• Journal of Korean Society of Water and Wastewater
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• v.20 no.1
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• pp.27-34
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• 2006

This study was conducted to evaluate the performance of a membrane bioreactor filled with high concentration of powdered activated carbon (HCPAC-MBR) to reduce DBPs at the drinking water treatment. The pilot system was installed after the rapid sand filtration process whose plant was the conventional treatment process. The removal efficiencies of DBPs were measured during pilot operation period of 2 years. HAA and THM removal rates could be maintained around 80~90% without any troubles and then tremendous reduction of HAA and THM reactivity were observed more than 52%. The average removal rate of HAA formation potential (FP) and THM formation potential (FP) were 70.5% and 67.6% respectively. It is clear that the PAC membrane bioreactor is highly applicable for advanced water treatment to control DBPs.

• Membrane and Water Treatment
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• v.1 no.4
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• pp.283-296
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• 2010

During the disinfection of potable water, humic substances present in the solution react with chlorine to form potential carcinogenic compounds. This study evaluates the feasibility of using a submerged membrane photocatalysis reactor (SMPR) process for treatment of humic substances through the characterization of both organic removal efficiency and membrane hydraulic performance. A simple SMPR was operated and led to the removal of up to 83% of the polluting humic matters. Temporal rates of organic removal and membrane fouling were found to decrease with filtration time. Using tighter membrane in the hybrid process resulted in not only higher organic removal, but also more significant membrane fouling. Under the experimental conditions tested, optimum $TiO_2$ concentration for humic removal was found to be 0.6 g/L, and increasing initial pollutant concentration expectedly resulted in a more substantial membrane fouling. The importance of the influent nature and pollutant characteristics in this type of treatment was also assessed as various water sources were tested (model humic acid solution vs. local water containing natural organic matters). Results from this study revealed the promising nature of the SMPR process as an alternative technique for organic removal in the existing water treatment system.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.6
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• pp.611-618
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• 2017

Recently, applications of high voltage impulse (hereafter HVI) technique to desalting, sludge solubilization and disinfection have gained great attention. However, information on how the operating condition of HVI changes the water qualities, particularly production of hydroxyl radical (${\cdot}OH$) is not sufficient yet. The aim of this study is to investigate the effect of operating conditions of the HVI on the generation of hydroxyl radical. Indirect quantification of hydroxyl radical using RNO which react with hydroxyl radical was used. The higher HVI voltage applied up to 15 kV, the more RNO decreased. However, 5 kV was not enough to produce hydroxyl radical, indicating there might be an critical voltage triggering hydroxyl radical generation. The concentration of RNO under the condition of high conductivity decreased more than those of the low conductivities. Moreover, the higher the air supplies to the HVI reactor, the greater RNO decreased. The conditions with high conductivity and/or air supply might encourage the corona discharge on the electrode surfaces, which can produce the hydroxyl radical more easily. The pH and conductivity of the sample water changed little during the course of HVI induction.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.895-904
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• 2006

The improved MLE (modified Ludzack-Ettinger) process was operated for piggery waste treatment in full-scale public livestock waste treatment plant. The treated waste from bioreactor was suitable for the strict effluent standard of 200 mgCOD/L and 60 mgTN/L as it was dewatered chemically without settling tank and passed through filtration process. Though this treatment method produced a great deal of sludge ($6.4m^3\;per\;m^3$ dewatered piggery waste) it was able to accomplish predominant effluent quality by removing non-biodegradable COD and color without advanced oxidation process as ozone, fenton and etc.. The nitrogen removal efficiency of bioreactor was rapidly declined from March to May (from 0.016 to 0.005 kgN/kgVSS-day) when disinfection is in earnest as well as from warm season when reactor temperature rises higher than $35^{\circ}C$(from 0.016 to 0.008 kgN/kgVSS-day). This study proves that counterplanes for infection residuals, bioreactor temperature and dewatering sludge reduction are necessary for piggery waste treatment.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.2
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• pp.63-70
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• 2013

Experiments in a pilot-scale hybrid multi-stage unit system (HMUS) combination of ATAD and EGSB followed by SBR process for pig slurry treatment were conducted to demonstrate the feasibility of using autothermal thermophilic aerobic digestion (ATAD) and expended granular sludge bed (EGSB) followed by sequencing batch reactor (SBR) system. Contaminants in pig slurry with high organic matter, nitrogen (N) and phosphorus (P) content were completely removed in the combined process. The highest removal rate for CODcr among contaminants in the feed pig slurry was attained by about 43.3% in ATAD unit process. Also TS removal rate of 96.5% was attained and the highest in the next coagulation unit process. The highest removal rate of CODcr under operating parameter conditions of OLR(organic loading rate), 3-6Kg $COD/m^3{\cdot}day$ and line velocity, 1.5-4m/h was earned at 3days of HRT. The disinfection of pathogens was effective at 50,000mg/L of TS in ATAD unit process. Biogas production per organic removal was $2.3{\sim}8.5m^3/kgTS{\cdot}d$ (average $5.2m^3/kgTS{\cdot}d$) in EGSB unit process. The average removal rates of CODcr 71.7%, TS 64.1%, TN 45.9%, and TP 50.4% were earned in the intermittent aeration SBR unit process.

• KSBB Journal
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• v.21 no.4
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• pp.317-323
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• 2006

This study focused on the availability of wastewater reclamation and reusing system as one of the alternatives against the global water shortage in near future, which system is composed of two treatment steps; first, wastewater is injected into upflow $A^2O$ biofilm process(anaerobic/anoxic/oxic) reactor filled with polyethylene fixed-media, and the effluent of 1st steps continuously passed through downflow nano silver sand filter. The pH of the effluent ranged from 7.39 to 8.06(average 7.84), the $COD_{Mn}$ was $8{\sim}18mg/L$(average 12.1 mg/L), and $BOD_5$ was $2.1{\sim}10.0mg/L$(average 4.9 mg/L), that met all the wastewater reclamation and reusing system criteria. Besides, the SS concentrations of the effluent which was $3{\sim}9mg/L$(average 4.95 mg/L) met the criteria(5 mg/L), showing 94.8% of average removal efficiency. The 99.1% of the average removal efficiency of the E-coliform did not met the criteria(Not detected), which indicates the needs for the following chlorine disinfection treatment with the residual chlorine concentration of above 0.2 mg/L. There are no bacteria on the sand surface coated by nano silver. The removal efficiency of T-N and T-P that could be included into the criteria in the future was 50.3% and 27.2% respectively.