Nanofiltration[NF45] and reverse osmosis membrane[HR98PP] separation treatment of dyestuff wastewater was carried out in order to seperate relatively pure water from synthetic dyestuff wastewater, which consists of reactive dye, acid dye, basic dye, direct dye, and disperse dye. The experiments were performed by using the plate and frame membrane module. In the nanoflltration and reverse osmosis membrane separation, When the NaCl concentration was 0.1, 5.0, and 20.0%, retention was 63.0, 46.0, 0.9%, respectively. When permeate flux was 125.0, 67.5, and 45.0 L/㎡·h, the osmotic pressure increased with increasing the NaCl concentration. Permeate flux of two membranes increased as temperature increased due to segmental movement of polymer of the membrane and the rejection rate of dyestuff was decreased gradually. It was found that the rejection rate was about 95% in the nanofiltration, while the reverse osmosis membrane showed a high rejection rate of 99% under all temperature and pressures conditions.

Because permeate flux was very low as it has the suspension solid of high concentration in the ultrafiltration membrane separation treatment of dyestuff wastewater, pre-treatment of Fenton reaction was carried out. In the case of pH 3, COD removal rate was the highest of 58%. When PAC was added into the pre-treatment supernatant, the COD removal rate was found to be 53%, and when COD was 153㎎/L, the removal rate was 92.3% in the ultrafiltration separation. In addition, the effect of the addition of PAC on the permeate flux was also investigated. The decrease of permeate flux in the presence of PAC was higher than in the abscence of PAC, but the recovery of permeability by cleaning was better in the case of PAC system.