Application of Counter Diffusion to Effective Treatment of Dye-Wastes

The effect of salt concentration on cell growth was investigated in biological treatment of dye-wastes with high salinity. Prior to or after the acclimation of activated sludge to various salt contents, the change of soluble COD and MLSS was observed with respect to the reaction time in different salt environments. Counter diffusion technology was introduced as a pretreatment process to reduce the salt contents of dye-wastes prior to the secondary activated sludge process. The salt removal was 20-40% with one path and the separation factor was 1,200-2,300. As the loss of dye molecules than , no secondary pollution problem occurred on the stripping water side. After reimmobilization of used membrane, the separation factor was increased, on the contrary, compared with the first immobilized one. Membrane permeabilities for sodium chloride() and dye molecules() were found to be 9.4 and , respectively.