Study of preozonation influence on the physical-chemical treatment of textile wastewater

After that, two different NF membranes were tested using as feeding stream the wastewater after the ozone and physical-chemical stages in order to reduce the water conductivity and COD. NF experiments were carried out in a laboratory plant containing a plane module with an effective area of 120 cm2. The membranes tested were Desal DK-5 from Osmonics and NF-90 from Dow Chemical. The results showed that the COD and conductivity of the nanofiltration permeates were around 100 mg/L and 0.5 mS/cm, respectively with NF-90 membrane.