EVS-LAB-MANUAL

Formulas and Calculations for Environmental Studies Laboratory Experiment

Determination of Solids

  • Total Solids Calculation: [ \text{Total Solids (mg/L)} = \frac{\text{Weight of dry residue}}{\text{Volume of sample}} \times 1000 ]

  • Total Fixed Solids Calculation: [ \text{Total Fixed Solids (mg/L)} = \frac{\text{Weight after burning}}{\text{Volume of sample}} \times 1000 ]

  • Total Dissolved Solids Calculation: [ \text{Total Dissolved Solids (mg/L)} = \frac{\text{Weight of filtered residue}}{\text{Volume of sample}} \times 1000 ]

  • Suspended Solids Calculation: [ \text{Suspended Solids (mg/L)} = \text{Total Solids} - \text{Total Dissolved Solids} ]

  • Volatile Solids Calculation: [ \text{Volatile Solids (mg/L)} = \text{Total Solids} - \text{Total Fixed Solids} ]

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Determination of Turbidity

  • Turbidity Measurement: Results are recorded as NTU (Nephelometric Turbidity Units) using the nephelometer, comparing the scattered light intensity of the sample to a standard suspension.

Key Terms for Viva

  • Total Solids: The sum of all solids in a sample after evaporation.

  • Suspended Solids: Solids that do not dissolve in water and can be filtered out.

  • Dissolved Solids: Solids that pass through a filter and remain in solution.

  • Fixed Solids: Solids remaining after burning the residue.

  • Volatile Solids: Organic matter that is lost upon heating.

  • Turbidity: A measure of water clarity affected by suspended materials.

  • Nephelometer: An instrument used to measure turbidity by comparing scattered light in samples.