What choose the depends on appropriate way ( from references Approved) to examine chemical test for waste water sample?

Dear Sir,

Initially you must specify the category of the industry from which the wastewater belongs.

Then you must know list of the chemicals added during manufacturing and sort out which chemicals are under pollution control norms.

Other than this, pH, BOD, COD and suspended solids are common lab test for waste water

I agree with the answer given by Ms. Rashmi.

To add on this, if specific chemial content is known then it can also be known by Spectrophotometer and Gas Chromatography.