv) Air is continuously monitored for dust and other particulate matter using these two methods.

v) Determination of molecular weight of macromolecules i.e. polymer.  Polymers have the property of scattering of light. The turbidity of the solution is related to molecular weight of the polymer. $$\tau =Hc{M}_w$$ Where H = constant, depends on polymer and medium.

vi) Turbidimetric Titrations: In this case, the solution of SO₄^-2 is taken in the cuvette and after each addition of the titrant i.e. BaCl₂ the precipitate formation takes place. This ppt, formation goes on increasing till all the SO₄^-2 ions are precipitated and so the turbidance goes on increasing and is maximum at the Equivalence point, after that, it remains constant.

vii) The phenomenon is used in sewage work.

viii) Used in pharmaceutical industries and petroleum refineries.

ix) Used in pulp and paper manufacturing.

x) The phenomenon is applied in the determination of suspended material in liquid found in nature.