• Journal of Korean Society of Environmental Engineers
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• v.35 no.6
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• pp.407-414
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• 2013

Full scale livestock wastewater treatment plant (100 t/d) was constructed and operated to develop compact and cost effective treatment process for public plant as well as individual farm. Liquid form of livestock wastewater after belt press filter was treated through MBR/NF/RO. NF/RO brine water was mixed with livestock wastewater sludge and treated using denitrification, coagulation and air flotation process. Mixed effluent of NF/RO and air flotation meet public livestock wastewater treatment standard, BOD, T-N and T-P, 30 mg/L, 60 mg/L, 8 mg/L below, respectively. Condensed sludge of air flotation returned belt press filter. Dewatered cake contained 90% water and could be used fertilizer after mixing sawdust.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.2
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• pp.76-93
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• 1997

Activated carbon is widely used for the treatment of water, wastewater and other liquid wastes. Biological activated carbon (BAC) process is water and wastewater treatment process developed in the 1970's. In addition to activated carbon adsorption, biodegradation organic pollutants occurs in the BAC bed where a large amount of aerobic biomass grows. This results in a long operation time of the carbon before having to be regenerated and thus a low treatment cost. Although the BAC process has been widely used, its mechanisms have not been well understood, especially the relationship between biodegradation and carbon adsorption, whether these two reactions can promote each other or whether they just simultaneously exist in the BAC bed. Also, the phenomenon of bioregeneration has been confused that previously occupied adsorption sites appear to be made available through the actions of microorganisms. And that, because biological process is influenced by low temperature, the mechanism of the BAC process is also effected by temperature variation in our country of winter temperature near the freezing point. Therefore, the objective of this study examines closely the mechanism of the BAC process by temperature variation using phenol as substrate. From this study, biological activated carbon is good substrate removal better than non adsorbing materials (charcoal, sand) as temperature variation, especially low temperature(near $5^{\circ}C$).

• Korean Chemical Engineering Research
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• v.48 no.5
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• pp.589-597
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• 2010

Strengthening the regulation standard of biological nutrient in wastewater treatment plant(WWTP), the necessity of repair of WWTP which is operated in conventional activated sludge process to advanced nutrient removal treatment is increased. However, in full-scale wastewater treatment system, it is not easy to fine the optimized operational condition of the advanced nutrient removal treatment through experiment due to the complex response of various influent conditions and operational conditions. Therefore, in this study, an upgrading design of conventional activated sludge process to advanced nutrient removal process using the modeling and simulation method based on activated sludge model(ASMs) is executed. And a design optimization of advanced treatment process using the response surface method(RSM) is carried out for statistical and systematic approach. In addition, for the operational optimization of full-scale WWTP, a correct analysis about kinetic variables of wastewater treatment is necessary. In this study, through partial least square(PLS) analysis which is one of the multivariable statistical analysis methods, a correlation between the kinetic variables of wastewater treatment system is comprehended, and the most effective variables to the advanced treatment operation result is deducted. Through this study, the methodology for upgrading design and operational optimization of advanced treatment process is provided, and an efficient repair of WWTP to advanced treatment can be expected reducing the design time and costs.

• Journal of Korean Society of Water and Wastewater
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• v.11 no.1
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• pp.64-73
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• 1997

Most of the municipal wastewater treatment plants operated in Korea are designed for high concentrations municipal sewage. However, activated sludge process employed by municipal wastewater treatment plant is operated at low organic loading. The objective of this study was to determine optimum operating condition of activated sludge process for treatment of low concentration municipal sewage. Three bench scale activated sludge reactors were operated to investigate the effect of HRT and SRT on the COD and TSS removal efficiency. The average concentration of TSS, SCOD, SBOD and TKN in influent were 118mg/l, 61mg/l, 21mg/l, and 12mg/l, respectively. The activated sludge reactors operated with various HRT and SRT showed about 89-93% TSS removal efficiency. HRT and SRT does not affect the TSS removal efficiency of actvatied sludge process significantly. However, HRT affected the SCOD removal efficiency slightly. As the HRT decreases from 13hours to 3hours, the SCOD removal efficiency decreases from 67% to 56%. The average effluent TCOD concentration of the reactor operated with 3hours of HRT was approximatly 40-45mg/l. Kinetic coefficient yield (Yt) and decay coefficients(Kd) were 0.594-0.954 mgMLVSS/mgCOD and $0.0197-0.0317day^{-1}$, respectively. Low concentration municipal sewage can be treated with 3 hours of HRT without effluent quality deterioration and SRT does not affect the substrate removal efficiency at this operation condition.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.698-701
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• 2000

To prevent surface and underground water pollution, wastewater treatment is essential. Four bench-scale activated sludge units (10 L operational volumes) were operated at 5, 10 and $20^{\circ}C$ for evaluation of treatment efficiencies with typical wastewater from swine housing. The units were set for a 24-hour cycle. As compared to the conventional process, high removal efficiencies for organic substances, nitrogen and phosphorus in swine wastewater were obtained simultaneously with an intermittent aeration process (lAP). The NOx-N produced during an aeration period was immediately reduced to nitrogen gas (e.g. $N_2$ or $N_2O$) in the subsequent non-aeration periods, and nitrification in aeration periods occurred smoothly. Under these conditions, phosphorus removal occurred with the release of phosphorus during the non-aeration periods followed by the excess uptake of phosphorus in the activated sludge during aeration periods. It was confirmed that the lAP had a better ability to remove pollutants under both low temperatures and high nitrogen loading conditions than the ordinary method did. In addition to that, the total emission of $N_2O$ from lAP was reduced to approximately 1/50 of the conventional process for the same loading. By adopting an adequate aeration programme for individual swine wastewater treatment, this system will provide a promising means for nitrogen and phosphorus control without pH control or addition of methanol.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.708-713
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• 2004

This study was performed to investigate the variations of hydrophilic and hydrophobic organic matter fractions in soluble organic matter according to livestock wastewater treatment by ionized gas and coagulation effect to these fractions after ionized gas contact. As a result of experiment, because of ionized gas contact, particle in the surface of livestock wastewater was more smaller and the result was consisted of particle size analysis and the amount of small size was increased. Also, we confirmed that organic matters in livestock wastewater by ionized gas contact were removed. The relation equation between ionized gas contact time(X) and $TCOD_{cr}$(Y) was shown as yscale(y)=3.748-0.431* xscale(X). That between ionized gas contact time(X) and $TCOD_{cr}$(Y) was yscale(y)=3.283-0.463* xscale(X). As respects the HPL(hydrophilic matter)and HPO(hydrophobic matter) fractions of raw in livestock wastewater treatment plant, HPL fraction was 53.2% and HPO fraction was 46.8%. But, HPO fraction according to ionized gas treatment was increased at 30min and after that time, HPL fraction was increased. Also, when we performed coagulation process after ionized gas treatment of raw wastewater, the removal efficiency of organic matter was the highest at 30min of ionized gas treatment because of the variation of HPL and HPO fractions in organic matter by ionized gas. In coagulation process following after ionized gas process, HPO was removed more effective than HPL.

• Membrane Journal
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• v.28 no.3
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• pp.143-156
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• 2018

In this review article, hybrid water/wastewater treatment processes of membrane and photocatalyst were summarized from papers published in various journals. It included (1) membrane photoreactor (MPR), (2) fouling control of a membrane coupled photocatalytic process, (3) photocatalytic membrane reactors for degradation of organic pollutants, (4) integration of photocatalysis with membrane processes for purification of water, (5) hybrid photocatalysis and ceramic membrane filtration process for humic acid degradation, (6) effect of $TiO_2$ nanoparticles on fouling mitigation of ultrafiltration membranes for activated sludge filtration, (7) hybrid photocatalysis/submerged microfiltration membrane system for drinking water treatment, (8) purification of bilge water by hybrid ultrafiltration and photocatalytic processes, and (9) Hybrid water treatment process of membrane and photocatalyst-coated polypropylene bead.

• Journal of Korean Society on Water Environment
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• v.25 no.2
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• pp.329-334
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• 2009

Bacterial numbers, such as endospore-formers, and treatment efficiencies were investigated for Rotating Activated Bacillus Contactors (RABC) and other advanced wastewater treatment processes including anaerobic-anoxic-oxic (A2O), sequencing batch reactor (SBR) and biological aerated filter (BAF). Endospore-forming bacterial numbers in the RABC showed 129-fold higher levels than those of the existing advanced systems. RABC process demonstrated the highest bacterial numbers in its bioreactors (paired t-test, p<0.01). RBC biofilms and aeration tanks of the RABC system showed 131- and 476-fold higher than other existing advanced processes, respectively. Mean treatment efficiencies of the existing systems were 83.5% for chemical oxygen demand (COD), 59.1% for total nitrogen (TN) and 76.8% for total phosphorus (TP). However, RABC process removed 96.9% for COD, 96.9% for TN and 91.9% for TP for highly concentrated food wastewater (COD>1,500 mg/L, TN>150 mg/L, TP>50 mg/L). Treatment efficiency was significantly reduced when the numbers of Bacillus genus in the bioreactors decreased below $10^6CFU/mL$. The automated RABC (A-RABC), in which dissolved oxygen concentrations are automatically controlled, showed higher treatment efficiencies compared to the RABC process. The RABC system maintained sufficient bacterial numbers for the effective treatment of highly concentrated food wastewater. Moreover, final effluent was in agreement to water quality standards.

• Journal of Korean Society on Water Environment
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• v.26 no.2
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• pp.289-296
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• 2010

The purpose of this study is to evaluate various pre-treatment methods and proprieties of water quality for wastewater reuse using reverse osmosis (RO) processes. Secondary effluents were sampled from wastewater treatment plants and lab scale pre-treatments and RO filtration test were conducted systematically. Specifically, different types of pre-treatments, such as coagulation, microfiltration and ultrafiltration, were employed to evaluate the removal efficiency of particle and organic matters which may affect the membrane fouling rate. RO process was later added to eliminate trace amounts of remaining organic matters and salt from the raw water for wastewater reclamation. The permeate through the RO process satisfied water quality regulations for industrial water uses. The experimental results showed that the initial fouling tendency differed not only by the feed water properties but also by the membrane characteristics. Membrane fouling was greater for the membranes with large surface roughness, regardless of the hydrophobicity and zeta potentials. Thus both careful consideration of pre-treatment options and proper selection of RO membrane are of paramount importance for an efficient operation of wastewater treatment.

• Journal of Environmental Science International
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• v.9 no.4
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• pp.351-367
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• 2000

Air-lift biofilm reactor should be an admirable process substituting conventional activated sludge process, because of its small area requirement as well as high volumetric loading capacity and stability against loading and chemical shocks. However most of the past research on the performance of ABR was focused on the sewage treatment. This research studied the applicability of ABR to treat high strength wastewater. A bench-scale ABR was operated to treat high strength synthetic wastewater, tannery wastewater and petrochemical wastewater, and its applicability was conclusive In case of synthetic wastewater, ABR showed good performance in which the substarate removal efficiency was higher that 80% even under short HRT(1.4 hr) and high volumetric loading rate(9.3 kgCODcr/$m^3$.day). When ABR was applied to treat tannery wastewater, it was suggested that the maximum volumetric loading rate and F/M ratio should be 7.7kgCODcr/$m^3$.day, 0.76 $day^{-1}$, respectively. And high substrate removal efficiency over than 90 % was observed with 4,000 mgCODcr/L of petrochemical wastewater. Even though effluent concentration was quite high, ABR should be applicable to treat the high strength wastewater, because of its high loading capacity.