• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.917-922
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• 2005

The wastewaters from textile and dyeing industries are difficult to treat due to its high pH, temperature, color intensity and non-biodegradable organic contents. This study investigated the removal of recalcitrant organics in a dyeing wastewater by using a packed bed reactor (PBR) that contained cell-immobilized pellets. The feed, obtained from an effluent of a biological treatment plant, had $SCOD_{Cr}$ of 330 mg/L and $SBOD_5$ of 20 mg/L on average. In immobilizing the cells to a Polyethylene Glycol(PEG) based medium, activated sludges from either a sewage treatment plant or an industrial wastewater treatment plant were used. When the empty bed contact time (EBCT) was above 8 hrs in the PBR, the $COD_{Cr}$ removal efficiency was over 50% and the $COD_{Mn}$ concentration was 72 mg/L or lower on average, which was substantially lower than the discharge standard of 90 mg/L. The results indicated that the optimum EBCT in the PBR was 8 hrs. The PBR with cell-immobilized pellets was effective as an advanced treatment process after an activated sludge process for treating dyeing wastewaters.

• Korean Journal of Environmental Biology
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• v.23 no.2 s.58
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• pp.146-151
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• 2005

Recent studies indicated the utility of whole effluent assessment as a measure to control discharge of toxic effluents to receiving water in Korea. However, most studies have been focussed on acute lethal effects of toxic wastewater with little consideration of chronic sublethal impacts which are of growing concern in protecting aquatic ecosystem. We conducted acute and chronic toxicity tests with effluents discharged from five different dyeing plants in Gyeong-gi province using a marine bacterium Vibrio fischeri and a freshwater macroinvertebrate Daphnia magna to demonstrate the importance of assessing chronic sublethal effects. Various levels of acute and chronic toxicities were observed in many samples tested in this study. In 21-d chronic toxicity tests using D. magna all samples showed effects on reproduction and growth. Notable mortalities were also noted in three out of five effluents. The result of the Microtox assay indicated that acute microbial toxicity existed in effluents from two out of five plants and acute daphnid toxicity was observed in only one effluent. The result of this study clearly suggests chronic toxicity tests are more suitable to assess biological effects of effluents because it was shown from this study that even an effluent with no acute toxicity could cause chronically lethal and/or sublethal adverse effects on aquatic biota which may affect the population dynamics in aquatic ecosystem.

• Journal of Environmental Science International
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• v.23 no.4
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• pp.681-695
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• 2014

In a pilot-scale dyeing wastewater treatment using two-type fluidizing media, each thickness of biofilm was 15 and 30 ${\mu}m$, respectively. The numbers of protozoa inhabited in small-size (PEMT A) and big-size (PEMT B) media were $7.5{\times}10^4$ and $1.25{\times}10^5$ 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.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.345-350
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• 2006

This study investigated the removal of recalcitrant organics in dyeing wastewater using a fluidized bed reactor(FBR) that contained cell-immobilized pellets. The pellets were manufactured and condensing the gel phase by mixing PEG-polymer and cells to form micro-porous PEG-polymer pellets whose size were ${\Phi}\;4mm{\times}H\;4mm$ on average. An industrial activated sludge without any pre-adaptation was used for the cell immobilization because it gave an equivalent removal efficiency to a pre-adapted sludges. The feed was obtained from an effluent of a biological treatment plant, which contained $SCOD_{Cr}$ of 330 mg/L and $SBOD_5$ of 20 mg/L. The $SCOD_{Cr}$ removal efficiency was over 45% and the effluent $COD_{Mn}$ concentration was less than 100 mg/L at HRTs from 6 to 24 hrs. The optimum HRT in the FBR was determined as 12 hrs considering the removal efficiency and cost. When a raw wastewater containing 768 mg/L of $COD_{Cr}$ was fed to the FBR, the effluent $COD_{Cr}$ concentration increased only slightly, giving a 70% of $COD_{Cr}$ removal or a 97% of $BCOD_5$ removal. This indicated that the FBR had an excellent capability of biodegradable organics removal also. In conclusion, the FBR could be applied to textile wastewater treatment in place of an activated sludge process.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.221-225
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• 2005

A Staphylococcus sp. EY-3 with the capability of decolorizing Congo Red was isolated from soil at an effluent treatment plant of a textile and dyeing industry. This strain was able to almost completely decolorize a high concentration of Congo Red in 48 h under aerobic conditions. Optimal color removal (more than 96%) was achieved at 30- 40oC, and no noticeable effects of different pH values (5.5- 8.0) on decolorization were observed. This strain also exhibited a remarkable decolorization capability against azo dyes under aerobic conditions, even at a high concentration (dyes 1 g/l) of dye. The metabolic product of Congo Red degradation by this strain was identified by gas chromatography with mass selective detection (GC/MSD) to be an amine derivative benzidine.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.9
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• pp.946-951
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• 2005

In this wort plasma treatment was evaluated as an alternative clean desizing technology. Size materials such as PVA(polyvinyl alcohol), PACL(polyacrylic acid esters) and their mixture on PET(polyethylene terephthalate) fabrics were treated by $N_2$ and $O_2$ plasma. $O_2$ plasma was more efficient in size removal than $N_2$ plasma, and the removal of PVA was higher than that of PACL. SEM(scanning emission microscopy) pictures of the plasma treated samples directly proved the disappearance of sizing agents. After $O_2$ plasma treatment, the PET fabrics were subjected to conventional desizing process. Compared with untreated fabrics, the desizing effluent from the treated fabrics gave lower TOC, COD and $BOD_5$ values. This indicates plasma treatment not only serves to directly remove sizing agents but also offered several advantages by changing the chemical properties of sizing agents. Lastly, the effect of plasma desizing process on dyeing was examined using color difference and dyeing fastness tests. The CCM(computer color matching) results showed rotor difference between PET fabric desized by $O_2$ plasma treatment for 20 min and reference PET fabric desized by the conventional wet desizing process was around 1. This suggests the treated PET fabric can be directly subjected to dyeing process without any additional process. The plasma treated fabric also gave a good result of dyeing fastness so that grades of laundering, crocking, heat and light fastness were same or even better than the reference PET fabric did.

• Resources Recycling
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• v.9 no.1
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• pp.36-43
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• 2000

This study was carried out for treatment and reuse of inorganic sludge from Fenton process at B dyeing wastewater treatment plant. The parameters for pilot-scale treatment system were derived from the results of this study. It was found that $COD_{cl}$ of the treated effluent became lower than 100 mg/l approximately on the optimal reaction condition. 2nd sludge which was generated after redissolving sludge was analyzed, and it showed that reduction ratio of ash in 2nd sludge and total dry sludge weight in comparison with current sludge were 85% and 65%. Also Fe salt in sludge was redissolved about 90~95% of initial Fe by weight. It was estimated almost ￦350,000,000 for sludge reuse process. It was estimated saving of about ￦1,300,000 per day (￦420,000,000 per year) in operating cost based on 30,000 $m^3$/d treatment, which these were about ￦430,000 per day in chemical, ￦1,100,000 per day in sludge transportation and ￦200,000 per day in equipment maintenance. Payback period with interest charge for investment cost was estimated about 10.5 months. Also, net present value (NPV) was ￦792,000,000 and internal rat of return (IRR) was about 110%.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.227-234
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• 2009

In this research, a retrofitting process, which consists of a pretreatment system (coagulation) for dye wastewater combined with a biological nutrient system (MLE process using media), for a sewage treatment plant that has to treat dye wastewater efficiently with domestic wastewater were developed and a pilot plant was operated for verifying adoptability and performance of the developed advanced process for dye wastewater. From the results of the pilot plant operation, BOD 52.9%, $COD_{Cr}$ 55.9%, and color 71.3% were removed in pretreatment of coagulation process and the biodegradability of dye wastewater was improved to $0.32{\sim}0.59BOD/COD_{Cr}$ of the coagulated wastewater from $0.29{\sim}0.43BOD/COD_{Cr}$ of the raw dye wastewater. The final effluent concentrations were BOD of 8 mg/L, $COD_{Cr}$ of 43 mg/L, $COD_{Mn}$ of 18 mg/L, T-N of 8 mg/L, and T-P of 1.3 mg/L, respectively. Color was removed from 1655 to 468 unit by coagulation and then to 123 unit by MLE process. The HPLC analysis of aromatic amines in wastewater showed that decolorization was achieved by cometabolism while aromatic amines were produced by cleavage of azo bonds under anaerobic conditions and these products were removed in an aerobic tank subsequently. Nitrification rates of attached and suspended microorganisms were evaluated comparatively and the acclimating conditions of bacteria on media were validated by the scanning electron microscope.

• Journal of Life Science
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• v.18 no.10
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• pp.1331-1335
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• 2008

A Klebsiella pneumoniae WL-5 with the capability of decolorizing several recalcitrant dyes was isolated from activated sludge of an effluent treatment plant of a textile and dyeing industry. This strain showed a higher dye decolorization under static condition and color removal was optimal at pH 6-8 and $30-35^{\circ}C$. More than 90% of its color of Congo Red were reduced within 12 hr at $200\;{\mu}M$ dye concentration. Malachite Green, Brilliant Green and Reactive Black-5 lost over 85% of their colors at $10\;{\mu}M$ dye concentration, but the percentage decolorization of Reactive Red-120, Reactive Orange-16, and Crystal Violet were about 46%, 25%, and 13%, respectively. Decolorizations of Congo Red and triphenylmethane dyes, such as Malachite Green, Brilliant Green, and Crystal Violet were mainly due to adsorption to cells, whereas azo dyes, such as Reactive Black-5, Reactive Red-120, and Reactive Orange-16 seemed to be removed by biodegradation through unknown enzymatic processes.