• 한국물환경학회지
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• 제25권2호
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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.

• Membrane and Water Treatment
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• 제10권3호
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• pp.239-244
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• 2019

Plating wastewater containing various heavy metals can be produced by several industries. Specifically, we focused on the removal of copper (Cu2+) and nickel (Ni+) ions from the plating wastewater because all these ions are strictly regulated when discharged into watershed in Korea. The application of both nanofiltration (NF) and reverse osmosis (RO) technologies for the treatment of wastewater containing copper and nickel ions to reduce fresh water consumption and environmental degradation was investigated. In this work, the removal of copper (Cu2+) and nickel (Ni+) ions from synthetic water was studied on pilot scale remove by before using two commercial nanofiltration (NF) and reverse osmosis(RO) spiral-wound membrane modules (NE2521-90 and RE2521-FEN by Toray Chemical). The influence of main operating parameters such as feed concentration on the heavy metals rejection and permeate flux of both membranes, was investigated. Synthetic plating wastewater samples containing copper ($Cu^{2+}$) and nickel ($Ni^{2+}$) ions at various concentrations(1, 20, 100, 400 mg/L) were prepared and subjected to treatment by NF and RO in the pilot plant. The results showed that NF, RO process, with 98% and 99% removal for copper and nickel, respectively, could achieve high removal efficiency of the heavy metals.

• 한국물환경학회지
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• 제20권1호
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• pp.37-41
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• 2004

This paper was studied about the characteristics of treatment by ionized gas for livestock wastewater, aiming at the effects of ionized gas on organic matter, hydrophobic and hydrophilic organic matter in livestock wastewater when the new process of advanced oxidation process was applied for meeting the improved the quality of effluent. The organic matter within treated livestock wastewater by ionized gas was partially mineralized according to the time increasement. The $TCOD_{Mn}$ in the livestock wastewater was decreased from 840mg/L to 340mg/L when treated by ionized gas by the enhancement of time. We occupied the equations of $TCOD_{Cr}$, $SCOD_{Cr}$, $TCOD_{Mn}$ and $SCOD_{Mn}$ as to ionized gas treated time. As $TCOD_{Mn}$ increasing ionized gas treated time, the concentration did not meet the water quality, $COD_{Mn}$ 4Omg/L. So, for removing of the remaining organic matter in the efflent after ionized gas, following process is necessary. After treating the livestock wastewater by ionized gas, coagulation was considerable for organic matter removal up to regulation water quality. From UV scans of the treated livestock wastewater by ionized gas, the wastewater has low aromaticity and good colour.

• 상하수도학회지
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• 제31권6호
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• pp.481-490
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• 2017

Water and wastewater treatment has always been a challenging task due to the continuous increase in amount and the change in characteristics of the poorly biodegradable and highly colored organic matters, as well as harmful micro-organisms. Advanced techniques are therefore required to successfully remove these pollutants from water before reuse or discharge to receiving water bodies. Application of ozone, which is a powerful oxidant and disinfectant, alone or as part of advanced oxidation process depends on the complex kinetic reactions and the mass transfer of ozone involved. Micro- and nano bubbling considerably improves gas dissolution compared to conventional bubbles and hence mass transfer. It can also intensify generation of hydroxyl radical due to collapse of the bubbles, which in turn facilitates oxidation reaction under both alkaline as well as acidic conditions. This review gives the overview of application of micro- and nano bubble ozonation for purification of water and wastewater. The drawbacks of previously considered techniques and the application of the hydrodynamic ozonation to synthetic aqueous solutions and various industrial wastewaters are systematically reviewed.

• Membrane and Water Treatment
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• 제11권3호
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• pp.201-206
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• 2020

Electrodialysis (ED) is used in wastewater treatment, during the processing and recovery of beneficial materials, to produce usable water. In this study, sulfate and chlorine ions, which are the anions majorly used for electroplating, were studied as factors affecting the recovery of copper, nickel and water from wastewater by electrodialysis. Although the removal rates of copper and nickel ions were slightly higher with the use of chlorine ions than of sulfate ions, the removal efficiencies were above 99.9% under all experimental conditions. The metal ions of the plating wastewater flowed through the ion exchange membrane of the diluate tank and the concentrate tank while all the water moved together due to electro-osmosis. The migration of water from the diluate tank to the concentrate tank was higher in the presence of a monovalent chloride ion compared to that of a divalent sulfate ion. When sulfate was the anion used, the recoveries of copper and nickel increased by about 25% and 30%, respectively, as compared to the chloride ion. Therefore, when divalent ions such as sulfate are present in the electrodialysis, it is possible to reduce the movement amount of water and highly concentrate the copper and nickel in the plating wastewater.

• Environmental Engineering Research
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• 제23권1호
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• pp.92-98
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• 2018

Suitability of aluminium-based water treatment sludge (WTS), a waste product from water treatment facilities, was assessed for removal of heavy metals from an electroplating wastewater which had high concentrations of copper and chromium along with other heavy metals. Batch tests with simulated wastewater in single- and multi-metal solutions indicated the influence of initial pH and WTS dose on removal of six metals namely Cu(II), Co(II), Cr(VI), Hg(II), Pb(II) and Zn(II). In general, removal of cationic metals such as Pb(II), Cu(II) and Zn(II) increased with increase in pH while that of anionic Cr(VI) showed a reduction with increased pH values. Tests with multi-metal solution showed that the influence of competition was more pronounced at lower WTS dosages. Column test with diluted (100 times) real electroplating wastewater showed complete removal of copper up to 100 bed volumes while chromium removal ranged between 78-92%. Other metals which were present in lower concentrations were also effectively removed. Mass balance for copper and chromium showed that the WTS media had Cu(II) and Cr(VI) sorption capacities of about 1.7 and 3.5 mg/g of dried sludge, respectively. The study thus indicates that WTS has the potential to be used as a filtration/adsorption medium for removal of metals from metal-bearing wastewaters.

• 상하수도학회지
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• 제20권3호
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• pp.339-343
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• 2006

• 한국환경보건학회지
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• 제28권2호
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• pp.61-69
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• 2002

Oship stream is located nearby south eastern coasts. This study was performed to find out waters quality modeling and then to predict water quality of Oship stream. Based on survey data, BOD, T-N, T-P calibration and verification result were in good agreement with measured value within mean coefficient variance(MSE) value, which were 13.9%, 9.0%, 26.5% and 19.5%, 12.0%, 16.5%, respectively. Sectional water quality predictions of the main stream of Oship stream are executed on the basis of the following cases 1) with sewage treatment of Dogye-eup 2) reduction of mine wastewater treatment of 80% in th basin. As a result, BOD, T-P improvement rates at down stream of Oship stream, case 1) were appeared 12.2%, 22.2%, case 2) maximum sulfate ion and conductivity reduction removal rate of Oship stream were 58%, 68%. The main pollution sources of Oship-stream were almost domestic wastewater and mine wastewater discharged from Dogye-eup which located in uppers stream. The large effects will appear after the construction of Dogye sewage water treatment plant which remove the organic matter and nutrients in these sewage water. The waste water from mine can not easily to treat for characteristics of effluence and economic problems. However, to achieve the goal of water quality in Oship-stream water system, treatments of those are necessary.

• 한국환경과학회지
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• 제21권10호
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• pp.1245-1253
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• 2012

In this study, how branches of Kumho River affect to the water quality on Kumho River was investigated. Water samples from six sampling points at Kumho River and three at each branch were taken from Dec. 2009 to Dec. 2011. As results, Namcheon affected BOD and T-P concentrations on Kumho River while Sincheon did only T-P concentrations. However, the water quality of Kumho River was improved because of Sincheon in terms of BOD and COD concentrations. This was the results from management of Sincheon wastewater treatment facility and Jisan wastewater treatment facility which might be the best example for managing wastewater treatment facilities. Dalsecheon would not affect the water quality of Kumho River although it had bad conditions of water quality because of lack of its water quantity comparing to Kumho River's.

• 상하수도학회지
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• 제18권4호
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• pp.453-460
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• 2004

The objective of this research is to develop the water quality management model to achieve the water quality goal and the minimization of the waste load abatement cost. Most of existing water quality management model can calculate BOD and DO. In addition to those variables, N and P are included in the management model of this study. With a genetic algorithm, calculation results from the mathematical water quality model can be used directly in this management model. Developed management model using genetic algorithm was applicated for the Youngsan River basin. To verify the management model, water quality and pollution source of the Youngsan River had been investigated. Treatment types and optimum treatment costs of the existing and planned WWTPs in the baisn were calculated from the model. The results of genetic algorithm indicate that Kwangju and Naju WWTP have to do the advanced treatment to achieve the water quality goal about BOD, DO and TP. Total annual treatment cost including the upgrade cost of existing WWTPs in the Youngsan River basin was about 50.3 billion Won.