In this posting we are going to discuss the ozonation of sump water. Sump water often is a good environment for the growth of micro organisms. In some cases the biological growth is significant and can create odors and potential blockage of the sump pump. To prevent this problem, many facilities will add a biocide to prevent the growth of the microorganisms. Ozone is a good choice for this application.
One of our customers, a manufacturer of small tractors, had a problem with odor from their sump. We supplied one of our AE series air cooled ozone generators and an Onyx oxygen concentrator. The ozone was introduced by a fine bubble diffuser on the bottom of the tank.
It is important to note that when ozone is used as the biocide that the tank needs to be closed and have a vent to outside the building. In the case of the specific customer referenced here. The tank in the case referenced here was eight feet deep. Typically this would not be deep enough for good ozone transfer efficiency, but since the requirement for ozone was rather low, high transfer efficiency was not critical.
The AE series ozone generators have a large turn down ratio. The client set the ozone generators so as to kill the unpleasant sump odor, but not to smell ozone in the work space. A light ozone smell would be acceptable since people can smell ozone at 0.01 to 0.04 ppm and people can work in an ozone environment with a concentration of up to 0.10 ppm. An ambient ozone monitor should be used to make sure that the ozone level in the work space does not exceed 0.1 ppm. In addition, the tank should be vented to further protect the work space from high ozone levels.
Our client reported that they were easily able to find the level of ozone to keep the odor down on the sump. This same approach could be used in other applications. For example, truck washing set-ups often recycle the wash water after filtration. This water is also subject to biological growth. The tank holding the recycled water could be handled using the same approach as above.
If you have a sump or recycled water tank that is creating odor problems, contact Spartan Environmental Technologies.