In a pilot-scale dyeing wastewater treatment using two-type fluidizing media, each thickness of biofilm was 15 and 30 μm, respectively. The numbers of protozoa inhabited in small-size (PEMT A) and big-size (PEMT B) media were 7.5 x 104 and 1.25 x 105 cells/ml, respectively, and dominant species were Entosiphon sulcatus var sulcatus in PEMT A and Chlamydomonas reinhardtii in PEMT B, respectively. Flask experiments using the two media revealed that the percentages of color removal were 25.8% in PEMT A and 27.1% in PEMT B after 72-h cultivation, indicating the necessity of bioaugmentation. Experiments for bioaugmentation effect on color removal were carried out in the pilot-scale treatment for 75 d by three-step operation under the control of wastewater loading rate and microbial input rate. Dye degradation occurred mainly in the second reaction tank, and the attachment of augmented dye-degrading microorganisms to media took at least 35 d. Final value of chromaticity in effluent was 227, meeting the required standard. Therefore bioaugmentation onto media was good for color treatment. In summary, thickness of biofilm formed on the media depended upon the size of media, resulting in different ecosystem inside the media. Hence, this affected microbial community and color treatment further. Accordingly, the reduction of operation cost is expected by efficient color-treatment process using bioaugmented media.

The objective of this research is to evaluate a feasibility of wastewater reuse by membrane treatment with vibrating membrane separation equipment. Molecular weight of compounds in wastewater, permeability of membrane and retentate characterization after membrane filtration were investigated in order to determine appropriate membrane pore size and materials for wastewater treatment. Selected membrane was evaluated with vibration membrane separation equipment to optimize operating conditions. The following conclusion are drawn. 1.We got as following test results after the distribution of particles in the semiconductor wastewater, are made up of 1～20㎛. Si, gold and Al in turn are contained in semiconductor wastewater. 2. Recovery rate is changeless under increasing recovery rate in operation. Though a value can be if pressure can be changed, the highest value of permeate rate is presented in 150 psi. 3.The AS-100(polysulpone) was selected as the most appropriate membranes for the treatment of semiconductor wastewater to VSEP system. The fouling almost did not occur during this experiments. The analyses of treated water with VSEP system showed conductivity:0.059㎲/cm, TDS:40㎎/ℓ, COD:20㎎/ℓ, SS:5㎎/ℓ, n-Hexane:8.3㎎/ℓ. Comparing previous systems, operating expenses is decreased by more 50%.