Cooling Towers Analysis of Deposits

The following quick and simple tests can be performed to qualitatively determine what type of deposition is occurring in your water systems. This list is not intended to be comprehensive. Rather it is based on the most likely deposits in cooling systems.

Calcium Carbonate

1. Add a small amount of hydrochloric acid to the sample.
   
   If the sample bubbles and fizzes it is releasing carbon dioxide that suggests carbonate is present.

Copper

1. Digest sample with 10ml hydrochloric acid.
2. Add sufficient distilled water to bring the sample volume to 50ml.
   
   A blue/green color typically indicates the presence of copper.

Iron

1. Place dry sample on a flat piece of paper or into a dry flask.
2. Run a magnet along the bottom.
   
   If the sample is magnetic it probably contains active iron oxide Fe3O4.

Microbiological - General

1. Place sample at the end of a wooden handle spatula.
2. Gently burn the sample with a propane torch.
   
   If the sample just burns, without supporting combustion, and has the smell of burning garbage, it is most likely microbiological.

Microbiological – Anaerobes

1. Place a drop of dilute hydrochloric acid on a fresh, moist sample.
   
   If the sample gives off a rotten egg smell (hydrogen sulfide) it is anaerobic. This test should be performed outside.

Oil

1. Place a small flake of chemically pure camphor in the sample.
   
   If the flake "dances" around in the sample, no oil is present. If the flake stops dead in the sample, this is a positive indication of oil contamination.