This procedure covers determination of total dissolved solids (TDS) in wastewater prior to treatment and disposal to marine outfall (inlet and outlet effluents of ETP) and applicable at laboratory.
- Collect 1 liter of sample to a clean polythene carboy, label the container and deliver it to the lab. Shake the contents of the container thoroughly before drawing the sample for testing.
- Draw a measure volume of sample quickly from the container.
- Transfer the sample to a clean and pre-weighted evaporating dish and evaporate to dryness in an oven at 180 oC
- Cool the dish in desiccator to an ambient temperature and re-weight it
- Calculate the TDS in mg/lit, using formula.
Total dissolved solids/TDS (mg/lit) =
(Final weight of dish –Initial weight of dish) ×10^6/Sample volume (ml)
- Record the measurements and the results.