Regarding ozonation of ...

Regarding ozonation of greywater - many years ago (1997) I used an Osmonics ozone pilot to pretreat denim wastewater before my fixed-film bioreactor pilot … at a large blue jean production facility ...with the following results, as best I remember:

1.  Ozone worked well to remove soluble COD in the blue (indigo) laundry water, with close to 4-5 g  COD removed per g O3 generated … this was surprisingly high ratio … and some stripping of volatile COD may have been part of the explanation.

2.  Ozone helped reduce polymer consumption in the DAF units, especially when dosed in higher quantities, even eliminating the need for polymers at high ozone dosage.

3.  Ozone had some effect in dropping pH in the wastewater. 

Overall the ozone worked very well in conjunction with my fixed-film bioreactors when used up front of them.  I would expect O3 to work well after bioreacters or filters as a disinfection step.